WEBVTT Kind: captions Language: en 00:00:00.000 --> 00:00:01.850 align:start position:0% I'm<00:00:00.390> going<00:00:00.719> to<00:00:00.870> talk<00:00:01.050> about<00:00:01.199> the<00:00:01.650> Pala 00:00:01.850 --> 00:00:01.860 align:start position:0% I'm going to talk about the Pala 00:00:01.860 --> 00:00:03.949 align:start position:0% I'm going to talk about the Pala consensus<00:00:02.490> protocol<00:00:02.879> this<00:00:03.360> is<00:00:03.510> giant<00:00:03.750> work 00:00:03.949 --> 00:00:03.959 align:start position:0% consensus protocol this is giant work 00:00:03.959 --> 00:00:06.499 align:start position:0% consensus protocol this is giant work with<00:00:04.140> the<00:00:04.290> hilbert<00:00:04.680> chandra<00:00:05.130> file<00:00:05.310> pass<00:00:05.520> so<00:00:06.330> in 00:00:06.499 --> 00:00:06.509 align:start position:0% with the hilbert chandra file pass so in 00:00:06.509 --> 00:00:09.470 align:start position:0% with the hilbert chandra file pass so in chinese<00:00:07.040> pili<00:00:08.040> pala<00:00:08.280> is<00:00:08.610> the<00:00:08.790> sound<00:00:09.269> of 00:00:09.470 --> 00:00:09.480 align:start position:0% chinese pili pala is the sound of 00:00:09.480 --> 00:00:10.070 align:start position:0% chinese pili pala is the sound of thunder 00:00:10.070 --> 00:00:10.080 align:start position:0% thunder 00:00:10.080 --> 00:00:13.100 align:start position:0% thunder it<00:00:10.440> also<00:00:10.650> means<00:00:10.889> fast<00:00:11.250> furious<00:00:12.110> and 00:00:13.100 --> 00:00:13.110 align:start position:0% it also means fast furious and 00:00:13.110 --> 00:00:16.849 align:start position:0% it also means fast furious and streamlined<00:00:14.269> okay<00:00:15.269> so<00:00:16.170> I<00:00:16.199> will<00:00:16.379> begin<00:00:16.710> by 00:00:16.849 --> 00:00:16.859 align:start position:0% streamlined okay so I will begin by 00:00:16.859 --> 00:00:18.650 align:start position:0% streamlined okay so I will begin by explaining<00:00:17.490> the<00:00:17.820> problem<00:00:18.029> I'm<00:00:18.330> trying<00:00:18.480> to 00:00:18.650 --> 00:00:18.660 align:start position:0% explaining the problem I'm trying to 00:00:18.660 --> 00:00:20.330 align:start position:0% explaining the problem I'm trying to solve<00:00:18.900> right<00:00:19.050> so<00:00:19.320> in<00:00:19.560> all<00:00:19.980> these 00:00:20.330 --> 00:00:20.340 align:start position:0% solve right so in all these 00:00:20.340 --> 00:00:21.890 align:start position:0% solve right so in all these cryptocurrency<00:00:20.850> systems<00:00:21.449> the<00:00:21.720> car 00:00:21.890 --> 00:00:21.900 align:start position:0% cryptocurrency systems the car 00:00:21.900 --> 00:00:23.509 align:start position:0% cryptocurrency systems the car abstraction<00:00:22.529> is<00:00:22.650> called<00:00:22.890> state<00:00:23.160> machine 00:00:23.509 --> 00:00:23.519 align:start position:0% abstraction is called state machine 00:00:23.519 --> 00:00:25.820 align:start position:0% abstraction is called state machine replication<00:00:24.350> also<00:00:25.350> referred<00:00:25.680> to<00:00:25.710> as 00:00:25.820 --> 00:00:25.830 align:start position:0% replication also referred to as 00:00:25.830 --> 00:00:28.640 align:start position:0% replication also referred to as blockchain<00:00:26.490> or<00:00:27.119> consensus<00:00:27.779> so<00:00:28.289> in<00:00:28.410> the<00:00:28.500> rest 00:00:28.640 --> 00:00:28.650 align:start position:0% blockchain or consensus so in the rest 00:00:28.650 --> 00:00:30.019 align:start position:0% blockchain or consensus so in the rest of<00:00:28.800> the<00:00:28.920> talk<00:00:29.160> these<00:00:29.460> terms<00:00:29.699> are<00:00:29.880> used 00:00:30.019 --> 00:00:30.029 align:start position:0% of the talk these terms are used 00:00:30.029 --> 00:00:34.160 align:start position:0% of the talk these terms are used interchangeably<00:00:30.269> and<00:00:31.550> we<00:00:32.550> have<00:00:32.759> a<00:00:33.140> set<00:00:34.140> of 00:00:34.160 --> 00:00:34.170 align:start position:0% interchangeably and we have a set of 00:00:34.170 --> 00:00:36.470 align:start position:0% interchangeably and we have a set of decentralized<00:00:34.860> nodes<00:00:35.340> and<00:00:35.610> these<00:00:36.090> nodes<00:00:36.300> are 00:00:36.470 --> 00:00:36.480 align:start position:0% decentralized nodes and these nodes are 00:00:36.480 --> 00:00:38.569 align:start position:0% decentralized nodes and these nodes are trying<00:00:36.719> to<00:00:36.989> reach<00:00:37.230> agreement<00:00:37.829> and 00:00:38.569 --> 00:00:38.579 align:start position:0% trying to reach agreement and 00:00:38.579 --> 00:00:41.720 align:start position:0% trying to reach agreement and ever-growing<00:00:39.770> linearly<00:00:40.770> or<00:00:41.040> the<00:00:41.219> lakh<00:00:41.460> of 00:00:41.720 --> 00:00:41.730 align:start position:0% ever-growing linearly or the lakh of 00:00:41.730 --> 00:00:46.130 align:start position:0% ever-growing linearly or the lakh of transactions<00:00:43.219> okay<00:00:44.989> there<00:00:45.989> are<00:00:46.020> two 00:00:46.130 --> 00:00:46.140 align:start position:0% transactions okay there are two 00:00:46.140 --> 00:00:47.840 align:start position:0% transactions okay there are two important<00:00:46.829> security<00:00:47.039> properties<00:00:47.610> that<00:00:47.730> we 00:00:47.840 --> 00:00:47.850 align:start position:0% important security properties that we 00:00:47.850 --> 00:00:49.400 align:start position:0% important security properties that we care<00:00:48.030> about<00:00:48.059> namely<00:00:48.690> consistency<00:00:49.289> and 00:00:49.400 --> 00:00:49.410 align:start position:0% care about namely consistency and 00:00:49.410 --> 00:00:52.639 align:start position:0% care about namely consistency and liveness<00:00:51.050> consistency<00:00:52.050> says<00:00:52.260> that<00:00:52.500> all<00:00:52.620> of 00:00:52.639 --> 00:00:52.649 align:start position:0% liveness consistency says that all of 00:00:52.649 --> 00:00:54.650 align:start position:0% liveness consistency says that all of the<00:00:52.890> honest<00:00:53.190> nodes<00:00:53.399> must<00:00:53.760> agree<00:00:54.180> on<00:00:54.329> the<00:00:54.480> same 00:00:54.650 --> 00:00:54.660 align:start position:0% the honest nodes must agree on the same 00:00:54.660 --> 00:00:56.990 align:start position:0% the honest nodes must agree on the same lock<00:00:54.960> so<00:00:55.590> it<00:00:55.620> could<00:00:55.920> be<00:00:56.070> your<00:00:56.280> log<00:00:56.489> is<00:00:56.699> a<00:00:56.730> little 00:00:56.990 --> 00:00:57.000 align:start position:0% lock so it could be your log is a little 00:00:57.000 --> 00:00:58.729 align:start position:0% lock so it could be your log is a little faster<00:00:57.390> than<00:00:57.600> mine<00:00:57.840> because<00:00:58.109> network<00:00:58.620> has 00:00:58.729 --> 00:00:58.739 align:start position:0% faster than mine because network has 00:00:58.739 --> 00:01:00.709 align:start position:0% faster than mine because network has delay<00:00:59.010> but<00:00:59.250> nonetheless<00:00:59.789> at<00:01:00.300> the<00:01:00.390> end<00:01:00.510> of<00:01:00.629> the 00:01:00.709 --> 00:01:00.719 align:start position:0% delay but nonetheless at the end of the 00:01:00.719 --> 00:01:03.500 align:start position:0% delay but nonetheless at the end of the day<00:01:00.840> we<00:01:00.960> have<00:01:01.079> to<00:01:01.199> all<00:01:01.320> agree<00:01:01.940> life<00:01:02.940> this<00:01:03.239> says 00:01:03.500 --> 00:01:03.510 align:start position:0% day we have to all agree life this says 00:01:03.510 --> 00:01:05.750 align:start position:0% day we have to all agree life this says that<00:01:03.809> whenever<00:01:04.110> I<00:01:04.199> want<00:01:04.530> to<00:01:04.589> buy<00:01:04.739> coffee<00:01:05.010> the 00:01:05.750 --> 00:01:05.760 align:start position:0% that whenever I want to buy coffee the 00:01:05.760 --> 00:01:07.340 align:start position:0% that whenever I want to buy coffee the transaction<00:01:06.330> will<00:01:06.479> appear<00:01:06.780> in<00:01:06.930> all<00:01:07.080> of<00:01:07.229> the 00:01:07.340 --> 00:01:07.350 align:start position:0% transaction will appear in all of the 00:01:07.350 --> 00:01:10.039 align:start position:0% transaction will appear in all of the honest<00:01:07.619> nodes<00:01:07.799> locks<00:01:08.070> very<00:01:08.369> quickly<00:01:09.150> it's<00:01:09.840> not 00:01:10.039 --> 00:01:10.049 align:start position:0% honest nodes locks very quickly it's not 00:01:10.049 --> 00:01:11.330 align:start position:0% honest nodes locks very quickly it's not like<00:01:10.200> I<00:01:10.320> want<00:01:10.470> to<00:01:10.560> wait<00:01:10.680> forever<00:01:10.890> for<00:01:11.100> my 00:01:11.330 --> 00:01:11.340 align:start position:0% like I want to wait forever for my 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building a linearly audit 00:01:20.970 --> 00:01:24.380 align:start position:0% exciting about building a linearly audit log<00:01:21.350> well<00:01:22.369> indeed<00:01:23.369> if<00:01:23.640> all<00:01:23.850> of<00:01:24.000> these<00:01:24.150> nodes 00:01:24.380 --> 00:01:24.390 align:start position:0% log well indeed if all of these nodes 00:01:24.390 --> 00:01:25.969 align:start position:0% log well indeed if all of these nodes were<00:01:24.630> honest<00:01:25.020> and<00:01:25.200> they<00:01:25.290> correctly<00:01:25.619> followed 00:01:25.969 --> 00:01:25.979 align:start position:0% were honest and they correctly followed 00:01:25.979 --> 00:01:27.260 align:start position:0% were honest and they correctly followed the<00:01:26.040> protocol<00:01:26.369> the<00:01:26.520> problem<00:01:26.850> would<00:01:26.970> have<00:01:27.030> been 00:01:27.260 --> 00:01:27.270 align:start position:0% the protocol the problem would have been 00:01:27.270 --> 00:01:29.780 align:start position:0% the protocol the problem would have been trivial<00:01:27.450> but<00:01:28.020> what's<00:01:28.229> challenging<00:01:29.009> about<00:01:29.490> it 00:01:29.780 --> 00:01:29.790 align:start position:0% trivial but what's challenging about it 00:01:29.790 --> 00:01:31.130 align:start position:0% trivial but what's challenging about it is<00:01:29.970> when<00:01:30.180> some<00:01:30.420> of<00:01:30.540> these<00:01:30.630> nodes<00:01:30.840> can<00:01:31.110> be 00:01:31.130 --> 00:01:31.140 align:start position:0% is when some of these nodes can be 00:01:31.140 --> 00:01:33.109 align:start position:0% is when some of these nodes can be corrupt<00:01:31.530> and<00:01:31.770> these<00:01:32.369> corrupt<00:01:32.670> nodes<00:01:32.880> can 00:01:33.109 --> 00:01:33.119 align:start position:0% corrupt and these corrupt nodes can 00:01:33.119 --> 00:01:34.550 align:start position:0% corrupt and these corrupt nodes can behave<00:01:33.360> arbitrarily<00:01:33.930> and<00:01:34.170> deviate 00:01:34.550 --> 00:01:34.560 align:start position:0% behave arbitrarily and deviate 00:01:34.560 --> 00:01:36.499 align:start position:0% behave arbitrarily and deviate arbitrarily<00:01:34.979> from<00:01:35.220> the<00:01:35.340> protocol<00:01:35.700> and<00:01:35.880> even 00:01:36.499 --> 00:01:36.509 align:start position:0% arbitrarily from the protocol and even 00:01:36.509 --> 00:01:39.080 align:start position:0% arbitrarily from the protocol and even in<00:01:36.659> such<00:01:36.840> add<00:01:37.049> adversarial<00:01:37.979> conditions<00:01:38.460> we 00:01:39.080 --> 00:01:39.090 align:start position:0% in such add adversarial conditions we 00:01:39.090 --> 00:01:41.060 align:start position:0% in such add adversarial conditions we want<00:01:39.210> to<00:01:39.390> make<00:01:39.540> sure<00:01:39.619> that<00:01:40.619> the<00:01:40.770> remaining 00:01:41.060 --> 00:01:41.070 align:start position:0% want to make sure that the remaining 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assume<00:01:47.939> that<00:01:48.409> less<00:01:49.409> than<00:01:49.439> one<00:01:49.920> third<00:01:50.159> of<00:01:50.220> the 00:01:50.569 --> 00:01:50.579 align:start position:0% assume that less than one third of the 00:01:50.579 --> 00:01:56.359 align:start position:0% assume that less than one third of the nodes<00:01:50.759> are<00:01:50.909> corrupt<00:01:53.840> okay<00:01:54.840> so<00:01:55.740> I<00:01:55.770> will<00:01:56.070> tell 00:01:56.359 --> 00:01:56.369 align:start position:0% nodes are corrupt okay so I will tell 00:01:56.369 --> 00:01:58.190 align:start position:0% nodes are corrupt okay so I will tell