WEBVTT Kind: captions Language: en 00:00:13.059 --> 00:00:16.000 align:start position:0% that<00:00:14.059> you<00:00:14.570> have<00:00:14.749> learned<00:00:15.019> something<00:00:15.799> about 00:00:16.000 --> 00:00:16.010 align:start position:0% that you have learned something about 00:00:16.010 --> 00:00:19.090 align:start position:0% that you have learned something about distributed<00:00:16.640> consensus<00:00:17.090> and<00:00:17.440> it<00:00:18.440> takes<00:00:18.680> a<00:00:18.890> lot 00:00:19.090 --> 00:00:19.100 align:start position:0% distributed consensus and it takes a lot 00:00:19.100 --> 00:00:21.010 align:start position:0% distributed consensus and it takes a lot more<00:00:19.430> than<00:00:19.790> just<00:00:19.820> the<00:00:20.180> consensus<00:00:20.630> protocol 00:00:21.010 --> 00:00:21.020 align:start position:0% more than just the consensus protocol 00:00:21.020 --> 00:00:22.300 align:start position:0% more than just the consensus protocol obviously<00:00:21.590> to<00:00:21.740> build<00:00:21.950> a<00:00:22.040> cryptocurrency 00:00:22.300 --> 00:00:22.310 align:start position:0% obviously to build a cryptocurrency 00:00:22.310 --> 00:00:23.920 align:start position:0% obviously to build a cryptocurrency right<00:00:22.880> so<00:00:23.060> for<00:00:23.210> instance<00:00:23.450> we<00:00:23.540> need<00:00:23.660> to<00:00:23.720> make 00:00:23.920 --> 00:00:23.930 align:start position:0% right so for instance we need to make 00:00:23.930 --> 00:00:25.750 align:start position:0% right so for instance we need to make sure<00:00:23.960> that<00:00:24.230> the<00:00:24.350> incentives<00:00:24.830> are<00:00:24.950> aligned<00:00:25.310> and 00:00:25.750 --> 00:00:25.760 align:start position:0% sure that the incentives are aligned and 00:00:25.760 --> 00:00:28.510 align:start position:0% sure that the incentives are aligned and there's<00:00:26.090> good<00:00:26.300> governance<00:00:26.690> policy<00:00:27.140> and<00:00:27.920> in 00:00:28.510 --> 00:00:28.520 align:start position:0% there's good governance policy and in 00:00:28.520 --> 00:00:30.880 align:start position:0% there's good governance policy and in the<00:00:28.640> interest<00:00:28.940> of<00:00:29.060> time<00:00:29.270> I'm<00:00:30.230> not<00:00:30.470> going<00:00:30.650> to<00:00:30.770> be 00:00:30.880 --> 00:00:30.890 align:start position:0% the interest of time I'm not going to be 00:00:30.890 --> 00:00:33.340 align:start position:0% the interest of time I'm not going to be able<00:00:31.010> to<00:00:31.250> cover<00:00:31.460> these<00:00:32.450> other<00:00:32.689> topics<00:00:32.930> in<00:00:33.230> the 00:00:33.340 --> 00:00:33.350 align:start position:0% able to cover these other topics in the 00:00:33.350 --> 00:00:37.030 align:start position:0% able to cover these other topics in the stock<00:00:33.559> okay<00:00:34.840> so<00:00:35.840> let's<00:00:36.050> begin<00:00:36.200> I'm<00:00:36.740> going<00:00:36.950> to 00:00:37.030 --> 00:00:37.040 align:start position:0% stock okay so let's begin I'm going to 00:00:37.040 --> 00:00:41.460 align:start position:0% stock okay so let's begin I'm going to begin<00:00:37.190> with<00:00:37.490> a<00:00:38.030> little<00:00:38.690> bit<00:00:38.840> of<00:00:38.900> story<00:00:39.230> telling 00:00:41.460 --> 00:00:41.470 align:start position:0% 00:00:41.470 --> 00:00:46.030 align:start position:0% in<00:00:42.470> early<00:00:43.310> May<00:00:43.880> this<00:00:44.150> year<00:00:44.590> so<00:00:45.590> there<00:00:45.739> was<00:00:45.920> this 00:00:46.030 --> 00:00:46.040 align:start position:0% in early May this year so there was this 00:00:46.040 --> 00:00:50.440 align:start position:0% in early May this year so there was this one<00:00:46.370> day<00:00:46.780> when<00:00:47.780> all<00:00:48.140> the<00:00:49.030> flights<00:00:50.030> out<00:00:50.300> of 00:00:50.440 --> 00:00:50.450 align:start position:0% one day when all the flights out of 00:00:50.450 --> 00:00:52.120 align:start position:0% one day when all the flights out of London<00:00:50.840> were<00:00:50.960> canceled<00:00:51.440> you<00:00:51.800> know<00:00:51.950> for 00:00:52.120 --> 00:00:52.130 align:start position:0% London were canceled you know for 00:00:52.130 --> 00:00:53.620 align:start position:0% London were canceled you know for British<00:00:52.430> Airways<00:00:52.670> and<00:00:52.850> this<00:00:53.090> was<00:00:53.210> because<00:00:53.480> of 00:00:53.620 --> 00:00:53.630 align:start position:0% British Airways and this was because of 00:00:53.630 --> 00:00:55.450 align:start position:0% British Airways and this was because of a<00:00:53.690> systems<00:00:54.050> failure<00:00:54.200> and<00:00:54.590> this<00:00:54.950> is<00:00:55.070> a<00:00:55.100> picture 00:00:55.450 --> 00:00:55.460 align:start position:0% a systems failure and this is a picture 00:00:55.460 --> 00:00:57.610 align:start position:0% a systems failure and this is a picture showing<00:00:55.489> people<00:00:56.030> lined<00:00:56.239> up<00:00:56.390> at<00:00:56.630> the<00:00:57.200> airport 00:00:57.610 --> 00:00:57.620 align:start position:0% showing people lined up at the airport 00:00:57.620 --> 00:01:02.530 align:start position:0% showing people lined up at the airport and<00:00:59.260> quite<00:01:00.260> interesting<00:01:00.590> lay<00:01:01.100> in<00:01:02.000> September 00:01:02.530 --> 00:01:02.540 align:start position:0% and quite interesting lay in September 00:01:02.540 --> 00:01:03.940 align:start position:0% and quite interesting lay in September last<00:01:02.570> year<00:01:02.870> something<00:01:03.320> very<00:01:03.649> similar 00:01:03.940 --> 00:01:03.950 align:start position:0% last year something very similar 00:01:03.950 --> 00:01:06.340 align:start position:0% last year something very similar happened<00:01:04.430> to<00:01:04.489> doubt<00:01:04.729> our<00:01:04.969> airlines<00:01:05.390> and<00:01:05.690> for 00:01:06.340 --> 00:01:06.350 align:start position:0% happened to doubt our airlines and for 00:01:06.350 --> 00:01:07.690 align:start position:0% happened to doubt our airlines and for this<00:01:06.470> one<00:01:06.650> day<00:01:06.860> you<00:01:07.100> know<00:01:07.130> everything<00:01:07.580> was 00:01:07.690 --> 00:01:07.700 align:start position:0% this one day you know everything was 00:01:07.700 --> 00:01:09.250 align:start position:0% this one day you know everything was shut<00:01:07.880> down<00:01:07.940> you<00:01:08.240> couldn't<00:01:08.570> fly<00:01:08.750> you<00:01:08.810> couldn't 00:01:09.250 --> 00:01:09.260 align:start position:0% shut down you couldn't fly you couldn't 00:01:09.260 --> 00:01:14.890 align:start position:0% shut down you couldn't fly you couldn't book<00:01:09.729> any<00:01:10.729> flights<00:01:11.590> and<00:01:12.590> Tata<00:01:13.310> suffered<00:01:13.900> 100 00:01:14.890 --> 00:01:14.900 align:start position:0% book any flights and Tata suffered 100 00:01:14.900 --> 00:01:17.920 align:start position:0% book any flights and Tata suffered 100 million<00:01:15.229> u.s.<00:01:16.220> dollars<00:01:16.640> last<00:01:16.790> you<00:01:17.659> know<00:01:17.720> in 00:01:17.920 --> 00:01:17.930 align:start position:0% million u.s. dollars last you know in 00:01:17.930 --> 00:01:20.969 align:start position:0% million u.s. dollars last you know in revenue<00:01:18.380> because<00:01:18.680> of<00:01:18.860> this<00:01:18.979> systems<00:01:19.670> failure 00:01:20.969 --> 00:01:20.979 align:start position:0% revenue because of this systems failure 00:01:20.979 --> 00:01:23.230 align:start position:0% revenue because of this systems failure so<00:01:21.979> what's<00:01:22.159> the<00:01:22.340> morrow<00:01:22.610> behind<00:01:23.060> these 00:01:23.230 --> 00:01:23.240 align:start position:0% so what's the morrow behind these 00:01:23.240 --> 00:01:26.050 align:start position:0% so what's the morrow behind these stories<00:01:23.979> we<00:01:24.979> need<00:01:25.190> replication<00:01:25.940> and 00:01:26.050 --> 00:01:26.060 align:start position:0% stories we need replication and 00:01:26.060 --> 00:01:28.649 align:start position:0% stories we need replication and robustness<00:01:26.510> right<00:01:27.260> so<00:01:27.380> it's<00:01:27.560> a<00:01:27.650> very<00:01:27.860> simple 00:01:28.649 --> 00:01:28.659 align:start position:0% robustness right so it's a very simple 00:01:28.659 --> 00:01:32.950 align:start position:0% robustness right so it's a very simple idea<00:01:29.740> but<00:01:30.740> it<00:01:31.460> is<00:01:31.610> precisely<00:01:32.180> this<00:01:32.479> very<00:01:32.750> very 00:01:32.950 --> 00:01:32.960 align:start position:0% idea but it is precisely this very very 00:01:32.960 --> 00:01:35.760 align:start position:0% idea but it is precisely this very very simple<00:01:33.229> idea<00:01:33.530> that<00:01:33.790> gave<00:01:34.790> birth<00:01:34.820> to<00:01:35.090> an<00:01:35.390> entire 00:01:35.760 --> 00:01:35.770 align:start position:0% simple idea that gave birth to an entire 00:01:35.770 --> 00:01:38.789 align:start position:0% simple idea that gave birth to an entire line<00:01:36.770> of<00:01:36.799> work<00:01:37.220> called<00:01:37.729> distributed<00:01:38.270> systems 00:01:38.789 --> 00:01:38.799 align:start position:0% line of work called distributed systems 00:01:38.799 --> 00:01:41.560 align:start position:0% line of work called distributed systems and<00:01:39.799> this<00:01:40.070> has<00:01:40.310> been<00:01:40.490> around<00:01:40.700> for<00:01:41.090> 30<00:01:41.270> years 00:01:41.560 --> 00:01:41.570 align:start position:0% and this has been around for 30 years 00:01:41.570 --> 00:01:44.410 align:start position:0% and this has been around for 30 years right<00:01:41.720> it's<00:01:41.900> not<00:01:42.020> something<00:01:42.380> new<00:01:43.420> in 00:01:44.410 --> 00:01:44.420 align:start position:0% right it's not something new in 00:01:44.420 --> 00:01:48.219 align:start position:0% right it's not something new in distributed<00:01:45.020> systems<00:01:45.670> we<00:01:46.670> care<00:01:47.000> about<00:01:47.150> a<00:01:47.600> very 00:01:48.219 --> 00:01:48.229 align:start position:0% distributed systems we care about a very 00:01:48.229 --> 00:01:50.350 align:start position:0% distributed systems we care about a very important<00:01:48.830> abstraction<00:01:49.460> which<00:01:49.729> I<00:01:49.909> will<00:01:50.119> call 00:01:50.350 --> 00:01:50.360 align:start position:0% important abstraction which I will call 00:01:50.360 --> 00:01:52.870 align:start position:0% important abstraction which I will call state<00:01:51.080> machine<00:01:51.380> replication<00:01:51.950> so<00:01:52.610> let<00:01:52.759> me 00:01:52.870 --> 00:01:52.880 align:start position:0% state machine replication so let me 00:01:52.880 --> 00:01:54.370 align:start position:0% state machine replication so let me quickly<00:01:53.060> explain<00:01:53.270> what<00:01:53.600> state<00:01:54.110> machine 00:01:54.370 --> 00:01:54.380 align:start position:0% quickly explain what state machine 00:01:54.380 --> 00:01:58.149 align:start position:0% quickly explain what state machine replication<00:01:54.890> is<00:01:56.470> okay<00:01:57.470> so<00:01:57.530> state<00:01:57.860> mature 00:01:58.149 --> 00:01:58.159 align:start position:0% replication is okay so state mature 00:01:58.159 --> 00:02:00.130 align:start position:0% replication is okay so state mature application<00:01:58.670> is<00:01:58.820> the<00:01:58.970> task<00:01:59.240> of<00:01:59.479> agreeing<00:01:59.930> on 00:02:00.130 --> 00:02:00.140 align:start position:0% application is the task of agreeing on 00:02:00.140 --> 00:02:03.039 align:start position:0% application is the task of agreeing on an<00:02:00.320> ever<00:02:00.560> growing<00:02:01.060> linearly<00:02:02.060> order<00:02:02.540> lag<00:02:02.810> all 00:02:03.039 --> 00:02:03.049 align:start position:0% an ever growing linearly order lag all 00:02:03.049 --> 00:02:05.200 align:start position:0% an ever growing linearly order lag all right<00:02:03.140> so<00:02:03.259> let's<00:02:03.439> imagine<00:02:03.619> we<00:02:04.579> have<00:02:04.759> a<00:02:04.790> set<00:02:05.060> of 00:02:05.200 --> 00:02:05.210 align:start position:0% right so let's imagine we have a set of 00:02:05.210 --> 00:02:06.550 align:start position:0% right so let's imagine we have a set of servers<00:02:05.479> in<00:02:05.810> this<00:02:05.960> case<00:02:06.140> we<00:02:06.259> have<00:02:06.380> Google 00:02:06.550 --> 00:02:06.560 align:start position:0% servers in this case we have Google 00:02:06.560 --> 00:02:09.339 align:start position:0% servers in this case we have Google Wallet<00:02:06.829> servers<00:02:07.369> and<00:02:08.200> obviously<00:02:09.200> Google 00:02:09.339 --> 00:02:09.349 align:start position:0% Wallet servers and obviously Google 00:02:09.349 --> 00:02:11.770 align:start position:0% Wallet servers and obviously Google Wallet<00:02:09.619> and<00:02:10.160> doesn't<00:02:10.940> want<00:02:11.180> the<00:02:11.360> kind<00:02:11.630> of 00:02:11.770 --> 00:02:11.780 align:start position:0% Wallet and doesn't want the kind of 00:02:11.780 --> 00:02:13.700 align:start position:0% Wallet and doesn't want the kind of disaster<00:02:12.530> that<00:02:12.650> data<00:02:12.860> align 00:02:13.700 --> 00:02:13.710 align:start position:0% disaster that data align 00:02:13.710 --> 00:02:16.040 align:start position:0% disaster that data align has<00:02:14.040> had<00:02:14.280> right<00:02:14.580> so<00:02:14.730> the<00:02:15.210> servers<00:02:15.660> would<00:02:15.840> like 00:02:16.040 --> 00:02:16.050 align:start position:0% has had right so the servers would like 00:02:16.050 --> 00:02:17.870 align:start position:0% has had right so the servers would like to<00:02:16.200> agree<00:02:16.410> on<00:02:16.500> the<00:02:16.770> linearly<00:02:17.130> order<00:02:17.520> log<00:02:17.700> of 00:02:17.870 --> 00:02:17.880 align:start position:0% to agree on the linearly order log of 00:02:17.880 --> 00:02:20.960 align:start position:0% to agree on the linearly order log of transactions<00:02:19.010> and<00:02:20.010> there<00:02:20.490> are<00:02:20.580> two<00:02:20.790> very 00:02:20.960 --> 00:02:20.970 align:start position:0% transactions and there are two very 00:02:20.970 --> 00:02:22.490 align:start position:0% transactions and there are two very important<00:02:21.480> security<00:02:21.870> properties<00:02:22.260> that<00:02:22.380> we 00:02:22.490 --> 00:02:22.500 align:start position:0% important security properties that we 00:02:22.500 --> 00:02:24.110 align:start position:0% important security properties that we care<00:02:22.650> about<00:02:22.680> namely<00:02:23.340> consistency<00:02:23.970> and 00:02:24.110 --> 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however<00:02:37.700> note<00:02:38.700> that<00:02:38.730> the 00:02:39.290 --> 00:02:39.300 align:start position:0% the same log however note that the 00:02:39.300 --> 00:02:41.030 align:start position:0% the same log however note that the Knauer<00:02:39.570> can<00:02:39.900> have<00:02:40.080> delay<00:02:40.410> right<00:02:40.620> so<00:02:40.770> it<00:02:40.890> could 00:02:41.030 --> 00:02:41.040 align:start position:0% Knauer can have delay right so it could 00:02:41.040 --> 00:02:42.770 align:start position:0% Knauer can have delay right so it could be<00:02:41.160> that<00:02:41.310> your<00:02:41.610> lock<00:02:41.880> is<00:02:42.090> a<00:02:42.120> little<00:02:42.420> faster 00:02:42.770 --> 00:02:42.780 align:start position:0% be that your lock is a little faster 00:02:42.780 --> 00:02:43.400 align:start position:0% be that your lock is a little faster than<00:02:42.960> mine 00:02:43.400 --> 00:02:43.410 align:start position:0% than mine 00:02:43.410 --> 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says<00:02:50.820> for<00:02:51.690> lightness<00:02:52.550> whenever<00:02:53.550> an<00:02:53.760> honest 00:02:54.170 --> 00:02:54.180 align:start position:0% says for lightness whenever an honest 00:02:54.180 --> 00:02:56.600 align:start position:0% says for lightness whenever an honest client<00:02:54.630> submits<00:02:54.960> a<00:02:55.230> transaction<00:02:55.740> we<00:02:56.310> want 00:02:56.600 --> 00:02:56.610 align:start position:0% client submits a transaction we want 00:02:56.610 --> 00:02:59.360 align:start position:0% client submits a transaction we want that<00:02:56.910> this<00:02:57.810> transaction<00:02:58.290> will<00:02:58.620> appear<00:02:59.040> in<00:02:59.220> all 00:02:59.360 --> 00:02:59.370 align:start position:0% that this transaction will appear in all 00:02:59.370 --> 00:03:03.190 align:start position:0% that this transaction will appear in all of<00:02:59.550> the<00:02:59.670> honest<00:02:59.970> servers<00:03:00.330> lock<00:03:00.650> very<00:03:01.650> quickly 00:03:03.190 --> 00:03:03.200 align:start position:0% of the honest servers lock very quickly 00:03:03.200 --> 00:03:06.200 align:start position:0% of the honest servers lock very quickly okay<00:03:04.200> so<00:03:04.830> any<00:03:05.010> questions<00:03:05.430> at<00:03:05.580> this<00:03:05.610> point<00:03:05.730> if 00:03:06.200 --> 00:03:06.210 align:start position:0% okay so any questions at this point if 00:03:06.210 --> 00:03:07.870 align:start position:0% okay so any questions at this point if you<00:03:06.360> guys<00:03:06.540> have<00:03:06.780> questions<00:03:06.930> feel<00:03:07.320> free<00:03:07.440> to 00:03:07.870 --> 00:03:07.880 align:start position:0% you guys have questions feel free to 00:03:07.880 --> 00:03:10.310 align:start position:0% you guys have questions feel free to interrupt<00:03:08.880> the<00:03:09.120> audience<00:03:09.480> has<00:03:09.630> reduced<00:03:10.200> a 00:03:10.310 --> 00:03:10.320 align:start position:0% interrupt the audience has reduced a 00:03:10.320 --> 00:03:11.600 align:start position:0% interrupt the audience has reduced a little<00:03:10.560> bit<00:03:10.680> which<00:03:10.830> is<00:03:10.980> good<00:03:11.160> for<00:03:11.280> asking 00:03:11.600 --> 00:03:11.610 align:start position:0% little bit which is good for asking 00:03:11.610 --> 00:03:20.000 align:start position:0% little bit which is good for asking questions<00:03:12.590> yes<00:03:18.200> quickly<00:03:19.200> so<00:03:19.590> typically 00:03:20.000 --> 00:03:20.010 align:start position:0% questions yes quickly so typically 00:03:20.010 --> 00:03:21.920 align:start position:0% questions yes quickly so typically there's<00:03:20.190> a<00:03:20.280> technical<00:03:20.580> definition<00:03:20.840> with<00:03:21.840> the 00:03:21.920 --> 00:03:21.930 align:start position:0% there's a technical definition with the 00:03:21.930 --> 00:03:23.870 align:start position:0% there's a technical definition with the liveness<00:03:22.140> parameters<00:03:22.830> so<00:03:23.040> that<00:03:23.250> the<00:03:23.520> lioness 00:03:23.870 --> 00:03:23.880 align:start position:0% liveness parameters so that the lioness 00:03:23.880 --> 00:03:25.370 align:start position:0% liveness parameters so that the lioness parameter<00:03:24.330> can<00:03:24.540> be<00:03:24.660> some<00:03:24.810> kind<00:03:24.930> of<00:03:25.110> polynomial 00:03:25.370 --> 00:03:25.380 align:start position:0% parameter can be some kind of polynomial 00:03:25.380 --> 00:03:27.680 align:start position:0% parameter can be some kind of polynomial functioning<00:03:26.010> over<00:03:26.450> parameters<00:03:27.450> of<00:03:27.600> the 00:03:27.680 --> 00:03:27.690 align:start position:0% functioning over parameters of the 00:03:27.690 --> 00:03:29.150 align:start position:0% functioning over parameters of the execution<00:03:28.170> like<00:03:28.260> the<00:03:28.380> security<00:03:28.770> parameter 00:03:29.150 --> 00:03:29.160 align:start position:0% execution like the security parameter 00:03:29.160 --> 00:03:32.030 align:start position:0% execution like the security parameter the<00:03:29.250> number<00:03:29.460> of<00:03:29.550> nodes<00:03:30.350> but<00:03:31.350> for<00:03:31.680> the<00:03:31.740> purpose 00:03:32.030 --> 00:03:32.040 align:start position:0% the number of nodes but for the purpose 00:03:32.040 --> 00:03:36.050 align:start position:0% the number of nodes but for the purpose of<00:03:32.160> this<00:03:32.280> talk<00:03:34.040> so<00:03:35.040> the<00:03:35.250> protocol<00:03:35.730> I'm<00:03:35.850> going 00:03:36.050 --> 00:03:36.060 align:start position:0% of this talk so the protocol I'm going 00:03:36.060 --> 00:03:38.480 align:start position:0% of this talk so the protocol I'm going to<00:03:36.180> describe<00:03:36.570> is<00:03:36.780> like<00:03:36.960> confirms<00:03:37.890> in<00:03:38.130> like<00:03:38.280> one 00:03:38.480 --> 00:03:38.490 align:start position:0% to describe is like confirms in like one 00:03:38.490 --> 00:03:40.850 align:start position:0% to describe is like confirms in like one to<00:03:38.670> two<00:03:38.700> rounds<00:03:39.180> but<00:03:39.360> in<00:03:39.510> general<00:03:39.990> this 00:03:40.850 --> 00:03:40.860 align:start position:0% to two rounds but in general this 00:03:40.860 --> 00:03:42.590 align:start position:0% to two rounds but in general this parameter<00:03:41.310> you<00:03:41.430> can<00:03:41.460> specify<00:03:41.820> as<00:03:42.180> a<00:03:42.210> function 00:03:42.590 --> 00:03:42.600 align:start position:0% parameter you can specify as a function 00:03:42.600 --> 00:03:44.030 align:start position:0% parameter you can specify as a function of<00:03:42.660> other<00:03:42.840> parameters<00:03:43.320> of<00:03:43.440> the<00:03:43.560> execution 00:03:44.030 --> 00:03:44.040 align:start position:0% of other parameters of the execution 00:03:44.040 --> 00:03:46.070 align:start position:0% of other parameters of the execution okay<00:03:44.790> all<00:03:44.970> right<00:03:45.120> so<00:03:45.540> that's<00:03:45.720> a<00:03:45.780> very<00:03:45.930> good 00:03:46.070 --> 00:03:46.080 align:start position:0% okay all right so that's a very good 00:03:46.080 --> 00:03:50.530 align:start position:0% okay all right so that's a very good question<00:03:46.230> and<00:03:47.780> in<00:03:48.780> you<00:03:49.440> know<00:03:49.470> at<00:03:49.800> first<00:03:50.130> sight 00:03:50.530 --> 00:03:50.540 align:start position:0% question and in you know at first sight 00:03:50.540 --> 00:03:53.330 align:start position:0% question and in you know at first sight this<00:03:51.540> definition<00:03:52.050> seems<00:03:52.440> like<00:03:52.680> deceptively 00:03:53.330 --> 00:03:53.340 align:start position:0% this definition seems like deceptively 00:03:53.340 --> 00:03:55.360 align:start position:0% this definition seems like deceptively simple<00:03:53.940> right<00:03:54.120> so<00:03:54.240> what<00:03:54.420> can<00:03:54.600> be<00:03:54.780> so<00:03:54.960> hard 00:03:55.360 --> 00:03:55.370 align:start position:0% simple right so what can be so hard 00:03:55.370 --> 00:03:58.450 align:start position:0% simple right so what can be so hard about<00:03:56.370> agreeing<00:03:57.000> on<00:03:57.210> a<00:03:57.240> linearly<00:03:57.660> order<00:03:57.990> log 00:03:58.450 --> 00:03:58.460 align:start position:0% about agreeing on a linearly order log 00:03:58.460 --> 00:04:02.030 align:start position:0% about agreeing on a linearly order log indeed<00:03:59.460> if<00:03:59.880> all<00:04:00.300> of<00:04:00.450> these<00:04:00.630> notes<00:04:01.040> behave 00:04:02.030 --> 00:04:02.040 align:start position:0% indeed if all of these notes behave 00:04:02.040 --> 00:04:04.940 align:start position:0% indeed if all of these notes behave correctly<00:04:02.840> then<00:04:03.840> the<00:04:04.020> problem<00:04:04.470> is<00:04:04.560> indeed 00:04:04.940 --> 00:04:04.950 align:start position:0% correctly then the problem is indeed 00:04:04.950 --> 00:04:06.260 align:start position:0% correctly then the problem is indeed trivial<00:04:05.370> like<00:04:05.520> there's<00:04:05.730> nothing<00:04:06.000> hard<00:04:06.180> about 00:04:06.260 --> 00:04:06.270 align:start position:0% trivial like there's nothing hard about 00:04:06.270 --> 00:04:08.420 align:start position:0% trivial like there's nothing hard about it<00:04:06.450> but<00:04:06.960> what's<00:04:07.140> interesting<00:04:07.440> is<00:04:07.800> if<00:04:07.950> some<00:04:08.280> of 00:04:08.420 --> 00:04:08.430 align:start position:0% it but what's interesting is if some of 00:04:08.430 --> 00:04:09.980 align:start position:0% it but what's interesting is if some of the<00:04:08.580> notes<00:04:08.760> are<00:04:08.970> compromised<00:04:09.540> let's<00:04:09.780> say<00:04:09.870> they 00:04:09.980 --> 00:04:09.990 align:start position:0% the notes are compromised let's say they 00:04:09.990 --> 00:04:11.570 align:start position:0% the notes are compromised let's say they have<00:04:10.140> malware<00:04:10.560> and<00:04:10.830> then<00:04:10.980> they<00:04:11.190> can<00:04:11.370> behave 00:04:11.570 --> 00:04:11.580 align:start position:0% have malware and then they can behave 00:04:11.580 --> 00:04:14.240 align:start position:0% have malware and then they can behave arbitrarily<00:04:12.120> and<00:04:12.600> deviate<00:04:13.590> arbitrarily<00:04:14.040> from 00:04:14.240 --> 00:04:14.250 align:start position:0% arbitrarily and deviate arbitrarily from 00:04:14.250 --> 00:04:16.820 align:start position:0% arbitrarily and deviate arbitrarily from the<00:04:14.400> protocol<00:04:14.760> and<00:04:14.970> even<00:04:15.750> in<00:04:15.930> these<00:04:16.170> cases<00:04:16.500> we 00:04:16.820 --> 00:04:16.830 align:start position:0% the protocol and even in these cases we 00:04:16.830 --> 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problem<00:04:23.970> is<00:04:24.090> highly 00:04:24.409 --> 00:04:24.419 align:start position:0% that's why the problem is highly 00:04:24.419 --> 00:04:27.159 align:start position:0% that's why the problem is highly non-trivial<00:04:24.830> okay 00:04:27.159 --> 00:04:27.169 align:start position:0% non-trivial okay 00:04:27.169 --> 00:04:29.420 align:start position:0% non-trivial okay so<00:04:28.169> for<00:04:28.320> the<00:04:28.410> rest<00:04:28.530> of<00:04:28.710> the<00:04:28.830> talk<00:04:29.010> whenever<00:04:29.190> I 00:04:29.420 --> 00:04:29.430 align:start position:0% so for the rest of the talk whenever I 00:04:29.430 --> 00:04:31.600 align:start position:0% so for the rest of the talk whenever I mentioned<00:04:30.060> the<00:04:30.120> word<00:04:30.300> consensus<00:04:30.990> I 00:04:31.600 --> 00:04:31.610 align:start position:0% mentioned the word consensus I 00:04:31.610 --> 00:04:33.680 align:start position:0% mentioned the word consensus I exclusively<00:04:32.610> mean<00:04:32.820> a<00:04:33.090> state<00:04:33.450> mission 00:04:33.680 --> 00:04:33.690 align:start position:0% exclusively mean a state mission 00:04:33.690 --> 00:04:36.820 align:start position:0% exclusively mean a state mission application<00:04:35.540> okay 00:04:36.820 --> 00:04:36.830 align:start position:0% application okay 00:04:36.830 --> 00:04:39.020 align:start position:0% application okay so<00:04:37.830> like<00:04:37.980> I<00:04:38.130> said<00:04:38.190> state<00:04:38.639> measure<00:04:38.910> application 00:04:39.020 --> 00:04:39.030 align:start position:0% so like I said state measure application 00:04:39.030 --> 00:04:40.760 align:start position:0% so like I said state measure application is<00:04:39.450> not<00:04:39.570> something<00:04:39.930> that's<00:04:40.050> new<00:04:40.320> right<00:04:40.350> it's 00:04:40.760 --> 00:04:40.770 align:start position:0% is not something that's new right it's 00:04:40.770 --> 00:04:42.500 align:start position:0% is not something that's new right it's not<00:04:40.889> just<00:04:41.310> like<00:04:41.490> you<00:04:41.850> know<00:04:41.970> black<00:04:42.210> cheese 00:04:42.500 --> 00:04:42.510 align:start position:0% not just like you know black cheese 00:04:42.510 --> 00:04:44.480 align:start position:0% not just like you know black cheese invented<00:04:43.230> state<00:04:43.440> machine<00:04:43.680> application<00:04:44.010> this 00:04:44.480 --> 00:04:44.490 align:start position:0% invented state machine application this 00:04:44.490 --> 00:04:46.159 align:start position:0% invented state machine application this has<00:04:44.730> been<00:04:44.910> around<00:04:45.030> for<00:04:45.419> a<00:04:45.450> really<00:04:45.630> long<00:04:45.870> time 00:04:46.159 --> 00:04:46.169 align:start position:0% has been around for a really long time 00:04:46.169 --> 00:04:48.290 align:start position:0% has been around for a really long time and<00:04:46.440> it<00:04:46.919> has<00:04:46.950> been<00:04:47.220> making<00:04:47.550> real<00:04:47.730> world<00:04:47.970> impact 00:04:48.290 --> 00:04:48.300 align:start position:0% and it has been making real world impact 00:04:48.300 --> 00:04:49.790 align:start position:0% and it has been making real world impact for<00:04:48.540> a<00:04:48.570> really<00:04:48.810> long<00:04:48.930> time<00:04:48.990> era<00:04:49.410> for<00:04:49.530> instance 00:04:49.790 --> 00:04:49.800 align:start position:0% for a really long time era for instance 00:04:49.800 --> 00:04:52.070 align:start position:0% for a really long time era for instance every<00:04:50.100> Silicon<00:04:50.490> Valley<00:04:50.669> company<00:04:51.150> actually 00:04:52.070 --> 00:04:52.080 align:start position:0% every Silicon Valley company actually 00:04:52.080 --> 00:04:53.780 align:start position:0% every Silicon Valley company actually implies<00:04:52.500> some<00:04:52.800> instance<00:04:53.190> of<00:04:53.310> state<00:04:53.520> machine 00:04:53.780 --> 00:04:53.790 align:start position:0% implies some instance of state machine 00:04:53.790 --> 00:04:55.879 align:start position:0% implies some instance of state machine application<00:04:54.150> protocol<00:04:54.660> to<00:04:55.139> replicate<00:04:55.710> their 00:04:55.879 --> 00:04:55.889 align:start position:0% application protocol to replicate their 00:04:55.889 --> 00:04:57.980 align:start position:0% application protocol to replicate their computing<00:04:56.310> infrastructure<00:04:56.850> so<00:04:57.570> for<00:04:57.720> instance 00:04:57.980 --> 00:04:57.990 align:start position:0% computing infrastructure so for instance 00:04:57.990 --> 00:05:00.800 align:start position:0% computing infrastructure so for instance for<00:04:58.590> Google<00:04:58.950> alright<00:04:59.220> and<00:04:59.520> they<00:05:00.300> run<00:05:00.540> a 00:05:00.800 --> 00:05:00.810 align:start position:0% for Google alright and they run a 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machine<00:05:08.970> application 00:05:09.760 --> 00:05:09.770 align:start position:0% version of state machine application 00:05:09.770 --> 00:05:12.200 align:start position:0% version of state machine application obviously<00:05:10.770> whatever<00:05:11.370> Google<00:05:11.580> test<00:05:11.910> you<00:05:12.090> know 00:05:12.200 --> 00:05:12.210 align:start position:0% obviously whatever Google test you know 00:05:12.210 --> 00:05:13.640 align:start position:0% obviously whatever Google test you know every<00:05:12.450> other<00:05:12.600> Silicon<00:05:13.020> Valley<00:05:13.169> company<00:05:13.590> is 00:05:13.640 --> 00:05:13.650 align:start position:0% every other Silicon Valley company is 00:05:13.650 --> 00:05:15.500 align:start position:0% every other Silicon Valley company is going<00:05:13.800> to<00:05:13.889> copy<00:05:14.190> and<00:05:14.550> that's<00:05:14.940> why<00:05:15.060> we<00:05:15.240> have<00:05:15.389> an 00:05:15.500 --> 00:05:15.510 align:start position:0% going to copy and that's why we have an 00:05:15.510 --> 00:05:17.870 align:start position:0% going to copy and that's why we have an open-source<00:05:16.280> counterpart<00:05:17.280> I<00:05:17.430> mean<00:05:17.580> sort<00:05:17.700> of 00:05:17.870 --> 00:05:17.880 align:start position:0% open-source counterpart I mean sort of 00:05:17.880 --> 00:05:21.379 align:start position:0% open-source counterpart I mean sort of counterpart<00:05:18.780> cut<00:05:19.010> Apache<00:05:20.010> zookeeper<00:05:20.639> and 00:05:21.379 --> 00:05:21.389 align:start position:0% counterpart cut Apache zookeeper and 00:05:21.389 --> 00:05:23.300 align:start position:0% counterpart cut Apache zookeeper and pretty<00:05:21.660> much<00:05:21.810> apart<00:05:22.200> from<00:05:22.380> Google<00:05:22.770> every 00:05:23.300 --> 00:05:23.310 align:start position:0% pretty much apart from Google every 00:05:23.310 --> 00:05:24.620 align:start position:0% pretty much apart from Google every other<00:05:23.490> company<00:05:24.030> in<00:05:24.150> the<00:05:24.180> Silicon<00:05:24.600> Valley 00:05:24.620 --> 00:05:24.630 align:start position:0% other company in the Silicon Valley 00:05:24.630 --> 00:05:30.140 align:start position:0% other company in the Silicon Valley implies<00:05:25.229> and<00:05:25.940> Apache<00:05:26.940> zookeeper<00:05:28.250> ok<00:05:29.250> so 00:05:30.140 --> 00:05:30.150 align:start position:0% implies and Apache zookeeper ok so 00:05:30.150 --> 00:05:32.210 align:start position:0% implies and Apache zookeeper ok so traditionally<00:05:30.960> when<00:05:31.800> we<00:05:32.010> talk<00:05:32.190> about 00:05:32.210 --> 00:05:32.220 align:start position:0% traditionally when we talk about 00:05:32.220 --> 00:05:34.340 align:start position:0% traditionally when we talk about distributed<00:05:32.940> consensus<00:05:33.419> the<00:05:33.900> kind<00:05:34.169> of 00:05:34.340 --> 00:05:34.350 align:start position:0% distributed consensus the kind of 00:05:34.350 --> 00:05:36.260 align:start position:0% distributed consensus the kind of scenario<00:05:34.890> that<00:05:34.919> conjures<00:05:35.520> up<00:05:35.640> in<00:05:35.850> our<00:05:36.000> minds 00:05:36.260 --> 00:05:36.270 align:start position:0% scenario that conjures up in our minds 00:05:36.270 --> 00:05:38.510 align:start position:0% scenario that conjures up in our minds is<00:05:36.990> exactly<00:05:37.560> what<00:05:37.740> I<00:05:37.770> said<00:05:38.039> right<00:05:38.280> there's<00:05:38.460> a 00:05:38.510 --> 00:05:38.520 align:start position:0% is exactly what I said right there's a 00:05:38.520 --> 00:05:40.340 align:start position:0% is exactly what I said right there's a single<00:05:38.850> company<00:05:39.150> there's<00:05:39.570> like<00:05:39.780> five<00:05:39.990> to<00:05:40.169> ten 00:05:40.340 --> 00:05:40.350 align:start position:0% single company there's like five to ten 00:05:40.350 --> 00:05:42.320 align:start position:0% single company there's like five to ten nodes<00:05:40.590> and<00:05:40.890> the<00:05:41.400> nodes<00:05:41.550> are<00:05:41.789> interconnected 00:05:42.320 --> 00:05:42.330 