you<00:01:56.490> a<00:01:56.520> very<00:01:56.909> simple<00:01:57.149> consensus<00:01:57.840> protocol 00:01:58.190 --> 00:01:58.200 align:start position:0% you a very simple consensus protocol 00:01:58.200 --> 00:01:59.539 align:start position:0% you a very simple consensus protocol that<00:01:58.350> satisfies<00:01:58.799> these<00:01:59.009> two<00:01:59.070> properties 00:01:59.539 --> 00:01:59.549 align:start position:0% that satisfies these two properties 00:01:59.549 --> 00:02:01.850 align:start position:0% that satisfies these two properties consistency<00:02:00.299> and<00:02:00.420> lightness<00:02:00.750> and<00:02:00.960> to<00:02:01.560> begin 00:02:01.850 --> 00:02:01.860 align:start position:0% consistency and lightness and to begin 00:02:01.860 --> 00:02:05.480 align:start position:0% consistency and lightness and to begin with<00:02:02.040> I<00:02:02.219> will<00:02:02.430> first<00:02:03.229> explain<00:02:04.250> somewhat<00:02:05.250> of<00:02:05.369> a 00:02:05.480 --> 00:02:05.490 align:start position:0% with I will first explain somewhat of a 00:02:05.490 --> 00:02:08.089 align:start position:0% with I will first explain somewhat of a strawman<00:02:05.790> scheme<00:02:06.299> a<00:02:06.509> protocol<00:02:07.439> that's<00:02:07.829> very 00:02:08.089 --> 00:02:08.099 align:start position:0% strawman scheme a protocol that's very 00:02:08.099 --> 00:02:08.570 align:start position:0% strawman scheme a protocol that's very natural 00:02:08.570 --> 00:02:08.580 align:start position:0% natural 00:02:08.580 --> 00:02:10.940 align:start position:0% natural it<00:02:08.729> works<00:02:08.910> by<00:02:09.149> single<00:02:10.110> round<00:02:10.319> of<00:02:10.470> voting<00:02:10.590> and 00:02:10.940 --> 00:02:10.950 align:start position:0% it works by single round of voting and 00:02:10.950 --> 00:02:11.770 align:start position:0% it works by single round of voting and this<00:02:11.520> is 00:02:11.770 --> 00:02:11.780 align:start position:0% this is 00:02:11.780 --> 00:02:14.620 align:start position:0% this is actually<00:02:12.050> Sounders<00:02:13.040> fast<00:02:13.760> path<00:02:14.030> consensus 00:02:14.620 --> 00:02:14.630 align:start position:0% actually Sounders fast path consensus 00:02:14.630 --> 00:02:17.320 align:start position:0% actually Sounders fast path consensus protocol<00:02:15.020> the<00:02:15.709> previous<00:02:16.250> version<00:02:16.610> if<00:02:17.120> you<00:02:17.240> are 00:02:17.320 --> 00:02:17.330 align:start position:0% protocol the previous version if you are 00:02:17.330 --> 00:02:19.270 align:start position:0% protocol the previous version if you are not<00:02:17.480> familiar<00:02:17.750> with<00:02:18.110> the<00:02:18.260> Sounders<00:02:18.860> protocol 00:02:19.270 --> 00:02:19.280 align:start position:0% not familiar with the Sounders protocol 00:02:19.280 --> 00:02:21.130 align:start position:0% not familiar with the Sounders protocol it<00:02:19.370> doesn't<00:02:19.610> matter<00:02:19.760> because<00:02:19.970> entire<00:02:20.810> talk<00:02:21.020> is 00:02:21.130 --> 00:02:21.140 align:start position:0% it doesn't matter because entire talk is 00:02:21.140 --> 00:02:23.530 align:start position:0% it doesn't matter because entire talk is going<00:02:21.290> to<00:02:21.380> be<00:02:21.440> self-contained<00:02:22.010> okay<00:02:22.850> so<00:02:23.360> let's 00:02:23.530 --> 00:02:23.540 align:start position:0% going to be self-contained okay so let's 00:02:23.540 --> 00:02:26.650 align:start position:0% going to be self-contained okay so let's start<00:02:23.810> with<00:02:24.740> this<00:02:24.920> very<00:02:25.700> simple<00:02:25.850> voting<00:02:26.450> place 00:02:26.650 --> 00:02:26.660 align:start position:0% start with this very simple voting place 00:02:26.660 --> 00:02:28.840 align:start position:0% start with this very simple voting place protocol<00:02:27.140> and<00:02:27.860> before<00:02:28.190> I<00:02:28.220> talk<00:02:28.459> about<00:02:28.610> the 00:02:28.840 --> 00:02:28.850 align:start position:0% protocol and before I talk about the 00:02:28.850 --> 00:02:31.870 align:start position:0% protocol and before I talk about the protocol<00:02:29.270> I<00:02:29.300> will<00:02:29.770> very<00:02:30.770> quickly<00:02:30.890> explain<00:02:31.550> the 00:02:31.870 --> 00:02:31.880 align:start position:0% protocol I will very quickly explain the 00:02:31.880 --> 00:02:34.470 align:start position:0% protocol I will very quickly explain the block<00:02:32.510> format<00:02:33.020> we<00:02:33.410> are<00:02:33.500> going<00:02:33.709> to<00:02:33.830> assume 00:02:34.470 --> 00:02:34.480 align:start position:0% block format we are going to assume 00:02:34.480 --> 00:02:37.000 align:start position:0% block format we are going to assume throughout<00:02:35.480> the<00:02:35.660> talk<00:02:35.870> right<00:02:36.140> so<00:02:36.260> in<00:02:36.440> the<00:02:36.800> talk 00:02:37.000 --> 00:02:37.010 align:start position:0% throughout the talk right so in the talk 00:02:37.010 --> 00:02:40.260 align:start position:0% throughout the talk right so in the talk we<00:02:37.910> are<00:02:37.940> going<00:02:38.030> to<00:02:38.330> assume<00:02:38.690> every<00:02:39.500> block 00:02:40.260 --> 00:02:40.270 align:start position:0% we are going to assume every block 00:02:40.270 --> 00:02:43.540 align:start position:0% we are going to assume every block contains<00:02:41.270> the<00:02:41.480> parent<00:02:41.870> hash<00:02:42.130> basically<00:02:43.130> it's 00:02:43.540 --> 00:02:43.550 align:start position:0% contains the parent hash basically it's 00:02:43.550 --> 00:02:45.250 align:start position:0% contains the parent hash basically it's a<00:02:43.670> cryptographic<00:02:44.030> digest<00:02:44.690> of<00:02:44.810> the<00:02:44.870> entire 00:02:45.250 --> 00:02:45.260 align:start position:0% a cryptographic digest of the entire 00:02:45.260 --> 00:02:48.250 align:start position:0% a cryptographic digest of the entire prefix<00:02:45.680> of<00:02:45.800> the<00:02:45.860> chain<00:02:46.390> it<00:02:47.390> has<00:02:47.690> an<00:02:47.870> epoch 00:02:48.250 --> 00:02:48.260 align:start position:0% prefix of the chain it has an epoch 00:02:48.260 --> 00:02:51.550 align:start position:0% prefix of the chain it has an epoch number<00:02:48.650> so<00:02:49.430> we<00:02:50.330> are<00:02:50.450> going<00:02:50.660> to<00:02:50.810> assume<00:02:51.110> every 00:02:51.550 --> 00:02:51.560 align:start position:0% number so we are going to assume every 00:02:51.560 --> 00:02:54.160 align:start position:0% number so we are going to assume every epoch<00:02:51.890> is<00:02:52.010> one<00:02:52.250> second<00:02:52.820> and<00:02:53.000> whenever<00:02:53.690> honest 00:02:54.160 --> 00:02:54.170 align:start position:0% epoch is one second and whenever honest 00:02:54.170 --> 00:02:56.229 align:start position:0% epoch is one second and whenever honest node<00:02:54.350> sent<00:02:54.709> a<00:02:54.890> message<00:02:55.280> the<00:02:55.610> message<00:02:55.760> is<00:02:56.060> going 00:02:56.229 --> 00:02:56.239 align:start position:0% node sent a message the message is going 00:02:56.239 --> 00:02:59.020 align:start position:0% node sent a message the message is going to<00:02:56.360> get<00:02:56.630> delivered<00:02:56.989> in<00:02:57.650> let's<00:02:58.580> say<00:02:58.730> a<00:02:58.760> quarter 00:02:59.020 --> 00:02:59.030 align:start position:0% to get delivered in let's say a quarter 00:02:59.030 --> 00:03:01.960 align:start position:0% to get delivered in let's say a quarter of<00:02:59.300> the<00:02:59.450> second<00:02:59.980> so<00:03:00.980> in<00:03:01.130> one<00:03:01.340> epic<00:03:01.670> you<00:03:01.819> can 00:03:01.960 --> 00:03:01.970 align:start position:0% of the second so in one epic you can 00:03:01.970 --> 00:03:06.640 align:start position:0% of the second so in one epic you can have<00:03:02.120> four<00:03:02.330> round<00:03:02.540> trips<00:03:04.630> for<00:03:05.630> simplicity<00:03:06.230> in 00:03:06.640 --> 00:03:06.650 align:start position:0% have four round trips for simplicity in 00:03:06.650 --> 00:03:08.050 align:start position:0% have four round trips for simplicity in this<00:03:06.860> talk<00:03:07.130> I'm<00:03:07.280> just<00:03:07.459> going<00:03:07.610> to<00:03:07.670> assume<00:03:07.910> the 00:03:08.050 --> 00:03:08.060 align:start position:0% this talk I'm just going to assume the 00:03:08.060 --> 00:03:09.850 align:start position:0% this talk I'm just going to assume the synchronous<00:03:08.540> model<00:03:08.900> basically<00:03:09.080> every<00:03:09.530> honest 00:03:09.850 --> 00:03:09.860 align:start position:0% synchronous model basically every honest 00:03:09.860 --> 00:03:11.500 align:start position:0% synchronous model basically every honest message<00:03:10.190> will<00:03:10.370> get<00:03:10.700> delivered<00:03:10.940> very<00:03:11.269> quickly 00:03:11.500 --> 00:03:11.510 align:start position:0% message will get delivered very quickly 00:03:11.510 --> 00:03:12.940 align:start position:0% message will get delivered very quickly but<00:03:11.989> at<00:03:12.140> the<00:03:12.230> end<00:03:12.380> of<00:03:12.500> the<00:03:12.590> talk<00:03:12.769> I<00:03:12.890> will 00:03:12.940 --> 00:03:12.950 align:start position:0% but at the end of the talk I will 00:03:12.950 --> 00:03:14.920 align:start position:0% but at the end of the talk I will mention<00:03:13.280> it's<00:03:13.940> actually<00:03:14.300> very<00:03:14.420> easy<00:03:14.540> to 00:03:14.920 --> 00:03:14.930 align:start position:0% mention it's actually very easy to 00:03:14.930 --> 00:03:16.420 align:start position:0% mention it's actually very easy to extend<00:03:15.260> the<00:03:15.530> approach<00:03:15.829> to<00:03:16.100> partial 00:03:16.420 --> 00:03:16.430 align:start position:0% extend the approach to partial 00:03:16.430 --> 00:03:19.270 align:start position:0% extend the approach to partial asynchronous<00:03:16.910> setting<00:03:17.209> to<00:03:17.390> okay<00:03:18.380> so<00:03:18.829> now<00:03:19.010> of 00:03:19.270 --> 00:03:19.280 align:start position:0% asynchronous setting to okay so now of 00:03:19.280 --> 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align:start position:0% make it more fun this is the scenario we are<00:03:29.720> going<00:03:29.900> to<00:03:30.019> work<00:03:30.170> with<00:03:30.410> Vitalik<00:03:31.250> acts<00:03:31.670> as 00:03:31.960 --> 00:03:31.970 align:start position:0% are going to work with Vitalik acts as 00:03:31.970 --> 00:03:33.520 align:start position:0% are going to work with Vitalik acts as the<00:03:32.120> proposer<00:03:32.450> and<00:03:32.720> everyone<00:03:33.110> else<00:03:33.320> is<00:03:33.500> a 00:03:33.520 --> 00:03:33.530 align:start position:0% the proposer and everyone else is a 00:03:33.530 --> 00:03:35.289 align:start position:0% the proposer and everyone else is a voter<00:03:33.799> right<00:03:34.430> so<00:03:34.549> some<00:03:34.730> of<00:03:34.760> these<00:03:34.970> notes<00:03:35.150> can 00:03:35.289 --> 00:03:35.299 align:start position:0% voter right so some of these notes can 00:03:35.299 --> 00:03:37.509 align:start position:0% voter right so some of these notes can be<00:03:35.450> corrupt<00:03:35.870> like<00:03:36.500> in<00:03:36.680> this<00:03:36.799> case<00:03:36.980> low<00:03:37.220> key<00:03:37.459> is 00:03:37.509 --> 00:03:37.519 align:start position:0% be corrupt like in this case low key is 00:03:37.519 --> 00:03:40.210 align:start position:0% be corrupt like in this case low key is corrupt<00:03:37.880> and<00:03:38.780> the<00:03:39.019> proposer<00:03:39.440> can<00:03:39.739> also<00:03:39.980> be 00:03:40.210 --> 00:03:40.220 align:start position:0% corrupt and the proposer can also be 00:03:40.220 --> 00:03:43.569 align:start position:0% corrupt and the proposer can also be corrupt<00:03:40.519> so<00:03:41.150> here's<00:03:41.420> how<00:03:42.290> a<00:03:42.650> very<00:03:43.310> natural 00:03:43.569 --> 00:03:43.579 align:start position:0% corrupt so here's how a very natural 00:03:43.579 --> 00:03:47.530 align:start position:0% corrupt so here's how a very natural protocol<00:03:44.180> would<00:03:44.810> work<00:03:45.459> step<00:03:46.459> number<00:03:46.640> one<00:03:46.970> the 00:03:47.530 --> 00:03:47.540 align:start position:0% protocol would work step number one the 00:03:47.540 --> 00:03:49.479 align:start position:0% protocol would work step number one the proposer<00:03:47.900> makes<00:03:48.260> a<00:03:48.380> proposal<00:03:48.709> and<00:03:49.220> the 00:03:49.479 --> 00:03:49.489 