align:start position:0% nodes and the nodes are interconnected 00:05:42.330 --> 00:05:45.080 align:start position:0% nodes and the nodes are interconnected with<00:05:42.539> fast<00:05:42.840> local<00:05:43.200> area<00:05:43.440> network<00:05:43.789> so<00:05:44.789> small 00:05:45.080 --> 00:05:45.090 align:start position:0% with fast local area network so small 00:05:45.090 --> 00:05:50.450 align:start position:0% with fast local area network so small scale<00:05:46.400> and<00:05:48.050> what<00:05:49.050> is<00:05:49.200> really<00:05:49.530> amazing<00:05:49.919> is<00:05:50.430> that 00:05:50.450 --> 00:05:50.460 align:start position:0% scale and what is really amazing is that 00:05:50.460 --> 00:05:52.010 align:start position:0% scale and what is really amazing is that you<00:05:50.820> know<00:05:50.970> with<00:05:51.120> crypto<00:05:51.479> currencies<00:05:51.900> like 00:05:52.010 --> 00:05:52.020 align:start position:0% you know with crypto currencies like 00:05:52.020 --> 00:05:55.700 align:start position:0% you know with crypto currencies like Bitcoin<00:05:52.100> aetherium<00:05:53.390> we<00:05:54.390> now<00:05:54.690> have<00:05:55.139> empirical 00:05:55.700 --> 00:05:55.710 align:start position:0% Bitcoin aetherium we now have empirical 00:05:55.710 --> 00:05:57.860 align:start position:0% Bitcoin aetherium we now have empirical evidence<00:05:56.100> that<00:05:56.310> distributed<00:05:57.060> consensus<00:05:57.479> is 00:05:57.860 --> 00:05:57.870 align:start position:0% evidence that distributed consensus is 00:05:57.870 --> 00:05:59.900 align:start position:0% evidence that distributed consensus is actually<00:05:58.440> possible<00:05:58.979> on<00:05:59.220> a<00:05:59.280> really<00:05:59.729> large 00:05:59.900 --> 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setting<00:06:17.160> like<00:06:17.280> we<00:06:17.310> want<00:06:17.550> consultant 00:06:18.110 --> 00:06:18.120 align:start position:0% setting like we want consultant 00:06:18.120 --> 00:06:20.450 align:start position:0% setting like we want consultant blockchains<00:06:18.720> the<00:06:19.500> banks<00:06:19.800> want<00:06:20.010> to<00:06:20.070> build<00:06:20.340> a 00:06:20.450 --> 00:06:20.460 align:start position:0% blockchains the banks want to build a 00:06:20.460 --> 00:06:22.100 align:start position:0% blockchains the banks want to build a distributed<00:06:20.970> ledger<00:06:21.090> among<00:06:21.539> amongst 00:06:22.100 --> 00:06:22.110 align:start position:0% distributed ledger among amongst 00:06:22.110 --> 00:06:25.219 align:start position:0% distributed ledger among amongst themselves<00:06:23.570> ok<00:06:24.570> for<00:06:24.750> instance<00:06:25.050> in<00:06:25.200> China 00:06:25.219 --> 00:06:25.229 align:start position:0% themselves ok for instance in China 00:06:25.229 --> 00:06:28.279 align:start position:0% themselves ok for instance in China right<00:06:25.919> we<00:06:26.310> have<00:06:26.550> China's<00:06:27.479> central<00:06:27.630> bank<00:06:27.810> wants 00:06:28.279 --> 00:06:28.289 align:start position:0% right we have China's central bank wants 00:06:28.289 --> 00:06:32.029 align:start position:0% right we have China's central bank wants to<00:06:28.440> build<00:06:28.590> such<00:06:28.830> a<00:06:29.360> distributed<00:06:30.360> ledger<00:06:31.039> among 00:06:32.029 --> 00:06:32.039 align:start position:0% to build such a distributed ledger among 00:06:32.039 --> 00:06:34.430 align:start position:0% to build such a distributed ledger among all<00:06:32.220> of<00:06:32.460> the<00:06:32.639> banks<00:06:32.910> in<00:06:33.060> China<00:06:33.090> and<00:06:33.750> the<00:06:34.229> kind 00:06:34.430 --> 00:06:34.440 align:start position:0% all of the banks in China and the kind 00:06:34.440 --> 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we<00:06:41.870> are 00:06:41.890 --> 00:06:41.900 align:start position:0% Bank contributes like 10 notes we are 00:06:41.900 --> 00:06:49.830 align:start position:0% Bank contributes like 10 notes we are looking<00:06:42.230> at<00:06:42.380> a<00:06:42.830> thousand<00:06:43.250> note<00:06:43.730> scale<00:06:45.880> okay<00:06:48.520> so 00:06:49.830 --> 00:06:49.840 align:start position:0% looking at a thousand note scale okay so 00:06:49.840 --> 00:06:52.870 align:start position:0% looking at a thousand note scale okay so and<00:06:50.840> perhaps<00:06:51.170> not<00:06:51.560> surprisingly<00:06:52.220> I<00:06:52.520> are<00:06:52.730> this 00:06:52.870 --> 00:06:52.880 align:start position:0% and perhaps not surprisingly I are this 00:06:52.880 --> 00:06:54.790 align:start position:0% and perhaps not surprisingly I are this large<00:06:53.120> industry<00:06:53.630> consulting<00:06:54.140> companies<00:06:54.620> in 00:06:54.790 --> 00:06:54.800 align:start position:0% large industry consulting companies in 00:06:54.800 --> 00:06:58.450 align:start position:0% large industry consulting companies in the<00:06:54.890> space<00:06:54.950> everyone's<00:06:56.200> racing<00:06:57.200> to<00:06:57.830> create 00:06:58.450 --> 00:06:58.460 align:start position:0% the space everyone's racing to create 00:06:58.460 --> 00:07:00.010 align:start position:0% the space everyone's racing to create the<00:06:58.670> dream<00:06:58.940> protocol<00:06:59.570> for<00:06:59.780> large-scale 00:07:00.010 --> 00:07:00.020 align:start position:0% the dream protocol for large-scale 00:07:00.020 --> 00:07:03.190 align:start position:0% the dream protocol for large-scale consensus<00:07:01.480> so<00:07:02.480> all<00:07:02.630> of<00:07:02.750> this<00:07:02.870> is<00:07:02.990> very 00:07:03.190 --> 00:07:03.200 align:start position:0% consensus so all of this is very 00:07:03.200 --> 00:07:05.650 align:start position:0% consensus so all of this is very exciting<00:07:03.520> but<00:07:04.520> then<00:07:04.760> again<00:07:05.060> at<00:07:05.270> the<00:07:05.330> end<00:07:05.420> of 00:07:05.650 --> 00:07:05.660 align:start position:0% exciting but then again at the end of 00:07:05.660 --> 00:07:07.000 align:start position:0% exciting but then again at the end of the<00:07:05.780> day<00:07:05.900> when<00:07:06.110> you<00:07:06.230> sit<00:07:06.470> down<00:07:06.500> and<00:07:06.830> think 00:07:07.000 --> 00:07:07.010 align:start position:0% the day when you sit down and think 00:07:07.010 --> 00:07:09.070 align:start position:0% the day when you sit down and think about<00:07:07.100> it<00:07:07.430> perhaps<00:07:08.300> it<00:07:08.570> doesn't<00:07:08.720> make<00:07:08.960> any 00:07:09.070 --> 00:07:09.080 align:start position:0% about it perhaps it doesn't make any 00:07:09.080 --> 00:07:10.960 align:start position:0% about it perhaps it doesn't make any sense<00:07:09.320> right<00:07:09.500> so<00:07:09.620> why<00:07:09.860> after<00:07:10.100> 30<00:07:10.460> years<00:07:10.640> of 00:07:10.960 --> 00:07:10.970 align:start position:0% sense right so why after 30 years of 00:07:10.970 --> 00:07:14.110 align:start position:0% sense right so why after 30 years of work<00:07:11.150> on<00:07:11.330> distributed<00:07:11.810> consensus<00:07:13.120> everyone 00:07:14.110 --> 00:07:14.120 align:start position:0% work on distributed consensus everyone 00:07:14.120 --> 00:07:15.550 align:start position:0% work on distributed consensus everyone still<00:07:14.390> has<00:07:14.570> to<00:07:14.780> roll<00:07:14.960> it<00:07:15.140> their<00:07:15.410> own 00:07:15.550 --> 00:07:15.560 align:start position:0% still has to roll it their own 00:07:15.560 --> 00:07:18.150 align:start position:0% still has to roll it their own implementation<00:07:16.240> right<00:07:17.240> after<00:07:17.660> all 00:07:18.150 --> 00:07:18.160 align:start position:0% implementation right after all 00:07:18.160 --> 00:07:20.590 align:start position:0% implementation right after all implementing<00:07:19.160> consensus<00:07:19.850> is<00:07:20.000> like<00:07:20.210> very<00:07:20.390> much 00:07:20.590 --> 00:07:20.600 align:start position:0% implementing consensus is like very much 00:07:20.600 --> 00:07:22.540 align:start position:0% implementing consensus is like very much like<00:07:20.870> implementing<00:07:21.650> crypto<00:07:22.010> right<00:07:22.220> it's<00:07:22.340> very 00:07:22.540 --> 00:07:22.550 align:start position:0% like implementing crypto right it's very 00:07:22.550 --> 00:07:23.160 align:start position:0% like implementing crypto right it's very tricky 00:07:23.160 --> 00:07:23.170 align:start position:0% tricky 00:07:23.170 --> 00:07:27.040 align:start position:0% tricky very<00:07:24.170> error-prone<00:07:24.500> and<00:07:25.780> normally<00:07:26.780> like<00:07:26.960> you 00:07:27.040 --> 00:07:27.050 align:start position:0% very error-prone and normally like you 00:07:27.050 --> 00:07:28.990 align:start position:0% very error-prone and normally like you know<00:07:27.170> for<00:07:27.320> crypto<00:07:27.650> we<00:07:27.860> tend<00:07:28.370> to<00:07:28.430> think<00:07:28.640> this<00:07:28.850> is 00:07:28.990 --> 00:07:29.000 align:start position:0% know for crypto we tend to think this is 00:07:29.000 --> 00:07:30.520 align:start position:0% know for crypto we tend to think this is not<00:07:29.180> something<00:07:29.570> that<00:07:29.600> you<00:07:29.870> should<00:07:29.900> like<00:07:30.260> roll 00:07:30.520 --> 00:07:30.530 align:start position:0% not something that you should like roll 00:07:30.530 --> 00:07:35.080 align:start position:0% not something that you should like roll your<00:07:30.770> own<00:07:30.890> implementation<00:07:31.130> for<00:07:32.230> okay<00:07:33.230> so<00:07:34.090> to 00:07:35.080 --> 00:07:35.090 align:start position:0% your own implementation for okay so to 00:07:35.090 --> 00:07:38.470 align:start position:0% your own implementation for okay so to understand<00:07:35.840> why<00:07:36.170> there<00:07:36.890> still<00:07:37.400> isn't<00:07:37.760> a<00:07:38.180> dream 00:07:38.470 --> 00:07:38.480 align:start position:0% understand why there still isn't a dream 00:07:38.480 --> 00:07:41.110 align:start position:0% understand why there still isn't a dream protocol<00:07:38.990> for<00:07:39.140> large-scale<00:07:39.380> consensus<00:07:40.190> it 00:07:41.110 --> 00:07:41.120 align:start position:0% protocol for large-scale consensus it 00:07:41.120 --> 00:07:42.640 align:start position:0% protocol for large-scale consensus it helps<00:07:41.450> to<00:07:41.570> understand<00:07:42.080> the<00:07:42.140> consensus 00:07:42.640 --> 00:07:42.650 align:start position:0% helps to understand the consensus 00:07:42.650 --> 00:07:44.620 align:start position:0% helps to understand the consensus landscape<00:07:43.160> so<00:07:43.790> I'm<00:07:43.850> going<00:07:44.060> to<00:07:44.120> talk<00:07:44.300> about<00:07:44.330> the 00:07:44.620 --> 00:07:44.630 align:start position:0% landscape so I'm going to talk about the 00:07:44.630 --> 00:07:46.270 align:start position:0% landscape so I'm going to talk about the consensus<00:07:45.080> landscape<00:07:45.530> a<00:07:45.560> little<00:07:45.740> bit<00:07:46.010> before 00:07:46.270 --> 00:07:46.280 align:start position:0% consensus landscape a little bit before 00:07:46.280 --> 00:07:50.590 align:start position:0% consensus landscape a little bit before I<00:07:46.310> start<00:07:46.640> to<00:07:46.730> talk<00:07:46.880> about<00:07:46.910> and<00:07:47.300> Arella<00:07:49.600> roughly 00:07:50.590 --> 00:07:50.600 align:start position:0% I start to talk about and Arella roughly 00:07:50.600 --> 00:07:52.300 align:start position:0% I start to talk about and Arella roughly speaking<00:07:50.810> there<00:07:51.170> are<00:07:51.200> two<00:07:51.320> broad<00:07:51.830> classes<00:07:52.280> of 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so<00:08:01.250> what<00:08:01.400> do<00:08:01.490> we<00:08:01.580> know 00:08:01.750 --> 00:08:01.760 align:start position:0% pbft unpack sauce so what do we know 00:08:01.760 --> 00:08:03.190 align:start position:0% pbft unpack sauce so what do we know about<00:08:01.790> classical<00:08:02.510> consensus<00:08:02.990> these 00:08:03.190 --> 00:08:03.200 align:start position:0% about classical consensus these 00:08:03.200 --> 00:08:06.100 align:start position:0% about classical consensus these protocols<00:08:03.500> are<00:08:03.770> fast<00:08:04.040> most<00:08:04.790> of<00:08:04.940> the<00:08:05.000> time<00:08:05.300> they 00:08:06.100 --> 00:08:06.110 align:start position:0% protocols are fast most of the time they 00:08:06.110 --> 00:08:07.630 align:start position:0% protocols are fast most of the time they can<00:08:06.320> confirm<00:08:06.530> transactions<00:08:07.310> like<00:08:07.460> in 00:08:07.630 --> 00:08:07.640 align:start position:0% can confirm transactions like in 00:08:07.640 --> 00:08:10.090 align:start position:0% can confirm transactions like in constant<00:08:08.030> number<00:08:08.180> of<00:08:08.270> rounds<00:08:08.830> but<00:08:09.830> on<00:08:09.980> the 00:08:10.090 --> 00:08:10.100 align:start position:0% constant number of rounds but on the 00:08:10.100 --> 00:08:13.240 align:start position:0% constant number of rounds but on the other<00:08:10.190> hand<00:08:11.380> these<00:08:12.380> protocols<00:08:12.920> are<00:08:13.040> also 00:08:13.240 --> 00:08:13.250 align:start position:0% other hand these protocols are also 00:08:13.250 --> 00:08:15.460 align:start position:0% other hand these protocols are also notorious<00:08:14.060> for<00:08:14.300> being<00:08:14.420> incredibly<00:08:15.050> complex 00:08:15.460 --> 00:08:15.470 align:start position:0% notorious for being incredibly complex 00:08:15.470 --> 00:08:17.680 align:start position:0% notorious for being incredibly complex and<00:08:15.770> there's<00:08:16.520> a<00:08:16.580> lot<00:08:16.730> of<00:08:16.880> like<00:08:17.060> there<00:08:17.570> are 00:08:17.680 --> 00:08:17.690 align:start position:0% and there's a lot of like there are 00:08:17.690 --> 00:08:20.380 align:start position:0% and there's a lot of like there are implications<00:08:18.050> for<00:08:18.590> what<00:08:19.460> complexity<00:08:20.180> means 00:08:20.380 --> 00:08:20.390 align:start position:0% implications for what complexity means 00:08:20.390 --> 00:08:23.080 align:start position:0% implications for what complexity means on<00:08:20.690> a<00:08:20.780> large<00:08:21.350> scale<00:08:21.680> right<00:08:22.430> so<00:08:22.610> I'm<00:08:22.730> going<00:08:22.910> to 00:08:23.080 --> 00:08:23.090 align:start position:0% on a large scale right so I'm going to 00:08:23.090 --> 00:08:26.200 align:start position:0% on a large scale right so I'm going to revisit<00:08:23.690> this<00:08:23.960> complexity<00:08:24.470> point<00:08:24.940> again<00:08:25.940> a 00:08:26.200 --> 00:08:26.210 align:start position:0% revisit this complexity point again a 00:08:26.210 --> 00:08:28.990 align:start position:0% revisit this complexity point again a little<00:08:26.570> bit<00:08:26.690> later<00:08:26.900> in<00:08:27.080> the<00:08:27.110> talk<00:08:27.880> there<00:08:28.880> are 00:08:28.990 --> 00:08:29.000 align:start position:0% little bit later in the talk there are 00:08:29.000 --> 00:08:30.670 align:start position:0% little bit later in the talk there are also<00:08:29.150> other<00:08:29.390> issues<00:08:29.540> with<00:08:30.080> this<00:08:30.230> classical 00:08:30.670 --> 00:08:30.680 align:start position:0% also other issues with this classical 00:08:30.680 --> 00:08:32.290 align:start position:0% also other issues with this classical protocols<00:08:31.130> like<00:08:31.250> for<00:08:31.640> instance<00:08:31.760> in<00:08:32.120> my 00:08:32.290 --> 00:08:32.300 align:start position:0% protocols like for instance in my 00:08:32.300 --> 00:08:34.390 align:start position:0% protocols like for instance in my research<00:08:32.660> earlier<00:08:33.080> in<00:08:33.620> Cornell<00:08:34.010> we<00:08:34.250> now 00:08:34.390 --> 00:08:34.400 align:start position:0% research earlier in Cornell we now 00:08:34.400 --> 00:08:36.520 align:start position:0% research earlier in Cornell we now mathematically<00:08:34.870> understand<00:08:35.870> why<00:08:36.470> this 00:08:36.520 --> 00:08:36.530 align:start position:0% mathematically understand why this 00:08:36.530 --> 00:08:39.310 align:start position:0% mathematically understand why this classical<00:08:37.220> protocols<00:08:37.730> aren't<00:08:38.480> robust<00:08:38.990> enough 00:08:39.310 --> 00:08:39.320 align:start position:0% classical protocols aren't robust enough 00:08:39.320 --> 00:08:41.530 align:start position:0% classical protocols aren't robust enough for<00:08:39.710> large-scale<00:08:39.950> so<00:08:40.610> this<00:08:40.910> is<00:08:41.030> a<00:08:41.060> point<00:08:41.420> that 00:08:41.530 --> 00:08:41.540 align:start position:0% for large-scale so this is a point that 00:08:41.540 --> 00:08:43.540 align:start position:0% for large-scale so this is a point that I<00:08:42.020> won't<00:08:42.290> have<00:08:42.470> time<00:08:42.650> to<00:08:42.800> articulate<00:08:43.250> in<00:08:43.400> this 00:08:43.540 --> 00:08:43.550 align:start position:0% I won't have time to articulate in this 00:08:43.550 --> 00:08:45.790 align:start position:0% I won't have time to articulate in this talk<00:08:43.790> but<00:08:44.570> you<00:08:45.020> have<00:08:45.140> to<00:08:45.260> take<00:08:45.410> a<00:08:45.470> leap<00:08:45.710> of 00:08:45.790 --> 00:08:45.800 align:start position:0% talk but you have to take a leap of 00:08:45.800 --> 00:08:46.810 align:start position:0% talk but you have to take a leap of faith<00:08:45.860> that<00:08:46.070> we<00:08:46.280> now<00:08:46.610> actually 00:08:46.810 --> 00:08:46.820 align:start position:0% faith that we now actually 00:08:46.820 --> 00:08:49.120 align:start position:0% faith that we now actually mathematically<00:08:47.720> understand<00:08:48.230> what 00:08:49.120 --> 00:08:49.130 align:start position:0% mathematically understand what 00:08:49.130 --> 00:08:50.660 align:start position:0% mathematically understand what robustness<00:08:49.640> means<00:08:50.000> on 00:08:50.660 --> 00:08:50.670 align:start position:0% robustness means on 00:08:50.670 --> 00:08:52.940 align:start position:0% robustness means on skel<00:08:50.940> and<00:08:51.570> why<00:08:51.900> these<00:08:51.960> protocols<00:08:52.500> aren't 00:08:52.940 --> 00:08:52.950 align:start position:0% skel and why these protocols aren't 00:08:52.950 --> 00:08:57.680 align:start position:0% skel and why these protocols aren't suited<00:08:54.140> okay<00:08:55.140> so<00:08:55.200> of<00:08:55.410> course<00:08:56.450> at<00:08:57.450> the<00:08:57.630> other 00:08:57.680 --> 00:08:57.690 align:start position:0% suited okay so of course at the other 00:08:57.690 --> 00:09:01.030 align:start position:0% suited okay so of course at the other side<00:08:58.620> of<00:08:58.800> the<00:08:58.950> spectrum<00:08:59.070> we<00:08:59.970> have<00:09:00.000> plug<00:09:00.390> chains 00:09:01.030 --> 00:09:01.040 align:start position:0% side of the spectrum we have plug chains 00:09:01.040 --> 00:09:08.510 align:start position:0% side of the spectrum we have plug chains right<00:09:03.530> so<00:09:04.530> block<00:09:04.800> chains<00:09:06.770> the<00:09:07.770> amazing<00:09:08.310> thing 00:09:08.510 --> 00:09:08.520 align:start position:0% right so block chains the amazing thing 00:09:08.520 --> 00:09:09.980 align:start position:0% right so block chains the amazing thing is<00:09:08.550> that<00:09:08.730> they're<00:09:09.060> not<00:09:09.090> just<00:09:09.270> an<00:09:09.690> empirical 00:09:09.980 --> 00:09:09.990 align:start position:0% is that they're not just an empirical 00:09:09.990 --> 00:09:13.490 align:start position:0% is that they're not just an empirical success<00:09:10.650> and<00:09:12.020> we<00:09:13.020> now<00:09:13.260> actually 00:09:13.490 --> 00:09:13.500 align:start position:0% success and we now actually 00:09:13.500 --> 00:09:16.610 align:start position:0% success and we now actually mathematically<00:09:14.090> understand<00:09:15.090> that<00:09:15.900> these 00:09:16.610 --> 00:09:16.620 align:start position:0% mathematically understand that these 00:09:16.620 --> 00:09:19.700 align:start position:0% mathematically understand that these protocols<00:09:16.980> actually<00:09:17.580> reach<00:09:17.760> consensus<00:09:18.710> using 00:09:19.700 --> 00:09:19.710 align:start position:0% protocols actually reach consensus using 00:09:19.710 --> 00:09:21.740 align:start position:0% protocols actually reach consensus using a<00:09:19.770> mathematical<00:09:20.030> mechanism<00:09:21.030> that<00:09:21.270> departs 00:09:21.740 --> 00:09:21.750 align:start position:0% a mathematical mechanism that departs 00:09:21.750 --> 00:09:24.830 align:start position:0% a mathematical mechanism that departs completely<00:09:22.710> from<00:09:22.920> classical<00:09:23.400> consensus<00:09:23.940> so 00:09:24.830 --> 00:09:24.840 align:start position:0% completely from classical consensus so 00:09:24.840 --> 00:09:26.330 align:start position:0% completely from classical consensus so in<00:09:24.960> other<00:09:25.080> words<00:09:25.350> block<00:09:25.680> chains<00:09:25.920> are<00:09:26.070> also<00:09:26.220> a 00:09:26.330 --> 00:09:26.340 align:start position:0% in other words block chains are also a 00:09:26.340 --> 00:09:32.900 align:start position:0% in other words block chains are also a theoretical<00:09:26.940> breakthrough<00:09:28.160> okay<00:09:31.910> whenever 00:09:32.900 --> 00:09:32.910 align:start position:0% theoretical breakthrough okay whenever 00:09:32.910 --> 00:09:34.520 align:start position:0% theoretical breakthrough okay whenever we<00:09:33.240> talk<00:09:33.420> about<00:09:33.450> block<00:09:33.900> chains<00:09:34.140> of<00:09:34.320> course 00:09:34.520 --> 00:09:34.530 align:start position:0% we talk about block chains of course 00:09:34.530 --> 00:09:36.290 align:start position:0% we talk about block chains of course your<00:09:34.710> first<00:09:34.980> reaction<00:09:35.520> might<00:09:35.700> be<00:09:35.850> that<00:09:36.060> you 00:09:36.290 --> 00:09:36.300 align:start position:0% your first reaction might be that you 00:09:36.300 --> 00:09:37.550 align:start position:0% your first reaction might be that you know<00:09:36.420> these<00:09:36.570> protocols<00:09:36.900> are<00:09:37.110> extremely 00:09:37.550 --> 00:09:37.560 align:start position:0% know these protocols are extremely 00:09:37.560 --> 00:09:39.880 align:start position:0% know these protocols are extremely wasteful<00:09:37.980> because<00:09:38.130> the<00:09:38.460> miners<00:09:38.820> are<00:09:39.030> you<00:09:39.240> know 00:09:39.880 --> 00:09:39.890 align:start position:0% wasteful because the miners are you know 00:09:39.890 --> 00:09:41.690 align:start position:0% wasteful because the miners are you know solving<00:09:40.890> computationally<00:09:41.580> expensive 00:09:41.690 --> 00:09:41.700 align:start position:0% solving computationally expensive 00:09:41.700 --> 00:09:44.990 align:start position:0% solving computationally expensive puzzles<00:09:42.560> and<00:09:43.560> in<00:09:44.010> order<00:09:44.250> to<00:09:44.400> make<00:09:44.550> progress<00:09:44.730> in 00:09:44.990 --> 00:09:45.000 align:start position:0% puzzles and in order to make progress in 00:09:45.000 --> 00:09:47.210 align:start position:0% puzzles and in order to make progress in this<00:09:45.240> talk<00:09:45.450> I'm<00:09:45.870> going<00:09:45.930> to<00:09:46.290> ask<00:09:46.470> you<00:09:46.710> to<00:09:46.920> take<00:09:47.160> a 00:09:47.210 --> 00:09:47.220 align:start position:0% this talk I'm going to ask you to take a 00:09:47.220 --> 00:09:50.780 align:start position:0% this talk I'm going to ask you to take a leap<00:09:47.430> of<00:09:47.550> faith<00:09:47.610> again<00:09:48.180> and<00:09:49.550> imagine<00:09:50.550> that<00:09:50.670> the 00:09:50.780 --> 00:09:50.790 align:start position:0% leap of faith again and imagine that the 00:09:50.790 --> 00:09:53.030 align:start position:0% leap of faith again and imagine that the proof-of-work<00:09:51.360> problem<00:09:52.200> has<00:09:52.650> already<00:09:52.860> been 00:09:53.030 --> 00:09:53.040 align:start position:0% proof-of-work problem has already been 00:09:53.040 --> 00:09:55.550 align:start position:0% proof-of-work problem has already been solved<00:09:53.580> so<00:09:54.300> we<00:09:54.450> did<00:09:54.660> have<00:09:54.870> an<00:09:54.990> earlier<00:09:55.350> work 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retain precisely the 00:10:03.870 --> 00:10:05.450 align:start position:0% still be able to retain precisely the same<00:10:04.020> mathematical<00:10:04.740> properties<00:10:05.130> of<00:10:05.310> these 00:10:05.450 --> 00:10:05.460 align:start position:0% same mathematical properties of these 00:10:05.460 --> 00:10:07.880 align:start position:0% same mathematical properties of these protocols<00:10:05.780> so<00:10:06.780> this<00:10:07.080> is<00:10:07.290> a<00:10:07.320> paper<00:10:07.620> called 00:10:07.880 --> 00:10:07.890 align:start position:0% protocols so this is a paper called 00:10:07.890 --> 00:10:09.560 align:start position:0% protocols so this is a paper called sleepy<00:10:08.280> consensus<00:10:08.730> it's<00:10:08.880> going<00:10:09.060> to<00:10:09.150> appear<00:10:09.420> in 00:10:09.560 --> 00:10:09.570 align:start position:0% sleepy consensus it's going to appear in 00:10:09.570 --> 00:10:14.810 align:start position:0% sleepy consensus it's going to appear in Asia<00:10:09.720> group<00:10:09.960> this<00:10:10.110> year<00:10:12.650> and<00:10:13.650> then<00:10:13.920> in<00:10:14.670> the 00:10:14.810 --> 00:10:14.820 align:start position:0% Asia group this year and then in the 00:10:14.820 --> 00:10:16.130 align:start position:0% Asia group this year and then in the rest<00:10:14.940> of<00:10:15.150> the<00:10:15.270> talk<00:10:15.450> whenever<00:10:15.780> I<00:10:15.840> mention 00:10:16.130 --> 00:10:16.140 align:start position:0% rest of the talk whenever I mention 00:10:16.140 --> 00:10:18.860 align:start position:0% rest of the talk whenever I mention black<00:10:16.530> cheese<00:10:16.770> it<00:10:17.700> can<00:10:18.000> either<00:10:18.210> be<00:10:18.390> proof<00:10:18.750> of 00:10:18.860 --> 00:10:18.870 align:start position:0% black cheese it can either be proof of 00:10:18.870 --> 00:10:21.400 align:start position:0% black cheese it can either be proof of work<00:10:19.080> based<00:10:19.350> or<00:10:19.620> non<00:10:19.800> proof<00:10:20.040> of<00:10:20.190> work<00:10:20.310> base 00:10:21.400 --> 00:10:21.410 align:start position:0% work based or non proof of work base 00:10:21.410 --> 00:10:25.670 align:start position:0% work based or non proof of work base okay<00:10:23.450> so<00:10:24.450> in<00:10:24.630> comparison<00:10:25.110> with<00:10:25.200> classical 00:10:25.670 --> 00:10:25.680 align:start position:0% okay so in comparison with classical 00:10:25.680 --> 00:10:27.020 align:start position:0% okay so in comparison with classical consensus<00:10:26.220> right<00:10:26.400> there<00:10:26.760> are<00:10:26.880> many 00:10:27.020 --> 00:10:27.030 align:start position:0% consensus right there are many 00:10:27.030 --> 00:10:29.300 align:start position:0% consensus right there are many advantages<00:10:27.360> of<00:10:27.780> blockchains<00:10:28.470> for<00:10:29.040> instance 00:10:29.300 --> 00:10:29.310 align:start position:0% advantages of blockchains for instance 00:10:29.310 --> 00:10:30.980 align:start position:0% advantages of blockchains for instance they're<00:10:29.490> very<00:10:29.730> robust<00:10:30.210> right<00:10:30.480> the<00:10:30.600> robustness 00:10:30.980 --> 00:10:30.990 align:start position:0% they're very robust right the robustness 00:10:30.990 --> 00:10:34.070 align:start position:0% they're very robust right the robustness has<00:10:31.230> been<00:10:31.380> empirically<00:10:31.650> proven<00:10:32.160> and<00:10:33.080> Bitcoin 00:10:34.070 --> 00:10:34.080 align:start position:0% has been empirically proven and Bitcoin 00:10:34.080 --> 00:10:35.630 align:start position:0% has been empirically proven and Bitcoin with<00:10:34.320> like<00:10:34.470> for<00:10:34.620> instance<00:10:34.740> often<00:10:35.130> refer<00:10:35.400> to<00:10:35.550> as 00:10:35.630 --> 00:10:35.640 align:start position:0% with like for instance often refer to as 00:10:35.640 --> 00:10:39.110 align:start position:0% with like for instance often refer to as the<00:10:35.790> honey<00:10:35.940> badger<00:10:36.180> of<00:10:36.360> money<00:10:37.670> the<00:10:38.670> protocols 00:10:39.110 --> 00:10:39.120 align:start position:0% the honey badger of money the protocols 00:10:39.120 --> 00:10:40.700 align:start position:0% the honey badger of money the protocols are<00:10:39.240> very<00:10:39.390> very<00:10:39.600> simple<00:10:40.020> right<00:10:40.200> if<00:10:40.440> you<00:10:40.530> look 00:10:40.700 --> 00:10:40.710 align:start position:0% are very very simple right if you look 00:10:40.710 --> 00:10:42.680 align:start position:0% are very very simple right if you look at<00:10:40.830> the<00:10:40.920> protocol<00:10:41.280> rule<00:10:41.490> it's<00:10:42.030> essentially 00:10:42.680 --> 00:10:42.690 align:start position:0% at the protocol rule it's essentially 00:10:42.690 --> 00:10:44.630 align:start position:0% at the protocol rule it's essentially everyone<00:10:43.500> picks<00:10:43.740> the<00:10:43.890> longest<00:10:44.220> chain<00:10:44.400> and 00:10:44.630 --> 00:10:44.640 align:start position:0% everyone picks the longest chain and 00:10:44.640 --> 00:10:46.220 align:start position:0% everyone picks the longest chain and they<00:10:44.970> try<00:10:45.120> to<00:10:45.150> extend<00:10:45.450> the<00:10:45.720> longest<00:10:46.050> chain 00:10:46.220 --> 00:10:46.230 align:start position:0% they try to extend the longest chain 00:10:46.230 --> 00:10:49.100 align:start position:0% they try to extend the longest chain that's<00:10:46.500> that's<00:10:46.920> it<00:10:47.180> so<00:10:48.180> simplicity<00:10:48.780> you<00:10:48.990> know 00:10:49.100 --> 00:10:49.110 align:start position:0% that's that's it so simplicity you know 00:10:49.110 --> 00:10:50.540 align:start position:0% that's that's it so simplicity you know in<00:10:49.260> the<00:10:49.350> large-scale<00:10:49.590> distributed<00:10:50.070> system 00:10:50.540 --> 00:10:50.550 align:start position:0% in the large-scale distributed system 00:10:50.550 --> 00:10:55.550 align:start position:0% in the large-scale distributed system can<00:10:51.120> often<00:10:51.420> be<00:10:51.600> your<00:10:52.260> friend<00:10:54.320> okay 00:10:55.550 --> 00:10:55.560 align:start position:0% can often be your friend okay 00:10:55.560 --> 00:10:59.660 align:start position:0% can often be your friend okay on<00:10:56.160> the<00:10:56.730> other<00:10:56.880> hand<00:10:57.380> even<00:10:58.380> though<00:10:58.620> the<00:10:59.400> proof 00:10:59.660 --> 00:10:59.670 align:start position:0% on the other hand even though the proof 00:10:59.670 --> 00:11:02.880 align:start position:0% on the other hand even though the proof of<00:10:59.850> work<00:11:00.090> problem<00:11:00.780> can<00:11:01.500> be<00:11:01.710> solved 00:11:02.880 --> 00:11:02.890 align:start position:0% of work problem can be solved 00:11:02.890 --> 00:11:05.100 align:start position:0% of work problem can be solved blockchains<00:11:03.670> still<00:11:04.030> suffer<00:11:04.360> from<00:11:04.390> slowness 00:11:05.100 --> 00:11:05.110 align:start position:0% blockchains still suffer from slowness 00:11:05.110 --> 00:11:07.830 align:start position:0% blockchains still suffer from slowness right<00:11:05.680> so<00:11:05.860> as<00:11:06.010> we<00:11:06.160> know<00:11:06.370> in<00:11:06.610> Bitcoin<00:11:07.030> it<00:11:07.540> takes 00:11:07.830 --> 00:11:07.840 align:start position:0% right so as we know in Bitcoin it takes 00:11:07.840 --> 00:11:11.040 align:start position:0% right so as we know in Bitcoin it takes like<00:11:08.020> ten<00:11:08.260> minutes<00:11:08.440> per<00:11:08.800> block<00:11:09.480> and<00:11:10.480> often<00:11:10.900> to 00:11:11.040 --> 00:11:11.050 align:start position:0% like ten minutes per block and often to 00:11:11.050 --> 00:11:12.480 align:start position:0% like ten minutes per block and often to get<00:11:11.230> enough<00:11:11.470> confidence<00:11:11.950> you<00:11:12.070> have<00:11:12.100> to<00:11:12.250> wait 00:11:12.480 --> 00:11:12.490 align:start position:0% get enough confidence you have to wait 00:11:12.490 --> 00:11:14.100 align:start position:0% get enough confidence you have to wait for<00:11:12.670> like<00:11:12.790> six<00:11:13.030> to<00:11:13.150> ten<00:11:13.360> blocks<00:11:13.630> which<00:11:13.900> means 00:11:14.100 --> 00:11:14.110 align:start position:0% for like six to ten blocks which means 00:11:14.110 --> 00:11:15.690 align:start position:0% for like six to ten blocks which means your<00:11:14.260> transaction<00:11:14.740> confirmation<00:11:14.890> is<00:11:15.460> on<00:11:15.610> the 00:11:15.690 --> 00:11:15.700 align:start position:0% your transaction confirmation is on the 00:11:15.700 --> 00:11:18.540 align:start position:0% your transaction confirmation is on the order<00:11:15.850> of<00:11:15.970> an<00:11:16.120> hour<00:11:16.300> right<00:11:17.260> so<00:11:18.070> I<00:11:18.100> know<00:11:18.520> a 00:11:18.540 --> 00:11:18.550 align:start position:0% order of an hour right so I know a 00:11:18.550 --> 00:11:21.120 align:start position:0% order of an hour right so I know a cerium<00:11:19.320> parameterize<00:11:20.320> the<00:11:20.530> block<00:11:20.710> interval 00:11:21.120 --> 00:11:21.130 align:start position:0% cerium parameterize the block interval 00:11:21.130 --> 00:11:22.590 align:start position:0% cerium parameterize the block interval differently<00:11:21.580> but<00:11:22.030> the<00:11:22.150> point<00:11:22.420> is<00:11:22.570> that 00:11:22.590 --> 00:11:22.600 align:start position:0% differently but the point is that 00:11:22.600 --> 00:11:24.330 align:start position:0% differently but the point is that there's<00:11:22.990> security<00:11:23.290> implications<00:11:24.070> when<00:11:24.220> you 00:11:24.330 --> 00:11:24.340 align:start position:0% there's security implications when you 00:11:24.340 --> 00:11:26.250 align:start position:0% there's security implications when you rip<00:11:24.550> Rama<00:11:24.760> ties<00:11:25.000> these<00:11:25.240> block<00:11:25.810> interval 00:11:26.250 --> 00:11:26.260 align:start position:0% rip Rama ties these block interval 00:11:26.260 --> 00:11:30.210 align:start position:0% rip Rama ties these block interval parameters<00:11:26.740> and<00:11:27.090> so<00:11:28.090> from<00:11:28.500> this<00:11:29.500> mathematical 00:11:30.210 --> 00:11:30.220 align:start position:0% parameters and so from this mathematical 00:11:30.220 --> 00:11:32.580 align:start position:0% parameters and so from this mathematical analysis<00:11:30.670> bypass<00:11:31.060> Dada<00:11:31.390> we<00:11:31.840> understand<00:11:32.380> that 00:11:32.580 --> 00:11:32.590 align:start position:0% analysis bypass Dada we understand that 00:11:32.590 --> 00:11:36.420 align:start position:0% analysis bypass Dada we understand that if<00:11:33.340> you<00:11:33.550> want<00:11:34.590> resistance<00:11:35.590> to<00:11:35.860> 49<00:11:36.400> percent 00:11:36.420 --> 00:11:36.430 align:start position:0% if you want resistance to 49 percent 00:11:36.430 --> 00:11:40.290 align:start position:0% if you want resistance to 49 percent attack<00:11:37.170> your<00:11:38.170> block<00:11:38.440> interval<00:11:38.950> should<00:11:39.130> be<00:11:39.340> 60 00:11:40.290 --> 00:11:40.300 align:start position:0% attack your block interval should be 60 00:11:40.300 --> 00:11:42.810 align:start position:0% attack your block interval should be 60 times<00:11:40.630> the<00:11:40.930> maximum<00:11:41.200> next<00:11:41.680> maximum<00:11:42.520> now<00:11:42.700> our 00:11:42.810 --> 00:11:42.820 align:start position:0% times the maximum next maximum now our 00:11:42.820 --> 00:11:44.910 align:start position:0% times the maximum next maximum now our delay<00:11:43.120> so<00:11:44.050> in<00:11:44.170> other<00:11:44.290> words<00:11:44.560> the<00:11:44.710> block 00:11:44.910 --> 00:11:44.920 align:start position:0% delay so in other words the block 00:11:44.920 --> 00:11:47.100 align:start position:0% delay so in other words the block interval<00:11:45.370> cannot<00:11:45.730> be<00:11:45.880> too<00:11:46.120> small<00:11:46.420> with 00:11:47.100 --> 00:11:47.110 align:start position:0% interval cannot be too small with 00:11:47.110 --> 00:11:49.410 align:start position:0% interval cannot be too small with respect<00:11:47.500> to<00:11:47.590> the<00:11:47.680> narrower<00:11:47.920> delay<00:11:48.240> so<00:11:49.240> this 00:11:49.410 --> 00:11:49.420 align:start position:0% respect to the narrower delay so this 00:11:49.420 --> 00:11:53.100 align:start position:0% respect to the narrower delay so this actually<00:11:49.870> seems<00:11:50.260> like<00:11:50.350> an<00:11:50.590> inherent<00:11:52.110> drawback 00:11:53.100 --> 00:11:53.110 align:start position:0% actually seems like an inherent drawback 00:11:53.110 --> 00:11:57.180 align:start position:0% actually seems like an inherent drawback of<00:11:53.350> blockchain<00:11:54.340> style<00:11:54.610> consensus<00:11:56.130> okay<00:11:57.130> so 00:11:57.180 --> 00:11:57.190 align:start position:0% of blockchain style consensus okay so 00:11:57.190 --> 00:11:59.070 align:start position:0% of blockchain style consensus okay so this<00:11:57.400> is<00:11:57.580> kind<00:11:57.820> of<00:11:57.940> the<00:11:58.390> overall<00:11:58.840> landscape 00:11:59.070 --> 00:11:59.080 align:start position:0% this is kind of the overall landscape 00:11:59.080 --> 00:12:02.280 align:start position:0% this is kind of the overall landscape and<00:11:59.650> what<00:12:00.340> this<00:12:00.460> tells<00:12:00.730> us<00:12:00.880> is<00:12:01.090> that<00:12:01.150> it<00:12:02.080> seems 00:12:02.280 --> 00:12:02.290 align:start position:0% and what this tells us is that it seems 00:12:02.290 --> 00:12:04.140 align:start position:0% and what this tells us is that it seems like<00:12:02.440> the<00:12:02.680> stream<00:12:02.980> protocol<00:12:03.490> for<00:12:03.640> large<00:12:03.820> scale 00:12:04.140 --> 00:12:04.150 align:start position:0% like the stream protocol for large scale 00:12:04.150 --> 00:12:07.830 align:start position:0% like the stream protocol for large scale is<00:12:04.720> still<00:12:05.080> eluding<00:12:05.590> us<00:12:06.090> unfortunately<00:12:07.090> and<00:12:07.360> in 00:12:07.830 --> 00:12:07.840 align:start position:0% is still eluding us unfortunately and in 00:12:07.840 --> 00:12:09.860 align:start position:0% is still eluding us unfortunately and in the<00:12:07.930> rest<00:12:08.110> of<00:12:08.290> the<00:12:08.380> talk<00:12:08.560> I'm<00:12:08.740> going<00:12:08.890> to<00:12:08.980> try<00:12:09.220> to 00:12:09.860 --> 00:12:09.870 align:start position:0% the rest of the talk I'm going to try to 00:12:09.870 --> 00:12:15.920 align:start position:0% the rest of the talk I'm going to try to answer<00:12:10.870> this<00:12:11.050> question<00:12:12.090> and<00:12:14.220> here's<00:12:15.220> the<00:12:15.400> plan 00:12:15.920 --> 00:12:15.930 align:start position:0% answer this question and here's the plan 00:12:15.930 --> 00:12:19.470 align:start position:0% answer this question and here's the plan I'm<00:12:16.930> going<00:12:17.290> to<00:12:17.590> start<00:12:18.210> talking<00:12:19.210> about<00:12:19.270> how 00:12:19.470 --> 00:12:19.480 align:start position:0% I'm going to start talking about how 00:12:19.480 --> 00:12:22.530 align:start position:0% I'm going to start talking about how classical<00:12:20.290> consensus<00:12:20.740> works<00:12:21.010> and<00:12:21.610> I'm<00:12:22.270> going 00:12:22.530 --> 00:12:22.540 align:start position:0% classical consensus works and I'm going 00:12:22.540 --> 00:12:25.380 align:start position:0% classical consensus works and I'm going to<00:12:22.600> go<00:12:22.840> on<00:12:23.110> until<00:12:23.530> I<00:12:23.830> get<00:12:24.280> stuck<00:12:24.580> and<00:12:25.180> when<00:12:25.360> I 00:12:25.380 --> 00:12:25.390 align:start position:0% to go on until I get stuck and when I 00:12:25.390 --> 00:12:27.300 align:start position:0% to go on until I get stuck and when I took<00:12:25.540> that<00:12:25.720> stack<00:12:26.170> I'm<00:12:26.710> going<00:12:26.980> to<00:12:27.070> try<00:12:27.250> to 00:12:27.300 --> 00:12:27.310 align:start position:0% took that stack I'm going to try to 00:12:27.310 --> 00:12:31.170 align:start position:0% took that stack I'm going to try to combine<00:12:27.610> the<00:12:27.880> best<00:12:28.060> of<00:12:28.210> both<00:12:28.270> worlds<00:12:28.750> and<00:12:30.180> get 00:12:31.170 --> 00:12:31.180 align:start position:0% combine the best of both worlds and get 00:12:31.180 --> 00:12:34.800 align:start position:0% combine the best of both worlds and get a<00:12:31.210> new<00:12:31.510> consensus<00:12:32.020> protocol<00:12:33.450> so<00:12:34.450> santarilla 00:12:34.800 --> 00:12:34.810 align:start position:0% a new consensus protocol so santarilla 00:12:34.810 --> 00:12:36.540 align:start position:0% a new consensus protocol so santarilla is<00:12:35.140> an<00:12:35.260> extremely<00:12:35.680> simple<00:12:35.980> consensus 00:12:36.540 --> 00:12:36.550 align:start position:0% is an extremely simple consensus 00:12:36.550 --> 00:12:37.980 align:start position:0% is an extremely simple consensus protocol<00:12:36.910> at<00:12:37.060> the<00:12:37.180> end<00:12:37.360> of<00:12:37.510> the<00:12:37.630> talk<00:12:37.810> I'm 00:12:37.980 --> 00:12:37.990 align:start position:0% protocol at the end of the talk I'm 00:12:37.990 --> 00:12:39.690 align:start position:0% protocol at the end of the talk I'm going<00:12:38.170> to<00:12:38.350> summarize<00:12:38.590> the<00:12:38.800> protocol<00:12:39.250> in<00:12:39.460> and 00:12:39.690 --> 00:12:39.700 align:start position:0% going to summarize the protocol in and 00:12:39.700 --> 00:12:43.410 align:start position:0% going to summarize the protocol in and two<00:12:40.540> sentences<00:12:41.490> okay<00:12:42.490> any<00:12:42.880> questions<00:12:43.240> at<00:12:43.390> this 00:12:43.410 --> 00:12:43.420 align:start position:0% two sentences okay any questions at this 00:12:43.420 --> 00:12:44.120 align:start position:0% two sentences okay any questions at this point 00:12:44.120 --> 00:12:44.130 align:start position:0% point 00:12:44.130 --> 00:12:47.460 align:start position:0% point all<00:12:45.130> right<00:12:45.370> so<00:12:45.610> without<00:12:45.880> further<00:12:46.090> ado<00:12:46.480> let's 00:12:47.460 --> 00:12:47.470 align:start position:0% all right so without further ado let's 00:12:47.470 --> 00:12:50.820 align:start position:0% all right so without further ado let's talk<00:12:47.860> about<00:12:48.010> consensus<00:12:48.670> and<00:12:49.630> today<00:12:50.470> we<00:12:50.620> have<00:12:50.800> a 00:12:50.820 --> 00:12:50.830 align:start position:0% talk about consensus and today we have a 00:12:50.830 --> 00:12:54.450 align:start position:0% talk about consensus and today we have a Vitalik<00:12:51.430> versus<00:12:51.910> the<00:12:52.420> superheroes<00:12:53.460> Vitalik 00:12:54.450 --> 00:12:54.460 align:start position:0% Vitalik versus the superheroes Vitalik 00:12:54.460 --> 00:12:58.410 align:start position:0% Vitalik versus the superheroes Vitalik will<00:12:54.670> act<00:12:54.910> as<00:12:55.120> the<00:12:55.300> leader<00:12:55.480> and<00:12:57.240> everyone<00:12:58.240> else 00:12:58.410 --> 00:12:58.420 align:start position:0% will act as the leader and everyone else 00:12:58.420 --> 00:13:00.480 align:start position:0% will act as the leader and everyone else is<00:12:58.570> the<00:12:58.720> voter<00:12:58.920> okay<00:12:59.920> so<00:12:59.980> some<00:13:00.220> of<00:13:00.250> these 00:13:00.480 --> 00:13:00.490 align:start position:0% is the voter okay so some of these 00:13:00.490 --> 00:13:03.240 align:start position:0% is the voter okay so some of these voters<00:13:00.910> can<00:13:01.180> be<00:13:01.360> compromised<00:13:02.350> and<00:13:02.560> behaving 00:13:03.240 --> 00:13:03.250 align:start position:0% voters can be compromised and behaving 00:13:03.250 --> 00:13:04.680 align:start position:0% voters can be compromised and behaving maliciously<00:13:03.760> right<00:13:04.090> so<00:13:04.210> for<00:13:04.360> instance<00:13:04.600> in 00:13:04.680 --> 00:13:04.690 align:start position:0% maliciously right so for instance in 00:13:04.690 --> 00:13:08.010 align:start position:0% maliciously right so for instance in this<00:13:04.780> case<00:13:04.840> loki<00:13:05.410> is<00:13:06.040> corrupt<00:13:06.520> and<00:13:07.390> also<00:13:07.960> to 00:13:08.010 --> 00:13:08.020 align:start position:0% this case loki is corrupt and also to 00:13:08.020 --> 00:13:10.560 align:start position:0% this case loki is corrupt and also to keep<00:13:08.380> in<00:13:08.530> mind<00:13:08.770> that<00:13:08.950> the<00:13:09.070> leader<00:13:09.280> himself<00:13:09.570> can 00:13:10.560 --> 00:13:10.570 align:start position:0% keep in mind that the leader himself can 00:13:10.570 --> 00:13:11.460 align:start position:0% keep in mind that the leader himself can also<00:13:10.720> be<00:13:10.930> corrupt 00:13:11.460 --> 00:13:11.470 align:start position:0% also be corrupt 00:13:11.470 --> 00:13:14.340 align:start position:0% also be corrupt so<00:13:11.620> Vitalik<00:13:12.040> can<00:13:12.190> also<00:13:12.370> be<00:13:12.580> malicious 00:13:14.340 --> 00:13:14.350 align:start position:0% so Vitalik can also be malicious 00:13:14.350 --> 00:13:17.560 align:start position:0% so Vitalik can also be malicious okay<00:13:15.350> so<00:13:16.040> here's<00:13:16.310> roughly<00:13:17.180> speaking<00:13:17.360> how 00:13:17.560 --> 00:13:17.570 align:start position:0% okay so here's roughly speaking how 00:13:17.570 --> 00:13:20.620 align:start position:0% okay so here's roughly speaking how these<00:13:17.810> classical<00:13:18.320> consensus<00:13:18.770> protocols<00:13:19.190> work 00:13:20.620 --> 00:13:20.630 align:start position:0% these classical consensus protocols work 00:13:20.630 --> 00:13:23.260 align:start position:0% these classical consensus protocols work Vitalik<00:13:21.320> as<00:13:21.800> the<00:13:22.070> leader<00:13:22.250> he's<00:13:22.730> first<00:13:23.000> going 00:13:23.260 --> 00:13:23.270 align:start position:0% Vitalik as the leader he's first going 00:13:23.270 --> 00:13:25.420 align:start position:0% Vitalik as the leader he's first going to<00:13:23.330> make<00:13:23.570> a<00:13:23.600> proposal<00:13:23.840> the<00:13:24.620> proposal<00:13:24.770> contains 00:13:25.420 --> 00:13:25.430 align:start position:0% to make a proposal the proposal contains 00:13:25.430 --> 00:13:28.240 align:start position:0% to make a proposal the proposal contains a<00:13:25.550> batch<00:13:25.730> of<00:13:25.910> transactions<00:13:27.010> packed<00:13:28.010> with<00:13:28.220> a 00:13:28.240 --> 00:13:28.250 align:start position:0% a batch of transactions packed with a 00:13:28.250 --> 00:13:30.160 align:start position:0% a batch of transactions packed with a sequence<00:13:28.700> number<00:13:28.760> right<00:13:29.630> so<00:13:29.780> the<00:13:29.870> sequence 00:13:30.160 --> 00:13:30.170 align:start position:0% sequence number right so the sequence 00:13:30.170 --> 00:13:33.130 align:start position:0% sequence number right so the sequence number<00:13:30.620> is<00:13:31.070> going<00:13:31.400> to<00:13:31.520> determine<00:13:31.940> where<00:13:32.900> in 00:13:33.130 --> 00:13:33.140 align:start position:0% number is going to determine where in 00:13:33.140 --> 00:13:36.900 align:start position:0% number is going to determine where in this<00:13:33.350> very<00:13:33.650> long<00:13:33.920> lock<00:13:34.190> this<00:13:35.150> batch<00:13:35.450> will<00:13:35.810> land 00:13:36.900 --> 00:13:36.910 align:start position:0% this very long lock this batch will land 00:13:36.910 --> 00:13:39.700 align:start position:0% this very long lock this batch will land okay<00:13:37.910> so<00:13:37.970> the<00:13:38.240> final<00:13:38.450> protocol<00:13:39.080> will<00:13:39.290> contain 00:13:39.700 --> 00:13:39.710 align:start position:0% okay so the final protocol will contain 00:13:39.710 --> 00:13:42.550 align:start position:0% okay so the final protocol will contain many<00:13:40.550> instances<00:13:41.300> of<00:13:41.510> this<00:13:41.630> little<00:13:42.110> protocol 00:13:42.550 --> 00:13:42.560 align:start position:0% many instances of this little protocol 00:13:42.560 --> 00:13:45.100 align:start position:0% many instances of this little protocol but<00:13:43.130> for<00:13:43.280> simplicity<00:13:43.400> for<00:13:43.910> now<00:13:44.090> let's<00:13:44.780> focus 00:13:45.100 --> 00:13:45.110 align:start position:0% but for simplicity for now let's focus 00:13:45.110 --> 00:13:46.900 align:start position:0% but for simplicity for now let's focus on<00:13:45.440> the<00:13:45.590> little<00:13:45.740> instance<00:13:46.250> with<00:13:46.430> a<00:13:46.460> single 00:13:46.900 --> 00:13:46.910 align:start position:0% on the little instance with a single 00:13:46.910 --> 00:13:50.680 align:start position:0% on the little instance with a single sequence<00:13:47.360> number<00:13:48.760> when<00:13:49.760> the<00:13:49.910> talaq<00:13:50.240> makes<00:13:50.480> the 00:13:50.680 --> 00:13:50.690 align:start position:0% sequence number when the talaq makes the 00:13:50.690 --> 00:13:54.430 align:start position:0% sequence number when the talaq makes the proposal<00:13:51.170> everyone's<00:13:51.980> going<00:13:52.190> to<00:13:52.250> vote<00:13:53.440> okay 00:13:54.430 --> 00:13:54.440 align:start position:0% proposal everyone's going to vote okay 00:13:54.440 --> 00:13:57.700 align:start position:0% proposal everyone's going to vote okay so<00:13:54.500> here<00:13:54.920> and<00:13:55.280> imagine<00:13:56.180> a<00:13:56.300> golden<00:13:56.480> vote<00:13:56.900> is 00:13:57.700 --> 00:13:57.710 align:start position:0% so here and imagine a golden vote is 00:13:57.710 --> 00:13:59.380 align:start position:0% so here and imagine a golden vote is voting<00:13:58.160> for<00:13:58.310> the<00:13:58.400> golden<00:13:58.700> transaction<00:13:59.240> which 00:13:59.380 --> 00:13:59.390 align:start position:0% voting for the golden transaction which 00:13:59.390 --> 00:14:00.820 align:start position:0% voting for the golden transaction which is<00:13:59.540> the<00:13:59.660> transaction<00:14:00.110> that<00:14:00.140> vitalik<00:14:00.680> has 00:14:00.820 --> 00:14:00.830 align:start position:0% is the transaction that vitalik has 00:14:00.830 --> 00:14:04.270 align:start position:0% is the transaction that vitalik has proposed<00:14:01.600> and<00:14:02.600> if<00:14:03.530> you<00:14:03.740> are<00:14:03.890> corrupt 00:14:04.270 --> 00:14:04.280 align:start position:0% proposed and if you are corrupt 00:14:04.280 --> 00:14:05.710 align:start position:0% proposed and if you are corrupt obviously<00:14:04.940> you<00:14:05.150> don't<00:14:05.240> have<00:14:05.360> to<00:14:05.540> vote 00:14:05.710 --> 00:14:05.720 align:start position:0% obviously you don't have to vote 00:14:05.720 --> 00:14:08.140 align:start position:0% obviously you don't have to vote according<00:14:06.710> to<00:14:06.830> the<00:14:06.920> protocol<00:14:07.310> rule<00:14:07.550> right<00:14:08.000> so 00:14:08.140 --> 00:14:08.150 align:start position:0% according to the protocol rule right so 00:14:08.150 --> 00:14:11.260 align:start position:0% according to the protocol rule right so Loki<00:14:08.660> in<00:14:08.810> this<00:14:08.930> case<00:14:09.140> is<00:14:09.770> voting<00:14:10.190> for<00:14:10.400> the<00:14:10.550> red 00:14:11.260 --> 00:14:11.270 align:start position:0% Loki in this case is voting for the red 00:14:11.270 --> 00:14:13.360 align:start position:0% Loki in this case is voting for the red transaction<00:14:11.900> and<00:14:12.050> the<00:14:12.140> blue<00:14:12.320> transaction<00:14:12.890> is 00:14:13.360 --> 00:14:13.370 align:start position:0% transaction and the blue transaction is 00:14:13.370 --> 00:14:15.960 align:start position:0% transaction and the blue transaction is that<00:14:13.640> of<00:14:13.790> the<00:14:13.970> the<00:14:14.360> golden 00:14:15.960 --> 00:14:15.970 align:start position:0% that of the the golden 00:14:15.970 --> 00:14:20.380 align:start position:0% that of the the golden okay<00:14:18.070> so<00:14:19.070> then<00:14:19.280> number<00:14:19.490> step<00:14:19.880> number<00:14:20.030> three 00:14:20.380 --> 00:14:20.390 align:start position:0% okay so then number step number three 00:14:20.390 --> 00:14:24.100 align:start position:0% okay so then number step number three I'm<00:14:20.930> going<00:14:21.290> to<00:14:21.440> wait<00:14:21.820> till<00:14:22.820> I<00:14:22.850> hear<00:14:23.450> enough 00:14:24.100 --> 00:14:24.110 align:start position:0% I'm going to wait till I hear enough 00:14:24.110 --> 00:14:25.720 align:start position:0% I'm going to wait till I hear enough people<00:14:24.350> voting<00:14:24.860> for<00:14:25.070> the<00:14:25.160> same<00:14:25.280> transaction 00:14:25.720 --> 00:14:25.730 align:start position:0% people voting for the same transaction 00:14:25.730 --> 00:14:28.180 align:start position:0% people voting for the same transaction and<00:14:26.090> then<00:14:26.510> I'm<00:14:26.690> going<00:14:26.900> to<00:14:27.080> confirm<00:14:27.560> or<00:14:27.950> in 00:14:28.180 --> 00:14:28.190 align:start position:0% and then I'm going to confirm or in 00:14:28.190 --> 00:14:33.510 align:start position:0% and then I'm going to confirm or in other<00:14:28.370> words<00:14:28.580> output<00:14:29.060> the<00:14:29.150> transaction<00:14:29.750> so 00:14:33.510 --> 00:14:33.520 align:start position:0% 00:14:33.520 --> 00:14:37.950 align:start position:0% this<00:14:34.520> is<00:14:34.610> a<00:14:34.640> very<00:14:34.940> simple<00:14:35.300> voting<00:14:35.630> protocol 00:14:37.950 --> 00:14:37.960 align:start position:0% this is a very simple voting protocol 00:14:37.960 --> 00:14:40.600 align:start position:0% this is a very simple voting protocol and<00:14:38.960> I'm<00:14:39.050> going<00:14:39.260> to<00:14:39.350> try<00:14:39.560> to<00:14:39.620> and<00:14:40.100> describe 00:14:40.600 --> 00:14:40.610 align:start position:0% and I'm going to try to and describe 00:14:40.610 --> 00:14:42.610 align:start position:0% and I'm going to try to and describe what<00:14:41.210> kind<00:14:41.270> of<00:14:41.570> properties<00:14:42.050> this<00:14:42.200> protocol 00:14:42.610 --> 00:14:42.620 align:start position:0% what kind of properties this protocol 00:14:42.620 --> 00:14:47.710 align:start position:0% what kind of properties this protocol can<00:14:42.800> achieve<00:14:43.450> okay<00:14:45.670> and<00:14:46.670> before<00:14:46.940> I<00:14:47.000> do<00:14:47.120> that<00:14:47.270> I 00:14:47.710 --> 00:14:47.720 align:start position:0% can achieve okay and before I do that I 00:14:47.720 --> 00:14:50.530 align:start position:0% can achieve okay and before I do that I want<00:14:48.200> to<00:14:48.290> stress<00:14:48.620> that<00:14:48.950> the<00:14:49.670> most<00:14:49.850> important 00:14:50.530 --> 00:14:50.540 align:start position:0% want to stress that the most important 00:14:50.540 --> 00:14:52.540 align:start position:0% want to stress that the most important invariant<00:14:51.200> of<00:14:51.350> this<00:14:51.500> protocol<00:14:51.980> is<00:14:52.190> that 00:14:52.540 --> 00:14:52.550 align:start position:0% invariant of this protocol is that 00:14:52.550 --> 00:14:55.150 align:start position:0% invariant of this protocol is that honest<00:14:53.300> notes<00:14:53.540> are<00:14:54.290> only<00:14:54.560> going<00:14:54.890> to<00:14:55.010> vote 00:14:55.150 --> 00:14:55.160 align:start position:0% honest notes are only going to vote 00:14:55.160 --> 00:14:57.790 align:start position:0% honest notes are only going to vote uniquely<00:14:55.790> for<00:14:56.210> every<00:14:56.480> sequence<00:14:56.840> number<00:14:57.140> so<00:14:57.680> if 00:14:57.790 --> 00:14:57.800 align:start position:0% uniquely for every sequence number so if 00:14:57.800 --> 00:15:00.430 align:start position:0% uniquely for every sequence number so if I'm<00:14:57.950> honest<00:14:58.490> I'm<00:14:58.760> going<00:14:59.480> to<00:14:59.570> wait<00:14:59.780> till<00:15:00.020> I<00:15:00.170> hear 00:15:00.430 --> 00:15:00.440 align:start position:0% I'm honest I'm going to wait till I hear 00:15:00.440 --> 00:15:02.890 align:start position:0% I'm honest I'm going to wait till I hear the<00:15:00.620> first<00:15:00.980> proposal<00:15:01.580> from<00:15:01.670> Vitalik<00:15:02.210> and<00:15:02.600> I'm 00:15:02.890 --> 00:15:02.900 align:start position:0% the first proposal from Vitalik and I'm 00:15:02.900 --> 00:15:04.510 align:start position:0% the first proposal from Vitalik and I'm only<00:15:03.380> going<00:15:03.650> to<00:15:03.800> vote<00:15:03.920> for<00:15:03.980> that<00:15:04.220> first 00:15:04.510 --> 00:15:04.520 align:start position:0% only going to vote for that first 00:15:04.520 --> 00:15:06.400 align:start position:0% only going to vote for that first proposal<00:15:05.000> I<00:15:05.090> hear<00:15:05.360> I'm<00:15:05.660> not<00:15:05.930> going<00:15:06.170> to<00:15:06.290> vote 00:15:06.400 --> 00:15:06.410 align:start position:0% proposal I hear I'm not going to vote 00:15:06.410 --> 00:15:11.530 align:start position:0% proposal I hear I'm not going to vote for<00:15:06.470> anything<00:15:06.800> else<00:15:07.870> okay<00:15:09.850> so<00:15:10.850> for<00:15:11.120> counting 00:15:11.530 --> 00:15:11.540 align:start position:0% for anything else okay so for counting 00:15:11.540 --> 00:15:13.390 align:start position:0% for anything else okay so for counting to<00:15:11.780> understand<00:15:12.680> the<00:15:12.770> security<00:15:13.010> of<00:15:13.220> the 00:15:13.390 --> 00:15:13.400 align:start position:0% to understand the security of the 00:15:13.400 --> 00:15:14.800 align:start position:0% to understand the security of the protocol<00:15:13.730> let's<00:15:13.940> consider<00:15:14.270> concrete 00:15:14.800 --> 00:15:14.810 align:start position:0% protocol let's consider concrete 00:15:14.810 --> 00:15:17.380 align:start position:0% protocol let's consider concrete parameters<00:15:15.260> and<00:15:15.500> equal<00:15:16.430> to<00:15:16.580> three<00:15:16.850> F<00:15:16.970> plus<00:15:17.180> one 00:15:17.380 --> 00:15:17.390 align:start position:0% parameters and equal to three F plus one 00:15:17.390 --> 00:15:19.120 align:start position:0% parameters and equal to three F plus one right<00:15:17.690> so<00:15:17.810> n<00:15:17.960> is<00:15:18.200> the<00:15:18.320> total<00:15:18.350> number<00:15:18.620> of<00:15:18.830> notes 00:15:19.120 --> 00:15:19.130 align:start position:0% right so n is the total number of notes 00:15:19.130 --> 00:15:23.260 align:start position:0% right so n is the total number of notes and<00:15:19.810> F<00:15:20.810> is<00:15:21.110> the<00:15:21.140> number<00:15:21.500> of<00:15:21.530> corrupt<00:15:22.160> notes<00:15:22.460> so 00:15:23.260 --> 00:15:23.270 align:start position:0% and F is the number of corrupt notes so 00:15:23.270 --> 00:15:25.810 align:start position:0% and F is the number of corrupt notes so this<00:15:23.420> is<00:15:23.600> saying<00:15:23.810> let's<00:15:24.710> imagine<00:15:25.100> the<00:15:25.580> number 00:15:25.810 --> 00:15:25.820 align:start position:0% this is saying let's imagine the number 00:15:25.820 --> 00:15:27.820 align:start position:0% this is saying let's imagine the number of<00:15:25.880> corrupt<00:15:26.240> notes<00:15:26.450> is<00:15:26.750> less<00:15:26.960> than<00:15:27.110> one<00:15:27.320> third 00:15:27.820 --> 00:15:27.830 align:start position:0% of corrupt notes is less than one third 00:15:27.830 --> 00:15:32.290 align:start position:0% of corrupt notes is less than one third and<00:15:28.000> in<00:15:29.000> this<00:15:29.120> case<00:15:29.420> I<00:15:29.690> claim<00:15:30.170> that<00:15:31.300> it's 00:15:32.290 --> 00:15:32.300 align:start position:0% and in this case I claim that it's 00:15:32.300 --> 00:15:35.860 align:start position:0% and in this case I claim that it's sufficient<00:15:33.050> to<00:15:33.769> wait<00:15:34.130> for<00:15:34.459> 2/3<00:15:35.450> of<00:15:35.600> the<00:15:35.750> people 00:15:35.860 --> 00:15:35.870 align:start position:0% sufficient to wait for 2/3 of the people 00:15:35.870 --> 00:15:38.380 align:start position:0% sufficient to wait for 2/3 of the people to<00:15:36.140> vote<00:15:36.350> so<00:15:37.339> I'm<00:15:37.490> going<00:15:37.700> to<00:15:37.760> set<00:15:38.029> my<00:15:38.209> threshold 00:15:38.380 --> 00:15:38.390 align:start position:0% to vote so I'm going to set my threshold 00:15:38.390 --> 00:15:40.960 align:start position:0% to vote so I'm going to set my threshold to<00:15:38.930> 2a<00:15:39.170> plus<00:15:39.470> 1<00:15:39.709> right<00:15:40.190> so<00:15:40.310> this<00:15:40.430> is<00:15:40.490> exactly 00:15:40.960 --> 00:15:40.970 align:start position:0% to 2a plus 1 right so this is exactly 00:15:40.970 --> 00:15:42.519 align:start position:0% to 2a plus 1 right so this is exactly waiting<00:15:41.240> for<00:15:41.390> 2/3<00:15:41.750> of<00:15:41.870> the<00:15:42.019> people<00:15:42.260> to<00:15:42.380> vote 00:15:42.519 --> 00:15:42.529 align:start position:0% waiting for 2/3 of the people to vote 00:15:42.529 --> 00:15:44.440 align:start position:0% waiting for 2/3 of the people to vote and<00:15:42.800> once<00:15:43.370> I<00:15:43.490> wait<00:15:43.700> for<00:15:43.850> enough<00:15:44.060> votes<00:15:44.300> I'm 00:15:44.440 --> 00:15:44.450 align:start position:0% and once I wait for enough votes I'm 00:15:44.450 --> 00:15:51.100 align:start position:0% and once I wait for enough votes I'm going<00:15:44.660> to<00:15:44.750> confirm<00:15:45.079> ok<00:15:49.570> so<00:15:50.570> why<00:15:50.750> does<00:15:50.959> this 00:15:51.100 --> 00:15:51.110 align:start position:0% going to confirm ok so why does this 00:15:51.110 --> 00:15:54.340 align:start position:0% going to confirm ok so why does this protocol<00:15:51.529> achieve<00:15:51.860> consistency<00:15:53.200> here's<00:15:54.200> a 00:15:54.340 --> 00:15:54.350 align:start position:0% protocol achieve consistency here's a 00:15:54.350 --> 00:15:57.220 align:start position:0% protocol achieve consistency here's a very<00:15:54.529> simple<00:15:54.950> argument<00:15:55.450> imagine<00:15:56.450> we<00:15:57.050> have 00:15:57.220 --> 00:15:57.230 align:start position:0% very simple argument imagine we have 00:15:57.230 --> 00:16:00.310 align:start position:0% very simple argument imagine we have spider-man<00:15:57.829> and<00:15:57.980> Iron<00:15:58.160> Man<00:15:58.519> spider-man<00:15:59.480> has 00:16:00.310 --> 00:16:00.320 align:start position:0% spider-man and Iron Man spider-man has 00:16:00.320 --> 00:16:03.790 align:start position:0% spider-man and Iron Man spider-man has heard<00:16:00.589> to<00:16:01.399> have<00:16:01.519> +1<00:16:01.820> people<00:16:02.529> voting<00:16:03.529> for<00:16:03.709> the 00:16:03.790 --> 00:16:03.800 align:start position:0% heard to have +1 people voting for the 00:16:03.800 --> 00:16:05.920 align:start position:0% heard to have +1 people voting for the red<00:16:03.950> transaction<00:16:04.610> so<00:16:05.360> I'm<00:16:05.510> going<00:16:05.660> to<00:16:05.779> call 00:16:05.920 --> 00:16:05.930 align:start position:0% red transaction so I'm going to call 00:16:05.930 --> 00:16:10.750 align:start position:0% red transaction so I'm going to call this<00:16:06.050> the<00:16:06.230> red<00:16:06.410> quorum<00:16:06.890> and<00:16:09.430> Ironman<00:16:10.430> has 00:16:10.750 --> 00:16:10.760 align:start position:0% this the red quorum and Ironman has 00:16:10.760 --> 00:16:13.170 align:start position:0% this the red quorum and Ironman has heard<00:16:11.029> also<00:16:11.390> heard<00:16:11.570> to<00:16:11.990> have<00:16:12.110> +1<00:16:12.380> people 00:16:13.170 --> 00:16:13.180 align:start position:0% heard also heard to have +1 people 00:16:13.180 --> 00:16:15.130 align:start position:0% heard also heard to have +1 people voting<00:16:14.180> for<00:16:14.390> let's<00:16:14.540> say<00:16:14.690> the<00:16:14.839> orange 00:16:15.130 --> 00:16:15.140 align:start position:0% voting for let's say the orange 00:16:15.140 --> 00:16:19.350 align:start position:0% voting for let's say the orange transaction<00:16:16.750> ok<00:16:17.750> so<00:16:18.019> these<00:16:18.350> two<00:16:18.620> currents 00:16:19.350 --> 00:16:19.360 align:start position:0% transaction ok so these two currents 00:16:19.360 --> 00:16:24.090 align:start position:0% transaction ok so these two currents they<00:16:20.360> may<00:16:20.510> not<00:16:20.690> be<00:16:20.870> the<00:16:20.990> same<00:16:21.670> however<00:16:22.670> by<00:16:23.660> a 00:16:24.090 --> 00:16:24.100 align:start position:0% they may not be the same however by a 00:16:24.100 --> 00:16:28.030 align:start position:0% they may not be the same however by a very<00:16:25.100> simple<00:16:25.550> pigeonhole<00:16:26.180> principle<00:16:26.560> right<00:16:27.560> n 00:16:28.030 --> 00:16:28.040 align:start position:0% very simple pigeonhole principle right n 00:16:28.040 --> 00:16:31.960 align:start position:0% very simple pigeonhole principle right n equal<00:16:28.490> to<00:16:28.610> 3r<00:16:28.820> plus<00:16:29.089> 1<00:16:29.980> it's<00:16:30.980> easy<00:16:31.310> to<00:16:31.610> see<00:16:31.790> that 00:16:31.960 --> 00:16:31.970 align:start position:0% equal to 3r plus 1 it's easy to see that 00:16:31.970 --> 00:16:35.170 align:start position:0% equal to 3r plus 1 it's easy to see that these<00:16:32.209> two<00:16:32.450> currents<00:16:32.899> must<00:16:33.290> intersect<00:16:33.980> at<00:16:34.430> an 00:16:35.170 --> 00:16:35.180 align:start position:0% these two currents must intersect at an 00:16:35.180 --> 00:16:37.660 align:start position:0% these two currents must intersect at an honest<00:16:35.540> node<00:16:35.750> and<00:16:36.250> that's<00:16:37.250> the<00:16:37.490> key 00:16:37.660 --> 00:16:37.670 align:start position:0% honest node and that's the key 00:16:37.670 --> 00:16:39.280 align:start position:0% honest node and that's the key observation<00:16:37.820> right<00:16:38.600> so<00:16:38.720> if<00:16:38.810> you<00:16:38.899> think<00:16:39.110> about 00:16:39.280 --> 00:16:39.290 align:start position:0% observation right so if you think about 00:16:39.290 --> 00:16:42.730 align:start position:0% observation right so if you think about it<00:16:39.470> this<00:16:39.620> is<00:16:39.770> like<00:16:39.920> very<00:16:40.339> very<00:16:40.790> easy<00:16:41.029> math<00:16:41.740> and 00:16:42.730 --> 00:16:42.740 align:start position:0% it this is like very very easy math and 00:16:42.740 --> 00:16:45.370 align:start position:0% it this is like very very easy math and because<00:16:43.490> of<00:16:43.520> this<00:16:43.790> remember<00:16:44.149> that<00:16:44.480> I<00:16:44.510> said<00:16:44.690> are 00:16:45.370 --> 00:16:45.380 align:start position:0% because of this remember that I said are 00:16:45.380 --> 00:16:48.400 align:start position:0% because of this remember that I said are missed<00:16:45.800> notes<00:16:45.980> vote<00:16:46.310> uniquely<00:16:47.079> so<00:16:48.079> we<00:16:48.230> can 00:16:48.400 --> 00:16:48.410 align:start position:0% missed notes vote uniquely so we can 00:16:48.410 --> 00:16:49.990 align:start position:0% missed notes vote uniquely so we can conclude<00:16:48.620> that<00:16:48.860> the<00:16:49.279> red<00:16:49.430> transaction<00:16:49.910> must 00:16:49.990 --> 00:16:50.000 align:start position:0% conclude that the red transaction must 00:16:50.000 --> 00:16:52.360 align:start position:0% conclude that the red transaction must be<00:16:50.180> the<00:16:50.270> same<00:16:50.450> as<00:16:50.600> the<00:16:50.779> orange<00:16:51.170> in<00:16:51.980> this<00:16:52.190> case 00:16:52.360 --> 00:16:52.370 align:start position:0% be the same as the orange in this case 00:16:52.370 --> 00:16:56.040 align:start position:0% be the same as the orange in this case so<00:16:53.180> consistency<00:16:53.750> is<00:16:53.899> guaranteed<00:16:54.529> and 00:16:56.040 --> 00:16:56.050 align:start position:0% so consistency is guaranteed and 00:16:56.050 --> 00:17:01.600 align:start position:0% so consistency is guaranteed and interestingly<00:16:57.050> I<00:16:59.140> want<00:17:00.140> you<00:17:00.260> to<00:17:00.470> notice<00:17:01.250> that 00:17:01.600 --> 00:17:01.610 align:start position:0% interestingly I want you to notice that 00:17:01.610 --> 00:17:02.949 align:start position:0% interestingly I want you to notice that in<00:17:01.910> this<00:17:02.180> argument 00:17:02.949 --> 00:17:02.959 align:start position:0% in this argument 00:17:02.959 --> 00:17:06.429 align:start position:0% in this argument I<00:17:03.669> never<00:17:04.669> relied<00:17:05.480> on<00:17:05.689> the<00:17:05.870> fact<00:17:05.900> that<00:17:06.230> the 