align:start position:0% proposer makes a proposal and the 00:03:49.489 --> 00:03:51.340 align:start position:0% proposer makes a proposal and the proposal<00:03:49.519> contains<00:03:50.239> a<00:03:50.359> block<00:03:50.570> and<00:03:50.810> the<00:03:51.320> block 00:03:51.340 --> 00:03:51.350 align:start position:0% proposal contains a block and the block 00:03:51.350 --> 00:03:54.539 align:start position:0% proposal contains a block and the block is<00:03:51.590> tagged<00:03:51.980> with<00:03:52.190> the<00:03:52.420> epoch<00:03:53.420> number 00:03:54.539 --> 00:03:54.549 align:start position:0% is tagged with the epoch number 00:03:54.549 --> 00:03:58.229 align:start position:0% is tagged with the epoch number indicating<00:03:55.549> the<00:03:55.640> current<00:03:55.940> epoch<00:03:56.299> okay<00:03:57.019> now 00:03:58.229 --> 00:03:58.239 align:start position:0% indicating the current epoch okay now 00:03:58.239 --> 00:04:02.199 align:start position:0% indicating the current epoch okay now when<00:03:59.239> the<00:04:00.019> voters<00:04:00.549> receive<00:04:01.549> the<00:04:01.730> proposal 00:04:02.199 --> 00:04:02.209 align:start position:0% when the voters receive the proposal 00:04:02.209 --> 00:04:03.970 align:start position:0% when the voters receive the proposal they<00:04:02.299> are<00:04:02.390> going<00:04:02.510> to<00:04:02.720> vote<00:04:02.930> on<00:04:03.230> the<00:04:03.620> proposal 00:04:03.970 --> 00:04:03.980 align:start position:0% they are going to vote on the proposal 00:04:03.980 --> 00:04:06.780 align:start position:0% they are going to vote on the proposal right<00:04:04.400> and<00:04:04.730> in<00:04:05.510> this<00:04:05.690> case 00:04:06.780 --> 00:04:06.790 align:start position:0% right and in this case 00:04:06.790 --> 00:04:11.170 align:start position:0% right and in this case Vitalik<00:04:07.790> proposed<00:04:08.239> an<00:04:08.510> orange<00:04:09.260> block<00:04:09.970> so<00:04:10.970> if 00:04:11.170 --> 00:04:11.180 align:start position:0% Vitalik proposed an orange block so if 00:04:11.180 --> 00:04:12.580 align:start position:0% Vitalik proposed an orange block so if you<00:04:11.299> are<00:04:11.390> honest<00:04:11.810> you<00:04:11.900> are<00:04:12.019> going<00:04:12.290> to<00:04:12.410> vote 00:04:12.580 --> 00:04:12.590 align:start position:0% you are honest you are going to vote 00:04:12.590 --> 00:04:15.210 align:start position:0% you are honest you are going to vote exactly<00:04:13.579> the<00:04:14.030> proposal<00:04:14.450> you<00:04:14.480> have<00:04:14.750> received 00:04:15.210 --> 00:04:15.220 align:start position:0% exactly the proposal you have received 00:04:15.220 --> 00:04:19.090 align:start position:0% exactly the proposal you have received so<00:04:16.220> everyone<00:04:16.609> almost<00:04:17.329> everyone<00:04:17.979> casts<00:04:18.979> an 00:04:19.090 --> 00:04:19.100 align:start position:0% so everyone almost everyone casts an 00:04:19.100 --> 00:04:21.759 align:start position:0% so everyone almost everyone casts an orange<00:04:19.519> vote<00:04:19.780> except<00:04:20.780> for<00:04:20.959> Loki<00:04:21.289> right<00:04:21.500> Loki 00:04:21.759 --> 00:04:21.769 align:start position:0% orange vote except for Loki right Loki 00:04:21.769 --> 00:04:22.990 align:start position:0% orange vote except for Loki right Loki is<00:04:21.890> corrupt 00:04:22.990 --> 00:04:23.000 align:start position:0% is corrupt 00:04:23.000 --> 00:04:25.690 align:start position:0% is corrupt and<00:04:23.090> instead<00:04:23.840> of<00:04:23.960> voting<00:04:24.650> honestly<00:04:25.280> he<00:04:25.490> voted 00:04:25.690 --> 00:04:25.700 align:start position:0% and instead of voting honestly he voted 00:04:25.700 --> 00:04:32.640 align:start position:0% and instead of voting honestly he voted for<00:04:26.380> you<00:04:27.380> know<00:04:27.500> two<00:04:27.610> blue<00:04:28.610> blocks<00:04:30.220> okay<00:04:31.220> so<00:04:31.700> now 00:04:32.640 --> 00:04:32.650 align:start position:0% for you know two blue blocks okay so now 00:04:32.650 --> 00:04:35.830 align:start position:0% for you know two blue blocks okay so now we<00:04:33.650> have<00:04:33.830> voted<00:04:34.220> what<00:04:34.850> do<00:04:34.970> we<00:04:35.090> do<00:04:35.240> next 00:04:35.830 --> 00:04:35.840 align:start position:0% we have voted what do we do next 00:04:35.840 --> 00:04:38.650 align:start position:0% we have voted what do we do next we<00:04:36.260> basically<00:04:36.470> wait<00:04:37.010> we<00:04:37.820> wait<00:04:38.030> until<00:04:38.330> we 00:04:38.650 --> 00:04:38.660 align:start position:0% we basically wait we wait until we 00:04:38.660 --> 00:04:41.310 align:start position:0% we basically wait we wait until we collect<00:04:38.990> enough<00:04:39.320> votes<00:04:39.620> on<00:04:39.860> the<00:04:40.490> same<00:04:40.670> block 00:04:41.310 --> 00:04:41.320 align:start position:0% collect enough votes on the same block 00:04:41.320 --> 00:04:43.480 align:start position:0% collect enough votes on the same block and<00:04:42.320> when<00:04:42.500> there<00:04:42.680> are<00:04:42.710> enough<00:04:43.010> votes<00:04:43.250> on<00:04:43.370> the 00:04:43.480 --> 00:04:43.490 align:start position:0% and when there are enough votes on the 00:04:43.490 --> 00:04:44.740 align:start position:0% and when there are enough votes on the same<00:04:43.670> block<00:04:43.880> we<00:04:44.090> have<00:04:44.120> high<00:04:44.480> enough 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2/3 the 00:04:53.120 --> 00:04:55.900 align:start position:0% going to assume votes from 2/3 the committee<00:04:53.420> is<00:04:54.200> considered<00:04:54.770> enough<00:04:55.160> and<00:04:55.430> in 00:04:55.900 --> 00:04:55.910 align:start position:0% committee is considered enough and in 00:04:55.910 --> 00:05:00.159 align:start position:0% committee is considered enough and in fact<00:04:56.140> if<00:04:57.220> we<00:04:58.220> have<00:04:58.370> 2/3<00:04:58.850> votes<00:04:59.120> we<00:04:59.870> are<00:04:59.990> going 00:05:00.159 --> 00:05:00.169 align:start position:0% fact if we have 2/3 votes we are going 00:05:00.169 --> 00:05:05.710 align:start position:0% fact if we have 2/3 votes we are going to<00:05:00.290> cut<00:05:00.470> that<00:05:00.650> a<00:05:00.890> notarization<00:05:02.200> okay<00:05:04.690> so<00:05:05.690> a 00:05:05.710 --> 00:05:05.720 align:start position:0% to cut that a notarization okay so a 00:05:05.720 --> 00:05:08.020 align:start position:0% to cut that a notarization okay so a very<00:05:05.990> important<00:05:06.560> thing<00:05:06.770> to<00:05:07.550> remember<00:05:07.640> about 00:05:08.020 --> 00:05:08.030 align:start position:0% very important thing to remember about 00:05:08.030 --> 00:05:12.250 align:start position:0% very important thing to remember about this<00:05:08.360> protocol<00:05:08.780> is<00:05:09.080> that<00:05:10.570> all<00:05:11.570> of<00:05:11.630> the<00:05:11.930> honest 00:05:12.250 --> 00:05:12.260 align:start position:0% this protocol is that all of the honest 00:05:12.260 --> 00:05:13.870 align:start position:0% this protocol is that all of the honest notes<00:05:12.470> are<00:05:12.650> going<00:05:12.860> to<00:05:12.980> vote<00:05:13.100> to<00:05:13.280> uniquely<00:05:13.700> in 00:05:13.870 --> 00:05:13.880 align:start position:0% notes are going to vote to uniquely in 00:05:13.880 --> 00:05:16.210 align:start position:0% notes are going to vote to uniquely in every<00:05:14.180> epoch<00:05:14.510> this<00:05:15.320> means<00:05:15.590> that<00:05:15.740> in<00:05:15.950> every 00:05:16.210 --> 00:05:16.220 align:start position:0% every epoch this means that in every 00:05:16.220 --> 00:05:19.000 align:start position:0% every epoch this means that in every epoch<00:05:16.580> I'm<00:05:17.390> going<00:05:17.750> to<00:05:17.900> wait<00:05:18.230> until<00:05:18.440> I<00:05:18.680> hear<00:05:18.950> the 00:05:19.000 --> 00:05:19.010 align:start position:0% epoch I'm going to wait until I hear the 00:05:19.010 --> 00:05:21.640 align:start position:0% epoch I'm going to wait until I hear the first<00:05:19.370> proposal<00:05:19.700> from<00:05:19.910> the<00:05:20.350> proposer<00:05:21.350> I'm 00:05:21.640 --> 00:05:21.650 align:start position:0% first proposal from the proposer I'm 00:05:21.650 --> 00:05:24.430 align:start position:0% first proposal from the proposer I'm going<00:05:22.460> to<00:05:22.550> vote<00:05:22.700> on<00:05:22.910> that<00:05:23.240> proposal<00:05:23.419> and<00:05:23.960> only 00:05:24.430 --> 00:05:24.440 align:start position:0% going to vote on that proposal and only 00:05:24.440 --> 00:05:25.870 align:start position:0% going to vote on that proposal and only that<00:05:24.590> proposal<00:05:25.070> I'm<00:05:25.160> not<00:05:25.340> going<00:05:25.490> to<00:05:25.580> vote<00:05:25.700> on 00:05:25.870 --> 00:05:25.880 align:start position:0% that proposal I'm not going to vote on 00:05:25.880 --> 00:05:26.500 align:start position:0% that proposal I'm not going to vote on anything<00:05:26.090> else 00:05:26.500 --> 00:05:26.510 align:start position:0% anything else 00:05:26.510 --> 00:05:28.840 align:start position:0% anything else so<00:05:27.169> this<00:05:27.380> invariant<00:05:27.950> is<00:05:28.100> very<00:05:28.310> important<00:05:28.729> for 00:05:28.840 --> 00:05:28.850 align:start position:0% so this invariant is very important for 00:05:28.850 --> 00:05:31.030 align:start position:0% so this invariant is very important for consistency<00:05:29.479> and<00:05:29.690> in<00:05:30.320> fact<00:05:30.500> given<00:05:30.919> this 00:05:31.030 --> 00:05:31.040 align:start position:0% consistency and in fact given this 00:05:31.040 --> 00:05:34.860 align:start position:0% consistency and in fact given this invariant<00:05:31.850> I<00:05:32.090> can<00:05:32.810> give<00:05:33.620> you<00:05:33.770> a<00:05:33.800> very<00:05:34.190> simple 00:05:34.860 --> 00:05:34.870 align:start position:0% invariant I can give you a very simple 00:05:34.870 --> 00:05:38.920 align:start position:0% invariant I can give you a very simple consistency<00:05:35.870> proof<00:05:36.640> ok<00:05:37.640> so<00:05:38.419> imagine 00:05:38.920 --> 00:05:38.930 align:start position:0% consistency proof ok so imagine 00:05:38.930 --> 00:05:41.850 align:start position:0% consistency proof ok so imagine let's<00:05:39.169> fix<00:05:39.380> an<00:05:39.590> epoch<00:05:40.000> ok<00:05:41.000> so<00:05:41.060> imagine<00:05:41.300> for 00:05:41.850 --> 00:05:41.860 align:start position:0% let's fix an epoch ok so imagine for 00:05:41.860 --> 00:05:45.490 align:start position:0% let's fix an epoch ok so imagine for this<00:05:42.860> epoch<00:05:43.280> the<00:05:43.550> blue<00:05:44.240> block<00:05:44.510> obtained 00:05:45.490 --> 00:05:45.500 align:start position:0% this epoch the blue block obtained 00:05:45.500 --> 00:05:47.500 align:start position:0% this epoch the blue block obtained notarization<00:05:46.040> and<00:05:46.430> the<00:05:47.030> orange<00:05:47.300> block 00:05:47.500 --> 00:05:47.510 align:start position:0% notarization and the orange block 00:05:47.510 --> 00:05:49.990 align:start position:0% notarization and the orange block obtained<00:05:47.960> notarization<00:05:48.440> -<00:05:48.770> and<00:05:49.040> what<00:05:49.700> I<00:05:49.729> want 00:05:49.990 --> 00:05:50.000 align:start position:0% obtained notarization - and what I want 00:05:50.000 --> 00:05:51.820 align:start position:0% obtained notarization - and what I want to<00:05:50.120> prove<00:05:50.330> is<00:05:50.570> that<00:05:50.630> the<00:05:50.810> blue<00:05:51.080> block<00:05:51.320> must<00:05:51.620> be 00:05:51.820 --> 00:05:51.830 align:start position:0% to prove is that the blue block must be 00:05:51.830 --> 00:05:53.460 align:start position:0% to prove is that the blue block must be the<00:05:51.950> same<00:05:52.130> as<00:05:52.370> the<00:05:52.580> orange<00:05:52.880> block<00:05:53.120> and 00:05:53.460 --> 00:05:53.470 align:start position:0% the same as the orange block and 00:05:53.470 --> 00:05:56.320 align:start position:0% the same as the orange block and remember<00:05:54.470> as<00:05:54.830> I<00:05:55.010> said<00:05:55.040> in<00:05:55.400> the<00:05:55.460> beginning<00:05:55.550> we 00:05:56.320 --> 00:05:56.330 align:start position:0% remember as I said in the beginning we 00:05:56.330 --> 00:05:57.760 align:start position:0% remember as I said in the beginning we are<00:05:56.360> going<00:05:56.630> to<00:05:56.750> assume<00:05:57.020> less<00:05:57.350> than<00:05:57.560> when 00:05:57.760 --> 00:05:57.770 align:start position:0% are going to assume less than when 00:05:57.770 --> 00:06:00.790 align:start position:0% are going to assume less than when certain<00:05:58.010> notes<00:05:58.310> are<00:05:58.820> corrupt<00:05:59.320> okay<00:06:00.320> so<00:06:00.650> how 00:06:00.790 --> 00:06:00.800 align:start position:0% certain notes are corrupt okay so how 00:06:00.800 --> 00:06:03.340 align:start position:0% certain notes are corrupt okay so how does<00:06:00.860> the<00:06:01.070> proof<00:06:01.250> work<00:06:01.600> if<00:06:02.600> you<00:06:02.810> look<00:06:03.080> at<00:06:03.229> the 00:06:03.340 --> 00:06:03.350 align:start position:0% does the proof work if you look at the 00:06:03.350 --> 00:06:06.580 align:start position:0% does the proof work if you look at the blue<00:06:03.530> set<00:06:03.770> and<00:06:03.800> orange<00:06:04.250> set<00:06:05.200> and<00:06:06.200> remember 00:06:06.580 --> 00:06:06.590 align:start position:0% blue set and orange set and remember 00:06:06.590 --> 00:06:08.740 align:start position:0% blue set and orange set and remember there<00:06:06.710> are<00:06:06.800> only<00:06:06.919> n<00:06:07.010> nodes<00:06:07.370> in<00:06:07.550> total<00:06:07.880> right<00:06:08.090> so 00:06:08.740 --> 00:06:08.750 align:start position:0% there are only n nodes in total right so 00:06:08.750 --> 00:06:09.820 align:start position:0% there are only n nodes in total right so it<00:06:08.870> must<00:06:09.050> be<00:06:09.200> the<00:06:09.320> case<00:06:09.500> that<00:06:09.680> the 00:06:09.820 --> 00:06:09.830 align:start position:0% it must be the case that the 00:06:09.830 --> 00:06:12.670 align:start position:0% it must be the case that the intersection<00:06:10.400> contains<00:06:10.880> at<00:06:11.060> at<00:06:11.870> least<00:06:12.229> one 00:06:12.670 --> 00:06:12.680 align:start position:0% intersection contains at at least one 00:06:12.680 --> 00:06:16.060 align:start position:0% intersection contains at at least one third<00:06:12.919> and<00:06:13.100> nodes<00:06:13.430> and<00:06:14.050> now<00:06:15.050> because<00:06:15.950> the 00:06:16.060 --> 00:06:16.070 align:start position:0% third and nodes and now because the 00:06:16.070 --> 00:06:17.909 align:start position:0% third and nodes and now because the adversary<00:06:16.340> controls<00:06:16.850> less<00:06:17.090> than<00:06:17.300> one<00:06:17.479> third 00:06:17.909 --> 00:06:17.919 align:start position:0% adversary controls less than one third 00:06:17.919 --> 00:06:20.350 align:start position:0% adversary controls less than one third this<00:06:18.919> means<00:06:19.190> there<00:06:19.370> must<00:06:19.610> be<00:06:19.760> an<00:06:19.850> honest<00:06:20.210> node 00:06:20.350 --> 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basically<00:06:35.030> the<00:06:35.150> blue<00:06:35.330> block 00:06:36.310 --> 00:06:36.320 align:start position:0% basically the blue block 00:06:36.320 --> 00:06:40.110 align:start position:0% basically the blue block be<00:06:36.470> the<00:06:36.590> same<00:06:36.770> as<00:06:36.950> orange<00:06:38.170> okay<00:06:39.170> so<00:06:39.740> this 00:06:40.110 --> 00:06:40.120 align:start position:0% be the same as orange okay so this 00:06:40.120 --> 00:06:42.700 align:start position:0% be the same as orange okay so this establishes<00:06:41.120> the<00:06:41.270> fact<00:06:41.450> that<00:06:41.630> with<00:06:42.290> this<00:06:42.500> very 00:06:42.700 --> 00:06:42.710 align:start position:0% establishes the fact that with this very 00:06:42.710 --> 00:06:45.970 align:start position:0% establishes the fact that with this very simple<00:06:43.070> protocol<00:06:43.460> for<00:06:44.090> every<00:06:44.570> epoch<00:06:44.990> only<00:06:45.680> one 00:06:45.970 --> 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align:start position:0% consistency proof doesn't rely on the proposer<00:06:56.450> being<00:06:56.780> honest<00:06:57.110> the<00:06:58.010> only<00:06:58.040> thing<00:06:58.400> it 00:06:58.510 --> 00:06:58.520 align:start position:0% proposer being honest the only thing it 00:06:58.520 --> 00:07:00.370 align:start position:0% proposer being honest the only thing it relies<00:06:58.850> on<00:06:59.090> is<00:06:59.360> the<00:06:59.510> fact<00:06:59.720> that<00:06:59.780> honest<00:07:00.200> notes 00:07:00.370 --> 00:07:00.380 align:start position:0% relies on is the fact that honest notes 00:07:00.380 --> 00:07:03.670 align:start position:0% relies on is the fact that honest notes vote<00:07:00.710> uniquely<00:07:01.840> okay<00:07:02.840> so<00:07:02.900> with<00:07:03.170> this<00:07:03.320> in<00:07:03.470> mind 00:07:03.670 --> 00:07:03.680 align:start position:0% vote uniquely okay so with this in mind 00:07:03.680 --> 00:07:06.550 align:start position:0% vote uniquely okay so with this in mind let's<00:07:04.630> take<00:07:05.630> a<00:07:05.660> step<00:07:05.960> back<00:07:06.140> and<00:07:06.320> think<00:07:06.500> about 00:07:06.550 --> 00:07:06.560 align:start position:0% let's take a step back and think about 00:07:06.560 --> 00:07:09.040 align:start position:0% let's take a step back and think about this<00:07:06.830> very<00:07:07.040> simple<00:07:07.400> protocol<00:07:07.760> right<00:07:07.940> as<00:07:08.840> I 00:07:09.040 --> 00:07:09.050 align:start position:0% this very simple protocol right as I 00:07:09.050 --> 00:07:10.510 align:start position:0% this very simple protocol right as I said<00:07:09.290> we<00:07:09.440> are<00:07:09.470> going<00:07:09.650> to<00:07:09.770> assume<00:07:10.010> two-thirds 00:07:10.510 --> 00:07:10.520 align:start position:0% said we are going to assume two-thirds 00:07:10.520 --> 00:07:12.190 align:start position:0% said we are going to assume two-thirds of<00:07:10.700> the<00:07:10.850> nodes<00:07:11.030> are<00:07:11.210> honest<00:07:11.510> and<00:07:11.690> online<00:07:11.960> and 00:07:12.190 --> 00:07:12.200 align:start position:0% of the nodes are honest and online and 00:07:12.200 --> 00:07:16.270 align:start position:0% of the nodes are honest and online and when<00:07:13.100> the<00:07:13.280> proposer<00:07:14.240> is<00:07:14.600> honest<00:07:15.020> life<00:07:15.890> is<00:07:16.100> all 00:07:16.270 --> 00:07:16.280 align:start position:0% when the proposer is honest life is all 00:07:16.280 --> 00:07:18.070 align:start position:0% when the proposer is honest life is all good<00:07:16.520> we<00:07:16.910> have<00:07:17.060> both<00:07:17.240> consistency<00:07:17.960> and 00:07:18.070 --> 00:07:18.080 align:start position:0% good we have both consistency and 00:07:18.080 --> 00:07:20.410 align:start position:0% good we have both consistency and liveness<00:07:18.670> consistency<00:07:19.670> I've<00:07:19.850> just<00:07:20.030> proved<00:07:20.300> to 00:07:20.410 --> 00:07:20.420 align:start position:0% liveness consistency I've just proved to 00:07:20.420 --> 00:07:22.600 align:start position:0% liveness consistency I've just proved to you<00:07:20.540> life<00:07:21.500> this<00:07:21.710> is<00:07:21.890> all<00:07:22.010> so<00:07:22.160> simple<00:07:22.370> because 00:07:22.600 --> 00:07:22.610 align:start position:0% you life this is all so simple because 00:07:22.610 --> 00:07:24.220 align:start position:0% you life this is all so simple because if<00:07:22.880> the<00:07:23.000> proposer<00:07:23.300> is<00:07:23.480> honesty<00:07:23.900> is<00:07:23.960> going<00:07:24.140> to 00:07:24.220 --> 00:07:24.230 align:start position:0% if the proposer is honesty is going to 00:07:24.230 --> 00:07:25.830 align:start position:0% if the proposer is honesty is going to propose<00:07:24.470> the<00:07:24.650> same<00:07:24.680> thing<00:07:24.980> to<00:07:25.070> everyone<00:07:25.460> and 00:07:25.830 --> 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collect enough votes and you make progress<00:07:32.200> so<00:07:33.200> when<00:07:33.350> the<00:07:33.500> proposer<00:07:33.800> is<00:07:34.040> corrupt 00:07:34.360 --> 00:07:34.370 align:start position:0% progress so when the proposer is corrupt 00:07:34.370 --> 00:07:37.300 align:start position:0% progress so when the proposer is corrupt what<00:07:35.300> happens<00:07:35.630> in<00:07:36.350> this<00:07:36.530> case<00:07:36.710> we<00:07:36.890> still<00:07:37.100> have 00:07:37.300 --> 00:07:37.310 align:start position:0% what happens in this case we still have 00:07:37.310 --> 00:07:39.400 align:start position:0% what happens in this case we still have consistency<00:07:37.880> because<00:07:38.270> as<00:07:38.450> I<00:07:38.480> argued<00:07:38.600> the 00:07:39.400 --> 00:07:39.410 align:start position:0% consistency because as I argued the 00:07:39.410 --> 00:07:40.870 align:start position:0% consistency because as I argued the consistency<00:07:39.980> proof<00:07:40.190> doesn't<00:07:40.400> rely<00:07:40.850> on 00:07:40.870 --> 00:07:40.880 align:start position:0% consistency proof doesn't rely on 00:07:40.880 --> 00:07:44.380 align:start position:0% consistency proof doesn't rely on proposer<00:07:41.870> being<00:07:42.170> honest<00:07:42.530> right<00:07:43.310> but<00:07:44.180> we<00:07:44.240> don't 00:07:44.380 --> 00:07:44.390 align:start position:0% proposer being honest right but we don't 00:07:44.390 --> 00:07:46.480 align:start position:0% proposer being honest right but we don't have<00:07:44.570> liveness<00:07:44.900> because<00:07:45.710> the<00:07:45.830> proposer<00:07:46.160> can't 00:07:46.480 --> 00:07:46.490 align:start position:0% have liveness because the proposer can't 00:07:46.490 --> 00:07:49.000 align:start position:0% have liveness because the proposer can't just<00:07:46.670> crash<00:07:47.450> and<00:07:47.780> fail<00:07:48.080> to<00:07:48.110> propose<00:07:48.560> anything 00:07:49.000 --> 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block and 00:07:54.440 --> 00:07:56.590 align:start position:0% end up voting on a different block and no<00:07:54.800> block<00:07:55.070> will<00:07:55.310> gain<00:07:55.550> notarization<00:07:56.210> in<00:07:56.480> this 00:07:56.590 --> 00:07:56.600 align:start position:0% no block will gain notarization in this 00:07:56.600 --> 00:07:59.650 align:start position:0% no block will gain notarization in this case<00:07:57.520> so<00:07:58.520> ok<00:07:58.700> so<00:07:58.730> now<00:07:58.940> if<00:07:59.120> you<00:07:59.210> look<00:07:59.240> at<00:07:59.540> this 00:07:59.650 --> 00:07:59.660 align:start position:0% case so ok so now if you look at this 00:07:59.660 --> 00:08:02.320 align:start position:0% case so ok so now if you look at this picture<00:08:00.080> we<00:08:00.890> have<00:08:00.920> three<00:08:01.490> out<00:08:01.760> of<00:08:01.820> the<00:08:02.150> four 00:08:02.320 --> 00:08:02.330 align:start position:0% picture we have three out of the four 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proposer is corrupt and if we can fix that<00:08:09.080> we<00:08:09.260> can<00:08:09.410> get<00:08:09.590> the<00:08:09.650> four<00:08:09.890> consensus 00:08:10.390 --> 00:08:10.400 align:start position:0% that we can get the four consensus 00:08:10.400 --> 00:08:13.720 align:start position:0% that we can get the four consensus protocol<00:08:11.590> okay<00:08:12.590> before<00:08:12.770> I<00:08:12.920> talk<00:08:13.190> about<00:08:13.220> Paulo 00:08:13.720 --> 00:08:13.730 align:start position:0% protocol okay before I talk about Paulo 00:08:13.730 --> 00:08:18.190 align:start position:0% protocol okay before I talk about Paulo I<00:08:14.110> want<00:08:15.110> to<00:08:15.200> quickly<00:08:15.410> mention<00:08:16.840> the<00:08:17.840> approach 00:08:18.190 --> 00:08:18.200 align:start position:0% I want to quickly mention the approach 00:08:18.200 --> 00:08:20.500 align:start position:0% I want to quickly mention the approach that's<00:08:18.500> used<00:08:18.650> by<00:08:19.460> the<00:08:19.520> previous<00:08:20.000> version<00:08:20.420> of 00:08:20.500 --> 00:08:20.510 align:start position:0% that's used by the previous version of 00:08:20.510 --> 00:08:21.820 align:start position:0% that's used by the previous version of the<00:08:20.660> standard<00:08:20.990> protocol<00:08:21.380> right<00:08:21.560> in<00:08:21.710> the 00:08:21.820 --> 00:08:21.830 align:start position:0% the standard protocol right in the 00:08:21.830 --> 00:08:22.870 align:start position:0% the standard protocol right in the previous<00:08:22.160> version<00:08:22.460> of<00:08:22.490> the<00:08:22.610> time<00:08:22.760> the 00:08:22.870 --> 00:08:22.880 align:start position:0% previous