00:17:06.429 --> 00:17:06.439 align:start position:0% I never relied on the fact that the 00:17:06.439 --> 00:17:08.919 align:start position:0% I never relied on the fact that the leader<00:17:06.620> has<00:17:06.829> to<00:17:06.860> be<00:17:07.100> honest<00:17:07.429> right<00:17:08.120> so<00:17:08.540> in<00:17:08.689> fact 00:17:08.919 --> 00:17:08.929 align:start position:0% leader has to be honest right so in fact 00:17:08.929 --> 00:17:12.490 align:start position:0% leader has to be honest right so in fact the<00:17:09.380> argument<00:17:09.589> holds<00:17:10.429> nonetheless<00:17:10.910> even<00:17:11.630> when 00:17:12.490 --> 00:17:12.500 align:start position:0% the argument holds nonetheless even when 00:17:12.500 --> 00:17:14.559 align:start position:0% the argument holds nonetheless even when the<00:17:12.650> leaders<00:17:12.919> corrupt<00:17:13.280> the<00:17:13.730> only<00:17:14.059> fact<00:17:14.360> I'm 00:17:14.559 --> 00:17:14.569 align:start position:0% the leaders corrupt the only fact I'm 00:17:14.569 --> 00:17:16.419 align:start position:0% the leaders corrupt the only fact I'm relying<00:17:14.900> on<00:17:15.140> here<00:17:15.470> is<00:17:15.650> that<00:17:15.919> honest<00:17:16.250> notes 00:17:16.419 --> 00:17:16.429 align:start position:0% relying on here is that honest notes 00:17:16.429 --> 00:17:23.799 align:start position:0% relying on here is that honest notes vote<00:17:16.640> uniquely<00:17:17.620> ok<00:17:21.010> ok<00:17:22.010> so<00:17:22.069> let's<00:17:22.339> now<00:17:22.809> imagine 00:17:23.799 --> 00:17:23.809 align:start position:0% vote uniquely ok ok so let's now imagine 00:17:23.809 --> 00:17:25.750 align:start position:0% vote uniquely ok ok so let's now imagine there<00:17:23.959> are<00:17:24.020> two<00:17:24.260> possible<00:17:24.740> worlds<00:17:25.130> right<00:17:25.280> on 00:17:25.750 --> 00:17:25.760 align:start position:0% there are two possible worlds right on 00:17:25.760 --> 00:17:27.640 align:start position:0% there are two possible worlds right on the<00:17:25.880> left<00:17:26.059> hand<00:17:26.270> side<00:17:26.569> imagine<00:17:27.110> Vitalik<00:17:27.530> is 00:17:27.640 --> 00:17:27.650 align:start position:0% the left hand side imagine Vitalik is 00:17:27.650 --> 00:17:30.040 align:start position:0% the left hand side imagine Vitalik is honest<00:17:28.040> and<00:17:28.220> on<00:17:29.059> the<00:17:29.210> right<00:17:29.330> hand<00:17:29.450> side<00:17:29.570> italic 00:17:30.040 --> 00:17:30.050 align:start position:0% honest and on the right hand side italic 00:17:30.050 --> 00:17:32.110 align:start position:0% honest and on the right hand side italic is<00:17:30.169> corrupt<00:17:30.470> when<00:17:30.980> the<00:17:31.130> talaq<00:17:31.460> is<00:17:31.610> honest 00:17:32.110 --> 00:17:32.120 align:start position:0% is corrupt when the talaq is honest 00:17:32.120 --> 00:17:33.520 align:start position:0% is corrupt when the talaq is honest everything's<00:17:32.510> are<00:17:32.690> good<00:17:32.929> we<00:17:33.169> have<00:17:33.350> both 00:17:33.520 --> 00:17:33.530 align:start position:0% everything's are good we have both 00:17:33.530 --> 00:17:35.830 align:start position:0% everything's are good we have both consistency<00:17:34.220> and<00:17:34.340> liveness<00:17:34.550> so<00:17:35.330> consistency 00:17:35.830 --> 00:17:35.840 align:start position:0% consistency and liveness so consistency 00:17:35.840 --> 00:17:38.110 align:start position:0% consistency and liveness so consistency I've<00:17:36.050> just<00:17:36.260> proved<00:17:36.559> for<00:17:37.400> liveness<00:17:37.580> it's<00:17:37.970> very 00:17:38.110 --> 00:17:38.120 align:start position:0% I've just proved for liveness it's very 00:17:38.120 --> 00:17:39.549 align:start position:0% I've just proved for liveness it's very easy<00:17:38.330> to<00:17:38.540> see<00:17:38.690> because<00:17:38.809> if<00:17:39.080> the<00:17:39.169> italic<00:17:39.500> is 00:17:39.549 --> 00:17:39.559 align:start position:0% easy to see because if the italic is 00:17:39.559 --> 00:17:41.670 align:start position:0% easy to see because if the italic is honest<00:17:39.950> he<00:17:40.429> is<00:17:40.460> going<00:17:40.730> to<00:17:40.850> propose<00:17:41.150> the<00:17:41.360> same 00:17:41.670 --> 00:17:41.680 align:start position:0% honest he is going to propose the same 00:17:41.680 --> 00:17:43.680 align:start position:0% honest he is going to propose the same transaction<00:17:42.190> to<00:17:42.280> everyone<00:17:42.640> right<00:17:43.330> and 00:17:43.680 --> 00:17:43.690 align:start position:0% transaction to everyone right and 00:17:43.690 --> 00:17:46.470 align:start position:0% transaction to everyone right and everyone<00:17:44.650> will<00:17:44.830> are<00:17:45.400> the<00:17:45.580> honest<00:17:45.910> people<00:17:46.240> will 00:17:46.470 --> 00:17:46.480 align:start position:0% everyone will are the honest people will 00:17:46.480 --> 00:17:48.500 align:start position:0% everyone will are the honest people will vote<00:17:46.720> on<00:17:46.780> the<00:17:46.960> same<00:17:47.200> transaction<00:17:47.770> and 00:17:48.500 --> 00:17:48.510 align:start position:0% vote on the same transaction and 00:17:48.510 --> 00:17:50.700 align:start position:0% vote on the same transaction and obviously<00:17:49.510> because<00:17:49.990> there<00:17:50.170> are<00:17:50.260> at<00:17:50.380> least<00:17:50.410> two 00:17:50.700 --> 00:17:50.710 align:start position:0% obviously because there are at least two 00:17:50.710 --> 00:17:53.430 align:start position:0% obviously because there are at least two F<00:17:50.800> plus<00:17:51.010> one<00:17:51.190> honest<00:17:51.460> people<00:17:51.790> soon<00:17:52.750> enough<00:17:53.170> I'm 00:17:53.430 --> 00:17:53.440 align:start position:0% F plus one honest people soon enough I'm 00:17:53.440 --> 00:17:55.110 align:start position:0% F plus one honest people soon enough I'm going<00:17:53.650> to<00:17:53.770> hear<00:17:54.010> to<00:17:54.160> half<00:17:54.280> plus<00:17:54.430> one<00:17:54.670> votes<00:17:54.880> and 00:17:55.110 --> 00:17:55.120 align:start position:0% going to hear to half plus one votes and 00:17:55.120 --> 00:17:58.020 align:start position:0% going to hear to half plus one votes and then<00:17:55.270> I<00:17:55.420> can<00:17:55.600> make<00:17:55.780> progress<00:17:55.990> on<00:17:56.910> the<00:17:57.910> other 00:17:58.020 --> 00:17:58.030 align:start position:0% then I can make progress on the other 00:17:58.030 --> 00:17:59.700 align:start position:0% then I can make progress on the other hand<00:17:58.300> what<00:17:58.480> if<00:17:58.600> vitalik<00:17:59.080> is<00:17:59.200> corrupt 00:17:59.700 --> 00:17:59.710 align:start position:0% hand what if vitalik is corrupt 00:17:59.710 --> 00:18:04.200 align:start position:0% hand what if vitalik is corrupt if<00:18:00.180> Vitalik<00:18:01.180> is<00:18:01.390> corrupt<00:18:03.090> fortunately<00:18:04.090> we 00:18:04.200 --> 00:18:04.210 align:start position:0% if Vitalik is corrupt fortunately we 00:18:04.210 --> 00:18:06.180 align:start position:0% if Vitalik is corrupt fortunately we still<00:18:04.240> have<00:18:04.660> consistency<00:18:05.290> right<00:18:05.620> like<00:18:05.830> I<00:18:05.950> said 00:18:06.180 --> 00:18:06.190 align:start position:0% still have consistency right like I said 00:18:06.190 --> 00:18:08.400 align:start position:0% still have consistency right like I said the<00:18:06.640> consistency<00:18:07.240> argument<00:18:07.690> didn't<00:18:08.110> rely<00:18:08.380> on 00:18:08.400 --> 00:18:08.410 align:start position:0% the consistency argument didn't rely on 00:18:08.410 --> 00:18:11.220 align:start position:0% the consistency argument didn't rely on Vitali<00:18:08.920> being<00:18:09.220> honest<00:18:09.810> however<00:18:10.810> we<00:18:11.080> don't 00:18:11.220 --> 00:18:11.230 align:start position:0% Vitali being honest however we don't 00:18:11.230 --> 00:18:13.470 align:start position:0% Vitali being honest however we don't have<00:18:11.410> live<00:18:11.620> in<00:18:11.740> this<00:18:11.830> anymore<00:18:12.100> right<00:18:12.460> so<00:18:13.330> why 00:18:13.470 --> 00:18:13.480 align:start position:0% have live in this anymore right so why 00:18:13.480 --> 00:18:15.060 align:start position:0% have live in this anymore right so why is<00:18:13.540> the<00:18:13.840> case<00:18:14.020> because<00:18:14.350> if<00:18:14.500> vitalik<00:18:14.950> is 00:18:15.060 --> 00:18:15.070 align:start position:0% is the case because if vitalik is 00:18:15.070 --> 00:18:17.190 align:start position:0% is the case because if vitalik is corrupt<00:18:15.430> he<00:18:15.670> can<00:18:16.150> propose<00:18:16.690> different 00:18:17.190 --> 00:18:17.200 align:start position:0% corrupt he can propose different 00:18:17.200 --> 00:18:18.830 align:start position:0% corrupt he can propose different transactions<00:18:17.770> to<00:18:17.890> different<00:18:18.160> people<00:18:18.460> and 00:18:18.830 --> 00:18:18.840 align:start position:0% transactions to different people and 00:18:18.840 --> 00:18:20.880 align:start position:0% transactions to different people and everyone's<00:18:19.840> going<00:18:20.020> to<00:18:20.110> end<00:18:20.290> up<00:18:20.380> voting<00:18:20.710> for<00:18:20.740> a 00:18:20.880 --> 00:18:20.890 align:start position:0% everyone's going to end up voting for a 00:18:20.890 --> 00:18:23.730 align:start position:0% everyone's going to end up voting for a different<00:18:21.220> thing<00:18:21.570> right<00:18:22.570> so<00:18:22.840> you<00:18:23.050> can<00:18:23.320> wait 00:18:23.730 --> 00:18:23.740 align:start position:0% different thing right so you can wait 00:18:23.740 --> 00:18:25.110 align:start position:0% different thing right so you can wait and<00:18:23.980> wait<00:18:24.160> and<00:18:24.370> wait<00:18:24.460> temple<00:18:24.880> you<00:18:24.940> never 00:18:25.110 --> 00:18:25.120 align:start position:0% and wait and wait temple you never 00:18:25.120 --> 00:18:26.550 align:start position:0% and wait and wait temple you never collect<00:18:25.480> enough<00:18:25.780> votes<00:18:26.020> for<00:18:26.290> the<00:18:26.410> same 00:18:26.550 --> 00:18:26.560 align:start position:0% collect enough votes for the same 00:18:26.560 --> 00:18:29.570 align:start position:0% collect enough votes for the same transaction<00:18:26.920> and<00:18:27.340> you<00:18:27.370> just<00:18:27.910> get<00:18:28.090> stuck<00:18:28.360> there 00:18:29.570 --> 00:18:29.580 align:start position:0% transaction and you just get stuck there 00:18:29.580 --> 00:18:35.550 align:start position:0% transaction and you just get stuck there okay<00:18:30.580> so<00:18:31.000> now<00:18:31.210> the<00:18:32.020> corrupt<00:18:32.440> of<00:18:33.900> consensus<00:18:34.900> is 00:18:35.550 --> 00:18:35.560 align:start position:0% okay so now the corrupt of consensus is 00:18:35.560 --> 00:18:38.220 align:start position:0% okay so now the corrupt of consensus is to<00:18:35.620> solve<00:18:36.250> the<00:18:36.460> liveness<00:18:36.700> problem<00:18:37.450> when<00:18:38.080> the 00:18:38.220 --> 00:18:38.230 align:start position:0% to solve the liveness problem when the 00:18:38.230 --> 00:18:40.830 align:start position:0% to solve the liveness problem when the leaders<00:18:38.530> corrupt<00:18:38.920> so<00:18:39.850> that's<00:18:40.060> what<00:18:40.480> we<00:18:40.630> want 00:18:40.830 --> 00:18:40.840 align:start position:0% leaders corrupt so that's what we want 00:18:40.840 --> 00:18:43.170 align:start position:0% leaders corrupt so that's what we want to<00:18:40.990> be<00:18:41.860> able<00:18:42.010> to<00:18:42.160> achieve<00:18:42.400> and<00:18:42.820> if<00:18:42.910> we<00:18:43.030> can 00:18:43.170 --> 00:18:43.180 align:start position:0% to be able to achieve and if we can 00:18:43.180 --> 00:18:44.700 align:start position:0% to be able to achieve and if we can achieve<00:18:43.300> that<00:18:43.510> then<00:18:43.690> everything's<00:18:44.290> good<00:18:44.500> okay 00:18:44.700 --> 00:18:44.710 align:start position:0% achieve that then everything's good okay 00:18:44.710 --> 00:18:48.090 align:start position:0% achieve that then everything's good okay so<00:18:45.670> how<00:18:45.850> can<00:18:45.910> we<00:18:46.120> a<00:18:46.150> guarantee<00:18:46.600> like<00:18:46.630> this<00:18:47.100> if 00:18:48.090 --> 00:18:48.100 align:start position:0% so how can we a guarantee like this if 00:18:48.100 --> 00:18:50.610 align:start position:0% so how can we a guarantee like this if you<00:18:48.430> look<00:18:48.670> at<00:18:48.910> this<00:18:49.600> classical<00:18:50.140> protocols 00:18:50.610 --> 00:18:50.620 align:start position:0% you look at this classical protocols 00:18:50.620 --> 00:18:56.340 align:start position:0% you look at this classical protocols like<00:18:50.770> pbft<00:18:51.220> and<00:18:51.610> paxos<00:18:54.000> they<00:18:55.000> rely<00:18:55.390> on<00:18:55.420> a<00:18:55.930> very 00:18:56.340 --> 00:18:56.350 align:start position:0% like pbft and paxos they rely on a very 00:18:56.350 --> 00:18:58.800 align:start position:0% like pbft and paxos they rely on a very complicated<00:18:56.950> leader<00:18:57.490> election<00:18:58.030> mechanism 00:18:58.800 --> 00:18:58.810 align:start position:0% complicated leader election mechanism 00:18:58.810 --> 00:19:00.680 align:start position:0% complicated leader election mechanism and<00:18:59.020> in<00:18:59.230> pbft<00:18:59.620> this<00:18:59.860> is<00:18:59.950> called<00:19:00.160> view<00:19:00.370> change 00:19:00.680 --> 00:19:00.690 align:start position:0% and in pbft this is called view change 00:19:00.690 --> 00:19:05.450 align:start position:0% and in pbft this is called view change so<00:19:01.690> I<00:19:01.720> don't<00:19:02.110> want<00:19:02.230> to<00:19:02.290> have<00:19:02.380> to<00:19:02.500> explain<00:19:02.830> this 00:19:05.450 --> 00:19:05.460 align:start position:0% 00:19:05.460 --> 00:19:08.100 align:start position:0% okay<00:19:06.460> so<00:19:06.520> again<00:19:06.700> this<00:19:07.150> is<00:19:07.300> like<00:19:07.480> the<00:19:07.630> anatomy 00:19:08.100 --> 00:19:08.110 align:start position:0% okay so again this is like the anatomy 00:19:08.110 --> 00:19:10.290 align:start position:0% okay so again this is like the anatomy of<00:19:08.140> a<00:19:08.590> white<00:19:09.070> class<00:19:09.340> of<00:19:09.580> classical<00:19:10.060> style 00:19:10.290 --> 00:19:10.300 align:start position:0% of a white class of classical style 00:19:10.300 --> 00:19:12.540 align:start position:0% of a white class of classical style protocols<00:19:10.780> there's<00:19:11.530> a<00:19:11.590> very<00:19:11.920> very<00:19:12.160> simple 00:19:12.540 --> 00:19:12.550 align:start position:0% protocols there's a very very simple 00:19:12.550 --> 00:19:15.720 align:start position:0% protocols there's a very very simple voting<00:19:12.970> path<00:19:13.810> the<00:19:14.140> normal<00:19:14.470> path<00:19:14.650> as<00:19:14.920> I 00:19:15.720 --> 00:19:15.730 align:start position:0% voting path the normal path as I 00:19:15.730 --> 00:19:17.820 align:start position:0% voting path the normal path as I explained<00:19:16.660> right<00:19:16.870> the<00:19:17.020> are<00:19:17.380> these<00:19:17.500> protocols 00:19:17.820 --> 00:19:17.830 align:start position:0% explained right the are these protocols 00:19:17.830 --> 00:19:22.020 align:start position:0% explained right the are these protocols have<00:19:18.580> a<00:19:18.610> similar<00:19:19.120> voting<00:19:19.450> and<00:19:19.810> path<00:19:20.250> but<00:19:21.250> when 00:19:22.020 --> 00:19:22.030 align:start position:0% have a similar voting and path but when 00:19:22.030 --> 00:19:24.360 align:start position:0% have a similar voting and path but when the<00:19:22.180> leaders<00:19:22.480> corrupt<00:19:22.870> they<00:19:23.680> go<00:19:23.860> to<00:19:23.920> this<00:19:24.130> very 00:19:24.360 --> 00:19:24.370 align:start position:0% the leaders corrupt they go to this very 00:19:24.370 --> 00:19:27.150 align:start position:0% the leaders corrupt they go to this very complicated<00:19:24.940> recovery<00:19:25.390> path<00:19:25.920> and<00:19:26.920> that's 00:19:27.150 --> 00:19:27.160 align:start position:0% complicated recovery path and that's 00:19:27.160 --> 00:19:29.810 align:start position:0% complicated recovery path and that's where<00:19:27.370> things<00:19:28.060> kind<00:19:28.360> of<00:19:28.540> get<00:19:29.200> extremely 00:19:29.810 --> 00:19:29.820 align:start position:0% where things kind of get extremely 00:19:29.820 --> 00:19:34.170 align:start position:0% where things kind of get extremely complicated<00:19:32.610> so<00:19:33.610> here's<00:19:33.850> an<00:19:34.030> interesting 00:19:34.170 --> 00:19:34.180 align:start position:0% complicated so here's an interesting 00:19:34.180 --> 00:19:36.210 align:start position:0% complicated so here's an interesting anecdote<00:19:34.810> right<00:19:35.170> so<00:19:35.320> change<00:19:35.590> outcome<00:19:35.980> is<00:19:36.190> a 00:19:36.210 --> 00:19:36.220 align:start position:0% anecdote right so change outcome is a 00:19:36.220 --> 00:19:38.130 align:start position:0% anecdote right so change outcome is a SAN<00:19:36.670> francisco-based<00:19:36.700> startup<00:19:37.360> company<00:19:37.960> they 00:19:38.130 --> 00:19:38.140 align:start position:0% SAN francisco-based startup company they 00:19:38.140 --> 00:19:40.020 align:start position:0% SAN francisco-based startup company they signed<00:19:38.410> a<00:19:38.530> high<00:19:38.710> profile<00:19:39.160> contract<00:19:39.640> with<00:19:39.820> visa 00:19:40.020 --> 00:19:40.030 align:start position:0% signed a high profile contract with visa 00:19:40.030 --> 00:19:43.110 align:start position:0% signed a high profile contract with visa and<00:19:40.420> and<00:19:41.260> what<00:19:41.740> they<00:19:41.950> the<00:19:42.310> way<00:19:42.460> they<00:19:42.640> deal<00:19:43.030> with 00:19:43.110 --> 00:19:43.120 align:start position:0% and and what they the way they deal with 00:19:43.120 --> 00:19:44.730 align:start position:0% and and what they the way they deal with this<00:19:43.360> problem<00:19:43.810> is<00:19:43.960> that<00:19:44.140> they<00:19:44.320> only 00:19:44.730 --> 00:19:44.740 align:start position:0% this problem is that they only 00:19:44.740 --> 00:19:48.150 align:start position:0% this problem is that they only implemented<00:19:45.520> the<00:19:45.610> normal<00:19:45.940> path<00:19:46.120> and<00:19:47.160> they 00:19:48.150 --> 00:19:48.160 align:start position:0% implemented the normal path and they 00:19:48.160 --> 00:19:49.710 align:start position:0% implemented the normal path and they basically<00:19:48.340> just<00:19:48.940> ditched<00:19:49.150> all<00:19:49.390> of<00:19:49.570> this 00:19:49.710 --> 00:19:49.720 align:start position:0% basically just ditched all of this 00:19:49.720 --> 00:19:51.990 align:start position:0% basically just ditched all of this complicated<00:19:49.960> recovery<00:19:50.800> path<00:19:51.010> and<00:19:51.640> what's 00:19:51.990 --> 00:19:52.000 align:start position:0% complicated recovery path and what's 00:19:52.000 --> 00:19:54.510 align:start position:0% complicated recovery path and what's going<00:19:52.180> to<00:19:52.270> happen<00:19:52.360> is<00:19:52.780> you<00:19:53.020> know<00:19:53.140> if<00:19:53.290> things 00:19:54.510 --> 00:19:54.520 align:start position:0% going to happen is you know if things 00:19:54.520 --> 00:19:59.370 align:start position:0% going to happen is you know if things the<00:19:54.940> protocol<00:19:55.410> is<00:19:56.410> under<00:19:56.740> attack<00:19:58.170> things<00:19:59.170> go 00:19:59.370 --> 00:19:59.380 align:start position:0% the protocol is under attack things go 00:19:59.380 --> 00:20:02.520 align:start position:0% the protocol is under attack things go go<00:19:59.650> round<00:19:59.920> the<00:20:00.520> leader<00:20:00.700> is<00:20:00.940> corrupt<00:20:01.720> then<00:20:02.380> you 00:20:02.520 --> 00:20:02.530 align:start position:0% go round the leader is corrupt then you 00:20:02.530 --> 00:20:04.530 align:start position:0% go round the leader is corrupt then you have<00:20:02.680> to<00:20:02.830> kind<00:20:03.040> of<00:20:03.100> do<00:20:03.310> this<00:20:03.460> manually<00:20:04.090> and 00:20:04.530 --> 00:20:04.540 align:start position:0% have to kind of do this manually and 00:20:04.540 --> 00:20:06.300 align:start position:0% have to kind of do this manually and it's<00:20:05.140> not<00:20:05.320> going<00:20:05.500> to<00:20:05.650> be<00:20:05.740> fun<00:20:05.920> if<00:20:06.100> you<00:20:06.130> have 00:20:06.300 --> 00:20:06.310 align:start position:0% it's not going to be fun if you have 00:20:06.310 --> 00:20:08.070 align:start position:0% it's not going to be fun if you have like<00:20:06.640> a<00:20:06.670> hundred<00:20:06.850> banks<00:20:07.360> and<00:20:07.600> running<00:20:07.990> the 00:20:08.070 --> 00:20:08.080 align:start position:0% like a hundred banks and running the 00:20:08.080 --> 00:20:09.330 align:start position:0% like a hundred banks and running the consensus<00:20:08.500> protocol<00:20:08.800> because<00:20:09.040> you<00:20:09.100> have<00:20:09.220> to 00:20:09.330 --> 00:20:09.340 align:start position:0% consensus protocol because you have to 00:20:09.340 --> 00:20:11.130 align:start position:0% consensus protocol because you have to go<00:20:09.460> to<00:20:09.520> all<00:20:09.700> of<00:20:09.730> them<00:20:10.000> and<00:20:10.180> say<00:20:10.330> okay<00:20:10.570> now<00:20:10.600> you 00:20:11.130 --> 00:20:11.140 align:start position:0% go to all of them and say okay now you 00:20:11.140 --> 00:20:14.880 align:start position:0% go to all of them and say okay now you know<00:20:11.440> Sinkler<00:20:11.860> log<00:20:12.130> to<00:20:12.310> this<00:20:12.480> this<00:20:13.480> state<00:20:13.960> and 00:20:14.880 --> 00:20:14.890 align:start position:0% know Sinkler log to this this state and 00:20:14.890 --> 00:20:20.160 align:start position:0% know Sinkler log to this this state and then<00:20:15.160> maybe<00:20:15.400> reboot<00:20:16.080> okay<00:20:18.090> so<00:20:19.090> essentially<00:20:19.750> I 00:20:20.160 --> 00:20:20.170 align:start position:0% then maybe reboot okay so essentially I 00:20:20.170 --> 00:20:23.130 align:start position:0% then maybe reboot okay so essentially I mean<00:20:20.260> we<00:20:21.220> are<00:20:21.370> kind<00:20:21.610> of<00:20:21.700> stuck<00:20:22.030> at<00:20:22.690> this<00:20:22.840> point 00:20:23.130 --> 00:20:23.140 align:start position:0% mean we are kind of stuck at this point 00:20:23.140 --> 00:20:25.890 align:start position:0% mean we are kind of stuck at this point and<00:20:24.100> like<00:20:24.580> I<00:20:24.730> promised<00:20:25.120> earlier<00:20:25.240> when<00:20:25.600> we<00:20:25.720> get 00:20:25.890 --> 00:20:25.900 align:start position:0% and like I promised earlier when we get 00:20:25.900 --> 00:20:27.870 align:start position:0% and like I promised earlier when we get stuck<00:20:26.170> we<00:20:26.320> are<00:20:26.410> going<00:20:26.590> to<00:20:26.680> try<00:20:26.830> to<00:20:26.890> combine<00:20:27.520> the 00:20:27.870 --> 00:20:27.880 align:start position:0% stuck we are going to try to combine the 00:20:27.880 --> 00:20:30.840 align:start position:0% stuck we are going to try to combine the best<00:20:28.030> of<00:20:28.210> both<00:20:28.270> worlds<00:20:29.340> all<00:20:30.340> right<00:20:30.520> any 00:20:30.840 --> 00:20:30.850 align:start position:0% best of both worlds all right any 00:20:30.850 --> 00:20:36.480 align:start position:0% best of both worlds all right any questions<00:20:31.240> at<00:20:31.390> this<00:20:31.510> point<00:20:32.700> okay<00:20:33.700> so<00:20:35.490> here's 00:20:36.480 --> 00:20:36.490 align:start position:0% questions at this point okay so here's 00:20:36.490 --> 00:20:39.510 align:start position:0% questions at this point okay so here's our<00:20:36.700> idea<00:20:37.260> we<00:20:38.260> still<00:20:38.500> have<00:20:38.710> this<00:20:38.830> very<00:20:39.100> simple 00:20:39.510 --> 00:20:39.520 align:start position:0% our idea we still have this very simple 00:20:39.520 --> 00:20:41.670 align:start position:0% our idea we still have this very simple voting<00:20:39.910> path<00:20:40.120> but<00:20:40.390> we<00:20:40.570> remove<00:20:41.500> the 00:20:41.670 --> 00:20:41.680 align:start position:0% voting path but we remove the 00:20:41.680 --> 00:20:43.770 align:start position:0% voting path but we remove the complicated<00:20:42.250> stuff<00:20:42.460> and<00:20:42.520> we<00:20:42.880> replace<00:20:43.510> it<00:20:43.660> with 00:20:43.770 --> 00:20:43.780 align:start position:0% complicated stuff and we replace it with 00:20:43.780 --> 00:20:45.870 align:start position:0% complicated stuff and we replace it with the<00:20:43.870> blockchain<00:20:44.110> and<00:20:44.500> that's<00:20:45.370> the<00:20:45.580> idea 00:20:45.870 --> 00:20:45.880 align:start position:0% the blockchain and that's the idea 00:20:45.880 --> 00:20:48.600 align:start position:0% the blockchain and that's the idea behind<00:20:46.030> Thunder<00:20:46.570> Ella<00:20:47.310> okay<00:20:48.310> so<00:20:48.370> it's<00:20:48.580> very 00:20:48.600 --> 00:20:48.610 align:start position:0% behind Thunder Ella okay so it's very 00:20:48.610 --> 00:20:51.390 align:start position:0% behind Thunder Ella okay so it's very easy<00:20:48.820> easily<00:20:49.690> set<00:20:49.930> and<00:20:50.200> there<00:20:50.920> there<00:20:51.250> are<00:20:51.280> a 00:20:51.390 --> 00:20:51.400 align:start position:0% easy easily set and there there are a 00:20:51.400 --> 00:20:54.090 align:start position:0% easy easily set and there there are a couple<00:20:51.780> tricks<00:20:52.780> to<00:20:53.290> doing<00:20:53.710> this<00:20:53.890> correctly 00:20:54.090 --> 00:20:54.100 align:start position:0% couple tricks to doing this correctly 00:20:54.100 --> 00:20:57.870 align:start position:0% couple tricks to doing this correctly which<00:20:54.730> I'm<00:20:54.910> going<00:20:55.150> to<00:20:55.300> explain<00:20:56.460> and<00:20:57.460> before<00:20:57.850> I 00:20:57.870 --> 00:20:57.880 align:start position:0% which I'm going to explain and before I 00:20:57.880 --> 00:21:00.960 align:start position:0% which I'm going to explain and before I explain<00:20:58.360> the<00:20:58.540> protocol<00:20:59.310> here's<00:21:00.310> the<00:21:00.580> kind<00:21:00.790> of 00:21:00.960 --> 00:21:00.970 align:start position:0% explain the protocol here's the kind of 00:21:00.970 --> 00:21:03.090 align:start position:0% explain the protocol here's the kind of guarantees<00:21:01.420> we<00:21:01.600> can<00:21:01.840> achieve<00:21:02.170> with<00:21:02.770> Thunder 00:21:03.090 --> 00:21:03.100 align:start position:0% guarantees we can achieve with Thunder 00:21:03.100 --> 00:21:07.740 align:start position:0% guarantees we can achieve with Thunder alley<00:21:03.250> right<00:21:03.580> so<00:21:04.710> number<00:21:05.710> one<00:21:06.210> we<00:21:07.210> are<00:21:07.540> a 00:21:07.740 --> 00:21:07.750 align:start position:0% alley right so number one we are a 00:21:07.750 --> 00:21:10.200 align:start position:0% alley right so number one we are a blockchain<00:21:08.050> based<00:21:08.470> protocol<00:21:09.210> fundamentally 00:21:10.200 --> 00:21:10.210 align:start position:0% blockchain based protocol fundamentally 00:21:10.210 --> 00:21:12.540 align:start position:0% blockchain based protocol fundamentally and<00:21:11.170> that's<00:21:11.380> why<00:21:11.560> we<00:21:11.770> are<00:21:11.800> just<00:21:12.070> like<00:21:12.250> almost 00:21:12.540 --> 00:21:12.550 align:start position:0% and that's why we are just like almost 00:21:12.550 --> 00:21:15.540 align:start position:0% and that's why we are just like almost as<00:21:12.790> simple<00:21:13.210> and<00:21:13.510> as<00:21:14.290> the<00:21:14.650> blockchain<00:21:15.100> itself 00:21:15.540 --> 00:21:15.550 align:start position:0% as simple and as the blockchain itself 00:21:15.550 --> 00:21:16.920 align:start position:0% as simple and as the blockchain itself and<00:21:15.760> we<00:21:15.850> are<00:21:15.880> just<00:21:16.090> as<00:21:16.270> robust<00:21:16.660> as<00:21:16.810> the 00:21:16.920 --> 00:21:16.930 align:start position:0% and we are just as robust as the 00:21:16.930 --> 00:21:20.580 align:start position:0% and we are just as robust as the blockchain<00:21:17.140> to<00:21:18.960> 95%<00:21:19.960> of<00:21:20.080> the<00:21:20.200> time<00:21:20.350> in 00:21:20.580 --> 00:21:20.590 align:start position:0% blockchain to 95% of the time in 00:21:20.590 --> 00:21:23.130 align:start position:0% blockchain to 95% of the time in practice<00:21:21.060> you<00:21:22.060> are<00:21:22.090> going<00:21:22.390> to<00:21:22.540> live<00:21:22.750> in<00:21:23.020> the 00:21:23.130 --> 00:21:23.140 align:start position:0% practice you are going to live in the 00:21:23.140 --> 00:21:25.170 align:start position:0% practice you are going to live in the fast<00:21:23.320> path<00:21:23.620> or<00:21:24.430> we<00:21:24.580> also<00:21:24.760> call<00:21:24.880> it<00:21:25.060> the 00:21:25.170 --> 00:21:25.180 align:start position:0% fast path or we also call it the 00:21:25.180 --> 00:21:27.750 align:start position:0% fast path or we also call it the optimistic<00:21:25.870> path<00:21:26.050> and<00:21:26.380> in<00:21:26.920> the<00:21:26.980> fast<00:21:27.310> path<00:21:27.580> you 00:21:27.750 --> 00:21:27.760 align:start position:0% optimistic path and in the fast path you 00:21:27.760 --> 00:21:29.400 align:start position:0% optimistic path and in the fast path you are<00:21:27.850> going<00:21:28.090> to<00:21:28.210> confirm<00:21:28.570> transactions<00:21:29.230> with<00:21:29.380> a 00:21:29.400 --> 00:21:29.410 align:start position:0% are going to confirm transactions with a 00:21:29.410 --> 00:21:31.410 align:start position:0% are going to confirm transactions with a single<00:21:29.830> round<00:21:29.980> of<00:21:30.160> voting<00:21:30.280> right<00:21:30.790> so<00:21:30.910> not<00:21:31.210> even 00:21:31.410 --> 00:21:31.420 align:start position:0% single round of voting right so not even 00:21:31.420 --> 00:21:35.040 align:start position:0% single round of voting right so not even a<00:21:31.810> block<00:21:32.470> interval<00:21:32.980> so<00:21:33.910> two<00:21:33.970> to<00:21:34.330> three<00:21:34.630> actual 00:21:35.040 --> 00:21:35.050 align:start position:0% a block interval so two to three actual 00:21:35.050 --> 00:21:38.100 align:start position:0% a block interval so two to three actual network<00:21:35.350> rounds<00:21:35.800> and<00:21:36.720> when<00:21:37.720> you're<00:21:37.900> under 00:21:38.100 --> 00:21:38.110 align:start position:0% network rounds and when you're under 00:21:38.110 --> 00:21:40.320 align:start position:0% network rounds and when you're under attack<00:21:38.310> it's<00:21:39.310> not<00:21:39.550> the<00:21:39.700> end<00:21:39.850> of<00:21:40.000> the<00:21:40.120> world 00:21:40.320 --> 00:21:40.330 align:start position:0% attack it's not the end of the world 00:21:40.330 --> 00:21:41.760 align:start position:0% attack it's not the end of the world because<00:21:40.750> you'll<00:21:40.900> fall<00:21:41.080> back<00:21:41.320> to<00:21:41.470> the<00:21:41.500> block 00:21:41.760 --> 00:21:41.770 align:start position:0% because you'll fall back to the block 00:21:41.770 --> 00:21:43.830 align:start position:0% because you'll fall back to the block chains<00:21:42.010> performance<00:21:42.550> and<00:21:43.150> guarantees<00:21:43.690> as 00:21:43.830 --> 00:21:43.840 align:start position:0% chains performance and guarantees as 00:21:43.840 --> 00:21:45.050 align:start position:0% chains performance and guarantees as well 00:21:45.050 --> 00:21:45.060 align:start position:0% well 00:21:45.060 --> 00:21:48.840 align:start position:0% well okay<00:21:47.040> so<00:21:48.040> Thunder<00:21:48.310> angler<00:21:48.550> can<00:21:48.730> be 00:21:48.840 --> 00:21:48.850 align:start position:0% okay so Thunder angler can be 00:21:48.850 --> 00:21:50.580 align:start position:0% okay so Thunder angler can be instantiated<00:21:49.180> for<00:21:49.720> both<00:21:49.870> permissions<00:21:50.440> and 00:21:50.580 --> 00:21:50.590 align:start position:0% instantiated for both permissions and 00:21:50.590 --> 00:21:51.870 align:start position:0% instantiated for both permissions and permission<00:21:50.980> list<00:21:51.100> settings<00:21:51.340> and<00:21:51.700> for 00:21:51.870 --> 00:21:51.880 align:start position:0% permission list settings and for 00:21:51.880 --> 00:21:53.400 align:start position:0% permission list settings and for concreteness<00:21:52.330> when<00:21:52.750> I<00:21:52.780> talk<00:21:53.050> about<00:21:53.170> the 00:21:53.400 --> 00:21:53.410 align:start position:0% concreteness when I talk about the 00:21:53.410 --> 00:21:55.080 align:start position:0% concreteness when I talk about the scheme<00:21:53.650> I'm<00:21:53.830> going<00:21:54.460> to<00:21:54.580> assume<00:21:54.850> the 00:21:55.080 --> 00:21:55.090 align:start position:0% scheme I'm going to assume the 00:21:55.090 --> 00:21:58.200 align:start position:0% scheme I'm going to assume the permission<00:21:55.540> list<00:21:55.660> setting<00:21:56.940> and<00:21:57.940> more 00:21:58.200 --> 00:21:58.210 align:start position:0% permission list setting and more 00:21:58.210 --> 00:22:01.860 align:start position:0% permission list setting and more concretely<00:21:58.720> let's<00:21:59.520> imagine<00:22:00.540> aetherium<00:22:01.540> what 00:22:01.860 --> 00:22:01.870 align:start position:0% concretely let's imagine aetherium what 00:22:01.870 --> 00:22:03.830 align:start position:0% concretely let's imagine aetherium what a<00:22:01.990> theorem<00:22:02.350> x'<00:22:02.380> wants<00:22:03.010> to<00:22:03.160> do<00:22:03.310> right<00:22:03.520> so 00:22:03.830 --> 00:22:03.840 align:start position:0% a theorem x' wants to do right so 00:22:03.840 --> 00:22:05.869 align:start position:0% a theorem x' wants to do right so theorem<00:22:04.840> has<00:22:05.080> like 00:22:05.869 --> 00:22:05.879 align:start position:0% theorem has like 00:22:05.879 --> 00:22:09.200 align:start position:0% theorem has like the<00:22:06.879> previous<00:22:07.419> speaker<00:22:07.480> talked<00:22:07.899> about<00:22:08.139> and 00:22:09.200 --> 00:22:09.210 align:start position:0% the previous speaker talked about and 00:22:09.210 --> 00:22:11.999 align:start position:0% the previous speaker talked about and