version of the time the 00:08:22.880 --> 00:08:26.620 align:start position:0% previous version of the time the protocol<00:08:23.410> the<00:08:24.410> idea<00:08:24.800> is<00:08:25.040> that<00:08:25.340> we<00:08:26.330> have<00:08:26.510> the 00:08:26.620 --> 00:08:26.630 align:start position:0% protocol the idea is that we have the 00:08:26.630 --> 00:08:28.720 align:start position:0% protocol the idea is that we have the fast<00:08:26.840> path<00:08:27.110> and<00:08:27.320> the<00:08:27.440> slow<00:08:27.650> chain<00:08:27.890> the<00:08:28.520> slow 00:08:28.720 --> 00:08:28.730 align:start position:0% fast path and the slow chain the slow 00:08:28.730 --> 00:08:30.640 align:start position:0% fast path and the slow chain the slow chain<00:08:28.940> is<00:08:29.090> basically<00:08:29.480> think<00:08:30.260> of<00:08:30.380> it<00:08:30.530> as 00:08:30.640 --> 00:08:30.650 align:start position:0% chain is basically think of it as 00:08:30.650 --> 00:08:33.040 align:start position:0% chain is basically think of it as aetherium<00:08:31.160> as<00:08:31.310> Bitcoin<00:08:31.580> but<00:08:32.330> it<00:08:32.510> can<00:08:32.719> also<00:08:32.870> be 00:08:33.040 --> 00:08:33.050 align:start position:0% aetherium as Bitcoin but it can also be 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00:08:42.339 align:start position:0% protocol like I just explained but when the<00:08:40.640> proposal<00:08:40.940> crashes<00:08:41.630> and<00:08:41.840> the<00:08:41.930> fast<00:08:42.110> path 00:08:42.339 --> 00:08:42.349 align:start position:0% the proposal crashes and the fast path 00:08:42.349 --> 00:08:45.070 align:start position:0% the proposal crashes and the fast path doesn't<00:08:42.680> have<00:08:42.800> liveness<00:08:43.480> we<00:08:44.480> will<00:08:44.720> fall<00:08:45.050> back 00:08:45.070 --> 00:08:45.080 align:start position:0% doesn't have liveness we will fall back 00:08:45.080 --> 00:08:47.800 align:start position:0% doesn't have liveness we will fall back to<00:08:45.290> the<00:08:45.560> slow<00:08:45.740> chain<00:08:46.010> and<00:08:46.310> we<00:08:47.120> use<00:08:47.420> the<00:08:47.600> slow 00:08:47.800 --> 00:08:47.810 align:start position:0% to the slow chain and we use the slow 00:08:47.810 --> 00:08:49.270 align:start position:0% to the slow chain and we use the slow chain<00:08:48.020> to<00:08:48.140> resolve<00:08:48.440> the<00:08:48.560> problem<00:08:48.920> and<00:08:49.040> to 00:08:49.270 --> 00:08:49.280 align:start position:0% chain to resolve the problem and to 00:08:49.280 --> 00:08:50.410 align:start position:0% chain to resolve the problem and to really 00:08:50.410 --> 00:08:50.420 align:start position:0% really 00:08:50.420 --> 00:08:52.840 align:start position:0% really the<00:08:50.660> next<00:08:50.960> proposer<00:08:51.320> and<00:08:51.650> now<00:08:52.250> you<00:08:52.310> can<00:08:52.520> reboot 00:08:52.840 --> 00:08:52.850 align:start position:0% the next proposer and now you can reboot 00:08:52.850 --> 00:08:56.470 align:start position:0% the next proposer and now you can reboot strap<00:08:53.120> the<00:08:53.240> fast<00:08:53.450> path<00:08:54.430> okay<00:08:55.430> so<00:08:56.060> this<00:08:56.210> is<00:08:56.450> a 00:08:56.470 --> 00:08:56.480 align:start position:0% strap the fast path okay so this is a 00:08:56.480 --> 00:08:59.080 align:start position:0% strap the fast path okay so this is a very<00:08:56.750> simple<00:08:57.110> and<00:08:57.260> powerful<00:08:57.410> idea<00:08:58.090> when 00:08:59.080 --> 00:08:59.090 align:start position:0% very simple and powerful idea when 00:08:59.090 --> 00:09:02.110 align:start position:0% very simple and powerful idea when drawback<00:08:59.630> is<00:08:59.870> that<00:09:00.110> if<00:09:01.010> you<00:09:01.279> use<00:09:01.520> this 00:09:02.110 --> 00:09:02.120 align:start position:0% drawback is that if you use this 00:09:02.120 --> 00:09:04.480 align:start position:0% drawback is that if you use this approach<00:09:02.510> to<00:09:03.290> fall<00:09:03.500> back<00:09:03.680> to<00:09:03.710> the<00:09:03.860> slow<00:09:04.190> chain 00:09:04.480 --> 00:09:04.490 align:start position:0% approach to fall back to the slow chain 00:09:04.490 --> 00:09:07.570 align:start position:0% approach to fall back to the slow chain to<00:09:05.360> fix<00:09:05.570> the<00:09:05.810> the<00:09:06.080> proposer<00:09:06.440> then<00:09:07.430> the 00:09:07.570 --> 00:09:07.580 align:start position:0% to fix the the proposer then the 00:09:07.580 --> 00:09:09.130 align:start position:0% to fix the the proposer then the proposal<00:09:08.060> switch<00:09:08.270> is<00:09:08.480> going<00:09:08.570> to<00:09:08.839> take<00:09:08.990> about 00:09:09.130 --> 00:09:09.140 align:start position:0% proposal switch is going to take about 00:09:09.140 --> 00:09:12.340 align:start position:0% proposal switch is going to take about ten<00:09:10.040> minutes<00:09:10.240> if<00:09:11.240> let's<00:09:11.660> say<00:09:11.839> we<00:09:11.990> use<00:09:12.020> a 00:09:12.340 --> 00:09:12.350 align:start position:0% ten minutes if let's say we use a 00:09:12.350 --> 00:09:14.079 align:start position:0% ten minutes if let's say we use a theorem<00:09:12.680> as<00:09:12.830> a<00:09:12.860> slow<00:09:13.160> chain<00:09:13.370> and<00:09:13.610> that's 00:09:14.079 --> 00:09:14.089 align:start position:0% theorem as a slow chain and that's 00:09:14.089 --> 00:09:16.630 align:start position:0% theorem as a slow chain and that's rather<00:09:14.480> slow<00:09:14.870> and<00:09:14.900> one<00:09:15.770> implication<00:09:16.130> of<00:09:16.460> this 00:09:16.630 --> 00:09:16.640 align:start position:0% rather slow and one implication of this 00:09:16.640 --> 00:09:21.310 align:start position:0% rather slow and one implication of this is<00:09:16.700> that<00:09:16.880> if<00:09:17.630> we<00:09:17.960> want<00:09:18.260> to<00:09:18.520> have<00:09:19.520> an<00:09:19.910> if<00:09:20.870> we<00:09:21.080> want 00:09:21.310 --> 00:09:21.320 align:start position:0% is that if we want to have an if we want 00:09:21.320 --> 00:09:23.230 align:start position:0% is that if we want to have an if we want the<00:09:21.470> proposer<00:09:21.860> to<00:09:22.100> be<00:09:22.220> like<00:09:22.370> decentralized<00:09:23.000> on 00:09:23.230 --> 00:09:23.240 align:start position:0% the proposer to be like decentralized on 00:09:23.240 --> 00:09:26.320 align:start position:0% the proposer to be like decentralized on the<00:09:23.779> fast<00:09:23.990> path<00:09:24.370> it's<00:09:25.370> kind<00:09:25.730> of<00:09:25.880> impossible 00:09:26.320 --> 00:09:26.330 align:start position:0% the fast path it's kind of impossible 00:09:26.330 --> 00:09:27.760 align:start position:0% the fast path it's kind of impossible because<00:09:26.750> every<00:09:26.990> time<00:09:27.140> we<00:09:27.320> switch<00:09:27.589> the 00:09:27.760 --> 00:09:27.770 align:start position:0% because every time we switch the 00:09:27.770 --> 00:09:28.720 align:start position:0% because every time we switch the proposer<00:09:28.070> it's<00:09:28.279> going<00:09:28.460> to<00:09:28.550> cause 00:09:28.720 --> 00:09:28.730 align:start position:0% proposer it's going to cause 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the mechanism to allow us to rotate<00:09:39.170> the<00:09:39.680> proposer<00:09:40.010> on<00:09:40.250> the<00:09:40.370> fast<00:09:40.580> path<00:09:40.820> in 00:09:41.230 --> 00:09:41.240 align:start position:0% rotate the proposer on the fast path in 00:09:41.240 --> 00:09:44.230 align:start position:0% rotate the proposer on the fast path in the<00:09:41.540> seamless<00:09:41.960> manner<00:09:42.370> and<00:09:43.370> that's<00:09:43.640> what<00:09:44.120> I'm 00:09:44.230 --> 00:09:44.240 align:start position:0% the seamless manner and that's what I'm 00:09:44.240 --> 00:09:45.519 align:start position:0% the seamless manner and that's what I'm going<00:09:44.420> to<00:09:44.570> talk<00:09:44.720> about<00:09:44.839> I'm<00:09:45.110> going<00:09:45.260> to<00:09:45.350> talk 00:09:45.519 --> 00:09:45.529 align:start position:0% going to talk about I'm going to talk 00:09:45.529 --> 00:09:48.190 align:start position:0% going to talk about I'm going to talk about<00:09:45.650> the<00:09:45.830> Pala<00:09:46.040> protocol<00:09:46.990> paula<00:09:47.990> is 00:09:48.190 --> 00:09:48.200 align:start position:0% about the Pala protocol paula is 00:09:48.200 --> 00:09:50.440 align:start position:0% about the Pala protocol paula is thunders<00:09:48.920> new<00:09:49.250> fast<00:09:49.580> path<00:09:49.820> consensus 00:09:50.440 --> 00:09:50.450 align:start position:0% thunders new fast path consensus 00:09:50.450 --> 00:09:52.630 align:start position:0% thunders new fast path consensus protocol<00:09:50.870> it's<00:09:51.470> actually<00:09:51.980> a<00:09:52.010> full-fledged 00:09:52.630 --> 00:09:52.640 align:start position:0% protocol it's actually a full-fledged 00:09:52.640 --> 00:09:54.430 align:start position:0% protocol it's actually a full-fledged consensus<00:09:53.240> it<00:09:53.390> gives<00:09:53.540> you<00:09:53.630> about<00:09:53.870> consistency 00:09:54.430 --> 00:09:54.440 align:start position:0% consensus it gives you about consistency 00:09:54.440 --> 00:09:55.060 align:start position:0% consensus it gives you about consistency and<00:09:54.560> liveness 00:09:55.060 --> 00:09:55.070 align:start position:0% and liveness 00:09:55.070 --> 00:09:59.860 align:start position:0% and liveness and<00:09:55.280> and<00:09:57.010> in<00:09:58.010> fact<00:09:58.250> you<00:09:58.460> can't<00:09:58.700> just<00:09:58.850> like<00:09:59.000> run 00:09:59.860 --> 00:09:59.870 align:start position:0% and and in fact you can't just like run 00:09:59.870 --> 00:10:02.410 align:start position:0% and and in fact you can't just like run Paula<00:10:00.230> in<00:10:00.500> a<00:10:00.650> standalone<00:10:01.610> fashion<00:10:02.180> even 00:10:02.410 --> 00:10:02.420 align:start position:0% Paula in a standalone fashion even 00:10:02.420 --> 00:10:04.750 align:start position:0% Paula in a standalone fashion even without<00:10:02.780> the<00:10:02.960> slow<00:10:03.170> chain<00:10:03.380> and<00:10:03.589> one<00:10:04.370> question 00:10:04.750 --> 00:10:04.760 align:start position:0% without the slow chain and one question 00:10:04.760 --> 00:10:06.520 align:start position:0% without the slow chain and one question you<00:10:04.850> might<00:10:04.880> want<00:10:05.240> to<00:10:05.270> ask<00:10:05.420> is<00:10:05.750> you<00:10:06.170> know<00:10:06.290> since 00:10:06.520 --> 00:10:06.530 align:start position:0% you might want to ask is you know since 00:10:06.530 --> 00:10:08.500 align:start position:0% you might want to ask is you know since now<00:10:06.680> Paula<00:10:06.980> itself<00:10:07.940> is<00:10:08.120> a<00:10:08.150> full-fledged 00:10:08.500 --> 00:10:08.510 align:start position:0% now Paula itself is a full-fledged 00:10:08.510 --> 00:10:10.150 align:start position:0% now Paula itself is a full-fledged consensus<00:10:09.140> protocol<00:10:09.470> do<00:10:09.589> we<00:10:09.680> still<00:10:09.920> need<00:10:10.130> a 00:10:10.150 --> 00:10:10.160 align:start position:0% consensus protocol do we still need a 00:10:10.160 --> 00:10:12.640 align:start position:0% consensus protocol do we still need a slow<00:10:10.430> chain<00:10:10.670> right<00:10:10.940> and<00:10:11.240> the<00:10:11.330> answer<00:10:11.690> is<00:10:12.020> you 00:10:12.640 --> 00:10:12.650 align:start position:0% slow chain right and the answer is you 00:10:12.650 --> 00:10:14.110 align:start position:0% slow chain right and the answer is you know<00:10:12.800> it<00:10:12.920> still<00:10:13.130> makes<00:10:13.339> sense<00:10:13.430> to<00:10:13.700> have<00:10:13.790> a<00:10:13.850> slow 00:10:14.110 --> 00:10:14.120 align:start position:0% know it still makes sense to have a slow 00:10:14.120 --> 00:10:15.670 align:start position:0% know it still makes sense to have a slow chain<00:10:14.360> because<00:10:14.660> the<00:10:14.690> slow<00:10:14.990> Qing<00:10:15.170> is<00:10:15.290> a<00:10:15.320> multi 00:10:15.670 --> 00:10:15.680 align:start position:0% chain because the slow Qing is a multi 00:10:15.680 --> 00:10:18.790 align:start position:0% chain because the slow Qing is a multi centralized<00:10:16.130> packing<00:10:16.550> you<00:10:17.480> can<00:10:17.800> have 00:10:18.790 --> 00:10:18.800 align:start position:0% centralized packing you can have 00:10:18.800 --> 00:10:20.890 align:start position:0% centralized