Assyrian<00:22:10.210> wants<00:22:10.509> to<00:22:10.659> move<00:22:10.960> towards<00:22:11.409> proof<00:22:11.830> of 00:22:11.999 --> 00:22:12.009 align:start position:0% Assyrian wants to move towards proof of 00:22:12.009 --> 00:22:15.810 align:start position:0% Assyrian wants to move towards proof of stake<00:22:12.309> but<00:22:13.269> as<00:22:13.869> a<00:22:13.929> first<00:22:14.259> step<00:22:14.529> the<00:22:15.369> goal<00:22:15.580> is<00:22:15.789> to 00:22:15.810 --> 00:22:15.820 align:start position:0% stake but as a first step the goal is to 00:22:15.820 --> 00:22:17.970 align:start position:0% stake but as a first step the goal is to have<00:22:16.149> the<00:22:16.659> stakeholders<00:22:17.289> form<00:22:17.559> a<00:22:17.679> committee 00:22:17.970 --> 00:22:17.980 align:start position:0% have the stakeholders form a committee 00:22:17.980 --> 00:22:22.080 align:start position:0% have the stakeholders form a committee and<00:22:18.279> vote<00:22:18.879> on<00:22:19.090> top<00:22:19.389> of<00:22:19.570> a<00:22:20.159> blockchain<00:22:21.159> so 00:22:22.080 --> 00:22:22.090 align:start position:0% and vote on top of a blockchain so 00:22:22.090 --> 00:22:23.460 align:start position:0% and vote on top of a blockchain so currently<00:22:22.450> this<00:22:22.869> is<00:22:22.929> a<00:22:23.049> proof-of-work 00:22:23.460 --> 00:22:23.470 align:start position:0% currently this is a proof-of-work 00:22:23.470 --> 00:22:25.080 align:start position:0% currently this is a proof-of-work blockchain<00:22:24.070> but<00:22:24.279> in<00:22:24.489> the<00:22:24.580> future<00:22:24.789> they<00:22:24.999> want 00:22:25.080 --> 00:22:25.090 align:start position:0% blockchain but in the future they want 00:22:25.090 --> 00:22:27.359 align:start position:0% blockchain but in the future they want to<00:22:25.210> prove<00:22:25.389> replace<00:22:26.379> it<00:22:26.559> with<00:22:26.739> proof<00:22:26.980> of<00:22:27.129> stake 00:22:27.359 --> 00:22:27.369 align:start position:0% to prove replace it with proof of stake 00:22:27.369 --> 00:22:33.749 align:start position:0% to prove replace it with proof of stake blockchain<00:22:28.200> okay<00:22:31.950> so<00:22:32.950> I'm<00:22:33.100> not<00:22:33.129> going<00:22:33.580> to 00:22:33.749 --> 00:22:33.759 align:start position:0% blockchain okay so I'm not going to 00:22:33.759 --> 00:22:36.090 align:start position:0% blockchain okay so I'm not going to mention<00:22:34.480> how<00:22:34.840> to<00:22:34.899> elect<00:22:35.350> the<00:22:35.470> committee<00:22:35.889> and 00:22:36.090 --> 00:22:36.100 align:start position:0% mention how to elect the committee and 00:22:36.100 --> 00:22:38.399 align:start position:0% mention how to elect the committee and elect<00:22:36.489> the<00:22:36.639> leader<00:22:36.820> as<00:22:37.179> I<00:22:37.360> said<00:22:37.600> up<00:22:37.809> front<00:22:37.869> this 00:22:38.399 --> 00:22:38.409 align:start position:0% elect the leader as I said up front this 00:22:38.409 --> 00:22:40.649 align:start position:0% elect the leader as I said up front this is<00:22:38.619> like<00:22:38.799> outside<00:22:39.489> the<00:22:39.940> scope<00:22:40.119> of<00:22:40.269> this<00:22:40.450> talk 00:22:40.649 --> 00:22:40.659 align:start position:0% is like outside the scope of this talk 00:22:40.659 --> 00:22:42.389 align:start position:0% is like outside the scope of this talk but<00:22:40.929> I<00:22:41.049> want<00:22:41.289> you<00:22:41.409> to<00:22:41.470> take<00:22:41.769> a<00:22:41.799> leap<00:22:42.129> of<00:22:42.340> faith 00:22:42.389 --> 00:22:42.399 align:start position:0% but I want you to take a leap of faith 00:22:42.399 --> 00:22:45.899 align:start position:0% but I want you to take a leap of faith and<00:22:42.909> imagine<00:22:43.840> that<00:22:43.960> there<00:22:44.139> exists<00:22:44.909> mechanisms 00:22:45.899 --> 00:22:45.909 align:start position:0% and imagine that there exists mechanisms 00:22:45.909 --> 00:22:47.669 align:start position:0% and imagine that there exists mechanisms to<00:22:46.119> elect<00:22:46.570> the<00:22:46.690> committee<00:22:46.989> and<00:22:47.230> elect<00:22:47.590> the 00:22:47.669 --> 00:22:47.679 align:start position:0% to elect the committee and elect the 00:22:47.679 --> 00:22:50.430 align:start position:0% to elect the committee and elect the leader<00:22:47.859> from<00:22:48.580> the<00:22:48.730> set<00:22:48.909> of<00:22:48.940> the<00:22:49.090> miners<00:22:49.539> and 00:22:50.430 --> 00:22:50.440 align:start position:0% leader from the set of the miners and 00:22:50.440 --> 00:22:53.820 align:start position:0% leader from the set of the miners and the<00:22:50.679> stake<00:22:50.889> holders<00:22:52.619> okay 00:22:53.820 --> 00:22:53.830 align:start position:0% the stake holders okay 00:22:53.830 --> 00:22:56.820 align:start position:0% the stake holders okay so<00:22:54.629> we<00:22:55.629> are<00:22:55.749> going<00:22:55.960> to<00:22:56.080> make<00:22:56.289> a<00:22:56.529> couple 00:22:56.820 --> 00:22:56.830 align:start position:0% so we are going to make a couple 00:22:56.830 --> 00:22:59.580 align:start position:0% so we are going to make a couple assumptions<00:22:57.429> in<00:22:57.609> order<00:22:57.730> to<00:22:58.139> achieve<00:22:59.139> our 00:22:59.580 --> 00:22:59.590 align:start position:0% assumptions in order to achieve our 00:22:59.590 --> 00:23:01.950 align:start position:0% assumptions in order to achieve our worst-case<00:23:00.070> guarantees<00:23:00.700> so<00:23:01.480> we<00:23:01.570> are<00:23:01.690> going<00:23:01.809> to 00:23:01.950 --> 00:23:01.960 align:start position:0% worst-case guarantees so we are going to 00:23:01.960 --> 00:23:03.509 align:start position:0% worst-case guarantees so we are going to assume<00:23:02.200> that<00:23:02.409> the<00:23:02.499> majority<00:23:02.619> of<00:23:02.980> the<00:23:03.159> miners 00:23:03.509 --> 00:23:03.519 align:start position:0% assume that the majority of the miners 00:23:03.519 --> 00:23:05.190 align:start position:0% assume that the majority of the miners are<00:23:03.669> honest<00:23:04.029> and<00:23:04.299> if<00:23:04.899> this<00:23:05.049> is<00:23:05.169> a 00:23:05.190 --> 00:23:05.200 align:start position:0% are honest and if this is a 00:23:05.200 --> 00:23:06.810 align:start position:0% are honest and if this is a proof-of-work<00:23:05.619> blockchain<00:23:06.249> we<00:23:06.429> are<00:23:06.519> assuming 00:23:06.810 --> 00:23:06.820 align:start position:0% proof-of-work blockchain we are assuming 00:23:06.820 --> 00:23:08.940 align:start position:0% proof-of-work blockchain we are assuming the<00:23:07.450> majority<00:23:07.899> of<00:23:07.929> the<00:23:08.080> computation<00:23:08.590> power<00:23:08.739> is 00:23:08.940 --> 00:23:08.950 align:start position:0% the majority of the computation power is 00:23:08.950 --> 00:23:11.729 align:start position:0% the majority of the computation power is honest<00:23:09.309> and<00:23:09.869> for<00:23:10.869> the<00:23:10.929> committee<00:23:11.259> we<00:23:11.499> are<00:23:11.590> also 00:23:11.729 --> 00:23:11.739 align:start position:0% honest and for the committee we are also 00:23:11.739 --> 00:23:13.200 align:start position:0% honest and for the committee we are also going<00:23:12.009> to<00:23:12.100> assume<00:23:12.429> that<00:23:12.489> the<00:23:12.789> majority<00:23:12.879> of 00:23:13.200 --> 00:23:13.210 align:start position:0% going to assume that the majority of 00:23:13.210 --> 00:23:15.599 align:start position:0% going to assume that the majority of them<00:23:13.509> are<00:23:13.539> honest<00:23:13.989> but<00:23:14.230> they<00:23:15.220> don't<00:23:15.399> have<00:23:15.489> to 00:23:15.599 --> 00:23:15.609 align:start position:0% them are honest but they don't have to 00:23:15.609 --> 00:23:17.399 align:start position:0% them are honest but they don't have to be<00:23:15.730> online<00:23:15.879> right<00:23:16.090> so<00:23:16.389> if<00:23:16.509> like<00:23:16.779> if<00:23:16.929> the<00:23:17.109> entire 00:23:17.399 --> 00:23:17.409 align:start position:0% be online right so if like if the entire 00:23:17.409 --> 00:23:19.560 align:start position:0% be online right so if like if the entire committee<00:23:17.799> is<00:23:17.950> offline<00:23:18.340> it's<00:23:18.909> not<00:23:19.149> the<00:23:19.299> end<00:23:19.450> of 00:23:19.560 --> 00:23:19.570 align:start position:0% committee is offline it's not the end of 00:23:19.570 --> 00:23:20.970 align:start position:0% committee is offline it's not the end of the<00:23:19.720> world<00:23:19.929> because<00:23:20.289> you<00:23:20.379> can<00:23:20.559> always<00:23:20.739> swap 00:23:20.970 --> 00:23:20.980 align:start position:0% the world because you can always swap 00:23:20.980 --> 00:23:27.899 align:start position:0% the world because you can always swap back<00:23:21.190> to<00:23:21.309> the<00:23:21.429> blockchain<00:23:22.769> okay<00:23:26.429> so<00:23:27.429> I'm<00:23:27.669> going 00:23:27.899 --> 00:23:27.909 align:start position:0% back to the blockchain okay so I'm going 00:23:27.909 --> 00:23:30.690 align:start position:0% back to the blockchain okay so I'm going to<00:23:27.970> take<00:23:28.179> a<00:23:28.210> slight<00:23:28.690> detour<00:23:28.929> to<00:23:29.499> talk<00:23:29.799> about<00:23:30.070> a 00:23:30.690 --> 00:23:30.700 align:start position:0% to take a slight detour to talk about a 00:23:30.700 --> 00:23:34.700 align:start position:0% to take a slight detour to talk about a scheme<00:23:31.659> that<00:23:31.690> others<00:23:32.200> have<00:23:32.379> considered<00:23:33.359> this 00:23:34.700 --> 00:23:34.710 align:start position:0% scheme that others have considered this 00:23:34.710 --> 00:23:37.950 align:start position:0% scheme that others have considered this I<00:23:35.710> like<00:23:36.519> this<00:23:36.730> example<00:23:37.119> because<00:23:37.299> it<00:23:37.659> kind<00:23:37.869> of 00:23:37.950 --> 00:23:37.960 align:start position:0% I like this example because it kind of 00:23:37.960 --> 00:23:39.779 align:start position:0% I like this example because it kind of helps<00:23:38.289> to<00:23:38.350> illustrate<00:23:38.559> what<00:23:39.070> approaches<00:23:39.580> work 00:23:39.779 --> 00:23:39.789 align:start position:0% helps to illustrate what approaches work 00:23:39.789 --> 00:23:41.879 align:start position:0% helps to illustrate what approaches work and<00:23:40.029> what<00:23:40.149> approach<00:23:40.450> is<00:23:40.629> stunt<00:23:40.929> so<00:23:41.619> here's<00:23:41.830> a 00:23:41.879 --> 00:23:41.889 align:start position:0% and what approach is stunt so here's a 00:23:41.889 --> 00:23:43.769 align:start position:0% and what approach is stunt so here's a very<00:23:42.129> simple<00:23:42.549> idea<00:23:42.940> I'm<00:23:43.059> going<00:23:43.359> to<00:23:43.480> run<00:23:43.629> the 00:23:43.769 --> 00:23:43.779 align:start position:0% very simple idea I'm going to run the 00:23:43.779 --> 00:23:47.129 align:start position:0% very simple idea I'm going to run the blockchain<00:23:44.289> and<00:23:45.480> I'm<00:23:46.480> going<00:23:46.779> to<00:23:46.869> have<00:23:47.019> the 00:23:47.129 --> 00:23:47.139 align:start position:0% blockchain and I'm going to have the 00:23:47.139 --> 00:23:50.099 align:start position:0% blockchain and I'm going to have the committee<00:23:47.470> vote<00:23:47.710> on<00:23:47.889> the<00:23:48.009> blocks<00:23:48.539> if<00:23:49.539> I<00:23:49.869> see 00:23:50.099 --> 00:23:50.109 align:start position:0% committee vote on the blocks if I see 00:23:50.109 --> 00:23:52.590 align:start position:0% committee vote on the blocks if I see enough<00:23:50.440> people<00:23:50.649> vote<00:23:51.549> on<00:23:51.789> the<00:23:51.940> same<00:23:52.090> block<00:23:52.330> I'm 00:23:52.590 --> 00:23:52.600 align:start position:0% enough people vote on the same block I'm 00:23:52.600 --> 00:23:55.430 align:start position:0% enough people vote on the same block I'm going<00:23:53.080> to<00:23:53.200> confirm<00:23:53.739> the<00:23:53.889> block<00:23:54.100> immediately 00:23:55.430 --> 00:23:55.440 align:start position:0% going to confirm the block immediately 00:23:55.440 --> 00:23:59.869 align:start position:0% going to confirm the block immediately without<00:23:56.440> waiting<00:23:57.100> for<00:23:57.249> my<00:23:57.609> blocks<00:23:57.940> to<00:23:58.749> grow 00:23:59.869 --> 00:23:59.879 align:start position:0% without waiting for my blocks to grow 00:23:59.879 --> 00:24:02.879 align:start position:0% without waiting for my blocks to grow okay<00:24:00.879> so<00:24:00.940> what<00:24:01.389> do<00:24:01.480> you<00:24:01.539> think<00:24:01.779> about<00:24:01.899> this 00:24:02.879 --> 00:24:02.889 align:start position:0% okay so what do you think about this 00:24:02.889 --> 00:24:05.159 align:start position:0% okay so what do you think about this very<00:24:03.159> simple<00:24:03.519> idea<00:24:03.669> where<00:24:04.539> people<00:24:04.840> vote<00:24:04.989> on 00:24:05.159 --> 00:24:05.169 align:start position:0% very simple idea where people vote on 00:24:05.169 --> 00:24:08.460 align:start position:0% very simple idea where people vote on blocks<00:24:05.440> and<00:24:05.759> you<00:24:06.759> want<00:24:06.940> to<00:24:07.029> confirm<00:24:07.480> as<00:24:07.720> soon 00:24:08.460 --> 00:24:08.470 align:start position:0% blocks and you want to confirm as soon 00:24:08.470 --> 00:24:10.320 align:start position:0% blocks and you want to confirm as soon as<00:24:08.649> you<00:24:08.799> hear<00:24:09.159> enough<00:24:09.489> votes<00:24:09.730> on<00:24:10.029> the<00:24:10.149> same 00:24:10.320 --> 00:24:10.330 align:start position:0% as you hear enough votes on the same 00:24:10.330 --> 00:24:14.159 align:start position:0% as you hear enough votes on the same block<00:24:12.090> okay<00:24:13.090> so<00:24:13.149> it<00:24:13.450> turns<00:24:13.659> out<00:24:13.809> that<00:24:13.869> the 00:24:14.159 --> 00:24:14.169 align:start position:0% block okay so it turns out that the 00:24:14.169 --> 00:24:16.169 align:start position:0% block okay so it turns out that the scheme<00:24:14.409> actually<00:24:15.129> doesn't<00:24:15.909> give<00:24:16.029> you<00:24:16.149> a 00:24:16.169 --> 00:24:16.179 align:start position:0% scheme actually doesn't give you a 00:24:16.179 --> 00:24:19.540 align:start position:0% scheme actually doesn't give you a consistency<00:24:16.840> and<00:24:17.049> here's<00:24:18.009> why<00:24:18.730> right 00:24:19.540 --> 00:24:19.550 align:start position:0% consistency and here's why right 00:24:19.550 --> 00:24:21.040 align:start position:0% consistency and here's why right explain<00:24:19.940> a<00:24:19.970> very<00:24:20.090> simple<00:24:20.630> reason<00:24:20.750> why<00:24:20.990> this 00:24:21.040 --> 00:24:21.050 align:start position:0% explain a very simple reason why this 00:24:21.050 --> 00:24:24.610 align:start position:0% explain a very simple reason why this protocol<00:24:21.590> doesn't<00:24:22.520> work<00:24:22.870> at<00:24:23.870> some<00:24:24.170> point<00:24:24.440> of 00:24:24.610 --> 00:24:24.620 align:start position:0% protocol doesn't work at some point of 00:24:24.620 --> 00:24:28.020 align:start position:0% protocol doesn't work at some point of time<00:24:25.180> maybe<00:24:26.180> people<00:24:26.690> see<00:24:26.870> the<00:24:27.020> farc<00:24:27.260> a<00:24:27.440> and 00:24:28.020 --> 00:24:28.030 align:start position:0% time maybe people see the farc a and 00:24:28.030 --> 00:24:31.780 align:start position:0% time maybe people see the farc a and they<00:24:29.030> all<00:24:29.180> voted<00:24:29.210> for<00:24:29.540> this<00:24:30.320> fork<00:24:30.680> so<00:24:31.610> this 00:24:31.780 --> 00:24:31.790 align:start position:0% they all voted for this fork so this 00:24:31.790 --> 00:24:34.930 align:start position:0% they all voted for this fork so this fork<00:24:32.060> collected<00:24:32.930> enough<00:24:33.200> votes<00:24:33.470> and<00:24:33.940> people 00:24:34.930 --> 00:24:34.940 align:start position:0% fork collected enough votes and people 00:24:34.940 --> 00:24:37.090 align:start position:0% fork collected enough votes and people would<00:24:35.150> have<00:24:35.390> confirmed<00:24:35.810> this<00:24:35.990> fork<00:24:36.350> very 00:24:37.090 --> 00:24:37.100 align:start position:0% would have confirmed this fork very 00:24:37.100 --> 00:24:41.860 align:start position:0% would have confirmed this fork very quickly<00:24:37.990> but<00:24:38.990> because<00:24:40.360> the<00:24:41.360> network<00:24:41.690> has 00:24:41.860 --> 00:24:41.870 align:start position:0% quickly but because the network has 00:24:41.870 --> 00:24:43.540 align:start position:0% quickly but because the network has delay<00:24:42.200> right<00:24:42.380> so<00:24:42.530> even<00:24:42.830> if<00:24:42.950> there<00:24:43.160> is<00:24:43.310> no 00:24:43.540 --> 00:24:43.550 align:start position:0% delay right so even if there is no 00:24:43.550 --> 00:24:45.670 align:start position:0% delay right so even if there is no attack<00:24:43.880> just<00:24:44.450> because<00:24:44.810> the<00:24:45.260> network<00:24:45.530> has 00:24:45.670 --> 00:24:45.680 align:start position:0% attack just because the network has 00:24:45.680 --> 00:24:48.700 align:start position:0% attack just because the network has delay<00:24:46.010> the<00:24:46.790> blockchain<00:24:47.090> can<00:24:47.360> have<00:24:47.660> Forks<00:24:48.020> like 00:24:48.700 --> 00:24:48.710 align:start position:0% delay the blockchain can have Forks like 00:24:48.710 --> 00:24:51.040 align:start position:0% delay the blockchain can have Forks like in<00:24:48.860> an<00:24:48.980> organic<00:24:49.250> fashion<00:24:49.670> so<00:24:50.660> it<00:24:50.810> could<00:24:51.020> be 00:24:51.040 --> 00:24:51.050 align:start position:0% in an organic fashion so it could be 00:24:51.050 --> 00:24:53.280 align:start position:0% in an organic fashion so it could be possible<00:24:51.650> that<00:24:51.710> at<00:24:52.070> the<00:24:52.310> end<00:24:52.490> of<00:24:52.670> time<00:24:52.940> the 00:24:53.280 --> 00:24:53.290 align:start position:0% possible that at the end of time the 00:24:53.290 --> 00:24:54.430 align:start position:0% possible that at the end of time the fork 00:24:54.430 --> 00:24:54.440 align:start position:0% fork 00:24:54.440 --> 00:24:57.040 align:start position:0% fork a<00:24:54.470> didn't<00:24:54.860> survive<00:24:55.190> it<00:24:56.060> is<00:24:56.240> fork<00:24:56.540> B<00:24:56.780> that 00:24:57.040 --> 00:24:57.050 align:start position:0% a didn't survive it is fork B that 00:24:57.050 --> 00:25:00.400 align:start position:0% a didn't survive it is fork B that survived<00:24:57.440> to<00:24:57.620> the<00:24:57.740> end<00:24:58.780> so<00:24:59.780> this<00:24:59.990> would<00:25:00.200> be 00:25:00.400 --> 00:25:00.410 align:start position:0% survived to the end so this would be 00:25:00.410 --> 00:25:03.090 align:start position:0% survived to the end so this would be problematic<00:25:01.010> because<00:25:01.430> earlier<00:25:01.970> if<00:25:02.180> you<00:25:02.300> had 00:25:03.090 --> 00:25:03.100 align:start position:0% problematic because earlier if you had 00:25:03.100 --> 00:25:06.970 align:start position:0% problematic because earlier if you had confirmed<00:25:04.100> the<00:25:05.090> fork<00:25:05.390> a<00:25:05.540> then<00:25:06.380> you<00:25:06.560> would<00:25:06.770> have 00:25:06.970 --> 00:25:06.980 align:start position:0% confirmed the fork a then you would have 00:25:06.980 --> 00:25:10.420 align:start position:0% confirmed the fork a then you would have risked<00:25:07.840> inconsistency<00:25:08.840> with<00:25:09.620> with<00:25:10.040> everyone 00:25:10.420 --> 00:25:10.430 align:start position:0% risked inconsistency with with everyone 00:25:10.430 --> 00:25:14.950 align:start position:0% risked inconsistency with with everyone else<00:25:10.670> at<00:25:10.910> the<00:25:10.940> end<00:25:11.150> of<00:25:11.270> the<00:25:11.420> time<00:25:13.540> okay 00:25:14.950 --> 00:25:14.960 align:start position:0% else at the end of the time okay 00:25:14.960 --> 00:25:24.730 align:start position:0% else at the end of the time okay is<00:25:15.890> this<00:25:16.040> clear<00:25:18.430> okay<00:25:19.430> so<00:25:19.490> yes<00:25:23.020> so<00:25:24.020> so<00:25:24.260> if<00:25:24.560> we 00:25:24.730 --> 00:25:24.740 align:start position:0% is this clear okay so yes so so if we 00:25:24.740 --> 00:25:26.740 align:start position:0% is this clear okay so yes so so if we are<00:25:24.860> going<00:25:24.980> to<00:25:25.130> assume<00:25:25.370> honest<00:25:26.150> majority<00:25:26.630> for 00:25:26.740 --> 00:25:26.750 align:start position:0% are going to assume honest majority for 00:25:26.750 --> 00:25:27.910 align:start position:0% are going to assume honest majority for the<00:25:26.840> committee<00:25:27.140> you<00:25:27.260> have<00:25:27.410> to<00:25:27.530> wait<00:25:27.680> for 00:25:27.910 --> 00:25:27.920 align:start position:0% the committee you have to wait for 00:25:27.920 --> 00:25:38.800 align:start position:0% the committee you have to wait for three-quarters<00:25:28.880> of<00:25:29.150> the<00:25:29.360> people<00:25:29.480> to<00:25:29.750> vote<00:25:37.810> has 00:25:38.800 --> 00:25:38.810 align:start position:0% three-quarters of the people to vote has 00:25:38.810 --> 00:25:40.870 align:start position:0% three-quarters of the people to vote has a<00:25:38.840> way<00:25:39.080> of<00:25:39.110> this<00:25:40.040> this<00:25:40.310> is<00:25:40.460> like<00:25:40.610> something 00:25:40.870 --> 00:25:40.880 align:start position:0% a way of this this is like something 00:25:40.880 --> 00:25:43.000 align:start position:0% a way of this this is like something that<00:25:41.030> I<00:25:41.180> said<00:25:41.330> is<00:25:41.960> outside<00:25:42.470> the<00:25:42.590> scope<00:25:42.680> for 00:25:43.000 --> 00:25:43.010 align:start position:0% that I said is outside the scope for 00:25:43.010 --> 00:25:44.380 align:start position:0% that I said is outside the scope for instance<00:25:43.250> a<00:25:43.310> theorem<00:25:43.580> has<00:25:43.730> a<00:25:43.790> mechanism<00:25:44.240> to 00:25:44.380 --> 00:25:44.390 align:start position:0% instance a theorem has a mechanism to 00:25:44.390 --> 00:25:47.890 align:start position:0% instance a theorem has a mechanism to alack<00:25:45.380> a<00:25:45.410> collector<00:25:46.280> Kemetic<00:25:46.670> and<00:25:47.060> maybe 00:25:47.890 --> 00:25:47.900 align:start position:0% alack a collector Kemetic and maybe 00:25:47.900 --> 00:25:49.750 align:start position:0% alack a collector Kemetic and maybe consisting<00:25:48.380> of<00:25:48.470> two<00:25:48.710> thousand<00:25:49.100> voters<00:25:49.370> or 00:25:49.750 --> 00:25:49.760 align:start position:0% consisting of two thousand voters or 00:25:49.760 --> 00:25:51.790 align:start position:0% consisting of two thousand voters or validators<00:25:50.390> maybe<00:25:50.780> 1,000<00:25:51.260> to<00:25:51.320> 2,000 00:25:51.790 --> 00:25:51.800 align:start position:0% validators maybe 1,000 to 2,000 00:25:51.800 --> 00:25:53.410 align:start position:0% validators maybe 1,000 to 2,000 validators<00:25:52.280> so<00:25:52.610> you'll<00:25:52.760> know<00:25:52.880> exactly<00:25:52.910> who 00:25:53.410 --> 00:25:53.420 align:start position:0% validators so you'll know exactly who 00:25:53.420 --> 00:25:59.630 align:start position:0% validators so you'll know exactly who the<00:25:53.510> committee<00:25:53.810> are 00:25:59.630 --> 00:25:59.640 align:start position:0% 00:25:59.640 --> 00:26:02.850 align:start position:0% black<00:26:00.640> black<00:26:00.970> Jean<00:26:01.000> Prodicus<00:26:01.630> can<00:26:01.840> not<00:26:01.990> on<00:26:02.170> our 00:26:02.850 --> 00:26:02.860 align:start position:0% black black Jean Prodicus can not on our 00:26:02.860 --> 00:26:04.860 align:start position:0% black black Jean Prodicus can not on our petition<00:26:03.160> tolerance<00:26:03.760> so<00:26:04.180> this<00:26:04.450> is<00:26:04.570> the<00:26:04.660> point 00:26:04.860 --> 00:26:04.870 align:start position:0% petition tolerance so this is the point 00:26:04.870 --> 00:26:06.420 align:start position:0% petition tolerance so this is the point I<00:26:05.020> will<00:26:05.170> mention<00:26:05.560> at<00:26:05.800> the<00:26:05.890> end<00:26:06.040> of<00:26:06.130> the<00:26:06.250> talk 00:26:06.420 --> 00:26:06.430 align:start position:0% I will mention at the end of the talk 00:26:06.430 --> 00:26:12.030 align:start position:0% I will mention at the end of the talk okay<00:26:09.390> okay<00:26:10.390> alright<00:26:10.540> so<00:26:10.900> the<00:26:11.590> point<00:26:11.830> is<00:26:11.980> that 00:26:12.030 --> 00:26:12.040 align:start position:0% okay okay alright so the point is that 00:26:12.040 --> 00:26:14.670 align:start position:0% okay okay alright so the point is that even<00:26:13.000> if<00:26:13.150> we<00:26:13.330> can<00:26:13.570> fix<00:26:13.840> the<00:26:14.050> consistency 00:26:14.670 --> 00:26:14.680 align:start position:0% even if we can fix the consistency 00:26:14.680 --> 00:26:17.100 align:start position:0% even if we can fix the consistency problem<00:26:15.100> this<00:26:15.670> is<00:26:15.730> not<00:26:15.940> the<00:26:16.360> kind<00:26:16.570> of<00:26:16.660> protocol 00:26:17.100 --> 00:26:17.110 align:start position:0% problem this is not the kind of protocol 00:26:17.110 --> 00:26:18.810 align:start position:0% problem this is not the kind of protocol that<00:26:17.230> we<00:26:17.380> want<00:26:17.620> because<00:26:18.160> you<00:26:18.310> don't<00:26:18.580> really 00:26:18.810 --> 00:26:18.820 align:start position:0% that we want because you don't really 00:26:18.820 --> 00:26:20.250 align:start position:0% that we want because you don't really want<00:26:19.090> to<00:26:19.180> be<00:26:19.300> voting<00:26:19.600> on<00:26:19.690> the<00:26:19.840> blocks 00:26:20.250 --> 00:26:20.260 align:start position:0% want to be voting on the blocks 00:26:20.260 --> 00:26:22.560 align:start position:0% want to be voting on the blocks if<00:26:20.680> you<00:26:20.860> are<00:26:20.950> voting<00:26:21.280> on<00:26:21.370> the<00:26:21.520> blocks<00:26:21.760> you<00:26:22.450> are 00:26:22.560 --> 00:26:22.570 align:start position:0% if you are voting on the blocks you are 00:26:22.570 --> 00:26:24.540 align:start position:0% if you are voting on the blocks you are slow<00:26:22.930> to<00:26:22.960> start<00:26:23.560> with<00:26:23.800> because<00:26:24.040> you're 00:26:24.540 --> 00:26:24.550 align:start position:0% slow to start with because you're 00:26:24.550 --> 00:26:27.150 align:start position:0% slow to start with because you're subject<00:26:25.150> to<00:26:25.240> this<00:26:25.360> one<00:26:25.570> block<00:26:25.810> interval<00:26:26.290> right 00:26:27.150 --> 00:26:27.160 align:start position:0% subject to this one block interval right 00:26:27.160 --> 00:26:31.290 align:start position:0% subject to this one block interval right like<00:26:27.610> I<00:26:27.730> said<00:26:27.970> we<00:26:28.570> want<00:26:28.840> to<00:26:28.990> confirm<00:26:29.790> in<00:26:30.790> two<00:26:31.120> to 00:26:31.290 --> 00:26:31.300 align:start position:0% like I said we want to confirm in two to 00:26:31.300 --> 00:26:34.170 align:start position:0% like I said we want to confirm in two to three<00:26:31.330> actual<00:26:32.230> round<00:26:32.620> trips<00:26:32.980> we<00:26:33.700> don't<00:26:33.940> even 00:26:34.170 --> 00:26:34.180 align:start position:0% three actual round trips we don't even 00:26:34.180 --> 00:26:36.740 align:start position:0% three actual round trips we don't even want<00:26:34.480> to<00:26:34.600> wait<00:26:34.750> for<00:26:35.200> a<00:26:35.230> single<00:26:35.740> block<00:26:35.950> interval 00:26:36.740 --> 00:26:36.750 align:start position:0% want to wait for a single block interval 00:26:36.750 --> 00:26:42.240 align:start position:0% want to wait for a single block interval okay<00:26:39.180> so<00:26:40.180> that's<00:26:40.390> our<00:26:40.570> goal<00:26:40.690> and<00:26:41.200> actually<00:26:42.130> in 00:26:42.240 --> 00:26:42.250 align:start position:0% okay so that's our goal and actually in 00:26:42.250 --> 00:26:44.790 align:start position:0% okay so that's our goal and actually in our<00:26:42.430> paper<00:26:42.670> we<00:26:42.880> call<00:26:43.060> this<00:26:43.210> and<00:26:43.800> technically 00:26:44.790 --> 00:26:44.800 align:start position:0% our paper we call this and technically 00:26:44.800 --> 00:26:46.020 align:start position:0% our paper we call this and technically we<00:26:44.920> refer<00:26:45.220> to<00:26:45.250> this<00:26:45.490> property<00:26:45.790> as 00:26:46.020 --> 00:26:46.030 align:start position:0% we refer to this property as 00:26:46.030 --> 00:26:47.700 align:start position:0% we refer to this property as responsiveness<00:26:46.660> you<00:26:47.020> don't<00:26:47.230> want<00:26:47.380> to<00:26:47.500> wait 00:26:47.700 --> 00:26:47.710 align:start position:0% responsiveness you don't want to wait 00:26:47.710 --> 00:26:51.060 align:start position:0% responsiveness you don't want to wait for<00:26:47.920> any<00:26:48.070> a<00:26:48.370> priori<00:26:49.030> set<00:26:50.070> synchronization 00:26:51.060 --> 00:26:51.070 align:start position:0% for any a priori set synchronization 00:26:51.070 --> 00:26:55.260 align:start position:0% for any a priori set synchronization delay<00:26:51.600> okay<00:26:52.650> so<00:26:53.650> now<00:26:53.770> let's<00:26:54.280> step<00:26:54.790> back<00:26:54.850> on<00:26:55.150> the 00:26:55.260 --> 00:26:55.270 align:start position:0% delay okay so now let's step back on the 00:26:55.270 --> 00:26:57.500 align:start position:0% delay okay so now let's step back on the right<00:26:55.420> track 00:26:57.500 --> 00:26:57.510 align:start position:0% right track 00:26:57.510 --> 00:27:02.160 align:start position:0% right track okay<00:26:58.510> so<00:26:59.230> this<00:26:59.410> was<00:26:59.680> like<00:26:59.920> the<00:27:00.270> kind<00:27:01.270> of<00:27:01.450> scheme 00:27:02.160 --> 00:27:02.170 align:start position:0% okay so this was like the kind of scheme 00:27:02.170 --> 00:27:03.780 align:start position:0% okay so this was like the kind of scheme I<00:27:02.320> talked<00:27:02.590> about<00:27:02.680> earlier<00:27:02.860> right<00:27:03.430> so<00:27:03.610> I'm 00:27:03.780 --> 00:27:03.790 align:start position:0% I talked about earlier right so I'm 00:27:03.790 --> 00:27:05.580 align:start position:0% I talked about earlier right so I'm going<00:27:04.030> to<00:27:04.120> quickly<00:27:04.300> recap<00:27:04.780> the<00:27:04.930> scheme<00:27:05.140> but 00:27:05.580 --> 00:27:05.590 align:start position:0% going to quickly recap the scheme but 00:27:05.590 --> 00:27:07.950 align:start position:0% going to quickly recap the scheme but now<00:27:05.800> I'm<00:27:06.250> going<00:27:06.760> to<00:27:06.910> keep<00:27:07.120> in<00:27:07.270> mind<00:27:07.510> that<00:27:07.750> there 00:27:07.950 --> 00:27:07.960 align:start position:0% now I'm going to keep in mind that there 00:27:07.960 --> 00:27:10.110 align:start position:0% now I'm going to keep in mind that there are<00:27:07.990> many<00:27:08.110> instances<00:27:08.860> of<00:27:09.040> this<00:27:09.220> little<00:27:09.820> voting 00:27:10.110 --> 00:27:10.120 align:start position:0% are many instances of this little voting 00:27:10.120 --> 00:27:12.390 align:start position:0% are many instances of this little voting protocol<00:27:10.570> so<00:27:11.110> vitalik<00:27:11.590> makes<00:27:11.830> the<00:27:11.950> proposal 00:27:12.390 --> 00:27:12.400 align:start position:0% protocol so vitalik makes the proposal 00:27:12.400 --> 00:27:14.880 align:start position:0% protocol so vitalik makes the proposal everyone<00:27:12.790> votes<00:27:13.030> and<00:27:13.360> we<00:27:14.260> are<00:27:14.350> going<00:27:14.500> to<00:27:14.620> wait 00:27:14.880 --> 00:27:14.890 align:start position:0% everyone votes and we are going to wait 00:27:14.890 --> 00:27:17.760 align:start position:0% everyone votes and we are going to wait to<00:27:15.370> hear<00:27:15.820> three<00:27:16.750> quarters<00:27:17.140> of<00:27:17.170> the<00:27:17.410> committee 00:27:17.760 --> 00:27:17.770 align:start position:0% to hear three quarters of the committee 00:27:17.770 --> 00:27:19.500 align:start position:0% to hear three quarters of the committee to<00:27:17.800> vote<00:27:17.950> that's<00:27:18.850> because<00:27:19.090> we<00:27:19.240> are<00:27:19.270> assuming 00:27:19.500 --> 00:27:19.510 align:start position:0% to vote that's because we are assuming 00:27:19.510 --> 00:27:21.720 align:start position:0% to vote that's because we are assuming honest<00:27:19.960> majority<00:27:20.380> of<00:27:20.470> the<00:27:20.590> committee<00:27:20.830> right 00:27:21.720 --> 00:27:21.730 align:start position:0% honest majority of the committee right 00:27:21.730 --> 00:27:23.370 align:start position:0% honest majority of the committee right earlier<00:27:22.210> we<00:27:22.360> used<00:27:22.390> like<00:27:22.750> slightly<00:27:22.990> different 00:27:23.370 --> 00:27:23.380 align:start position:0% earlier we used like slightly different 00:27:23.380 --> 00:27:27.270 align:start position:0% earlier we used like slightly different parameters<00:27:23.880> okay<00:27:24.880> so<00:27:25.180> here<00:27:25.830> every<00:27:26.830> batch<00:27:27.040> of 00:27:27.270 --> 00:27:27.280 align:start position:0% parameters okay so here every batch of 00:27:27.280 --> 00:27:30.720 align:start position:0% parameters okay so here every batch of transactions<00:27:27.880> that<00:27:28.560> has<00:27:29.560> an<00:27:29.860> a<00:27:30.280> sequence 00:27:30.720 --> 00:27:30.730 align:start position:0% transactions that has an a sequence 00:27:30.730 --> 00:27:32.190 align:start position:0% transactions that has an a sequence number<00:27:30.790> so<00:27:31.330> this<00:27:31.540> means<00:27:31.780> that<00:27:31.900> this 00:27:32.190 --> 00:27:32.200 align:start position:0% number so this means that this 00:27:32.200 --> 00:27:34.560 align:start position:0% number so this means that this transaction<00:27:32.620> has<00:27:33.490> collected<00:27:33.850> enough<00:27:34.120> votes 00:27:34.560 --> 00:27:34.570 align:start position:0% transaction has collected enough votes 00:27:34.570 --> 00:27:38.280 align:start position:0% transaction has collected enough votes and<00:27:35.460> I'm<00:27:36.460> going<00:27:36.730> to<00:27:36.790> call<00:27:37.030> this<00:27:37.210> as<00:27:37.390> card<00:27:38.170> s 00:27:38.280 --> 00:27:38.290 align:start position:0% and I'm