packing you can have decentralized<00:10:19.430> monitoring<00:10:20.120> of<00:10:20.420> the<00:10:20.690> fast 00:10:20.890 --> 00:10:20.900 align:start position:0% decentralized monitoring of the fast 00:10:20.900 --> 00:10:23.680 align:start position:0% decentralized monitoring of the fast path<00:10:21.140> through<00:10:22.010> the<00:10:22.130> slow<00:10:22.339> chain<00:10:22.640> and<00:10:22.880> whenever 00:10:23.680 --> 00:10:23.690 align:start position:0% path through the slow chain and whenever 00:10:23.690 --> 00:10:25.800 align:start position:0% path through the slow chain and whenever you<00:10:24.500> know<00:10:24.620> under<00:10:24.890> these<00:10:25.040> extraordinary 00:10:25.800 --> 00:10:25.810 align:start position:0% you know under these extraordinary 00:10:25.810 --> 00:10:28.329 align:start position:0% you know under these extraordinary circumstances<00:10:26.810> let's<00:10:27.110> say<00:10:27.290> maybe<00:10:27.830> the<00:10:28.010> entire 00:10:28.329 --> 00:10:28.339 align:start position:0% circumstances let's say maybe the entire 00:10:28.339 --> 00:10:30.370 align:start position:0% circumstances let's say maybe the entire committee<00:10:28.670> can<00:10:28.970> be<00:10:29.089> corrupt<00:10:29.390> in<00:10:29.870> these<00:10:30.140> cases 00:10:30.370 --> 00:10:30.380 align:start position:0% committee can be corrupt in these cases 00:10:30.380 --> 00:10:31.870 align:start position:0% committee can be corrupt in these cases you<00:10:30.589> can<00:10:30.800> still<00:10:30.980> use<00:10:31.160> the<00:10:31.310> slow<00:10:31.520> Qin<00:10:31.730> to 00:10:31.870 --> 00:10:31.880 align:start position:0% you can still use the slow Qin to 00:10:31.880 --> 00:10:33.180 align:start position:0% you can still use the slow Qin to recover 00:10:33.180 --> 00:10:33.190 align:start position:0% recover 00:10:33.190 --> 00:10:35.829 align:start position:0% recover okay<00:10:34.190> so<00:10:34.250> again<00:10:34.580> if<00:10:34.790> you<00:10:34.910> are<00:10:34.940> not<00:10:35.150> familiar 00:10:35.829 --> 00:10:35.839 align:start position:0% okay so again if you are not familiar 00:10:35.839 --> 00:10:37.600 align:start position:0% okay so again if you are not familiar with<00:10:36.110> Sanders<00:10:36.560> current<00:10:36.920> approach<00:10:37.190> it<00:10:37.339> doesn't 00:10:37.600 --> 00:10:37.610 align:start position:0% with Sanders current approach it doesn't 00:10:37.610 --> 00:10:38.949 align:start position:0% with Sanders current approach it doesn't matter<00:10:37.760> because<00:10:37.940> the<00:10:38.209> protocol<00:10:38.570> I'm<00:10:38.630> going<00:10:38.870> to 00:10:38.949 --> 00:10:38.959 align:start position:0% matter because the protocol I'm going to 00:10:38.959 --> 00:10:41.410 align:start position:0% matter because the protocol I'm going to explain<00:10:39.290> as<00:10:39.920> I<00:10:40.040> said<00:10:40.250> is<00:10:40.459> self-contained<00:10:41.120> and 00:10:41.410 --> 00:10:41.420 align:start position:0% explain as I said is self-contained and 00:10:41.420 --> 00:10:43.300 align:start position:0% explain as I said is self-contained and the<00:10:41.900> full-fledged<00:10:42.200> consensus<00:10:42.830> protocol<00:10:43.190> in 00:10:43.300 --> 00:10:43.310 align:start position:0% the full-fledged consensus protocol in 00:10:43.310 --> 00:10:46.860 align:start position:0% the full-fledged consensus protocol in itself<00:10:44.260> okay 00:10:46.860 --> 00:10:46.870 align:start position:0% itself okay 00:10:46.870 --> 00:10:48.910 align:start position:0% itself okay so<00:10:47.870> since<00:10:48.140> we<00:10:48.320> are<00:10:48.440> going<00:10:48.620> to<00:10:48.740> talk<00:10:48.890> about 00:10:48.910 --> 00:10:48.920 align:start position:0% so since we are going to talk about 00:10:48.920 --> 00:10:53.170 align:start position:0% so since we are going to talk about proposal<00:10:49.610> rotation<00:10:51.250> the<00:10:52.250> most<00:10:52.520> challenging 00:10:53.170 --> 00:10:53.180 align:start position:0% proposal rotation the most challenging 00:10:53.180 --> 00:10:56.470 align:start position:0% proposal rotation the most challenging case<00:10:53.390> is<00:10:53.690> if<00:10:54.110> every<00:10:54.589> block<00:10:54.890> can<00:10:55.700> allow<00:10:56.029> a<00:10:56.270> new 00:10:56.470 --> 00:10:56.480 align:start position:0% case is if every block can allow a new 00:10:56.480 --> 00:10:58.690 align:start position:0% case is if every block can allow a new proposal<00:10:56.870> and<00:10:57.260> that's<00:10:57.860> what<00:10:58.100> we<00:10:58.250> are<00:10:58.280> going<00:10:58.490> to 00:10:58.690 --> 00:10:58.700 align:start position:0% proposal and that's what we are going to 00:10:58.700 --> 00:11:01.750 align:start position:0% proposal and that's what we are going to stick<00:10:59.690> to<00:10:59.870> in<00:11:00.050> this<00:11:00.170> talk<00:11:00.440> we<00:11:01.400> are<00:11:01.430> going<00:11:01.670> to 00:11:01.750 --> 00:11:01.760 align:start position:0% stick to in this talk we are going to 00:11:01.760 --> 00:11:03.430 align:start position:0% stick to in this talk we are going to assume<00:11:02.000> a<00:11:02.180> very<00:11:02.270> simple<00:11:02.660> around<00:11:02.870> robbing 00:11:03.430 --> 00:11:03.440 align:start position:0% assume a very simple around robbing 00:11:03.440 --> 00:11:08.740 align:start position:0% assume a very simple around robbing and<00:11:04.009> in<00:11:04.970> epic<00:11:05.389> I<00:11:05.660> note<00:11:06.620> I<00:11:06.829> is<00:11:06.920> the<00:11:07.220> proposer<00:11:07.750> so 00:11:08.740 --> 00:11:08.750 align:start position:0% and in epic I note I is the proposer so 00:11:08.750 --> 00:11:11.110 align:start position:0% and in epic I note I is the proposer so if<00:11:08.899> we<00:11:09.050> can<00:11:09.230> solve<00:11:09.440> this<00:11:10.069> extreme<00:11:10.550> case<00:11:10.819> then 00:11:11.110 --> 00:11:11.120 align:start position:0% if we can solve this extreme case then 00:11:11.120 --> 00:11:12.910 align:start position:0% if we can solve this extreme case then the<00:11:11.569> other<00:11:11.720> cases<00:11:12.019> are<00:11:12.290> simpler<00:11:12.620> like<00:11:12.769> for 00:11:12.910 --> 00:11:12.920 align:start position:0% the other cases are simpler like for 00:11:12.920 --> 00:11:14.829 align:start position:0% the other cases are simpler like for instance<00:11:13.160> you<00:11:13.279> can<00:11:13.540> have<00:11:14.540> a<00:11:14.569> stability 00:11:14.829 --> 00:11:14.839 align:start position:0% instance you can have a stability 00:11:14.839 --> 00:11:18.100 align:start position:0% instance you can have a stability favoring<00:11:15.560> policy<00:11:15.980> where<00:11:16.430> you<00:11:16.579> only<00:11:17.110> switch 00:11:18.100 --> 00:11:18.110 align:start position:0% favoring policy where you only switch 00:11:18.110 --> 00:11:19.509 align:start position:0% favoring policy where you only switch the<00:11:18.290> proposer<00:11:18.620> when<00:11:18.949> the<00:11:19.100> current<00:11:19.370> one 00:11:19.509 --> 00:11:19.519 align:start position:0% the proposer when the current one 00:11:19.519 --> 00:11:21.759 align:start position:0% the proposer when the current one doesn't<00:11:19.790> work<00:11:19.990> ok<00:11:20.990> but<00:11:21.019> this<00:11:21.290> is<00:11:21.439> what<00:11:21.589> we<00:11:21.680> are 00:11:21.759 --> 00:11:21.769 align:start position:0% doesn't work ok but this is what we are 00:11:21.769 --> 00:11:28.030 align:start position:0% doesn't work ok but this is what we are going<00:11:21.889> to<00:11:22.040> stick<00:11:22.279> to<00:11:22.430> in<00:11:22.639> this<00:11:22.910> talk<00:11:26.350> ok<00:11:27.379> so 00:11:28.030 --> 00:11:28.040 align:start position:0% going to stick to in this talk ok so 00:11:28.040 --> 00:11:31.059 align:start position:0% going to stick to in this talk ok so let's<00:11:28.339> kind<00:11:29.089> of<00:11:29.240> quickly<00:11:30.050> recap<00:11:30.680> the<00:11:30.860> fast 00:11:31.059 --> 00:11:31.069 align:start position:0% let's kind of quickly recap the fast 00:11:31.069 --> 00:11:33.429 align:start position:0% let's kind of quickly recap the fast path<00:11:31.339> the<00:11:32.060> one<00:11:32.269> round<00:11:32.569> voting<00:11:32.930> protocol<00:11:33.350> we 00:11:33.429 --> 00:11:33.439 align:start position:0% path the one round voting protocol we 00:11:33.439 --> 00:11:37.329 align:start position:0% path the one round voting protocol we mentioned<00:11:33.860> right<00:11:35.379> and<00:11:36.379> let's<00:11:36.889> try<00:11:37.040> to<00:11:37.100> work 00:11:37.329 --> 00:11:37.339 align:start position:0% mentioned right and let's try to work 00:11:37.339 --> 00:11:39.129 align:start position:0% mentioned right and let's try to work the<00:11:37.519> proposal<00:11:37.970> rotation<00:11:38.389> into<00:11:38.509> this<00:11:38.720> protocol 00:11:39.129 --> 00:11:39.139 align:start position:0% the proposal rotation into this protocol 00:11:39.139 --> 00:11:42.460 align:start position:0% the proposal rotation into this protocol so<00:11:39.560> as<00:11:40.339> I<00:11:40.519> said<00:11:40.759> the<00:11:40.910> protocol<00:11:41.629> goes<00:11:41.810> by<00:11:42.019> epochs 00:11:42.460 --> 00:11:42.470 align:start position:0% so as I said the protocol goes by epochs 00:11:42.470 --> 00:11:44.920 align:start position:0% so as I said the protocol goes by epochs in<00:11:42.709> every<00:11:43.550> epoch<00:11:43.910> we<00:11:44.300> are<00:11:44.389> going<00:11:44.569> to<00:11:44.689> do<00:11:44.810> the 00:11:44.920 --> 00:11:44.930 align:start position:0% in every epoch we are going to do the 00:11:44.930 --> 00:11:47.259 align:start position:0% in every epoch we are going to do the following<00:11:45.050> very<00:11:45.649> natural<00:11:46.069> if<00:11:46.579> I'm<00:11:46.939> the 00:11:47.259 --> 00:11:47.269 align:start position:0% following very natural if I'm the 00:11:47.269 --> 00:11:49.829 align:start position:0% following very natural if I'm the proposer<00:11:47.600> of<00:11:47.839> this<00:11:48.019> epoch<00:11:48.379> I<00:11:48.589> will<00:11:49.189> take<00:11:49.519> my 00:11:49.829 --> 00:11:49.839 align:start position:0% proposer of this epoch I will take my 00:11:49.839 --> 00:11:52.569 align:start position:0% proposer of this epoch I will take my freshest<00:11:50.839> notarize<00:11:51.290> chain<00:11:51.620> and<00:11:51.860> I<00:11:52.370> will 00:11:52.569 --> 00:11:52.579 align:start position:0% freshest notarize chain and I will 00:11:52.579 --> 00:11:54.759 align:start position:0% freshest notarize chain and I will propose<00:11:52.910> the<00:11:53.149> next<00:11:53.449> block<00:11:53.689> extending<00:11:54.680> the 00:11:54.759 --> 00:11:54.769 align:start position:0% propose the next block extending the 00:11:54.769 --> 00:11:57.119 align:start position:0% propose the next block extending the freshest<00:11:55.160> notarize<00:11:55.550> chain<00:11:55.819> so<00:11:56.360> very<00:11:56.540> natural 00:11:57.119 --> 00:11:57.129 align:start position:0% freshest notarize chain so very natural 00:11:57.129 --> 00:11:59.379 align:start position:0% freshest notarize chain so very natural when<00:11:58.129> people<00:11:58.430> receive<00:11:58.699> the<00:11:58.850> proposal<00:11:59.269> they 00:11:59.379 --> 00:11:59.389 align:start position:0% when people receive the proposal they 00:11:59.389 --> 00:12:02.910 align:start position:0% when people receive the proposal they are<00:11:59.449> going<00:11:59.600> to<00:11:59.720> vote<00:12:00.759> as<00:12:01.759> I<00:12:01.970> explained<00:12:02.420> earlier 00:12:02.910 --> 00:12:02.920 align:start position:0% are going to vote as I explained earlier 00:12:02.920 --> 00:12:05.559 align:start position:0% are going to vote as I explained earlier everyone<00:12:03.920> votes<00:12:04.189> uniquely<00:12:04.759> in<00:12:04.910> each<00:12:05.089> epoch 00:12:05.559 --> 00:12:05.569 align:start position:0% everyone votes uniquely in each epoch 00:12:05.569 --> 00:12:08.470 align:start position:0% everyone votes uniquely in each epoch but<00:12:06.410> I'm<00:12:06.949> also<00:12:07.250> going<00:12:07.490> to<00:12:07.610> assume<00:12:07.790> that<00:12:08.209> when 00:12:08.470 --> 00:12:08.480 align:start position:0% but I'm also going to assume that when 00:12:08.480 --> 00:12:10.569 align:start position:0% but I'm also going to assume that when people<00:12:08.810> vote<00:12:08.990> on<00:12:09.050> the<00:12:09.350> block<00:12:09.560> they<00:12:10.339> are<00:12:10.399> going 00:12:10.569 --> 00:12:10.579 align:start position:0% people vote on the block they are going 00:12:10.579 --> 00:12:13.090 align:start position:0% people vote on the block they are going to<00:12:10.790> check<00:12:11.089> that<00:12:11.360> the<00:12:11.540> parent<00:12:11.750> chain<00:12:12.259> has<00:12:13.069> been 00:12:13.090 --> 00:12:13.100 align:start position:0% to check that the parent chain has been 00:12:13.100 --> 00:12:15.579 align:start position:0% to check that the parent chain has been notarized<00:12:13.730> because<00:12:14.540> if<00:12:14.689> the<00:12:14.810> block<00:12:15.019> extends 00:12:15.579 --> 00:12:15.589 align:start position:0% notarized because if the block extends 00:12:15.589 --> 00:12:17.620 align:start position:0% notarized because if the block extends from<00:12:15.829> an<00:12:15.980> invalid<00:12:16.459> parent<00:12:16.819> you<00:12:17.300> shouldn't 00:12:17.620 --> 00:12:17.630 align:start position:0% from an invalid parent you shouldn't 00:12:17.630 --> 00:12:21.129 align:start position:0% from an invalid parent you shouldn't vote<00:12:17.660> on<00:12:17.959> that<00:12:18.110> block<00:12:18.579> ok<00:12:19.579> so<00:12:19.779> the<00:12:20.779> protocol 00:12:21.129 --> 00:12:21.139 align:start position:0% vote on that block ok so the protocol 00:12:21.139 --> 00:12:23.290 align:start position:0% vote on that block ok so the protocol goes<00:12:21.319> by<00:12:21.470> proposed<00:12:21.829> vote<00:12:22.040> proposed<00:12:22.430> vote<00:12:22.610> very 00:12:23.290 --> 00:12:23.300 align:start position:0% goes by proposed vote proposed vote very 00:12:23.300 --> 00:12:24.639 align:start position:0% goes by proposed vote proposed vote very simple<00:12:23.689> of<00:12:23.839> course<00:12:24.050> it<00:12:24.170> doesn't<00:12:24.319> quite<00:12:24.589> work 00:12:24.639 --> 00:12:24.649 align:start position:0% simple of course it doesn't quite work 00:12:24.649 --> 00:12:30.639 align:start position:0% simple of course it doesn't quite work yet<00:12:25.420> and<00:12:27.610> what<00:12:28.610> I'm<00:12:28.759> going<00:12:28.970> to<00:12:29.180> do<00:12:29.329> next<00:12:29.540> is<00:12:29.959> to 00:12:30.639 --> 00:12:30.649 align:start position:0% yet and what I'm going to do next is to 00:12:30.649 --> 00:12:32.889 align:start position:0% yet and what I'm going to do next is to kind<00:12:31.490> of<00:12:31.610> describe<00:12:32.000> the<00:12:32.029> problems<00:12:32.600> with<00:12:32.779> this 00:12:32.889 --> 00:12:32.899 align:start position:0% kind of describe the problems with this 00:12:32.899 --> 00:12:34.929 align:start position:0% kind of describe the problems with this protocol<00:12:33.290> and<00:12:33.500> introduce<00:12:33.980> two<00:12:34.370> very<00:12:34.670> simple 00:12:34.929 --> 00:12:34.939 align:start position:0% protocol and introduce two very simple 00:12:34.939 --> 00:12:39.040 align:start position:0% protocol and introduce two very simple fixes<00:12:35.930> to<00:12:36.350> this<00:12:36.470> very<00:12:36.680> simple<00:12:37.459> protocol<00:12:38.050> ok 00:12:39.040 --> 00:12:39.050 align:start position:0% fixes to this very simple protocol ok 00:12:39.050 --> 00:12:40.780 align:start position:0% fixes to this very simple protocol ok and<00:12:39.259> then<00:12:39.410> the<00:12:39.649> resulting<00:12:40.130> protocol<00:12:40.490> would<00:12:40.639> be 00:12:40.780 --> 00:12:40.790 align:start position:0% and then the resulting protocol would be 00:12:40.790 --> 00:12:46.090 align:start position:0% and then the resulting protocol would be actually<00:12:41.569> provably<00:12:41.990> correct<00:12:43.120> ok<00:12:44.120> well<00:12:45.100> the 00:12:46.090 --> 00:12:46.100 align:start position:0% actually provably correct ok well the 00:12:46.100 --> 00:12:48.819 align:start position:0% actually provably correct ok well the nice<00:12:46.339> thing<00:12:46.370> is<00:12:46.850> that<00:12:46.990> this<00:12:47.990> very<00:12:48.350> simple 00:12:48.819 --> 00:12:48.829 align:start position:0% nice thing is that this very simple 00:12:48.829 --> 00:12:50.829 align:start position:0% nice thing is that this very simple protocol<00:12:49.189> already<00:12:49.490> works<00:12:49.819> in<00:12:50.120> ideal<00:12:50.569> world 00:12:50.829 --> 00:12:50.839 align:start position:0% protocol already works in ideal world 00:12:50.839 --> 00:12:52.420 align:start position:0% protocol already works in ideal world when<00:12:51.110> everyone<00:12:51.620> is<00:12:51.769> honest<00:12:52.130> right<00:12:52.279> if 00:12:52.420 --> 00:12:52.430 align:start position:0% when everyone is honest right if 00:12:52.430 --> 00:12:54.910 align:start position:0% when everyone is honest right if everyone<00:12:52.610> is<00:12:53.000> honest<00:12:53.389> we<00:12:54.079> should<00:12:54.290> what<00:12:54.680> you 00:12:54.910 --> 00:12:54.920 align:start position:0% everyone is honest we should what you 00:12:54.920 --> 00:12:57.490 align:start position:0% everyone is honest we should what you should<00:12:55.160> expect<00:12:55.339> is<00:12:56.329> that<00:12:56.389> you<00:12:57.199> know<00:12:57.319> as<00:12:57.470> the 00:12:57.490 --> 00:12:57.500 align:start position:0% should expect is that you know as the 00:12:57.500 --> 00:13:00.100 align:start position:0% should expect is that you know as the epochs<00:12:58.009> go<00:12:58.189> by<00:12:58.399> these<00:12:59.029> blocks<00:12:59.329> get<00:12:59.660> notarized 00:13:00.100 --> 00:13:00.110 align:start position:0% epochs go by these blocks get notarized 00:13:00.110 --> 00:13:02.199 align:start position:0% epochs go by these blocks get notarized one<00:13:00.259> by<00:13:00.410> one<00:13:00.620> and<00:13:00.800> nothing<00:13:01.579> will<00:13:01.730> be<00:13:01.910> skipped 00:13:02.199 --> 00:13:02.209 align:start position:0% one by one and nothing will be skipped 00:13:02.209 --> 00:13:06.790 align:start position:0% one by one and nothing will be skipped and<00:13:02.980> things<00:13:03.980> are<00:13:04.129> all<00:13:04.279> good<00:13:05.230> but<00:13:06.230> when<00:13:06.350> some<00:13:06.649> of 00:13:06.790 --> 00:13:06.800 align:start position:0% and things are all good but when some of 00:13:06.800 --> 00:13:08.829 align:start position:0% and things are all good but when some of these<00:13:06.949> people<00:13:07.189> can<00:13:07.459> be<00:13:07.519> corrupt<00:13:07.939> so<00:13:08.629> by<00:13:08.779> the 00:13:08.829 --> 00:13:08.839 align:start position:0% these people can be corrupt so by the 00:13:08.839 --> 00:13:10.990 align:start position:0% these people can be corrupt so by the way<00:13:09.019> I<00:13:09.050> forgot<00:13:09.259> to<00:13:09.439> mention<00:13:09.649> and<00:13:10.040> I'm<00:13:10.730> just 00:13:10.990 --> 00:13:11.000 align:start position:0% way I forgot to mention and I'm just 00:13:11.000 --> 00:13:12.639 align:start position:0% way I forgot to mention and I'm just going<00:13:11.540> to<00:13:11.600> assume<00:13:11.930> like<00:13:12.199> the<00:13:12.319> committee 00:13:12.639 --> 00:13:12.649 align:start position:0% going to assume like the committee 00:13:12.649 --> 00:13:15.009 align:start position:0% going to assume like the committee itself<00:13:13.519> will<00:13:13.759> act<00:13:13.970> as<00:13:14.149> the<00:13:14.269> proposer<00:13:14.569> I'm<00:13:14.809> not 00:13:15.009 --> 00:13:15.019 align:start position:0% itself will act as the proposer I'm not 00:13:15.019 --> 00:13:16.040 align:start position:0% itself will act as the proposer I'm not going<00:13:15.170> to<00:13:15.259> distinguish<00:13:15.649> the 00:13:16.040 --> 00:13:16.050 align:start position:0% going to distinguish the 00:13:16.050 --> 00:13:18.050 align:start position:0% going to distinguish the and<00:13:16.290> the<00:13:16.350> proposer<00:13:16.649> anymore<00:13:17.100> okay<00:13:17.940> because 00:13:18.050 --> 00:13:18.060 align:start position:0% and the proposer anymore okay because 00:13:18.060 --> 00:13:19.250 align:start position:0% and the proposer anymore okay because the<00:13:18.269> proposer<00:13:18.540> is<00:13:18.720> like<00:13:18.870> you<00:13:19.019> know<00:13:19.140> by 00:13:19.250 --> 00:13:19.260 align:start position:0% the proposer is like you know by 00:13:19.260 --> 00:13:22.970 align:start position:0% the proposer is like you know by rotation<00:13:19.769> okay<00:13:20.760> now<00:13:21.470> when<00:13:22.470> some<00:13:22.709> of<00:13:22.830> these 00:13:22.970 --> 00:13:22.980 align:start position:0% rotation okay now when some of these 00:13:22.980 --> 00:13:25.550 align:start position:0% rotation okay now when some of these notes<00:13:23.160> are<00:13:23.399> corrupt<00:13:23.750> then<00:13:24.750> you'll<00:13:25.170> run<00:13:25.350> into 00:13:25.550 --> 00:13:25.560 align:start position:0% notes are corrupt then you'll run into 00:13:25.560 --> 00:13:28.970 align:start position:0% notes are corrupt then you'll run into these<00:13:26.029> somewhat<00:13:27.029> tricky<00:13:27.240> problems<00:13:27.810> and<00:13:28.050> I 00:13:28.970 --> 00:13:28.980 align:start position:0% these somewhat tricky problems and I 00:13:28.980 --> 00:13:32.300 align:start position:0% these somewhat tricky problems and I will<00:13:29.279> use<00:13:29.490> this<00:13:30.330> as<00:13:30.600> a<00:13:30.660> running<00:13:31.080> example<00:13:31.310> to 00:13:32.300 --> 00:13:32.310 align:start position:0% will use this as a running example to 00:13:32.310 --> 00:13:35.329 align:start position:0% will use this as a running example to illustrate<00:13:32.459> the<00:13:32.880> problems<00:13:33.269> and<00:13:33.540> to<00:13:34.339> introduce 00:13:35.329 --> 00:13:35.339 align:start position:0% illustrate the problems and to introduce 00:13:35.339 --> 00:13:39.590 align:start position:0% illustrate the problems and to introduce the<00:13:35.760> two<00:13:35.940> simple<00:13:36.390> fixes<00:13:37.310> okay<00:13:38.310> so<00:13:38.700> let's<00:13:38.910> look 00:13:39.590 --> 00:13:39.600 align:start position:0% the two simple fixes okay so let's look 00:13:39.600 --> 00:13:42.740 align:start position:0% the two simple fixes okay so let's look at<00:13:39.950> this<00:13:40.950> scenario<00:13:41.220> right<00:13:41.640> so<00:13:42.000> imagine<00:13:42.570> this 00:13:42.740 --> 00:13:42.750 align:start position:0% at this scenario right so imagine this 00:13:42.750 --> 00:13:46.220 align:start position:0% at this scenario right so imagine this is<00:13:42.990> a<00:13:43.019> notarized<00:13:43.620> chain<00:13:43.920> that<00:13:44.550> I<00:13:44.790> see<00:13:45.230> during 00:13:46.220 --> 00:13:46.230 align:start position:0% is a notarized chain that I see during 00:13:46.230 --> 00:13:49.360 align:start position:0% is a notarized chain that I see during the<00:13:46.410> protocol<00:13:46.829> what<00:13:47.700> are<00:13:47.850> the<00:13:47.970> problems<00:13:48.390> here 00:13:49.360 --> 00:13:49.370 align:start position:0% the protocol what are the problems here 00:13:49.370 --> 00:13:52.130 align:start position:0% the protocol what are the problems here one<00:13:50.370> problem<00:13:50.910> is<00:13:51.089> that<00:13:51.149> the<00:13:51.450> block<00:13:51.660> number<00:13:51.839> two 00:13:52.130 --> 00:13:52.140 align:start position:0% one problem is that the block number two 00:13:52.140 --> 00:13:53.930 align:start position:0% one problem is that the block number two is<00:13:52.290> being<00:13:52.529> skipped<00:13:52.829> there<00:13:53.339> is<00:13:53.490> no<00:13:53.700> block 00:13:53.930 --> 00:13:53.940 align:start position:0% is being skipped there is no block 00:13:53.940 --> 00:13:58.550 align:start position:0% is being skipped there is no block number<00:13:54.209> two<00:13:54.829> and<00:13:55.829> another<00:13:56.160> problem<00:13:56.899> is<00:13:57.899> that 00:13:58.550 --> 00:13:58.560 align:start position:0% number two and another problem is that 00:13:58.560 --> 00:14:01.220 align:start position:0% number two and another problem is that the<00:13:59.279> fifth<00:13:59.519> block<00:13:59.790> is<00:14:00.209> extending<00:14:00.750> from<00:14:00.870> three 00:14:01.220 --> 00:14:01.230 align:start position:0% the fifth block is extending from three 00:14:01.230 --> 00:14:04.610 align:start position:0% the fifth block is extending from three and<00:14:01.410> not<00:14:02.370> extending<00:14:02.880> from<00:14:02.970> four<00:14:03.300> right<00:14:04.050> so 00:14:04.610 --> 00:14:04.620 align:start position:0% and not extending from four right so 00:14:04.620 --> 