going to call this as card s 00:27:38.290 --> 00:27:42.180 align:start position:0% and I'm going to call this as card s notarized<00:27:39.330> so<00:27:40.330> here<00:27:40.660> one<00:27:41.230> two<00:27:41.470> three<00:27:41.740> five<00:27:42.130> six 00:27:42.180 --> 00:27:42.190 align:start position:0% notarized so here one two three five six 00:27:42.190 --> 00:27:44.690 align:start position:0% notarized so here one two three five six and<00:27:42.610> otherwise<00:27:42.910> but<00:27:43.180> four<00:27:43.570> is<00:27:43.750> missing<00:27:44.170> and 00:27:44.690 --> 00:27:44.700 align:start position:0% and otherwise but four is missing and 00:27:44.700 --> 00:27:46.710 align:start position:0% and otherwise but four is missing and because<00:27:45.700> we<00:27:45.880> have<00:27:46.000> to<00:27:46.150> process<00:27:46.570> these 00:27:46.710 --> 00:27:46.720 align:start position:0% because we have to process these 00:27:46.720 --> 00:27:50.510 align:start position:0% because we have to process these transactions<00:27:47.760> in<00:27:48.760> the<00:27:49.000> linear<00:27:49.330> fashion<00:27:49.390> right 00:27:50.510 --> 00:27:50.520 align:start position:0% transactions in the linear fashion right 00:27:50.520 --> 00:27:53.280 align:start position:0% transactions in the linear fashion right in<00:27:51.520> this<00:27:51.700> case<00:27:51.880> I<00:27:52.060> can<00:27:52.240> only<00:27:52.450> process<00:27:52.930> the 00:27:53.280 --> 00:27:53.290 align:start position:0% in this case I can only process the 00:27:53.290 --> 00:27:57.060 align:start position:0% in this case I can only process the first<00:27:53.530> three<00:27:53.860> transactions<00:27:55.800> and<00:27:56.800> for<00:27:57.010> the 00:27:57.060 --> 00:27:57.070 align:start position:0% first three transactions and for the 00:27:57.070 --> 00:27:58.980 align:start position:0% first three transactions and for the lack<00:27:57.220> of<00:27:57.400> a<00:27:57.460> better<00:27:57.610> term<00:27:57.760> I'm<00:27:58.180> going<00:27:58.540> to<00:27:58.690> call 00:27:58.980 --> 00:27:58.990 align:start position:0% lack of a better term I'm going to call 00:27:58.990 --> 00:28:05.730 align:start position:0% lack of a better term I'm going to call this<00:27:59.230> the<00:27:59.500> maximum<00:28:00.100> lucky<00:28:00.550> sequence<00:28:01.980> okay<00:28:04.740> so 00:28:05.730 --> 00:28:05.740 align:start position:0% this the maximum lucky sequence okay so 00:28:05.740 --> 00:28:08.130 align:start position:0% this the maximum lucky sequence okay so I'm<00:28:05.890> always<00:28:06.100> going<00:28:06.370> to<00:28:06.490> confirm<00:28:07.000> the<00:28:07.930> the 00:28:08.130 --> 00:28:08.140 align:start position:0% I'm always going to confirm the the 00:28:08.140 --> 00:28:11.570 align:start position:0% I'm always going to confirm the the maximum<00:28:08.500> lucky<00:28:08.950> sequence 00:28:11.570 --> 00:28:11.580 align:start position:0% 00:28:11.580 --> 00:28:14.220 align:start position:0% okay<00:28:12.580> so<00:28:12.640> again<00:28:13.090> the<00:28:13.419> problem<00:28:13.779> I'm<00:28:13.899> trying<00:28:14.080> to 00:28:14.220 --> 00:28:14.230 align:start position:0% okay so again the problem I'm trying to 00:28:14.230 --> 00:28:15.840 align:start position:0% okay so again the problem I'm trying to solve<00:28:14.470> here<00:28:14.710> is<00:28:14.769> how<00:28:15.250> do<00:28:15.309> we<00:28:15.429> get<00:28:15.610> liveness 00:28:15.840 --> 00:28:15.850 align:start position:0% solve here is how do we get liveness 00:28:15.850 --> 00:28:17.909 align:start position:0% solve here is how do we get liveness when<00:28:16.210> the<00:28:16.330> leaders<00:28:16.600> corrupt<00:28:16.960> or<00:28:17.260> let's<00:28:17.769> say 00:28:17.909 --> 00:28:17.919 align:start position:0% when the leaders corrupt or let's say 00:28:17.919 --> 00:28:21.899 align:start position:0% when the leaders corrupt or let's say when<00:28:18.100> the<00:28:18.220> committee<00:28:18.519> is<00:28:18.730> not<00:28:18.909> online<00:28:20.909> okay 00:28:21.899 --> 00:28:21.909 align:start position:0% when the committee is not online okay 00:28:21.909 --> 00:28:23.399 align:start position:0% when the committee is not online okay and<00:28:21.940> that's<00:28:22.330> where<00:28:22.570> we<00:28:22.720> want<00:28:22.960> to<00:28:23.019> make<00:28:23.169> use<00:28:23.380> of 00:28:23.399 --> 00:28:23.409 align:start position:0% and that's where we want to make use of 00:28:23.409 --> 00:28:25.110 align:start position:0% and that's where we want to make use of the<00:28:23.710> blockchain<00:28:23.919> right<00:28:24.340> so<00:28:24.490> we<00:28:24.580> haven't<00:28:24.730> used 00:28:25.110 --> 00:28:25.120 align:start position:0% the blockchain right so we haven't used 00:28:25.120 --> 00:28:27.840 align:start position:0% the blockchain right so we haven't used the<00:28:25.240> blockchain<00:28:25.480> yet<00:28:26.309> we<00:28:27.309> are<00:28:27.399> going<00:28:27.580> to<00:28:27.669> use 00:28:27.840 --> 00:28:27.850 align:start position:0% the blockchain yet we are going to use 00:28:27.850 --> 00:28:29.669 align:start position:0% the blockchain yet we are going to use the<00:28:28.029> blockchain<00:28:28.269> for<00:28:28.750> two<00:28:28.960> purposes 00:28:29.669 --> 00:28:29.679 align:start position:0% the blockchain for two purposes 00:28:29.679 --> 00:28:33.000 align:start position:0% the blockchain for two purposes first<00:28:30.490> to<00:28:31.179> collect<00:28:31.539> evidence<00:28:31.840> to<00:28:32.470> detect<00:28:32.799> when 00:28:33.000 --> 00:28:33.010 align:start position:0% first to collect evidence to detect when 00:28:33.010 --> 00:28:35.039 align:start position:0% first to collect evidence to detect when something<00:28:33.399> is<00:28:33.519> going<00:28:33.700> on<00:28:33.909> so<00:28:34.539> the<00:28:34.659> blockchain 00:28:35.039 --> 00:28:35.049 align:start position:0% something is going on so the blockchain 00:28:35.049 --> 00:28:37.320 align:start position:0% something is going on so the blockchain can<00:28:35.080> tell<00:28:35.440> us<00:28:35.649> okay<00:28:35.919> now<00:28:36.070> the<00:28:36.130> fast<00:28:36.460> path<00:28:36.730> has 00:28:37.320 --> 00:28:37.330 align:start position:0% can tell us okay now the fast path has 00:28:37.330 --> 00:28:38.880 align:start position:0% can tell us okay now the fast path has failed<00:28:37.659> and<00:28:37.990> you<00:28:38.110> should<00:28:38.320> fall<00:28:38.529> back<00:28:38.710> to<00:28:38.860> the 00:28:38.880 --> 00:28:38.890 align:start position:0% failed and you should fall back to the 00:28:38.890 --> 00:28:43.440 align:start position:0% failed and you should fall back to the blockchain<00:28:39.450> and<00:28:40.450> once<00:28:40.690> we<00:28:40.870> detect<00:28:42.149> we<00:28:43.149> make 00:28:43.440 --> 00:28:43.450 align:start position:0% blockchain and once we detect we make 00:28:43.450 --> 00:28:46.350 align:start position:0% blockchain and once we detect we make such<00:28:43.690> a<00:28:43.720> detection<00:28:44.370> we'll<00:28:45.370> make<00:28:45.820> use<00:28:46.059> of<00:28:46.210> the 00:28:46.350 --> 00:28:46.360 align:start position:0% such a detection we'll make use of the 00:28:46.360 --> 00:28:49.680 align:start position:0% such a detection we'll make use of the blockchain<00:28:46.600> to<00:28:47.220> enter<00:28:48.220> the<00:28:48.340> slow<00:28:48.580> mode<00:28:48.820> and<00:28:49.120> of 00:28:49.680 --> 00:28:49.690 align:start position:0% blockchain to enter the slow mode and of 00:28:49.690 --> 00:28:51.000 align:start position:0% blockchain to enter the slow mode and of course<00:28:49.929> you<00:28:50.019> don't<00:28:50.230> want<00:28:50.260> to<00:28:50.409> be<00:28:50.529> stuck<00:28:50.740> in<00:28:50.799> the 00:28:51.000 --> 00:28:51.010 align:start position:0% course you don't want to be stuck in the 00:28:51.010 --> 00:28:52.590 align:start position:0% course you don't want to be stuck in the slow<00:28:51.220> mode<00:28:51.429> forever<00:28:51.789> right<00:28:52.120> once<00:28:52.360> you<00:28:52.450> are 00:28:52.590 --> 00:28:52.600 align:start position:0% slow mode forever right once you are 00:28:52.600 --> 00:28:54.360 align:start position:0% slow mode forever right once you are backing<00:28:52.840> the<00:28:53.080> blockchain<00:28:53.320> mode<00:28:53.710> you<00:28:54.190> can 00:28:54.360 --> 00:28:54.370 align:start position:0% backing the blockchain mode you can 00:28:54.370 --> 00:28:56.190 align:start position:0% backing the blockchain mode you can always<00:28:54.549> use<00:28:54.820> the<00:28:54.970> smart<00:28:55.210> contract<00:28:55.389> to<00:28:55.750> reelect 00:28:56.190 --> 00:28:56.200 align:start position:0% always use the smart contract to reelect 00:28:56.200 --> 00:28:58.769 align:start position:0% always use the smart contract to reelect a<00:28:56.350> new<00:28:56.500> leader<00:28:56.740> and<00:28:57.010> new<00:28:57.610> committee<00:28:57.970> and<00:28:58.269> then 00:28:58.769 --> 00:28:58.779 align:start position:0% a new leader and new committee and then 00:28:58.779 --> 00:29:01.940 align:start position:0% a new leader and new committee and then you<00:28:58.899> can<00:28:59.110> try<00:28:59.260> to<00:28:59.289> reboot<00:28:59.769> strap<00:29:00.070> a<00:29:00.370> fast<00:29:00.760> path 00:29:01.940 --> 00:29:01.950 align:start position:0% you can try to reboot strap a fast path 00:29:01.950 --> 00:29:04.320 align:start position:0% you can try to reboot strap a fast path okay<00:29:02.950> so<00:29:03.010> number<00:29:03.399> one<00:29:03.700> and<00:29:03.850> two<00:29:03.909> and<00:29:04.179> I'm<00:29:04.299> going 00:29:04.320 --> 00:29:04.330 align:start position:0% okay so number one and two and I'm going 00:29:04.330 --> 00:29:06.930 align:start position:0% okay so number one and two and I'm going to<00:29:04.539> talk<00:29:04.720> about<00:29:04.840> how<00:29:05.019> to<00:29:05.080> achieve<00:29:05.230> and<00:29:05.760> one<00:29:06.760> and 00:29:06.930 --> 00:29:06.940 align:start position:0% to talk about how to achieve and one and 00:29:06.940 --> 00:29:10.830 align:start position:0% to talk about how to achieve and one and two<00:29:06.970> respectively<00:29:08.760> first<00:29:09.760> how<00:29:10.480> can<00:29:10.510> we 00:29:10.830 --> 00:29:10.840 align:start position:0% two respectively first how can we 00:29:10.840 --> 00:29:13.860 align:start position:0% two respectively first how can we collect<00:29:11.139> evidence<00:29:12.299> so<00:29:13.299> the<00:29:13.450> detection 00:29:13.860 --> 00:29:13.870 align:start position:0% collect evidence so the detection 00:29:13.870 --> 00:29:17.370 align:start position:0% collect evidence so the detection mechanism<00:29:14.679> needs<00:29:14.889> to<00:29:15.070> be<00:29:15.190> robust<00:29:16.380> in 00:29:17.370 --> 00:29:17.380 align:start position:0% mechanism needs to be robust in 00:29:17.380 --> 00:29:20.419 align:start position:0% mechanism needs to be robust in particular<00:29:18.039> we<00:29:18.700> want<00:29:18.970> that<00:29:19.299> the<00:29:19.539> faulty<00:29:20.080> nodes 00:29:20.419 --> 00:29:20.429 align:start position:0% particular we want that the faulty nodes 00:29:20.429 --> 00:29:23.279 align:start position:0% particular we want that the faulty nodes cannot<00:29:21.429> falsely<00:29:21.850> accuse<00:29:22.480> metallic<00:29:23.049> right 00:29:23.279 --> 00:29:23.289 align:start position:0% cannot falsely accuse metallic right 00:29:23.289 --> 00:29:25.110 align:start position:0% cannot falsely accuse metallic right Vitalik<00:29:23.830> is<00:29:23.919> honest<00:29:24.279> we<00:29:24.429> don't<00:29:24.580> want<00:29:24.789> him<00:29:24.940> to 00:29:25.110 --> 00:29:25.120 align:start position:0% Vitalik is honest we don't want him to 00:29:25.120 --> 00:29:28.860 align:start position:0% Vitalik is honest we don't want him to be<00:29:26.010> falsely<00:29:27.010> accused<00:29:27.240> as<00:29:28.240> well<00:29:28.480> as<00:29:28.690> the 00:29:28.860 --> 00:29:28.870 align:start position:0% be falsely accused as well as the 00:29:28.870 --> 00:29:34.169 align:start position:0% be falsely accused as well as the current<00:29:29.289> committee<00:29:30.120> okay<00:29:32.490> so<00:29:33.490> I<00:29:33.519> know<00:29:33.700> today 00:29:34.169 --> 00:29:34.179 align:start position:0% current committee okay so I know today 00:29:34.179 --> 00:29:35.279 align:start position:0% current committee okay so I know today you<00:29:34.240> know<00:29:34.539> when<00:29:34.659> we<00:29:34.750> think<00:29:34.960> about<00:29:35.049> the 00:29:35.279 --> 00:29:35.289 align:start position:0% you know when we think about the 00:29:35.289 --> 00:29:37.110 align:start position:0% you know when we think about the blockchain<00:29:35.500> we<00:29:36.340> tend<00:29:36.580> to<00:29:36.639> think<00:29:36.850> that<00:29:37.000> the 00:29:37.110 --> 00:29:37.120 align:start position:0% blockchain we tend to think that the 00:29:37.120 --> 00:29:40.649 align:start position:0% blockchain we tend to think that the blockchain<00:29:37.330> collects<00:29:37.899> transactions<00:29:39.539> for<00:29:40.539> the 00:29:40.649 --> 00:29:40.659 align:start position:0% blockchain collects transactions for the 00:29:40.659 --> 00:29:41.940 align:start position:0% blockchain collects transactions for the purpose<00:29:40.899> of<00:29:41.019> this<00:29:41.139> talk<00:29:41.350> I'm<00:29:41.500> going<00:29:41.529> to<00:29:41.769> ask 00:29:41.940 --> 00:29:41.950 align:start position:0% purpose of this talk I'm going to ask 00:29:41.950 --> 00:29:43.409 align:start position:0% purpose of this talk I'm going to ask ask<00:29:42.340> you<00:29:42.549> to<00:29:42.700> think<00:29:42.909> of<00:29:43.059> the<00:29:43.210> blockchain 00:29:43.409 --> 00:29:43.419 align:start position:0% ask you to think of the blockchain 00:29:43.419 --> 00:29:45.120 align:start position:0% ask you to think of the blockchain slightly<00:29:44.080> differently<00:29:44.500> right<00:29:44.889> so<00:29:45.010> when 00:29:45.120 --> 00:29:45.130 align:start position:0% slightly differently right so when 00:29:45.130 --> 00:29:49.289 align:start position:0% slightly differently right so when miners<00:29:45.399> mined<00:29:46.389> the<00:29:46.510> block<00:29:47.850> when<00:29:48.850> I<00:29:48.880> mined<00:29:49.210> the 00:29:49.289 --> 00:29:49.299 align:start position:0% miners mined the block when I mined the 00:29:49.299 --> 00:29:51.750 align:start position:0% miners mined the block when I mined the block<00:29:49.510> I'm<00:29:49.750> going<00:29:50.019> to<00:29:50.279> put<00:29:51.279> in<00:29:51.429> the<00:29:51.549> block 00:29:51.750 --> 00:29:51.760 align:start position:0% block I'm going to put in the block 00:29:51.760 --> 00:29:54.419 align:start position:0% block I'm going to put in the block everything<00:29:52.750> I've<00:29:53.139> observed<00:29:53.679> in<00:29:53.950> the<00:29:54.039> protocol 00:29:54.419 --> 00:29:54.429 align:start position:0% everything I've observed in the protocol 00:29:54.429 --> 00:29:57.360 align:start position:0% everything I've observed in the protocol so<00:29:54.580> far<00:29:54.820> so<00:29:55.480> this<00:29:55.600> is<00:29:55.750> a<00:29:55.779> conceptual<00:29:56.309> way<00:29:57.309> to 00:29:57.360 --> 00:29:57.370 align:start position:0% so far so this is a conceptual way to 00:29:57.370 --> 00:29:58.409 align:start position:0% so far so this is a conceptual way to think<00:29:57.669> about<00:29:57.789> it<00:29:58.059> when<00:29:58.210> you<00:29:58.269> actually 00:29:58.409 --> 00:29:58.419 align:start position:0% think about it when you actually 00:29:58.419 --> 00:30:00.509 align:start position:0% think about it when you actually implement<00:29:58.960> the<00:29:59.019> protocol<00:29:59.409> there's<00:30:00.190> a<00:30:00.279> way<00:30:00.460> to 00:30:00.509 --> 00:30:00.519 align:start position:0% implement the protocol there's a way to 00:30:00.519 --> 00:30:02.370 align:start position:0% implement the protocol there's a way to implement<00:30:00.880> it<00:30:01.269> such<00:30:01.539> that<00:30:01.570> you<00:30:01.779> don't<00:30:02.080> have<00:30:02.230> to 00:30:02.370 --> 00:30:02.380 align:start position:0% implement it such that you don't have to 00:30:02.380 --> 00:30:03.570 align:start position:0% implement it such that you don't have to put<00:30:02.620> so<00:30:02.769> much<00:30:02.889> information<00:30:03.399> in<00:30:03.490> the 00:30:03.570 --> 00:30:03.580 align:start position:0% put so much information in the 00:30:03.580 --> 00:30:05.279 align:start position:0% put so much information in the blockchain<00:30:03.789> and<00:30:04.240> that's<00:30:04.720> going<00:30:04.929> to<00:30:05.049> be<00:30:05.139> more 00:30:05.279 --> 00:30:05.289 align:start position:0% blockchain and that's going to be more 00:30:05.289 --> 00:30:08.820 align:start position:0% blockchain and that's going to be more scalable<00:30:05.649> so<00:30:06.340> for<00:30:06.519> simplicity<00:30:07.230> for<00:30:08.230> this<00:30:08.529> talk 00:30:08.820 --> 00:30:08.830 align:start position:0% scalable so for simplicity for this talk 00:30:08.830 --> 00:30:11.610 align:start position:0% scalable so for simplicity for this talk I'm<00:30:09.100> going<00:30:09.760> to<00:30:09.909> ask<00:30:10.090> you<00:30:10.299> to<00:30:10.450> imagine<00:30:10.779> when 00:30:11.610 --> 00:30:11.620 align:start position:0% I'm going to ask you to imagine when 00:30:11.620 --> 00:30:13.830 align:start position:0% I'm going to ask you to imagine when miners<00:30:11.919> mined<00:30:12.399> the<00:30:12.519> block<00:30:12.760> they<00:30:13.389> tell<00:30:13.659> the 00:30:13.830 --> 00:30:13.840 align:start position:0% miners mined the block they tell the 00:30:13.840 --> 00:30:15.659 align:start position:0% miners mined the block they tell the blockchain<00:30:14.080> whatever<00:30:14.710> they<00:30:14.919> know<00:30:15.100> everything 00:30:15.659 --> 00:30:15.669 align:start position:0% blockchain whatever they know everything 00:30:15.669 --> 00:30:18.810 align:start position:0% blockchain whatever they know everything they<00:30:15.850> have<00:30:16.059> observed<00:30:16.389> so<00:30:16.630> far<00:30:17.399> okay<00:30:18.399> so<00:30:18.460> here 00:30:18.810 --> 00:30:18.820 align:start position:0% they have observed so far okay so here 00:30:18.820 --> 00:30:20.430 align:start position:0% they have observed so far okay so here the<00:30:19.270> transaction<00:30:19.809> is<00:30:19.870> tacked<00:30:20.139> with<00:30:20.350> the 00:30:20.430 --> 00:30:20.440 align:start position:0% the transaction is tacked with the 00:30:20.440 --> 00:30:21.840 align:start position:0% the transaction is tacked with the sequence<00:30:20.799> number 00:30:21.840 --> 00:30:21.850 align:start position:0% sequence number 00:30:21.850 --> 00:30:23.970 align:start position:0% sequence number unauthorized<00:30:22.660> and<00:30:22.960> otherwise<00:30:23.680> there<00:30:23.950> are 00:30:23.970 --> 00:30:23.980 align:start position:0% unauthorized and otherwise there are 00:30:23.980 --> 00:30:27.660 align:start position:0% unauthorized and otherwise there are notarized<00:30:24.960> okay<00:30:25.960> imagine<00:30:26.290> the<00:30:27.070> following<00:30:27.220> is 00:30:27.660 --> 00:30:27.670 align:start position:0% notarized okay imagine the following is 00:30:27.670 --> 00:30:31.620 align:start position:0% notarized okay imagine the following is happening<00:30:28.120> in<00:30:28.600> some<00:30:28.870> plaque<00:30:29.310> there<00:30:30.310> is<00:30:30.490> a<00:30:30.760> read 00:30:31.620 --> 00:30:31.630 align:start position:0% happening in some plaque there is a read 00:30:31.630 --> 00:30:35.070 align:start position:0% happening in some plaque there is a read unauthorized<00:30:32.500> transaction<00:30:34.020> okay<00:30:35.020> so 00:30:35.070 --> 00:30:35.080 align:start position:0% unauthorized transaction okay so 00:30:35.080 --> 00:30:37.500 align:start position:0% unauthorized transaction okay so normally<00:30:35.320> what's<00:30:36.220> going<00:30:36.460> to<00:30:36.520> happen<00:30:36.910> is<00:30:37.090> that 00:30:37.500 --> 00:30:37.510 align:start position:0% normally what's going to happen is that 00:30:37.510 --> 00:30:39.630 align:start position:0% normally what's going to happen is that if<00:30:37.930> the<00:30:38.050> leaders<00:30:38.320> honest<00:30:38.740> and<00:30:38.950> he<00:30:39.250> observes 00:30:39.630 --> 00:30:39.640 align:start position:0% if the leaders honest and he observes 00:30:39.640 --> 00:30:42.840 align:start position:0% if the leaders honest and he observes this<00:30:39.820> he<00:30:40.750> will<00:30:40.900> propose<00:30:41.260> it<00:30:41.440> very<00:30:41.650> quickly<00:30:41.890> to 00:30:42.840 --> 00:30:42.850 align:start position:0% this he will propose it very quickly to 00:30:42.850 --> 00:30:45.230 align:start position:0% this he will propose it very quickly to the<00:30:42.970> committee<00:30:43.300> members<00:30:43.450> and<00:30:43.900> soon<00:30:44.470> enough 00:30:45.230 --> 00:30:45.240 align:start position:0% the committee members and soon enough 00:30:45.240 --> 00:30:48.960 align:start position:0% the committee members and soon enough this<00:30:46.240> red<00:30:46.630> guy<00:30:46.900> is<00:30:47.200> going<00:30:47.710> to<00:30:47.830> become<00:30:48.220> part<00:30:48.880> of 00:30:48.960 --> 00:30:48.970 align:start position:0% this red guy is going to become part of 00:30:48.970 --> 00:30:52.170 align:start position:0% this red guy is going to become part of a<00:30:49.210> lucky<00:30:49.390> sequence<00:30:50.160> right<00:30:51.160> so<00:30:51.670> suppose<00:30:51.970> this 00:30:52.170 --> 00:30:52.180 align:start position:0% a lucky sequence right so suppose this 00:30:52.180 --> 00:30:55.350 align:start position:0% a lucky sequence right so suppose this has<00:30:52.720> not<00:30:53.020> happened<00:30:53.320> even<00:30:54.190> after<00:30:54.550> kappa<00:30:55.120> blocks 00:30:55.350 --> 00:30:55.360 align:start position:0% has not happened even after kappa blocks 00:30:55.360 --> 00:30:58.080 align:start position:0% has not happened even after kappa blocks where<00:30:55.600> taka<00:30:55.900> is<00:30:56.020> a<00:30:56.050> security<00:30:56.530> parameter<00:30:57.090> then 00:30:58.080 --> 00:30:58.090 align:start position:0% where taka is a security parameter then 00:30:58.090 --> 00:31:00.270 align:start position:0% where taka is a security parameter then something<00:30:58.510> has<00:30:58.660> to<00:30:58.810> be<00:30:58.930> wrong<00:30:58.960> right<00:30:59.170> if<00:30:59.560> red 00:31:00.270 --> 00:31:00.280 align:start position:0% something has to be wrong right if red 00:31:00.280 --> 00:31:02.610 align:start position:0% something has to be wrong right if red has<00:31:00.520> not<00:31:00.760> become<00:31:01.120> part<00:31:01.720> of<00:31:01.840> a<00:31:01.930> lucky<00:31:02.200> sequence 00:31:02.610 --> 00:31:02.620 align:start position:0% has not become part of a lucky sequence 00:31:02.620 --> 00:31:04.110 align:start position:0% has not become part of a lucky sequence it's<00:31:02.770> either<00:31:02.980> the<00:31:03.250> leaders<00:31:03.550> corrupt<00:31:03.940> and 00:31:04.110 --> 00:31:04.120 align:start position:0% it's either the leaders corrupt and 00:31:04.120 --> 00:31:06.540 align:start position:0% it's either the leaders corrupt and trying<00:31:04.360> to<00:31:04.660> censor<00:31:05.590> this<00:31:05.740> red<00:31:05.980> transaction 00:31:06.540 --> 00:31:06.550 align:start position:0% trying to censor this red transaction 00:31:06.550 --> 00:31:08.730 align:start position:0% trying to censor this red transaction maybe<00:31:07.390> the<00:31:07.570> committee<00:31:07.810> is<00:31:08.020> just<00:31:08.200> not<00:31:08.380> online 00:31:08.730 --> 00:31:08.740 align:start position:0% maybe the committee is just not online 00:31:08.740 --> 00:31:11.850 align:start position:0% maybe the committee is just not online in<00:31:09.520> either<00:31:09.730> case<00:31:10.120> we<00:31:10.480> want<00:31:11.170> to<00:31:11.230> fall<00:31:11.440> back<00:31:11.650> to 00:31:11.850 --> 00:31:11.860 align:start position:0% in either case we want to fall back to 00:31:11.860 --> 00:31:21.360 align:start position:0% in either case we want to fall back to the<00:31:11.890> slow<00:31:12.340> mode<00:31:14.400> okay<00:31:15.400> any<00:31:15.880> questions<00:31:16.320> yes<00:31:20.370> I'm 00:31:21.360 --> 00:31:21.370 align:start position:0% the slow mode okay any questions yes I'm 00:31:21.370 --> 00:31:22.860 align:start position:0% the slow mode okay any questions yes I'm going<00:31:21.580> to<00:31:21.670> explain<00:31:22.000> how<00:31:22.060> to<00:31:22.180> go<00:31:22.420> to<00:31:22.480> this<00:31:22.690> la 00:31:22.860 --> 00:31:22.870 align:start position:0% going to explain how to go to this la 00:31:22.870 --> 00:31:24.240 align:start position:0% going to explain how to go to this la mode<00:31:23.020> it's<00:31:23.170> actually<00:31:23.440> slightly<00:31:23.620> tricky<00:31:24.040> to<00:31:24.130> do 00:31:24.240 --> 00:31:24.250 align:start position:0% mode it's actually slightly tricky to do 00:31:24.250 --> 00:31:26.850 align:start position:0% mode it's actually slightly tricky to do your<00:31:24.370> correctly<00:31:25.050> so<00:31:26.050> how<00:31:26.200> do<00:31:26.260> we<00:31:26.380> fall<00:31:26.650> back<00:31:26.800> to 00:31:26.850 --> 00:31:26.860 align:start position:0% your correctly so how do we fall back to 00:31:26.860 --> 00:31:29.130 align:start position:0% your correctly so how do we fall back to the<00:31:27.070> slow-mo<00:31:27.430> so<00:31:27.610> now<00:31:27.760> we<00:31:28.210> have<00:31:28.390> observed<00:31:28.780> this 00:31:29.130 --> 00:31:29.140 align:start position:0% the slow-mo so now we have observed this 00:31:29.140 --> 00:31:33.600 align:start position:0% the slow-mo so now we have observed this and<00:31:29.380> we<00:31:29.890> all<00:31:30.040> want<00:31:30.220> to<00:31:30.340> fall<00:31:30.550> back<00:31:32.370> how<00:31:33.370> do<00:31:33.430> we 00:31:33.600 --> 00:31:33.610 align:start position:0% and we all want to fall back how do we 00:31:33.610 --> 00:31:36.360 align:start position:0% and we all want to fall back how do we do<00:31:33.760> this<00:31:34.290> the<00:31:35.290> tricky<00:31:35.620> part<00:31:35.650> here<00:31:35.950> is<00:31:36.340> that 00:31:36.360 --> 00:31:36.370 align:start position:0% do this the tricky part here is that 00:31:36.370 --> 00:31:39.540 align:start position:0% do this the tricky part here is that when<00:31:37.150> we<00:31:37.180> all<00:31:37.510> want<00:31:37.720> to<00:31:37.750> fall<00:31:38.020> back<00:31:38.260> our<00:31:39.130> fast 00:31:39.540 --> 00:31:39.550 align:start position:0% when we all want to fall back our fast 00:31:39.550 --> 00:31:42.630 align:start position:0% when we all want to fall back our fast padlock<00:31:40.320> may<00:31:41.320> have<00:31:41.530> different<00:31:41.920> lengths<00:31:42.310> right 00:31:42.630 --> 00:31:42.640 align:start position:0% padlock may have different lengths right 00:31:42.640 --> 00:31:44.550 align:start position:0% padlock may have different lengths right because<00:31:42.940> Nara<00:31:43.240> has<00:31:43.330> delay<00:31:43.780> like<00:31:44.080> your<00:31:44.320> lock 00:31:44.550 --> 00:31:44.560 align:start position:0% because Nara has delay like your lock 00:31:44.560 --> 00:31:47.070 align:start position:0% because Nara has delay like your lock can<00:31:44.860> be<00:31:44.890> a<00:31:45.010> little<00:31:45.160> longer<00:31:45.490> than<00:31:45.760> mine<00:31:46.080> so 00:31:47.070 --> 00:31:47.080 align:start position:0% can be a little longer than mine so 00:31:47.080 --> 00:31:48.510 align:start position:0% can be a little longer than mine so essentially<00:31:47.500> at<00:31:47.710> this<00:31:47.860> moment<00:31:48.040> we<00:31:48.280> have<00:31:48.310> to 00:31:48.510 --> 00:31:48.520 align:start position:0% essentially at this moment we have to 00:31:48.520 --> 00:31:51.510 align:start position:0% essentially at this moment we have to decide<00:31:48.880> on<00:31:49.090> the<00:31:49.210> cutoff<00:31:49.480> and<00:31:50.020> this<00:31:50.890> is<00:31:51.070> will<00:31:51.340> be 00:31:51.510 --> 00:31:51.520 align:start position:0% decide on the cutoff and this is will be 00:31:51.520 --> 00:31:54.090 align:start position:0% decide on the cutoff and this is will be the<00:31:51.610> cutoff<00:31:51.850> of<00:31:52.000> the<00:31:52.390> fast<00:31:52.600> padlock<00:31:53.110> before 00:31:54.090 --> 00:31:54.100 align:start position:0% the cutoff of the fast padlock before 00:31:54.100 --> 00:32:03.789 align:start position:0% the cutoff of the fast padlock before switching<00:31:54.370> to<00:31:54.550> the<00:31:54.730> blockchain<00:31:55.830> okay<00:31:56.830> yes 00:32:03.789 --> 00:32:03.799 align:start position:0% 00:32:03.799 --> 00:32:07.190 align:start position:0% so<00:32:04.799> direct<00:32:05.070> transaction<00:32:05.640> is<00:32:06.000> like<00:32:06.240> one<00:32:06.990> of<00:32:07.110> the 00:32:07.190 --> 00:32:07.200 align:start position:0% so direct transaction is like one of the 00:32:07.200 --> 00:32:10.190 align:start position:0% so direct transaction is like one of the transactions<00:32:07.860> that<00:32:08.010> appears<00:32:08.520> to<00:32:09.120> use<00:32:09.330> one<00:32:10.080> of 00:32:10.190 --> 00:32:10.200 align:start position:0% transactions that appears to use one of 00:32:10.200 --> 00:32:11.960 align:start position:0% transactions that appears to use one of the<00:32:10.320> miners<00:32:10.710> that<00:32:10.740> were<00:32:11.070> able<00:32:11.309> to<00:32:11.490> kind<00:32:11.940> of 00:32:11.960 --> 00:32:11.970 align:start position:0% the miners that were able to kind of 00:32:11.970 --> 00:32:14.900 align:start position:0% the miners that were able to kind of like<00:32:12.120> finalize<00:32:12.570> a<00:32:12.600> block<00:32:12.929> or<00:32:13.350> we're<00:32:14.190> like<00:32:14.580> how 00:32:14.900 --> 00:32:14.910 align:start position:0% like finalize a block or we're like how 00:32:14.910 --> 00:32:20.000 align:start position:0% like finalize a block or we're like how do<00:32:14.970> we<00:32:15.240> get<00:32:15.480> it<00:32:16.309> the<00:32:17.309> red<00:32:17.460> transaction<00:32:18.090> like<00:32:19.010> so 00:32:20.000 --> 00:32:20.010 align:start position:0% do we get it the red transaction like so 00:32:20.010 --> 00:32:21.230 align:start position:0% do we get it the red transaction like so I'm<00:32:20.100> not<00:32:20.309> sure<00:32:20.460> that<00:32:20.490> I<00:32:20.700> understand<00:32:21.210> the 00:32:21.230 --> 00:32:21.240 align:start position:0% I'm not sure that I understand the 00:32:21.240 --> 00:32:25.010 align:start position:0% I'm not sure that I understand the question<00:32:21.570> but<00:32:21.740> like<00:32:22.740> who<00:32:23.640> picks<00:32:23.910> who<00:32:24.809> picks 00:32:25.010 --> 00:32:25.020 align:start position:0% question but like who picks who picks 00:32:25.020 --> 00:32:26.480 align:start position:0% question but like who picks who picks the<00:32:25.140> transaction<00:32:25.770> that<00:32:25.890> gets<00:32:26.190> checked 00:32:26.480 --> 00:32:26.490 align:start position:0% the transaction that gets checked 00:32:26.490 --> 00:32:30.860 align:start position:0% the transaction that gets checked against<00:32:26.910> this<00:32:27.120> security<00:32:27.690> sequence<00:32:29.540> if<00:32:30.540> you<00:32:30.690> do 00:32:30.860 --> 00:32:30.870 align:start position:0% against this security sequence if you do 00:32:30.870 --> 00:32:32.270 align:start position:0% against this security sequence if you do pay<00:32:31.049> transaction<00:32:31.440> fee<00:32:31.770> you<00:32:31.920> can<00:32:32.100> put 00:32:32.270 --> 00:32:32.280 align:start position:0% pay transaction fee you can put 00:32:32.280 --> 00:32:34.220 align:start position:0% pay transaction fee you can put transactions<00:32:32.790> on<00:32:33.330> the<00:32:33.540> blockchain<00:32:33.780> and 00:32:34.220 --> 00:32:34.230 align:start position:0% transactions on the blockchain and 00:32:34.230 --> 00:32:35.870 align:start position:0% transactions on the blockchain and number<00:32:34.950> Li<00:32:35.070> you<00:32:35.250> know<00:32:35.370> this<00:32:35.520> transaction 00:32:35.870 --> 00:32:35.880 align:start position:0% number Li you know this transaction 00:32:35.880 --> 00:32:37.460 align:start position:0% number Li you know this transaction should<00:32:36.120> become<00:32:36.330> part<00:32:36.690> of<00:32:36.780> a<00:32:36.870> lucky<00:32:37.049> sequence 00:32:37.460 --> 00:32:37.470 align:start position:0% should become part of a lucky sequence 00:32:37.470 --> 00:32:38.840 align:start position:0% should become part of a lucky sequence or<00:32:37.590> everyone<00:32:37.890> should<00:32:38.040> notarize<00:32:38.429> it<00:32:38.460> the 00:32:38.840 --> 00:32:38.850 align:start position:0% or everyone should notarize it the 00:32:38.850 --> 00:32:40.640 align:start position:0% or everyone should notarize it the leader<00:32:39.030> should<00:32:39.210> propose<00:32:39.480> it<00:32:39.690> and<00:32:39.900> if<00:32:40.350> it<00:32:40.470> has 00:32:40.640 --> 00:32:40.650 align:start position:0% leader should propose it and if it has 00:32:40.650 --> 00:32:42.730 align:start position:0% leader should propose it and if it has not<00:32:40.679> happened<00:32:41.100> and<00:32:41.400> the<00:32:41.520> Fastpass<00:32:41.820> has<00:32:42.179> failed 00:32:42.730 --> 00:32:42.740 align:start position:0% not happened and the Fastpass has failed 00:32:42.740 --> 00:32:45.890 align:start position:0% not happened and the Fastpass has failed but<00:32:43.740> like<00:32:43.980> you<00:32:44.309> as<00:32:44.520> the<00:32:44.910> initiating<00:32:45.450> party<00:32:45.809> and 00:32:45.890 --> 00:32:45.900 align:start position:0% but like you as the initiating party and 00:32:45.900 --> 00:32:49.970 align:start position:0% but like you as the initiating party and then<00:32:45.990> half<00:32:46.400> has<00:32:47.400> to<00:32:47.429> go<00:32:47.700> like<00:32:48.200> and<00:32:49.200> go<00:32:49.440> yeah<00:32:49.799> my 00:32:49.970 --> 00:32:49.980 align:start position:0% then half has to go like and go yeah my 00:32:49.980 --> 00:32:54.200 align:start position:0% then half has to go like and go yeah my my<00:32:50.429> transactions<00:32:51.120> got<00:32:51.330> not<00:32:52.760> sequence<00:32:53.760> and<00:32:54.030> and 00:32:54.200 --> 00:32:54.210 align:start position:0% my transactions got not sequence and and 00:32:54.210 --> 00:32:55.909 align:start position:0% my transactions got not sequence and and the<00:32:54.270> lucky<00:32:54.450> sequence<00:32:54.929> so<00:32:55.230> now<00:32:55.500> I'm<00:32:55.710> calling 00:32:55.909 --> 00:32:55.919 align:start position:0% the lucky sequence so now I'm calling 00:32:55.919 --> 00:32:59.480 align:start position:0% the lucky sequence so now I'm calling off<00:32:56.390> like<00:32:57.390> the<00:32:57.510> security<00:32:58.130> everyone's<00:32:59.130> making 00:32:59.480 --> 00:32:59.490 align:start position:0% off like the security everyone's making 00:32:59.490 --> 00:33:02.390 align:start position:0% off like the security everyone's making this<00:32:59.700> check<00:33:00.620> so<00:33:01.620> everyone<00:33:01.950> can<00:33:02.100> see<00:33:02.280> the 00:33:02.390 --> 00:33:02.400 align:start position:0% this check so everyone can see the 00:33:02.400 --> 00:33:03.830 align:start position:0% this check so everyone can see the blockchain<00:33:02.610> and<00:33:02.970> everyone<00:33:03.270> is<00:33:03.390> going<00:33:03.510> to<00:33:03.660> make 00:33:03.830 --> 00:33:03.840 align:start position:0% blockchain and everyone is going to make 00:33:03.840 --> 00:33:06.370 align:start position:0% blockchain and everyone is going to make this<00:33:03.960> check<00:33:04.260> to<00:33:04.799> see<00:33:04.980> if<00:33:05.100> the<00:33:05.220> blockchain<00:33:05.429> has 00:33:06.370 --> 00:33:06.380 align:start position:0% this check to see if the blockchain has 00:33:06.380 --> 00:33:08.810 align:start position:0% this check to see if the blockchain has it's<00:33:07.380> assuming<00:33:07.799> that's<00:33:08.010> like<00:33:08.250> more<00:33:08.460> miners 00:33:08.810 --> 00:33:08.820 align:start position:0% it's assuming that's like more miners 00:33:08.820 --> 00:33:12.380 align:start position:0% it's assuming that's like more miners that<00:33:10.250> we're<00:33:11.250> able<00:33:11.400> to<00:33:11.640> like<00:33:11.820> finalize<00:33:12.270> the 00:33:12.380 --> 00:33:12.390 align:start position:0% that we're able to like finalize the 00:33:12.390 --> 00:33:14.960 align:start position:0% that we're able to like finalize the block<00:33:12.570> because<00:33:13.110> though<00:33:13.410> it<00:33:14.130> still<00:33:14.520> works<00:33:14.760> in<00:33:14.880> a 00:33:14.960 --> 00:33:14.970 align:start position:0% block because though it still works in a 00:33:14.970 --> 00:33:17.720 align:start position:0% block because though it still works in a sense<00:33:15.210> that<00:33:15.740> like<00:33:16.740> individual<00:33:17.429> miner 00:33:17.720 --> 00:33:17.730 align:start position:0% sense that like individual miner 00:33:17.730 --> 00:33:20.000 align:start position:0% sense that like individual miner finalizes<00:33:18.690> the<00:33:18.809> block<00:33:19.020> or<00:33:19.260> like<00:33:19.559> all<00:33:19.770> of<00:33:19.919> the 00:33:20.000 --> 00:33:20.010 align:start position:0% finalizes the block or like all of the 00:33:20.010 --> 00:33:21.620 align:start position:0% finalizes the block or like all of the miners<00:33:20.220> kind<00:33:20.580> of<00:33:20.669> participate<00:33:21.240> in<00:33:21.360> the<00:33:21.450> block 00:33:21.620 --> 00:33:21.630 align:start position:0% miners kind of participate in the block 00:33:21.630 --> 00:33:22.940 align:start position:0% miners kind of participate in the block this<00:33:22.200> sounds<00:33:22.500> like<00:33:22.530> a<00:33:22.650> very<00:33:22.860> interesting 00:33:22.940 --> 00:33:22.950 align:start position:0% this sounds like a very interesting 00:33:22.950 --> 00:33:25.159 align:start position:0% this sounds like a very interesting question<00:33:23.610> I<00:33:23.700> think<00:33:23.760> maybe<00:33:24.330> we<00:33:24.510> should<00:33:24.660> take<00:33:25.020> it 00:33:25.159 --> 00:33:25.169 align:start position:0% question I think maybe we should take it 00:33:25.169 --> 00:33:26.659 align:start position:0% question I think maybe we should take it offline<00:33:25.410> because<00:33:25.890> I<00:33:26.070> would<00:33:26.429> like<00:33:26.549> to 00:33:26.659 --> 00:33:26.669 align:start position:0% offline because I would like to 00:33:26.669 --> 00:33:28.039 align:start position:0% offline because I would like to understand<00:33:27.090> your<00:33:27.210> question<00:33:27.540> a<00:33:27.630> little<00:33:27.720> better 00:33:28.039 --> 00:33:28.049 align:start position:0% understand your question a little better 00:33:28.049 --> 00:33:30.500 align:start position:0% understand your question a little better before<00:33:28.260> I<00:33:28.860> can<00:33:29.160> answer<00:33:29.340> it<00:33:29.490> okay<00:33:30.210> all<00:33:30.360> right 00:33:30.500 --> 00:33:30.510 align:start position:0% before I can answer it okay all right 00:33:30.510 --> 00:33:35.630 align:start position:0% before I can answer it okay all right okay<00:33:33.230> so<00:33:34.230> the<00:33:34.500> the<00:33:34.530> problem<00:33:35.070> we<00:33:35.220> want<00:33:35.370> to<00:33:35.400> solve 00:33:35.630 --> 00:33:35.640 align:start position:0% okay so the the problem we want to solve 00:33:35.640 --> 00:33:37.610 align:start position:0% okay so the the problem we want to solve is<00:33:36.090> how<00:33:36.390> do<00:33:36.450> people<00:33:36.809> agree<00:33:36.929> on<00:33:37.260> the<00:33:37.380> cutoff 00:33:37.610 --> 00:33:37.620 align:start position:0% is how do people agree on the cutoff 00:33:37.620 --> 00:33:40.159 align:start position:0% is how do people agree on the cutoff right<00:33:38.610> so<00:33:38.820> so<00:33:38.970> this<00:33:39.120> seems<00:33:39.780> like<00:33:39.870> a<00:33:39.990> very 00:33:40.159 --> 00:33:40.169 align:start position:0% right so so this seems like a very 00:33:40.169 --> 00:33:42.680 align:start position:0% right so so this seems like a very simple<00:33:40.380> problem<00:33:40.730> you<00:33:41.730> may<00:33:41.910> have<00:33:42.120> some<00:33:42.330> kind<00:33:42.600> of 00:33:42.680 --> 00:33:42.690 align:start position:0% simple problem you may have some kind of 00:33:42.690 --> 00:33:44.960 align:start position:0% simple problem you may have some kind of ideas<00:33:43.140> on<00:33:43.320> your<00:33:43.500> mind<00:33:43.710> how<00:33:44.010> do<00:33:44.070> how<00:33:44.520> to<00:33:44.580> resolve 00:33:44.960 --> 00:33:44.970 align:start position:0% ideas on your mind how do how to resolve 00:33:44.970 --> 00:33:47.570 align:start position:0% ideas on your mind how do how to resolve this<00:33:45.120> problem<00:33:45.740> but<00:33:46.740> the<00:33:46.890> first<00:33:47.160> thing<00:33:47.340> to 00:33:47.570 --> 00:33:47.580 align:start position:0% this problem but the first thing to 00:33:47.580 --> 00:33:50.270 align:start position:0% this problem but the first thing to notice<00:33:47.820> is<00:33:48.270> that<00:33:48.470> the<00:33:49.470> first<00:33:49.740> thing<00:33:49.919> to<00:33:50.070> notice 00:33:50.270 --> 00:33:50.280 align:start position:0% notice is that the first thing to notice 00:33:50.280 --> 00:33:52.669 align:start position:0% notice is that the first thing to notice is<00:33:50.669> that<00:33:50.700> this<00:33:51.150> is<00:33:51.390> an<00:33:51.540> agreement<00:33:51.809> problem<00:33:52.530> in 00:33:52.669 --> 00:33:52.679 align:start position:0% is that this is an agreement problem in 00:33:52.679 --> 00:33:56.930 align:start position:0% is that this is an agreement problem in itself<00:33:53.100> and<00:33:54.290> here<00:33:55.290> we<00:33:55.470> need<00:33:55.710> both<00:33:56.070> consistency 00:33:56.930 --> 00:33:56.940 align:start position:0% itself and here we need both consistency 00:33:56.940 --> 00:33:59.090 align:start position:0% itself and here we need both consistency and<00:33:57.150> liveness<00:33:57.450> right<00:33:57.840> unlike<00:33:58.410> earlier<00:33:58.679> when 00:33:59.090 --> 00:33:59.100 align:start position:0% and liveness right unlike earlier when 00:33:59.100 --> 00:34:01.039 align:start position:0% and liveness right unlike earlier when we<00:33:59.130> were<00:33:59.250> talking<00:33:59.340> about<00:33:59.610> the<00:33:59.880> fast<00:34:00.120> path<00:34:00.360> we 00:34:01.039 --> 00:34:01.049 align:start position:0% we were talking about the fast path we 00:34:01.049 --> 00:34:04.100 align:start position:0% we were talking about the fast path we punted<00:34:01.559> on<00:34:01.740> liveness<00:34:02.240> here<00:34:03.240> we<00:34:03.419> cannot<00:34:03.780> plant 00:34:04.100 --> 00:34:04.110 align:start position:0% punted on liveness here we cannot plant 00:34:04.110 --> 00:34:06.200 align:start position:0% punted on liveness here we cannot plant on<00:34:04.230> liveness<00:34:04.440> anymore<00:34:05.010> we<00:34:05.549> have<00:34:05.580> to<00:34:05.700> solve<00:34:06.030> the 00:34:06.200 --> 00:34:06.210 align:start position:0% on liveness anymore we have to solve the 00:34:06.210 --> 00:34:10.010 align:start position:0% on liveness anymore we have to solve the agreement<00:34:06.630> problem<00:34:06.960> info<00:34:08.389> so<00:34:09.389> again<00:34:09.690> how<00:34:09.960> do 00:34:10.010 --> 00:34:10.020 align:start position:0% agreement problem info so again how do 00:34:10.020 --> 00:34:12.740 align:start position:0% agreement problem info so again how do we<00:34:10.169> do<00:34:10.320> it<00:34:10.350> the<00:34:10.980> blockchain<00:34:11.250> is<00:34:11.550> your<00:34:11.700> friend 00:34:12.740 --> 00:34:12.750 align:start position:0% we do it the blockchain is your friend 00:34:12.750 --> 00:34:16.310 align:start position:0% we do it the blockchain is your friend and<00:34:12.840> and<00:34:13.530> the<00:34:13.770> key<00:34:14.010> is<00:34:14.280> that<00:34:14.340> you<00:34:15.230> don't<00:34:16.230> just 00:34:16.310 --> 00:34:16.320 align:start position:0% and and the key is that you don't just 00:34:16.320 --> 00:34:18.919 align:start position:0% and and the key is that you don't just immediately<00:34:16.889> enter<00:34:17.250> the<00:34:17.399> slow<00:34:17.609> mode<00:34:17.929> you 00:34:18.919 --> 00:34:18.929 align:start position:0% immediately enter the slow mode you 00:34:18.929 --> 00:34:20.930 align:start position:0% immediately enter the slow mode you introduce<00:34:19.500> a<00:34:19.710> grace<00:34:19.950> period<00:34:19.980> the<00:34:20.730> grace 00:34:20.930 --> 00:34:20.940 align:start position:0% introduce a grace period the grace 00:34:20.940 --> 00:34:23.060 align:start position:0% introduce a grace period the grace period<00:34:21.300> is<00:34:21.389> for<00:34:21.599> people<00:34:21.750> to<00:34:21.869> cool<00:34:22.200> down<00:34:22.440> and 00:34:23.060 --> 00:34:23.070 align:start position:0% period is for people to cool down and 00:34:23.070 --> 00:34:25.190 align:start position:0% period is for people to cool down and once<00:34:23.580> you<00:34:23.730> pass<00:34:24.000> the<00:34:24.240> grace<00:34:24.419> period<00:34:24.450> you<00:34:24.899> enter 00:34:25.190 --> 00:34:25.200 align:start position:0% once you pass the grace period you enter 00:34:25.200 --> 00:34:26.810 align:start position:0% once you pass the grace period you enter the<00:34:25.320> slow<00:34:25.530> mode<00:34:25.740> and<00:34:25.980> how<00:34:26.340> does<00:34:26.399> the<00:34:26.609> grace 00:34:26.810 --> 00:34:26.820 align:start position:0% the slow mode and how does the grace 00:34:26.820 --> 00:34:31.339 align:start position:0% the slow mode and how does the grace period<00:34:26.849> work<00:34:27.980> okay<00:34:28.980> so<00:34:29.040> imagine<00:34:30.349> roughly 00:34:31.339 --> 00:34:31.349 align:start position:0% period work okay so imagine roughly 00:34:31.349 --> 00:34:35.089 align:start position:0% period work okay so imagine roughly speaking<00:34:31.560> at<00:34:32.280> this<00:34:32.490> block<00:34:32.790> we<00:34:33.720> we<00:34:33.990> start<00:34:34.290> to 00:34:35.089 --> 00:34:35.099 align:start position:0% speaking at this block we we start to 00:34:35.099 --> 00:34:39.200 align:start position:0% speaking at this block we we start to detect<00:34:35.490> that<00:34:35.990> something<00:34:36.990> has<00:34:37.109> gone<00:34:37.290> bad<00:34:38.210> so 00:34:39.200 --> 00:34:39.210 align:start position:0% detect that something has gone bad so 00:34:39.210 --> 00:34:41.629 align:start position:0% detect that something has gone bad so now<00:34:39.240> everyone<00:34:39.960> stops<00:34:40.320> stops<00:34:40.889> participating 00:34:41.629 --> 00:34:41.639 align:start position:0% now everyone stops stops participating 00:34:41.639 --> 00:34:43.820 align:start position:0% now everyone stops stops participating in<00:34:41.730> the<00:34:41.820> fast<00:34:42.030> path<00:34:42.270> and<00:34:43.080> we're<00:34:43.409> just<00:34:43.530> going<00:34:43.710> to 00:34:43.820 --> 00:34:43.830 align:start position:0% in the fast path and we're just going to 00:34:43.830 --> 00:34:45.859 align:start position:0% in the fast path and we're just going to tell<00:34:44.010> each<00:34:44.159> other<00:34:44.310> what<00:34:44.580> we<00:34:44.700> know<00:34:44.879> and<00:34:45.149> we<00:34:45.629> tell 00:34:45.859 --> 00:34:45.869 align:start position:0% tell each other what we know and we tell 00:34:45.869 --> 00:34:48.139 align:start position:0% tell each other what we know and we tell the<00:34:46.020> blockchain<00:34:46.260> what<00:34:46.560> we<00:34:46.679> know<00:34:46.859> right 00:34:48.139 --> 00:34:48.149 align:start position:0% the blockchain what we know right 00:34:48.149 --> 00:34:51.950 align:start position:0% the blockchain what we know right so<00:34:48.899> the<00:34:49.050> first<00:34:49.260> path<00:34:49.500> stops<00:34:50.070> at<00:34:50.310> this<00:34:50.460> point<00:34:50.960> so 00:34:51.950 --> 00:34:51.960 align:start position:0% so the first path stops at this point so 00:34:51.960 --> 00:34:54.980 align:start position:0% so the first path stops at this point so soon<00:34:52.230> enough<00:34:52.679> after<00:34:53.250> kappa<00:34:54.119> blocks<00:34:54.359> where<00:34:54.570> is 00:34:54.980 --> 00:34:54.990 align:start position:0% soon enough after kappa blocks where is 00:34:54.990 --> 00:34:58.240 align:start position:0% soon enough after kappa blocks where is the<00:34:55.050> security<00:34:55.290> parameter<00:34:55.919> I<00:34:56.129> claim<00:34:56.879> that 00:34:58.240 --> 00:34:58.250 align:start position:0% the security parameter I claim that 00:34:58.250 --> 00:35:00.589 align:start position:0% the security parameter I claim that let's<00:34:59.250> look<00:34:59.520> at<00:34:59.670> the<00:34:59.849> prefix<00:35:00.330> of<00:35:00.450> the 00:35:00.589 --> 00:35:00.599 align:start position:0% let's look at the prefix of the 00:35:00.599 --> 00:35:02.750 align:start position:0% let's look at the prefix of the blockchain<00:35:00.810> from<00:35:01.230> the<00:35:01.770> very<00:35:01.950> beginning<00:35:02.430> up 00:35:02.750 --> 00:35:02.760 align:start position:0% blockchain from the very beginning up 00:35:02.760 --> 00:35:07.220 align:start position:0% blockchain from the very beginning up till<00:35:03.240> here<00:35:04.490> so<00:35:05.490> what's<00:35:06.210> going<00:35:06.480> to<00:35:06.510> happen<00:35:06.960> is 00:35:07.220 --> 00:35:07.230 align:start position:0% till here so what's going to happen is 00:35:07.230 --> 00:35:08.960 align:start position:0% till here so what's going to happen is that<00:35:07.290> the<00:35:07.710> maximum<00:35:08.280> lucky<00:35:08.609> sequence 00:35:08.960 --> 00:35:08.970 align:start position:0% that the maximum lucky sequence 00:35:08.970 --> 00:35:12.020 align:start position:0% that the maximum lucky sequence contained<00:35:09.480> up<00:35:09.720> till<00:35:10.020> here<00:35:10.320> is<00:35:10.890> going<00:35:11.400> to<00:35:11.520> be<00:35:11.849> at 00:35:12.020 --> 00:35:12.030 align:start position:0% contained up till here is going to be at 00:35:12.030 --> 00:35:15.230 align:start position:0% contained up till here is going to be at least<00:35:12.060> as<00:35:12.599> long<00:35:13.080> as<00:35:13.460> everyone's<00:35:14.460> f<00:35:14.640> king<00:35:15.000> lock 00:35:15.230 --> 00:35:15.240 align:start position:0% least as long as everyone's f king lock 00:35:15.240 --> 00:35:18.800 align:start position:0% least as long as everyone's f king lock and<00:35:16.369> this<00:35:17.369> is<00:35:17.640> the<00:35:17.820> cutoff<00:35:18.089> we<00:35:18.420> are<00:35:18.480> going<00:35:18.660> to 00:35:18.800 --> 00:35:18.810 align:start position:0% and this is the cutoff we are going to 00:35:18.810 --> 00:35:22.760 align:start position:0% and this is the cutoff we are going to decide<00:35:19.050> on<00:35:20.540> okay<00:35:21.540> so<00:35:21.599> once<00:35:21.990> we<00:35:22.109> decide<00:35:22.410> on<00:35:22.560> this 00:35:22.760 --> 00:35:22.770 align:start position:0% decide on okay so once we decide on this 00:35:22.770 --> 00:35:26.120 align:start position:0% decide on okay so once we decide on this cutoff<00:35:23.810> we<00:35:24.810> can<00:35:25.050> proceed<00:35:25.410> and<00:35:25.619> move<00:35:25.830> to<00:35:26.010> the 00:35:26.120 --> 00:35:26.130 align:start position:0% cutoff we can proceed and move to the 00:35:26.130 --> 00:35:31.700 align:start position:0% cutoff we can proceed and move to the slow<00:35:26.339> mode<00:35:26.580> and<00:35:28.910> to<00:35:29.910> quickly<00:35:30.119> recap<00:35:30.660> this<00:35:31.530> is 00:35:31.700 --> 00:35:31.710 align:start position:0% slow mode and to quickly recap this is 00:35:31.710 --> 00:35:33.320 align:start position:0% slow mode and to quickly recap this is the<00:35:31.830> protocol<00:35:32.280> you<00:35:32.460> use<00:35:32.490> the<00:35:32.760> blockchain<00:35:33.000> to 00:35:33.320 --> 00:35:33.330 align:start position:0% the protocol you use the blockchain to 00:35:33.330 --> 00:35:35.720 align:start position:0% the protocol you use the blockchain to detect<00:35:33.720> that<00:35:34.410> the<00:35:34.530> fast<00:35:34.740> path<00:35:34.980> has<00:35:35.160> failed<00:35:35.460> and 00:35:35.720 --> 00:35:35.730 align:start position:0% detect that the fast path has failed and 00:35:35.730 --> 00:35:38.650 align:start position:0% detect that the fast path has failed and then<00:35:36.359> you<00:35:36.510> leverage<00:35:36.930> a<00:35:37.140> grace<00:35:37.380> period<00:35:37.640> to 00:35:38.650 --> 00:35:38.660 align:start position:0% then you leverage a grace period to 00:35:38.660 --> 00:35:41.390 align:start position:0% then you leverage a grace period to enter<00:35:39.660> the<00:35:39.780> slow<00:35:39.990> mode<00:35:40.260> and<00:35:40.859> when<00:35:41.010> you're<00:35:41.220> in 00:35:41.390 --> 00:35:41.400 align:start position:0% enter the slow mode and when you're in 00:35:41.400 --> 00:35:42.680 align:start position:0% enter the slow mode and when you're in the<00:35:41.490> slow<00:35:41.700> mode<00:35:41.910> you<00:35:42.030> can<00:35:42.210> always<00:35:42.390> try<00:35:42.660> to 00:35:42.680 --> 00:35:42.690 align:start position:0% the slow mode you can always try to 00:35:42.690 --> 00:35:45.170 align:start position:0% the slow mode you can always try to reelect<00:35:43.230> leader<00:35:43.440> and<00:35:43.740> bootstrap<00:35:44.730> another 00:35:45.170 --> 00:35:45.180 align:start position:0% reelect leader and bootstrap another 00:35:45.180 --> 00:35:51.020 align:start position:0% reelect leader and bootstrap another fast<00:35:45.450> path<00:35:46.280> okay<00:35:47.690> so<00:35:48.690> to<00:35:48.750> quickly<00:35:49.109> and<00:35:50.030> recap 00:35:51.020 --> 00:35:51.030 align:start position:0% fast path okay so to quickly and recap 00:35:51.030 --> 00:35:52.790 align:start position:0% fast path okay so to quickly and recap the<00:35:51.180> security<00:35:51.660> guarantees<00:35:52.109> right<00:35:52.410> so<00:35:52.619> when 00:35:52.790 --> 00:35:52.800 align:start position:0% the security guarantees right so when 00:35:52.800 --> 00:35:55.310 align:start position:0% the security guarantees right so when the<00:35:53.150> miners<00:35:54.150> a<00:35:54.300> majority<00:35:54.750> understand<00:35:55.230> the 00:35:55.310 --> 00:35:55.320 align:start position:0% the miners a majority understand the 00:35:55.320 --> 00:35:58.670 align:start position:0% the miners a majority understand the committee<00:35:55.650> is<00:35:56.280> also<00:35:56.490> majority<00:35:57.060> honest<00:35:57.440> we<00:35:58.440> can 00:35:58.670 --> 00:35:58.680 align:start position:0% committee is also majority honest we can 00:35:58.680 --> 00:36:01.550 align:start position:0% committee is also majority honest we can have<00:35:58.920> our<00:35:59.070> worst-case<00:35:59.490> guarantees<00:36:00.560> however 00:36:01.550 --> 00:36:01.560 align:start position:0% have our worst-case guarantees however 00:36:01.560 --> 00:36:03.890 align:start position:0% have our worst-case guarantees however when<00:36:01.890> things<00:36:02.190> are<00:36:02.369> good<00:36:02.580> let's<00:36:03.240> say<00:36:03.420> the<00:36:03.599> the 00:36:03.890 --> 00:36:03.900 align:start position:0% when things are good let's say the the 00:36:03.900 --> 00:36:07.400 align:start position:0% when things are good let's say the the leader<00:36:04.109> is<00:36:04.349> honest<00:36:04.800> and<00:36:05.070> online<00:36:05.849> and<00:36:06.410> imagine 00:36:07.400 --> 00:36:07.410 align:start position:0% leader is honest and online and imagine 00:36:07.410 --> 00:36:09.260 align:start position:0% leader is honest and online and imagine three<00:36:08.010> quarters<00:36:08.400> of<00:36:08.430> the<00:36:08.670> committee<00:36:08.970> are<00:36:09.119> also 00:36:09.260 --> 00:36:09.270 align:start position:0% three quarters of the committee are also 00:36:09.270 --> 00:36:11.630 align:start position:0% three quarters of the committee are also honest<00:36:09.690> and<00:36:09.839> online<00:36:10.170> and<00:36:10.589> in<00:36:11.250> this<00:36:11.369> case 00:36:11.630 --> 00:36:11.640 align:start position:0% honest and online and in this case 00:36:11.640 --> 00:36:14.150 align:start position:0% honest and online and in this case things<00:36:12.450> are<00:36:12.630> all<00:36:12.810> good<00:36:13.080> and<00:36:13.349> we<00:36:13.770> confirm 00:36:14.150 --> 00:36:14.160 align:start position:0% things are all good and we confirm 00:36:14.160 --> 00:36:16.130 align:start position:0% things are all good and we confirm transactions<00:36:14.730> in<00:36:15.060> two<00:36:15.270> narrow<00:36:15.630> cron<00:36:15.900> trips 00:36:16.130 --> 00:36:16.140 align:start position:0% transactions in two narrow cron trips 00:36:16.140 --> 00:36:18.470 align:start position:0% transactions in two narrow cron trips not<00:36:17.130> even<00:36:17.550> waiting<00:36:17.730> for<00:36:17.849> a<00:36:18.000> single<00:36:18.300> block 00:36:18.470 --> 00:36:18.480 align:start position:0% not even waiting for a single block 00:36:18.480 --> 00:36:20.830 align:start position:0% not even waiting for a single block interval 00:36:20.830 --> 00:36:20.840 align:start position:0% interval 00:36:20.840 --> 00:36:24.700 align:start position:0% interval so<00:36:21.440> a<00:36:21.470> small<00:36:21.890> side<00:36:22.220> note<00:36:22.250> is<00:36:22.790> that<00:36:23.350> this<00:36:24.350> thing 00:36:24.700 --> 00:36:24.710 align:start position:0% so a small side note is that this thing 00:36:24.710 --> 00:36:27.400 align:start position:0% so a small side note is that this thing this<00:36:24.890> parameter<00:36:25.400> is<00:36:25.430> actually<00:36:26.030> tunable<00:36:26.630> right 00:36:27.400 --> 00:36:27.410 align:start position:0% this parameter is actually tunable right 00:36:27.410 --> 00:36:29.980 align:start position:0% this parameter is actually tunable right like<00:36:28.130> maybe<00:36:28.340> I'm<00:36:28.610> very<00:36:28.880> paranoid<00:36:29.240> and<00:36:29.390> I<00:36:29.720> don't 00:36:29.980 --> 00:36:29.990 align:start position:0% like maybe I'm very paranoid and I don't 00:36:29.990 --> 00:36:31.360 align:start position:0% like maybe I'm very paranoid and I don't want<00:36:30.140> to<00:36:30.230> trust<00:36:30.470> that<00:36:30.620> the<00:36:30.800> majority<00:36:31.010> of<00:36:31.280> the 00:36:31.360 --> 00:36:31.370 align:start position:0% want to trust that the majority of the 00:36:31.370 --> 00:36:34.200 align:start position:0% want to trust that the majority of the committee<00:36:31.610> be<00:36:31.880> honest<00:36:32.290> which<00:36:33.290> is<00:36:33.500> fine<00:36:33.800> and 00:36:34.200 --> 00:36:34.210 align:start position:0% committee be honest which is fine and 00:36:34.210 --> 00:36:36.940 align:start position:0% committee be honest which is fine and for<00:36:35.210> instance<00:36:35.480> I<00:36:35.660> want<00:36:35.840> to<00:36:35.930> say<00:36:36.140> I<00:36:36.380> want 00:36:36.940 --> 00:36:36.950 align:start position:0% for instance I want to say I want 00:36:36.950 --> 00:36:39.400 align:start position:0% for instance I want to say I want security<00:36:37.640> as<00:36:38.030> long<00:36:38.240> as<00:36:38.420> a<00:36:38.600> single<00:36:39.110> member<00:36:39.380> of 00:36:39.400 --> 00:36:39.410 align:start position:0% security as long as a single member of 00:36:39.410 --> 00:36:41.500 align:start position:0% security as long as a single member of the<00:36:39.620> committee<00:36:39.890> is<00:36:40.040> honest<00:36:40.400> and<00:36:40.610> the<00:36:41.030> single 00:36:41.500 --> 00:36:41.510 align:start position:0% the committee is honest and the single 00:36:41.510 --> 00:36:42.910 align:start position:0% the committee is honest and the single honest<00:36:41.810> member<00:36:42.080> doesn't<00:36:42.290> even<00:36:42.500> have<00:36:42.680> to<00:36:42.800> be 00:36:42.910 --> 00:36:42.920 align:start position:0% honest member doesn't even have to be 00:36:42.920 --> 00:36:44.670 align:start position:0% honest member doesn't even have to be online<00:36:43.040> and<00:36:43.430> that's<00:36:43.970> okay<00:36:44.360> too 00:36:44.670 --> 00:36:44.680 align:start position:0% online and that's okay too 00:36:44.680 --> 00:36:47.710 align:start position:0% online and that's okay too but<00:36:45.680> you'll<00:36:45.860> pay<00:36:46.070> a<00:36:46.100> little<00:36:46.430> bit<00:36:46.580> in<00:36:47.180> terms<00:36:47.480> of 00:36:47.710 --> 00:36:47.720 align:start position:0% but you'll pay a little bit in terms of 00:36:47.720 --> 00:36:49.270 align:start position:0% but you'll pay a little bit in terms of the<00:36:47.900> the<00:36:48.170> condition<00:36:48.590> that's<00:36:48.770> necessary<00:36:49.220> for 00:36:49.270 --> 00:36:49.280 align:start position:0% the the condition that's necessary for 00:36:49.280 --> 00:36:52.030 align:start position:0% the the condition that's necessary for the<00:36:49.550> fast<00:36:49.790> path<00:36:50.030> in<00:36:50.660> other<00:36:50.840> words<00:36:51.110> you<00:36:51.890> would 00:36:52.030 --> 00:36:52.040 align:start position:0% the fast path in other words you would 00:36:52.040 --> 00:36:54.520 align:start position:0% the fast path in other words you would have<00:36:52.220> to<00:36:52.340> require<00:36:52.640> that<00:36:52.700> all<00:36:53.120> the<00:36:53.540> committee 00:36:54.520 --> 00:36:54.530 align:start position:0% have to require that all the committee 00:36:54.530 --> 00:36:56.860 align:start position:0% have to require that all the committee members<00:36:54.740> are<00:36:55.010> online<00:36:55.190> and<00:36:55.580> honest<00:36:55.940> in<00:36:56.510> order 00:36:56.860 --> 00:36:56.870 align:start position:0% members are online and honest in order 00:36:56.870 --> 00:37:02.020 align:start position:0% members are online and honest in order to<00:36:57.020> be<00:36:57.140> fast<00:36:58.000> okay<00:37:00.250> okay<00:37:01.250> so<00:37:01.310> here<00:37:01.550> are<00:37:01.730> the<00:37:01.820> two 00:37:02.020 --> 00:37:02.030 align:start position:0% to be fast okay okay so here are the two 00:37:02.030 --> 00:37:05.860 align:start position:0% to be fast okay okay so here are the two sentences<00:37:02.420> and<00:37:03.790> to<00:37:04.790> remember<00:37:05.090> about<00:37:05.570> thunder 00:37:05.860 --> 00:37:05.870 align:start position:0% sentences and to remember about thunder 00:37:05.870 --> 00:37:06.300 align:start position:0% sentences and to remember about thunder Ella 00:37:06.300 --> 00:37:06.310 align:start position:0% Ella 00:37:06.310 --> 00:37:08.980 align:start position:0% Ella here's<00:37:07.310> hot<00:37:07.520> under<00:37:07.760> Ella<00:37:08.000> works<00:37:08.210> when<00:37:08.750> things 00:37:08.980 --> 00:37:08.990 align:start position:0% here's hot under Ella works when things 00:37:08.990 --> 00:37:10.960 align:start position:0% here's hot under Ella works when things are<00:37:09.170> good<00:37:09.380> we<00:37:09.710> conduct<00:37:10.190> a<00:37:10.340> single<00:37:10.670> round<00:37:10.820> of 00:37:10.960 --> 00:37:10.970 align:start position:0% are good we conduct a single round of 00:37:10.970 --> 00:37:13.540 align:start position:0% are good we conduct a single round of voting<00:37:11.090> and<00:37:11.420> when<00:37:11.930> things<00:37:12.170> go<00:37:12.320> bad<00:37:12.590> we<00:37:13.190> use<00:37:13.370> the 00:37:13.540 --> 00:37:13.550 align:start position:0% voting and when things go bad we use the 00:37:13.550 --> 00:37:15.580 align:start position:0% voting and when things go bad we use the blockchain<00:37:13.760> to<00:37:14.060> do<00:37:14.150> a<00:37:14.180> view<00:37:14.390> change<00:37:14.690> so<00:37:15.470> it's 00:37:15.580 --> 00:37:15.590 align:start position:0% blockchain to do a view change so it's 00:37:15.590 --> 00:37:19.150 align:start position:0% blockchain to do a view change so it's as<00:37:15.800> simple<00:37:15.950> as<00:37:16.190> this<00:37:17.320> in<00:37:18.320> our<00:37:18.500> paper<00:37:18.770> we<00:37:18.980> have<00:37:19.130> a 00:37:19.150 --> 00:37:19.160 align:start position:0% as simple as this in our paper we have a 00:37:19.160 --> 00:37:21.400 align:start position:0% as simple as this in our paper we have a lot<00:37:19.370> of<00:37:19.520> other<00:37:19.700> discussions<00:37:19.970> on<00:37:20.450> how<00:37:20.810> to<00:37:20.870> elect 00:37:21.400 --> 00:37:21.410 align:start position:0% lot of other discussions on how to elect 00:37:21.410 --> 00:37:24.580 align:start position:0% lot of other discussions on how to elect the<00:37:21.530> leader<00:37:21.710> and<00:37:21.950> the<00:37:22.010> committee<00:37:22.340> how<00:37:23.180> to<00:37:23.590> have 00:37:24.580 --> 00:37:24.590 align:start position:0% the leader and the committee how to have 00:37:24.590 --> 00:37:26.290 align:start position:0% the leader and the committee how to have practical<00:37:25.010> optimizations<00:37:25.850> that<00:37:26.000> make<00:37:26.180> the 00:37:26.290 --> 00:37:26.300 align:start position:0% practical optimizations that make the 00:37:26.300 --> 00:37:28.210 align:start position:0% practical optimizations that make the protocol<00:37:26.660> even<00:37:26.810> faster<00:37:27.290> and<00:37:27.470> more<00:37:27.620> scalable 00:37:28.210 --> 00:37:28.220 align:start position:0% protocol even faster and more scalable 00:37:28.220 --> 00:37:31.270 align:start position:0% protocol even faster and more scalable we<00:37:28.910> have<00:37:29.060> formal<00:37:29.420> proofs<00:37:29.630> of<00:37:29.750> security<00:37:30.290> okay 00:37:31.270 --> 00:37:31.280 align:start position:0% we have formal proofs of security okay 00:37:31.280 --> 00:37:33.340 align:start position:0% we have formal proofs of security okay I've<00:37:32.210> mostly<00:37:32.720> focused<00:37:33.110> on<00:37:33.230> the 00:37:33.340 --> 00:37:33.350 align:start position:0% I've mostly focused on the 00:37:33.350 --> 00:37:35.260 align:start position:0% I've mostly focused on the permissionless<00:37:33.770> setting<00:37:34.220> but<00:37:34.850> actually 00:37:35.260 --> 00:37:35.270 align:start position:0% permissionless setting but actually 00:37:35.270 --> 00:37:36.670 align:start position:0% permissionless setting but actually sounder<00:37:35.540> Ella<00:37:35.720> can<00:37:35.960> also<00:37:36.140> be<00:37:36.350> instantiated 00:37:36.670 --> 00:37:36.680 align:start position:0% sounder Ella can also be instantiated 00:37:36.680 --> 00:37:39.340 align:start position:0% sounder Ella can also be instantiated for<00:37:37.390> permissions<00:37:38.390> right<00:37:38.630> so<00:37:38.750> if<00:37:38.900> you<00:37:38.990> are<00:37:39.140> you 00:37:39.340 --> 00:37:39.350 align:start position:0% for permissions right so if you are you 00:37:39.350 --> 00:37:41.010 align:start position:0% for permissions right so if you are you have<00:37:39.500> a<00:37:39.530> company<00:37:39.890> that's<00:37:40.130> commercializing 00:37:41.010 --> 00:37:41.020 align:start position:0% have a company that's commercializing 00:37:41.020 --> 00:37:45.160 align:start position:0% have a company that's commercializing consortium<00:37:42.020> blockchain<00:37:42.500> and<00:37:43.120> you<00:37:44.120> can<00:37:44.360> if<00:37:44.990> you 00:37:45.160 --> 00:37:45.170 align:start position:0% consortium blockchain and you can if you 00:37:45.170 --> 00:37:47.940 align:start position:0% consortium blockchain and you can if you if<00:37:45.350> your<00:37:45.500> customer<00:37:46.010> wants<00:37:46.280> high<00:37:46.640> volume<00:37:47.180> and 00:37:47.940 --> 00:37:47.950 align:start position:0% if your customer wants high volume and 00:37:47.950 --> 00:37:51.220 align:start position:0% if your customer wants high volume and fast<00:37:48.950> confirmation<00:37:49.670> Thunder<00:37:50.600> Ella<00:37:50.780> can<00:37:51.050> also 00:37:51.220 --> 00:37:51.230 align:start position:0% fast confirmation Thunder Ella can also 00:37:51.230 --> 00:37:52.300 align:start position:0% fast confirmation Thunder Ella can also be<00:37:51.470> a<00:37:51.500> good<00:37:51.770> choice 00:37:52.300 --> 00:37:52.310 align:start position:0% be a good choice 00:37:52.310 --> 00:37:54.040 align:start position:0% be a good choice so<00:37:52.850> I'm<00:37:53.000> actually<00:37:53.150> talking<00:37:53.660> to<00:37:53.690> a<00:37:53.810> couple 00:37:54.040 --> 00:37:54.050 align:start position:0% so I'm actually talking to a couple 00:37:54.050 --> 00:37:56.860 align:start position:0% so I'm actually talking to a couple companies<00:37:54.460> including<00:37:55.460> her<00:37:55.580> Sarah<00:37:55.850> and<00:37:56.180> crypt 00:37:56.860 --> 00:37:56.870 align:start position:0% companies including her Sarah and crypt 00:37:56.870 --> 00:37:59.590 align:start position:0% companies including her Sarah and crypt tape<00:37:57.080> to<00:37:57.890> see<00:37:58.340> if<00:37:58.520> their<00:37:58.730> to<00:37:59.090> understand<00:37:59.510> if 00:37:59.590 --> 00:37:59.600 align:start position:0% tape to see if their to understand if 00:37:59.600 --> 00:38:01.750 align:start position:0% tape to see if their to understand if their<00:37:59.750> customers<00:37:59.900> would<00:38:00.830> like<00:38:01.040> something 00:38:01.750 --> 00:38:01.760 align:start position:0% their customers would like something 00:38:01.760 --> 00:38:02.710 align:start position:0% their customers would like something like<00:38:02.000> Cinderella 00:38:02.710 --> 00:38:02.720 align:start position:0% like Cinderella 00:38:02.720 --> 00:38:07.890 align:start position:0% like Cinderella okay<00:38:04.210> so<00:38:05.210> I'm<00:38:05.300> going<00:38:05.570> to<00:38:05.690> try<00:38:05.870> to<00:38:05.900> conclude<00:38:06.230> and 00:38:07.890 --> 00:38:07.900 align:start position:0% okay so I'm going to try to conclude and 00:38:07.900 --> 00:38:11.470 align:start position:0% okay so I'm going to try to conclude and before<00:38:08.900> I<00:38:08.960> conclude<00:38:09.230> I<00:38:09.940> want<00:38:10.940> to<00:38:11.090> talk<00:38:11.300> about 00:38:11.470 --> 00:38:11.480 align:start position:0% before I conclude I want to talk about 00:38:11.480 --> 00:38:13.150 align:start position:0% before I conclude I want to talk about some<00:38:11.780> of<00:38:11.810> the<00:38:12.050> deeper<00:38:12.410> insights<00:38:12.830> we<00:38:13.010> have 00:38:13.150 --> 00:38:13.160 align:start position:0% some of the deeper insights we have 00:38:13.160 --> 00:38:14.650 align:start position:0% some of the deeper insights we have gained<00:38:13.430> in<00:38:13.610> this<00:38:13.760> process<00:38:14.150> right<00:38:14.330> so<00:38:14.390> why 00:38:14.650 --> 00:38:14.660 align:start position:0% gained in this process right so why 00:38:14.660 --> 00:38:16.930 align:start position:0% gained in this process right so why after<00:38:14.960> 30<00:38:15.350> years<00:38:15.440> of<00:38:15.740> research<00:38:15.800> we<00:38:16.760> can 00:38:16.930 --> 00:38:16.940 align:start position:0% after 30 years of research we can 00:38:16.940 --> 00:38:18.820 align:start position:0% after 30 years of research we can suddenly<00:38:17.120> claim<00:38:17.600> to<00:38:17.810> be<00:38:17.930> a<00:38:17.960> lot<00:38:18.230> faster<00:38:18.680> and 00:38:18.820 --> 00:38:18.830 align:start position:0% suddenly claim to be a lot faster and 00:38:18.830 --> 00:38:21.070 align:start position:0% suddenly claim to be a lot faster and simpler<00:38:19.130> than<00:38:19.370> everyone<00:38:19.700> else<00:38:20.050> there<00:38:21.050> is 00:38:21.070 --> 00:38:21.080 align:start position:0% simpler than everyone else there is 00:38:21.080 --> 00:38:23.830 align:start position:0% simpler than everyone else there is actually<00:38:21.560> a<00:38:21.590> reason<00:38:22.400> because<00:38:22.550> sander<00:38:23.180> Ella<00:38:23.390> is 00:38:23.830 --> 00:38:23.840 align:start position:0% actually a reason because sander Ella is 00:38:23.840 --> 00:38:27.760 align:start position:0% actually a reason because sander Ella is in<00:38:24.230> fact<00:38:24.440> a<00:38:24.620> new<00:38:24.830> theoretical<00:38:25.460> paradigm<00:38:26.770> okay 00:38:27.760 --> 00:38:27.770 align:start position:0% in fact a new theoretical paradigm okay 00:38:27.770 --> 00:38:30.510 align:start position:0% in fact a new theoretical paradigm okay so<00:38:27.830> classically<00:38:28.580> and<00:38:29.360> these<00:38:30.110> are<00:38:30.290> what 00:38:30.510 --> 00:38:30.520 align:start position:0% so classically and these are what 00:38:30.520 --> 00:38:33.130 align:start position:0% so classically and these are what classical<00:38:31.520> protocols<00:38:31.970> are<00:38:32.120> like<00:38:32.300> and<00:38:32.600> the 00:38:33.130 --> 00:38:33.140 align:start position:0% classical protocols are like and the 00:38:33.140 --> 00:38:34.450 align:start position:0% classical protocols are like and the reason<00:38:33.470> why<00:38:33.590> they're<00:38:33.770> complex 00:38:34.450 --> 00:38:34.460 align:start position:0% reason why they're complex 00:38:34.460 --> 00:38:36.160 align:start position:0% reason why they're complex because<00:38:34.790> they<00:38:34.970> work<00:38:35.150> with<00:38:35.390> asynchrony<00:38:35.960> right 00:38:36.160 --> 00:38:36.170 align:start position:0% because they work with asynchrony right 00:38:36.170 --> 00:38:38.349 align:start position:0% because they work with asynchrony right these<00:38:36.589> protocols<00:38:37.040> tries<00:38:37.250> to<00:38:37.460> reach<00:38:37.640> consensus 00:38:38.349 --> 00:38:38.359 align:start position:0% these protocols tries to reach consensus 00:38:38.359 --> 00:38:40.480 align:start position:0% these protocols tries to reach consensus in<00:38:39.140> asynchronous<00:38:39.619> are<00:38:40.099> partially 00:38:40.480 --> 00:38:40.490 align:start position:0% in asynchronous are partially 00:38:40.490 --> 00:38:42.370 align:start position:0% in asynchronous are partially synchronous<00:38:40.970> and<00:38:41.210> networks<00:38:41.599> where<00:38:42.200> the 00:38:42.370 --> 00:38:42.380 align:start position:0% synchronous and networks where the 00:38:42.380 --> 00:38:45.730 align:start position:0% synchronous and networks where the protocol<00:38:43.210> isn't<00:38:44.210> aware<00:38:44.720> of<00:38:44.990> the<00:38:45.200> maximum<00:38:45.650> an 00:38:45.730 --> 00:38:45.740 align:start position:0% protocol isn't aware of the maximum an 00:38:45.740 --> 00:38:47.740 align:start position:0% protocol isn't aware of the maximum an hour<00:38:45.859> delay<00:38:46.250> so<00:38:46.940> this<00:38:47.119> means<00:38:47.359> that<00:38:47.510> in<00:38:47.720> the 00:38:47.740 --> 00:38:47.750 align:start position:0% hour delay so this means that in the 00:38:47.750 --> 00:38:51.130 align:start position:0% hour delay so this means that in the protocol<00:38:48.230> I<00:38:48.440> cannot<00:38:49.359> you<00:38:50.359> know<00:38:50.390> wait<00:38:50.690> for<00:38:50.960> 5 00:38:51.130 --> 00:38:51.140 align:start position:0% protocol I cannot you know wait for 5 00:38:51.140 --> 00:38:53.049 align:start position:0% protocol I cannot you know wait for 5 seconds<00:38:51.530> to<00:38:51.710> receive<00:38:52.010> a<00:38:52.040> message<00:38:52.280> and<00:38:52.670> then<00:38:52.790> if 00:38:53.049 --> 00:38:53.059 align:start position:0% seconds to receive a message and then if 00:38:53.059 --> 00:38:54.609 align:start position:0% seconds to receive a message and then if the<00:38:53.180> message<00:38:53.450> doesn't<00:38:53.599> arrive<00:38:54.020> I<00:38:54.200> can<00:38:54.380> assume 00:38:54.609 --> 00:38:54.619 align:start position:0% the message doesn't arrive I can assume 00:38:54.619 --> 00:38:58.260 align:start position:0% the message doesn't arrive I can assume that<00:38:54.680> in<00:38:55.010> everywhere<00:38:56.200> so<00:38:57.200> a<00:38:57.230> synchrony<00:38:57.859> makes 00:38:58.260 --> 00:38:58.270 align:start position:0% that in everywhere so a synchrony makes 00:38:58.270 --> 00:39:02.620 align:start position:0% that in everywhere so a synchrony makes life<00:38:59.270> a<00:38:59.690> lot<00:39:00.500> more<00:39:00.800> difficult<00:39:01.280> and<00:39:01.790> and<00:39:02.420> in 00:39:02.620 --> 00:39:02.630 align:start position:0% life a lot more difficult and and in 00:39:02.630 --> 00:39:05.230 align:start position:0% life a lot more difficult and and in some<00:39:02.809> times<00:39:03.020> we<00:39:03.170> paid<00:39:03.440> it<00:39:03.589> and<00:39:04.000> paid<00:39:05.000> it<00:39:05.119> and 00:39:05.230 --> 00:39:05.240 align:start position:0% some times we paid it and paid it and 00:39:05.240 --> 00:39:07.480 align:start position:0% some times we paid it and paid it and switched<00:39:05.599> to<00:39:06.349> a<00:39:06.380> synchronous<00:39:06.950> protocol 00:39:07.480 --> 00:39:07.490 align:start position:0% switched to a synchronous protocol 00:39:07.490 --> 00:39:09.490 align:start position:0% switched to a synchronous protocol underneath<00:39:07.910> so<00:39:08.540> this<00:39:08.690> is<00:39:08.869> also<00:39:09.170> saying<00:39:09.349> that 00:39:09.490 --> 00:39:09.500 align:start position:0% underneath so this is also saying that 00:39:09.500 --> 00:39:11.260 align:start position:0% underneath so this is also saying that block<00:39:09.829> chains<00:39:10.099> are<00:39:10.280> by<00:39:10.400> nature<00:39:10.460> synchronous 00:39:11.260 --> 00:39:11.270 align:start position:0% block chains are by nature synchronous 00:39:11.270 --> 00:39:14.319 align:start position:0% block chains are by nature synchronous and<00:39:12.819> there<00:39:13.819> are<00:39:13.910> a<00:39:13.940> couple<00:39:14.059> ways<00:39:14.300> to 00:39:14.319 --> 00:39:14.329 align:start position:0% and there are a couple ways to 00:39:14.329 --> 00:39:16.240 align:start position:0% and there are a couple ways to understand<00:39:14.930> this<00:39:15.079> right<00:39:15.290> so<00:39:15.470> in<00:39:15.619> block<00:39:15.800> G<00:39:15.829> as 00:39:16.240 --> 00:39:16.250 align:start position:0% understand this right so in block G as 00:39:16.250 --> 00:39:20.500 align:start position:0% understand this right so in block G as we<00:39:16.849> know<00:39:17.059> we<00:39:17.240> have<00:39:17.359> to<00:39:17.510> set<00:39:17.720> the<00:39:19.270> the<00:39:20.270> block 00:39:20.500 --> 00:39:20.510 align:start position:0% we know we have to set the the block 00:39:20.510 --> 00:39:23.020 align:start position:0% we know we have to set the the block interval<00:39:21.050> right<00:39:21.410> and<00:39:21.740> as<00:39:22.460> I<00:39:22.550> said<00:39:22.609> that<00:39:22.819> the 00:39:23.020 --> 00:39:23.030 align:start position:0% interval right and as I said that the 00:39:23.030 --> 00:39:25.089 align:start position:0% interval right and as I said that the block<00:39:23.210> interval<00:39:23.660> has<00:39:23.809> to<00:39:23.960> be<00:39:24.099> reasonably 00:39:25.089 --> 00:39:25.099 align:start position:0% block interval has to be reasonably 00:39:25.099 --> 00:39:27.520 align:start position:0% block interval has to be reasonably large<00:39:25.369> with<00:39:25.730> respect<00:39:25.760> to<00:39:26.300> the<00:39:26.450> narrow<00:39:27.109> delay 00:39:27.520 --> 00:39:27.530 align:start position:0% large with respect to the narrow delay 00:39:27.530 --> 00:39:31.680 align:start position:0% large with respect to the narrow delay for<00:39:28.309> the<00:39:28.400> protocol<00:39:28.730> to<00:39:28.880> retain<00:39:29.119> consistency 00:39:31.680 --> 00:39:31.690 align:start position:0% for the protocol to retain consistency 00:39:31.690 --> 00:39:34.780 align:start position:0% for the protocol to retain consistency actually<00:39:32.690> interestingly<00:39:32.990> I<00:39:33.559> have<00:39:34.250> a<00:39:34.280> position 00:39:34.780 --> 00:39:34.790 align:start position:0% actually interestingly I have a position 00:39:34.790 --> 00:39:37.630 align:start position:0% actually interestingly I have a position paper<00:39:34.940> with<00:39:35.270> Rafael<00:39:35.930> in<00:39:36.260> CSF<00:39:36.800> we<00:39:37.250> actually 00:39:37.630 --> 00:39:37.640 align:start position:0% paper with Rafael in CSF we actually 00:39:37.640 --> 00:39:39.400 align:start position:0% paper with Rafael in CSF we actually show<00:39:37.880> that<00:39:38.150> in<00:39:38.359> the<00:39:38.450> permissionless<00:39:38.930> setting 00:39:39.400 --> 00:39:39.410 align:start position:0% show that in the permissionless setting 00:39:39.410 --> 00:39:42.700 align:start position:0% show that in the permissionless setting when<00:39:40.309> you<00:39:40.339> are<00:39:41.240> not<00:39:41.450> sure<00:39:41.839> how<00:39:41.869> many<00:39:42.140> notes<00:39:42.559> are 00:39:42.700 --> 00:39:42.710 align:start position:0% when you are not sure how many notes are 00:39:42.710 --> 00:39:47.319 align:start position:0% when you are not sure how many notes are going<00:39:42.829> to<00:39:43.010> show<00:39:43.220> up<00:39:43.369> in<00:39:44.359> fact<00:39:45.700> any<00:39:46.700> consensus 00:39:47.319 --> 00:39:47.329 align:start position:0% going to show up in fact any consensus 00:39:47.329 --> 00:39:48.700 align:start position:0% going to show up in fact any consensus protocol<00:39:47.720> has<00:39:47.930> to<00:39:48.079> be<00:39:48.200> synchronous 00:39:48.700 --> 00:39:48.710 align:start position:0% protocol has to be synchronous 00:39:48.710 --> 00:39:51.280 align:start position:0% protocol has to be synchronous asynchronous<00:39:49.510> consensus<00:39:50.510> is<00:39:50.630> basically<00:39:50.960> not 00:39:51.280 --> 00:39:51.290 align:start position:0% asynchronous consensus is basically not 00:39:51.290 --> 00:39:53.740 align:start position:0% asynchronous consensus is basically not possible<00:39:51.829> when<00:39:52.579> you<00:39:52.700> are<00:39:53.000> not<00:39:53.150> sure<00:39:53.480> how<00:39:53.690> many 00:39:53.740 --> 00:39:53.750 align:start position:0% possible when you are not sure how many 00:39:53.750 --> 00:39:55.329 align:start position:0% possible when you are not sure how many nodes<00:39:54.079> are<00:39:54.200> going<00:39:54.260> to<00:39:54.470> show<00:39:54.619> up<00:39:54.770> so<00:39:55.190> this 00:39:55.329 --> 00:39:55.339 align:start position:0% nodes are going to show up so this 00:39:55.339 --> 00:39:56.920 align:start position:0% nodes are going to show up so this actually<00:39:55.700> has<00:39:55.730> a<00:39:55.849> very<00:39:56.180> simple<00:39:56.569> lower<00:39:56.720> bound 00:39:56.920 --> 00:39:56.930 align:start position:0% actually has a very simple lower bound 00:39:56.930 --> 00:40:00.819 align:start position:0% actually has a very simple lower bound proof<00:39:57.220> ok<00:39:58.660> so<00:39:59.660> now<00:39:59.869> we<00:39:59.930> can<00:40:00.260> look<00:40:00.290> at<00:40:00.619> things 00:40:00.819 --> 00:40:00.829 align:start position:0% proof ok so now we can look at things 00:40:00.829 --> 00:40:02.650 align:start position:0% proof ok so now we can look at things from<00:40:00.920> the<00:40:01.099> perspective<00:40:01.250> of<00:40:01.910> a<00:40:02.089> synchronous 00:40:02.650 --> 00:40:02.660 align:start position:0% from the perspective of a synchronous 00:40:02.660 --> 00:40:04.720 align:start position:0% from the perspective of a synchronous versus<00:40:03.020> synchrony<00:40:03.740> right<00:40:04.040> so<00:40:04.160> asynchronous 00:40:04.720 --> 00:40:04.730 align:start position:0% versus synchrony right so asynchronous 00:40:04.730 --> 00:40:07.230 align:start position:0% versus synchrony right so asynchronous protocols<00:40:05.180> are<00:40:05.390> fast<00:40:05.660> because<00:40:06.589> the<00:40:06.740> protocol 00:40:07.230 --> 00:40:07.240 align:start position:0% protocols are fast because the protocol 00:40:07.240 --> 00:40:10.750 align:start position:0% protocols are fast because the protocol does<00:40:08.240> another<00:40:08.630> narrow<00:40:08.900> delay<00:40:09.250> the<00:40:10.250> only<00:40:10.549> way 00:40:10.750 --> 00:40:10.760 align:start position:0% does another narrow delay the only way 00:40:10.760 --> 00:40:14.559 align:start position:0% does another narrow delay the only way to<00:40:10.819> make<00:40:11.150> progress<00:40:11.390> is<00:40:12.260> if<00:40:12.650> I<00:40:12.890> make<00:40:13.270> actions<00:40:14.270> as 00:40:14.559 --> 00:40:14.569 align:start position:0% to make progress is if I make actions as 00:40:14.569 --> 00:40:16.539 align:start position:0% to make progress is if I make actions as soon<00:40:14.839> as<00:40:14.990> I<00:40:15.109> receive<00:40:15.410> messages<00:40:15.619> so<00:40:16.040> of<00:40:16.250> course 00:40:16.539 --> 00:40:16.549 align:start position:0% soon as I receive messages so of course 00:40:16.549 --> 00:40:19.030 align:start position:0% soon as I receive messages so of course the<00:40:16.760> protocol<00:40:17.119> is<00:40:17.180> going<00:40:17.210> to<00:40:17.619> proceed<00:40:18.619> as<00:40:18.799> fast 00:40:19.030 --> 00:40:19.040 align:start position:0% the protocol is going to proceed as fast 00:40:19.040 --> 00:40:22.870 align:start position:0% the protocol is going to proceed as fast as<00:40:19.190> the<00:40:19.309> network<00:40:19.579> makes<00:40:19.790> progress<00:40:20.980> ok<00:40:21.980> so<00:40:22.670> this 00:40:22.870 --> 00:40:22.880 align:start position:0% as the network makes progress ok so this 00:40:22.880 --> 00:40:24.670 align:start position:0% as the network makes progress ok so this is<00:40:23.030> all<00:40:23.210> very<00:40:23.240> nice<00:40:23.630> but<00:40:23.930> if<00:40:24.079> you<00:40:24.170> try<00:40:24.380> to<00:40:24.440> work 00:40:24.670 --> 00:40:24.680 align:start position:0% is all very nice but if you try to work 00:40:24.680 --> 00:40:27.010 align:start position:0% is all very nice but if you try to work with<00:40:24.859> asynchronous<00:40:25.250> directly<00:40:25.970> there<00:40:26.809> are 00:40:27.010 --> 00:40:27.020 align:start position:0% with asynchronous directly there are 00:40:27.020 --> 00:40:29.440 align:start position:0% with asynchronous directly there are problems<00:40:27.530> like<00:40:28.250> not<00:40:28.579> only<00:40:28.700> are<00:40:28.970> the<00:40:29.059> protocol 00:40:29.440 --> 00:40:29.450 align:start position:0% problems like not only are the protocol 00:40:29.450 --> 00:40:31.120 align:start position:0% problems like not only are the protocol complex<00:40:29.839> there<00:40:30.440> are<00:40:30.470> also<00:40:30.680> fundamental 00:40:31.120 --> 00:40:31.130 align:start position:0% complex there are also fundamental 00:40:31.130 --> 00:40:32.920 align:start position:0% complex there are also fundamental barriers<00:40:31.880> like<00:40:32.150> for<00:40:32.329> instance<00:40:32.450> there<00:40:32.750> is<00:40:32.809> a 00:40:32.920 --> 00:40:32.930 align:start position:0% barriers like for instance there is a 00:40:32.930 --> 00:40:35.530 align:start position:0% barriers like for instance there is a very<00:40:33.230> well-known<00:40:33.440> lower<00:40:34.369> bound<00:40:34.670> by<00:40:34.880> Dwarka<00:40:35.390> da 00:40:35.530 --> 00:40:35.540 align:start position:0% very well-known lower bound by Dwarka da 00:40:35.540 --> 00:40:37.599 align:start position:0% very well-known lower bound by Dwarka da that<00:40:36.170> any<00:40:36.380> asynchronous<00:40:37.069> protocol<00:40:37.460> can 00:40:37.599 --> 00:40:37.609 align:start position:0% that any asynchronous protocol can 00:40:37.609 --> 00:40:41.319 align:start position:0% that any asynchronous protocol can tolerate<00:40:37.790> only<00:40:38.089> 1/3<00:40:39.049> corruptions<00:40:39.589> and<00:40:40.150> like<00:40:41.150> I 00:40:41.319 --> 00:40:41.329 align:start position:0% tolerate only 1/3 corruptions and like I 00:40:41.329 --> 00:40:44.020 align:start position:0% tolerate only 1/3 corruptions and like I said<00:40:41.390> if<00:40:42.170> you<00:40:42.380> want<00:40:42.650> permissionless<00:40:43.309> it's 00:40:44.020 --> 00:40:44.030 align:start position:0% said if you want permissionless it's 00:40:44.030 --> 00:40:45.520 align:start position:0% said if you want permissionless it's going<00:40:44.299> to<00:40:44.420> be<00:40:44.510> even<00:40:44.660> worse<00:40:44.990> because<00:40:45.290> a 00:40:45.520 --> 00:40:45.530 align:start position:0% going to be even worse because a 00:40:45.530 --> 00:40:47.490 align:start position:0% going to be even worse because a synchrony<00:40:45.950> is<00:40:46.069> not<00:40:46.280> possible 00:40:47.490 --> 00:40:47.500 align:start position:0% synchrony is not possible 00:40:47.500 --> 00:40:54.390 align:start position:0% synchrony is not possible permissionless<00:40:48.869> okay<00:40:51.930> if<00:40:52.930> you<00:40:53.140> look<00:40:53.349> at<00:40:53.560> like 00:40:54.390 --> 00:40:54.400 align:start position:0% permissionless okay if you look at like 00:40:54.400 --> 00:40:57.750 align:start position:0% permissionless okay if you look at like the<00:40:55.270> the<00:40:55.510> line<00:40:55.690> of<00:40:55.900> work<00:40:56.109> in<00:40:56.440> let's<00:40:57.250> say<00:40:57.400> as<00:40:57.550> so 00:40:57.750 --> 00:40:57.760 align:start position:0% the the line of work in let's say as so 00:40:57.760 --> 00:41:00.480 align:start position:0% the the line of work in let's say as so as<00:40:57.940> P<00:40:58.180> these<00:40:59.170> are<00:40:59.349> top<00:40:59.530> systems<00:40:59.950> conferences 00:41:00.480 --> 00:41:00.490 align:start position:0% as P these are top systems conferences 00:41:00.490 --> 00:41:01.890 align:start position:0% as P these are top systems conferences right<00:41:00.609> and<00:41:00.790> also<00:41:01.060> the<00:41:01.150> systems<00:41:01.480> that<00:41:01.660> will<00:41:01.810> go 00:41:01.890 --> 00:41:01.900 align:start position:0% right and also the systems that will go 00:41:01.900 --> 00:41:03.900 align:start position:0% right and also the systems that will go and<00:41:02.080> Facebook<00:41:02.470> implemented<00:41:03.040> like<00:41:03.670> none<00:41:03.880> of 00:41:03.900 --> 00:41:03.910 align:start position:0% and Facebook implemented like none of 00:41:03.910 --> 00:41:05.550 align:start position:0% and Facebook implemented like none of these<00:41:04.210> systems<00:41:04.690> actually<00:41:05.080> considered 00:41:05.550 --> 00:41:05.560 align:start position:0% these systems actually considered 00:41:05.560 --> 00:41:09.150 align:start position:0% these systems actually considered synchrony<00:41:06.630> and<00:41:07.630> why<00:41:07.810> is<00:41:07.869> this<00:41:08.200> the<00:41:08.260> case<00:41:08.410> so 00:41:09.150 --> 00:41:09.160 align:start position:0% synchrony and why is this the case so 00:41:09.160 --> 00:41:10.560 align:start position:0% synchrony and why is this the case so classically<00:41:09.760> we<00:41:09.910> tend<00:41:10.119> to<00:41:10.180> think<00:41:10.450> that 00:41:10.560 --> 00:41:10.570 align:start position:0% classically we tend to think that 00:41:10.570 --> 00:41:12.589 align:start position:0% classically we tend to think that synchronous<00:41:11.109> protocols<00:41:11.530> are<00:41:11.650> kind<00:41:11.830> of<00:41:11.950> slow 00:41:12.589 --> 00:41:12.599 align:start position:0% synchronous protocols are kind of slow 00:41:12.599 --> 00:41:15.810 align:start position:0% synchronous protocols are kind of slow because<00:41:13.599> in<00:41:14.290> a<00:41:14.410> synchronous<00:41:14.800> protocol<00:41:15.280> there 00:41:15.810 --> 00:41:15.820 align:start position:0% because in a synchronous protocol there 00:41:15.820 --> 00:41:17.730 align:start position:0% because in a synchronous protocol there is<00:41:15.970> a<00:41:16.000> very<00:41:16.359> important<00:41:16.960> parameter<00:41:17.080> to<00:41:17.500> set 00:41:17.730 --> 00:41:17.740 align:start position:0% is a very important parameter to set 00:41:17.740 --> 00:41:19.560 align:start position:0% is a very important parameter to set which<00:41:18.130> is<00:41:18.310> like<00:41:18.520> the<00:41:18.640> synchrony<00:41:19.030> delay<00:41:19.300> right 00:41:19.560 --> 00:41:19.570 align:start position:0% which is like the synchrony delay right 00:41:19.570 --> 00:41:21.890 align:start position:0% which is like the synchrony delay right so<00:41:19.840> if<00:41:19.960> you<00:41:20.050> are<00:41:20.140> average<00:41:20.320> now<00:41:20.680> or<00:41:20.830> delay<00:41:21.099> is 00:41:21.890 --> 00:41:21.900 align:start position:0% so if you are average now or delay is 00:41:21.900 --> 00:41:24.900 align:start position:0% so if you are average now or delay is like<00:41:22.900> one<00:41:23.230> second<00:41:23.650> you<00:41:24.160> might<00:41:24.340> want<00:41:24.580> to<00:41:24.700> set 00:41:24.900 --> 00:41:24.910 align:start position:0% like one second you might want to set 00:41:24.910 --> 00:41:26.400 align:start position:0% like one second you might want to set the<00:41:25.030> synchrony<00:41:25.390> delay<00:41:25.599> to<00:41:25.660> be<00:41:25.840> ten<00:41:26.050> seconds 00:41:26.400 --> 00:41:26.410 align:start position:0% the synchrony delay to be ten seconds 00:41:26.410 --> 00:41:27.900 align:start position:0% the synchrony delay to be ten seconds just<00:41:26.560> to<00:41:26.680> be<00:41:26.830> safe<00:41:27.010> because<00:41:27.310> if<00:41:27.580> this 00:41:27.900 --> 00:41:27.910 align:start position:0% just to be safe because if this 00:41:27.910 --> 00:41:30.030 align:start position:0% just to be safe because if this assumption<00:41:28.270> is<00:41:28.480> violated<00:41:28.599> your<00:41:29.440> protocol<00:41:29.920> can 00:41:30.030 --> 00:41:30.040 align:start position:0% assumption is violated your protocol can 00:41:30.040 --> 00:41:33.180 align:start position:0% assumption is violated your protocol can lose<00:41:30.280> out<00:41:30.490> our<00:41:30.730> security<00:41:31.359> guarantees<00:41:32.130> okay<00:41:33.130> so 00:41:33.180 --> 00:41:33.190 align:start position:0% lose out our security guarantees okay so 00:41:33.190 --> 00:41:35.430 align:start position:0% lose out our security guarantees okay so the<00:41:33.400> classical<00:41:33.910> wisdom<00:41:34.330> is<00:41:34.510> that<00:41:34.720> you<00:41:35.349> know 00:41:35.430 --> 00:41:35.440 align:start position:0% the classical wisdom is that you know 00:41:35.440 --> 00:41:38.750 align:start position:0% the classical wisdom is that you know synchronous<00:41:35.950> protocols<00:41:36.400> are<00:41:36.520> kind<00:41:36.700> of<00:41:36.820> slow 00:41:38.750 --> 00:41:38.760 align:start position:0% synchronous protocols are kind of slow 00:41:38.760 --> 00:41:41.550 align:start position:0% synchronous protocols are kind of slow like<00:41:39.760> in<00:41:40.119> Google<00:41:40.359> scenario<00:41:41.080> they<00:41:41.260> actually 00:41:41.550 --> 00:41:41.560 align:start position:0% like in Google scenario they actually 00:41:41.560 --> 00:41:45.750 align:start position:0% like in Google scenario they actually want<00:41:41.770> microsecond<00:41:42.580> latency<00:41:43.060> right<00:41:44.430> so<00:41:45.430> our 00:41:45.750 --> 00:41:45.760 align:start position:0% want microsecond latency right so our 00:41:45.760 --> 00:41:49.349 align:start position:0% want microsecond latency right so our insight<00:41:46.359> is<00:41:46.599> that<00:41:46.630> this<00:41:47.340> classical<00:41:48.340> wisdom<00:41:48.760> in 00:41:49.349 --> 00:41:49.359 align:start position:0% insight is that this classical wisdom in 00:41:49.359 --> 00:41:51.349 align:start position:0% insight is that this classical wisdom in some<00:41:49.660> sense<00:41:49.930> is<00:41:50.080> incorrect 00:41:51.349 --> 00:41:51.359 align:start position:0% some sense is incorrect 00:41:51.359 --> 00:41:55.680 align:start position:0% some sense is incorrect so<00:41:52.359> to<00:41:52.420> under<00:41:52.750> Ella<00:41:54.089> it's<00:41:55.089> very<00:41:55.359> interesting 00:41:55.680 --> 00:41:55.690 align:start position:0% so to under Ella it's very interesting 00:41:55.690 --> 00:41:58.380 align:start position:0% so to under Ella it's very interesting because<00:41:55.990> most<00:41:56.410> of<00:41:56.650> the<00:41:56.800> time<00:41:57.060> 95%<00:41:58.060> of<00:41:58.150> the<00:41:58.240> time 00:41:58.380 --> 00:41:58.390 align:start position:0% because most of the time 95% of the time 00:41:58.390 --> 00:42:02.070 align:start position:0% because most of the time 95% of the time we<00:41:58.900> live<00:41:59.109> in<00:41:59.140> the<00:41:59.920> asynchrony<00:42:00.520> world<00:42:00.760> and<00:42:01.089> when 00:42:02.070 --> 00:42:02.080 align:start position:0% we live in the asynchrony world and when 00:42:02.080 --> 00:42:04.170 align:start position:0% we live in the asynchrony world and when things<00:42:02.320> go<00:42:02.589> around<00:42:02.830> right<00:42:03.250> in<00:42:03.430> the<00:42:03.520> 1%<00:42:03.970> of<00:42:04.060> the 00:42:04.170 --> 00:42:04.180 align:start position:0% things go around right in the 1% of the 00:42:04.180 --> 00:42:06.150 align:start position:0% things go around right in the 1% of the time<00:42:04.390> we<00:42:04.990> fall<00:42:05.230> back<00:42:05.410> to<00:42:05.470> the<00:42:05.650> synchronous 00:42:06.150 --> 00:42:06.160 align:start position:0% time we fall back to the synchronous 00:42:06.160 --> 00:42:11.579 align:start position:0% time we fall back to the synchronous mode<00:42:09.270> so<00:42:10.270> that's<00:42:10.480> why<00:42:10.630> we<00:42:10.839> can<00:42:11.080> circumvent 00:42:11.579 --> 00:42:11.589 align:start position:0% mode so that's why we can circumvent 00:42:11.589 --> 00:42:14.280 align:start position:0% mode so that's why we can circumvent these<00:42:12.400> fundamental<00:42:13.030> barriers<00:42:13.480> related<00:42:14.140> to<00:42:14.260> a 00:42:14.280 --> 00:42:14.290 align:start position:0% these fundamental barriers related to a 00:42:14.290 --> 00:42:16.500 align:start position:0% these fundamental barriers related to a synchrony<00:42:14.830> right<00:42:15.070> like<00:42:15.310> there's<00:42:15.940> a<00:42:16.030> 1/3 00:42:16.500 --> 00:42:16.510 align:start position:0% synchrony right like there's a 1/3 00:42:16.510 --> 00:42:20.430 align:start position:0% synchrony right like there's a 1/3 barrier<00:42:16.930> which<00:42:17.140> we<00:42:17.320> can<00:42:17.500> overcome<00:42:19.050> because<00:42:20.050> we 00:42:20.430 --> 00:42:20.440 align:start position:0% barrier which we can overcome because we 00:42:20.440 --> 00:42:24.570 align:start position:0% barrier which we can overcome because we can<00:42:20.650> tolerate<00:42:20.830> an<00:42:21.810> minority<00:42:22.810> corruption<00:42:23.550> in<00:42:24.550> a 00:42:24.570 --> 00:42:24.580 align:start position:0% can tolerate an minority corruption in a 00:42:24.580 --> 00:42:28.710 align:start position:0% can tolerate an minority corruption in a permissionless<00:42:25.510> study<00:42:25.839> and<00:42:27.300> in<00:42:28.300> fact<00:42:28.510> if 00:42:28.710 --> 00:42:28.720 align:start position:0% permissionless study and in fact if 00:42:28.720 --> 00:42:30.150 align:start position:0% permissionless study and in fact if you're<00:42:28.869> in<00:42:29.020> the<00:42:29.140> classical<00:42:29.650> setting<00:42:29.920> we<00:42:30.130> can 00:42:30.150 --> 00:42:30.160 align:start position:0% you're in the classical setting we can 00:42:30.160 --> 00:42:32.579 align:start position:0% you're in the classical setting we can even<00:42:30.670> tolerate<00:42:31.020> arbitrarily<00:42:32.020> many<00:42:32.230> faults 00:42:32.579 --> 00:42:32.589 align:start position:0% even tolerate arbitrarily many faults 00:42:32.589 --> 00:42:34.800 align:start position:0% even tolerate arbitrarily many faults for<00:42:32.890> instance<00:42:33.130> if<00:42:33.250> you<00:42:33.369> instantiate<00:42:34.180> the 00:42:34.800 --> 00:42:34.810 align:start position:0% for instance if you instantiate the 00:42:34.810 --> 00:42:36.870 align:start position:0% for instance if you instantiate the underlying<00:42:35.230> blockchain<00:42:35.890> with<00:42:36.460> the<00:42:36.580> toll-f 00:42:36.870 --> 00:42:36.880 align:start position:0% underlying blockchain with the toll-f 00:42:36.880 --> 00:42:38.730 align:start position:0% underlying blockchain with the toll-f strong<00:42:37.180> like<00:42:37.390> protocol<00:42:37.869> so<00:42:38.440> we<00:42:38.560> can 00:42:38.730 --> 00:42:38.740 align:start position:0% strong like protocol so we can 00:42:38.740 --> 00:42:42.240 align:start position:0% strong like protocol so we can theoretically<00:42:39.160> circumvent<00:42:40.060> these<00:42:41.250> barriers 00:42:42.240 --> 00:42:42.250 align:start position:0% theoretically circumvent these barriers 00:42:42.250 --> 00:42:45.780 align:start position:0% theoretically circumvent these barriers related<00:42:42.520> to<00:42:42.849> a<00:42:42.880> synchrony<00:42:44.190> ok<00:42:45.190> so<00:42:45.250> to<00:42:45.430> conclude 00:42:45.780 --> 00:42:45.790 align:start position:0% related to a synchrony ok so to conclude 00:42:45.790 --> 00:42:48.630 align:start position:0% related to a synchrony ok so to conclude you<00:42:46.270> know<00:42:46.780> simplicity<00:42:47.410> is<00:42:47.560> really<00:42:47.950> your<00:42:48.460> good 00:42:48.630 --> 00:42:48.640 align:start position:0% you know simplicity is really your good 00:42:48.640 --> 00:42:50.099 align:start position:0% you know simplicity is really your good friend<00:42:48.970> especially<00:42:49.690> for<00:42:49.869> large-scale 00:42:50.099 --> 00:42:50.109 align:start position:0% friend especially for large-scale 00:42:50.109 --> 00:42:54.630 align:start position:0% friend especially for large-scale distributed<00:42:50.619> systems<00:42:51.190> and<00:42:51.839> and<00:42:53.160> our<00:42:54.160> company 00:42:54.630 --> 00:42:54.640 align:start position:0% distributed systems and and our company 00:42:54.640 --> 00:42:56.640 align:start position:0% distributed systems and and our company is<00:42:54.670> currently<00:42:54.970> hiring<00:42:55.660> if<00:42:56.410> you<00:42:56.560> are 00:42:56.640 --> 00:42:56.650 align:start position:0% is currently hiring if you are 00:42:56.650 --> 00:42:59.880 align:start position:0% is currently hiring if you are interested<00:42:57.099> you<00:42:57.130> can<00:42:57.280> email<00:42:58.200> these<00:42:59.200> addresses 00:42:59.880 --> 00:42:59.890 align:start position:0% interested you can email these addresses 00:42:59.890 --> 00:43:01.170 align:start position:0% interested you can email these addresses if<00:43:00.130> you<00:43:00.220> want<00:43:00.430> to<00:43:00.550> be 00:43:01.170 --> 00:43:01.180 align:start position:0% if you want to be 00:43:01.180 --> 00:43:03.900 align:start position:0% if you want to be and<00:43:01.559> one<00:43:02.559> of<00:43:02.680> the<00:43:02.859> key<00:43:03.039> contributors<00:43:03.670> of<00:43:03.789> an 00:43:03.900 --> 00:43:03.910 align:start position:0% and one of the key contributors of an 00:43:03.910 --> 00:43:13.580 align:start position:0% and one of the key contributors of an early<00:43:04.240> stage<00:43:04.510> startup<00:43:04.920> thank<00:43:05.920> you<00:43:06.010> very<00:43:06.220> much 00:43:13.580 --> 00:43:13.590 align:start position:0% 00:43:13.590 --> 00:43:21.169 align:start position:0% [Music]