00:14:09.620 align:start position:0% and not extending from four right so this<00:14:04.800> actually<00:14:05.339> creates<00:14:05.459> a<00:14:05.790> fork<00:14:08.600> what<00:14:09.600> I 00:14:09.620 --> 00:14:09.630 align:start position:0% this actually creates a fork what I 00:14:09.630 --> 00:14:11.210 align:start position:0% this actually creates a fork what I really<00:14:10.019> want<00:14:10.170> to<00:14:10.260> talk<00:14:10.350> about<00:14:10.500> is<00:14:10.769> the<00:14:10.890> second 00:14:11.210 --> 00:14:11.220 align:start position:0% really want to talk about is the second 00:14:11.220 --> 00:14:12.670 align:start position:0% really want to talk about is the second problem<00:14:11.399> but<00:14:11.730> let<00:14:11.970> me<00:14:12.060> just<00:14:12.089> very<00:14:12.390> quickly 00:14:12.670 --> 00:14:12.680 align:start position:0% problem but let me just very quickly 00:14:12.680 --> 00:14:16.150 align:start position:0% problem but let me just very quickly explain<00:14:13.680> the<00:14:13.829> first<00:14:14.010> one<00:14:14.250> right<00:14:14.459> so<00:14:15.329> how<00:14:15.630> can 00:14:16.150 --> 00:14:16.160 align:start position:0% explain the first one right so how can 00:14:16.160 --> 00:14:17.930 align:start position:0% explain the first one right so how can plug<00:14:17.160> to<00:14:17.339> be<00:14:17.490> skipped 00:14:17.930 --> 00:14:17.940 align:start position:0% plug to be skipped 00:14:17.940 --> 00:14:20.870 align:start position:0% plug to be skipped so<00:14:18.720> if<00:14:18.899> proposer<00:14:19.380> two<00:14:19.649> is<00:14:19.800> corrupt<00:14:20.160> let's<00:14:20.730> say 00:14:20.870 --> 00:14:20.880 align:start position:0% so if proposer two is corrupt let's say 00:14:20.880 --> 00:14:22.790 align:start position:0% so if proposer two is corrupt let's say he<00:14:21.029> just<00:14:21.240> crashes<00:14:21.630> and<00:14:21.810> he<00:14:21.899> didn't<00:14:22.410> make<00:14:22.560> any 00:14:22.790 --> 00:14:22.800 align:start position:0% he just crashes and he didn't make any 00:14:22.800 --> 00:14:26.240 align:start position:0% he just crashes and he didn't make any proposal<00:14:23.339> I<00:14:23.490> mean<00:14:24.060> of<00:14:24.149> course<00:14:24.290> no<00:14:25.290> epic<00:14:26.040> two 00:14:26.240 --> 00:14:26.250 align:start position:0% proposal I mean of course no epic two 00:14:26.250 --> 00:14:29.510 align:start position:0% proposal I mean of course no epic two block<00:14:26.490> will<00:14:26.670> get<00:14:26.850> notarized<00:14:27.380> right<00:14:28.380> so<00:14:29.100> what 00:14:29.510 --> 00:14:29.520 align:start position:0% block will get notarized right so what 00:14:29.520 --> 00:14:33.110 align:start position:0% block will get notarized right so what we<00:14:29.700> don't<00:14:29.940> want<00:14:30.360> is<00:14:31.170> for<00:14:31.709> a<00:14:32.190> single<00:14:32.490> bad<00:14:32.880> guy<00:14:33.060> to 00:14:33.110 --> 00:14:33.120 align:start position:0% we don't want is for a single bad guy to 00:14:33.120 --> 00:14:38.329 align:start position:0% we don't want is for a single bad guy to kill<00:14:33.510> liveness<00:14:33.779> and<00:14:35.329> we<00:14:36.329> can<00:14:36.540> do<00:14:36.750> this<00:14:36.959> if<00:14:37.770> we 00:14:38.329 --> 00:14:38.339 align:start position:0% kill liveness and we can do this if we 00:14:38.339 --> 00:14:39.769 align:start position:0% kill liveness and we can do this if we just<00:14:38.670> basically<00:14:38.880> were<00:14:39.180> just<00:14:39.360> going<00:14:39.480> to<00:14:39.570> allow 00:14:39.769 --> 00:14:39.779 align:start position:0% just basically were just going to allow 00:14:39.779 --> 00:14:42.680 align:start position:0% just basically were just going to allow skipping<00:14:40.260> in<00:14:40.770> a<00:14:40.950> notarized<00:14:41.399> chain<00:14:41.730> the<00:14:42.329> epic 00:14:42.680 --> 00:14:42.690 align:start position:0% skipping in a notarized chain the epic 00:14:42.690 --> 00:14:44.269 align:start position:0% skipping in a notarized chain the epic numbers<00:14:43.020> don't<00:14:43.200> have<00:14:43.410> to<00:14:43.529> be<00:14:43.620> consecutive<00:14:43.920> you 00:14:44.269 --> 00:14:44.279 align:start position:0% numbers don't have to be consecutive you 00:14:44.279 --> 00:14:47.199 align:start position:0% numbers don't have to be consecutive you can<00:14:44.490> skip<00:14:45.079> okay 00:14:47.199 --> 00:14:47.209 align:start position:0% can skip okay 00:14:47.209 --> 00:14:51.560 align:start position:0% can skip okay but<00:14:48.380> this<00:14:49.380> skipping<00:14:50.160> behavior<00:14:50.640> kind<00:14:51.450> of 00:14:51.560 --> 00:14:51.570 align:start position:0% but this skipping behavior kind of 00:14:51.570 --> 00:14:53.420 align:start position:0% but this skipping behavior kind of introduces<00:14:52.170> the<00:14:52.320> second<00:14:52.620> problem<00:14:52.829> which<00:14:53.160> is<00:14:53.310> I 00:14:53.420 --> 00:14:53.430 align:start position:0% introduces the second problem which is I 00:14:53.430 --> 00:14:55.699 align:start position:0% introduces the second problem which is I would<00:14:53.579> I<00:14:53.880> want<00:14:54.149> to<00:14:54.209> focus<00:14:54.450> on<00:14:54.810> right<00:14:55.440> in<00:14:55.560> this 00:14:55.699 --> 00:14:55.709 align:start position:0% would I want to focus on right in this 00:14:55.709 --> 00:14:58.490 align:start position:0% would I want to focus on right in this case<00:14:55.920> you<00:14:56.610> may<00:14:56.760> ask<00:14:56.970> why<00:14:57.300> does<00:14:57.360> the<00:14:57.750> block 00:14:58.490 --> 00:14:58.500 align:start position:0% case you may ask why does the block 00:14:58.500 --> 00:15:00.290 align:start position:0% case you may ask why does the block number<00:14:58.860> five<00:14:59.040> extend<00:14:59.399> from<00:14:59.579> three<00:14:59.880> and<00:15:00.060> not 00:15:00.290 --> 00:15:00.300 align:start position:0% number five extend from three and not 00:15:00.300 --> 00:15:04.939 align:start position:0% number five extend from three and not from<00:15:00.449> four<00:15:01.940> okay<00:15:02.940> so<00:15:03.260> let's<00:15:04.260> think<00:15:04.440> about<00:15:04.589> it 00:15:04.939 --> 00:15:04.949 align:start position:0% from four okay so let's think about it 00:15:04.949 --> 00:15:08.210 align:start position:0% from four okay so let's think about it well<00:15:05.550> very<00:15:06.000> natural<00:15:06.690> explanation<00:15:07.350> is<00:15:07.920> that 00:15:08.210 --> 00:15:08.220 align:start position:0% well very natural explanation is that 00:15:08.220 --> 00:15:10.670 align:start position:0% well very natural explanation is that perhaps<00:15:08.399> the<00:15:08.790> proposer<00:15:09.120> five<00:15:09.480> is<00:15:10.140> corrupt 00:15:10.670 --> 00:15:10.680 align:start position:0% perhaps the proposer five is corrupt 00:15:10.680 --> 00:15:15.079 align:start position:0% perhaps the proposer five is corrupt although<00:15:11.670> he<00:15:11.850> sees<00:15:12.120> block<00:15:12.600> four<00:15:13.010> notarized<00:15:14.089> he 00:15:15.079 --> 00:15:15.089 align:start position:0% although he sees block four notarized he 00:15:15.089 --> 00:15:17.360 align:start position:0% although he sees block four notarized he tries<00:15:15.329> to<00:15:15.600> you<00:15:15.959> know<00:15:16.019> undo<00:15:16.410> block<00:15:16.649> four<00:15:16.949> by 00:15:17.360 --> 00:15:17.370 align:start position:0% tries to you know undo block four by 00:15:17.370 --> 00:15:21.290 align:start position:0% tries to you know undo block four by extending<00:15:17.940> from<00:15:18.149> a<00:15:18.440> previous<00:15:19.440> block<00:15:20.149> okay<00:15:21.149> and 00:15:21.290 --> 00:15:21.300 align:start position:0% extending from a previous block okay and 00:15:21.300 --> 00:15:24.949 align:start position:0% extending from a previous block okay and that's<00:15:21.480> not<00:15:21.980> going<00:15:22.980> to<00:15:23.100> be<00:15:23.220> okay<00:15:23.370> and<00:15:23.750> in<00:15:24.750> fact 00:15:24.949 --> 00:15:24.959 align:start position:0% that's not going to be okay and in fact 00:15:24.959 --> 00:15:26.329 align:start position:0% that's not going to be okay and in fact you<00:15:25.140> know<00:15:25.260> in<00:15:25.380> the<00:15:25.470> extreme<00:15:25.800> case<00:15:26.010> if<00:15:26.220> I'm 00:15:26.329 --> 00:15:26.339 align:start position:0% you know in the extreme case if I'm 00:15:26.339 --> 00:15:28.880 align:start position:0% you know in the extreme case if I'm malicious<00:15:26.850> I<00:15:27.089> can<00:15:27.660> extend<00:15:28.050> from<00:15:28.230> a<00:15:28.440> very<00:15:28.649> very 00:15:28.880 --> 00:15:28.890 align:start position:0% malicious I can extend from a very very 00:15:28.890 --> 00:15:29.660 align:start position:0% malicious I can extend from a very very ancient<00:15:29.010> block 00:15:29.660 --> 00:15:29.670 align:start position:0% ancient block 00:15:29.670 --> 00:15:31.550 align:start position:0% ancient block from<00:15:29.760> the<00:15:29.910> past<00:15:30.090> and<00:15:30.450> that's<00:15:30.780> that's<00:15:31.290> not 00:15:31.550 --> 00:15:31.560 align:start position:0% from the past and that's that's not 00:15:31.560 --> 00:15:32.780 align:start position:0% from the past and that's that's not going<00:15:31.680> to<00:15:31.770> be<00:15:31.950> okay<00:15:32.280> right 00:15:32.780 --> 00:15:32.790 align:start position:0% going to be okay right 00:15:32.790 --> 00:15:36.980 align:start position:0% going to be okay right so<00:15:33.650> the<00:15:34.650> fix<00:15:34.890> is<00:15:35.040> actually<00:15:35.370> very<00:15:35.490> natural<00:15:36.030> and 00:15:36.980 --> 00:15:36.990 align:start position:0% so the fix is actually very natural and 00:15:36.990 --> 00:15:40.480 align:start position:0% so the fix is actually very natural and this<00:15:37.620> was<00:15:37.860> the<00:15:38.010> protocol<00:15:38.430> we<00:15:38.580> had<00:15:39.360> earlier<00:15:39.870> and 00:15:40.480 --> 00:15:40.490 align:start position:0% this was the protocol we had earlier and 00:15:40.490 --> 00:15:42.290 align:start position:0% this was the protocol we had earlier and I'm<00:15:41.490> just<00:15:41.670> going<00:15:41.790> to<00:15:41.940> add<00:15:42.060> an<00:15:42.210> additional 00:15:42.290 --> 00:15:42.300 align:start position:0% I'm just going to add an additional 00:15:42.300 --> 00:15:45.560 align:start position:0% I'm just going to add an additional route<00:15:42.990> to<00:15:43.200> the<00:15:43.350> voting<00:15:43.650> to<00:15:44.100> say<00:15:44.510> whenever<00:15:45.510> I 00:15:45.560 --> 00:15:45.570 align:start position:0% route to the voting to say whenever I 00:15:45.570 --> 00:15:48.260 align:start position:0% route to the voting to say whenever I vote<00:15:45.840> for<00:15:46.050> a<00:15:46.110> block<00:15:46.320> I<00:15:46.620> will<00:15:47.610> make<00:15:47.850> sure<00:15:47.880> that 00:15:48.260 --> 00:15:48.270 align:start position:0% vote for a block I will make sure that 00:15:48.270 --> 00:15:51.110 align:start position:0% vote for a block I will make sure that the<00:15:48.390> parent<00:15:48.840> chain<00:15:49.440> is<00:15:49.710> fresh<00:15:50.340> enough<00:15:50.670> right 00:15:51.110 --> 00:15:51.120 align:start position:0% the parent chain is fresh enough right 00:15:51.120 --> 00:15:53.720 align:start position:0% the parent chain is fresh enough right if<00:15:51.270> this<00:15:51.450> proposed<00:15:51.750> block<00:15:52.020> is<00:15:52.520> extending<00:15:53.520> from 00:15:53.720 --> 00:15:53.730 align:start position:0% if this proposed block is extending from 00:15:53.730 --> 00:15:55.790 align:start position:0% if this proposed block is extending from something<00:15:54.060> way<00:15:54.510> way<00:15:54.780> way<00:15:55.020> back<00:15:55.260> in<00:15:55.320> the<00:15:55.530> past 00:15:55.790 --> 00:15:55.800 align:start position:0% something way way way back in the past 00:15:55.800 --> 00:15:59.630 align:start position:0% something way way way back in the past I'm<00:15:56.130> going<00:15:56.940> to<00:15:57.030> refuse<00:15:57.360> to<00:15:57.570> vote<00:15:57.690> on<00:15:57.900> it<00:15:58.640> so 00:15:59.630 --> 00:15:59.640 align:start position:0% I'm going to refuse to vote on it so 00:15:59.640 --> 00:16:02.120 align:start position:0% I'm going to refuse to vote on it so technically<00:16:00.300> we<00:16:00.510> have<00:16:00.660> to<00:16:00.840> specify<00:16:01.530> what<00:16:01.830> it 00:16:02.120 --> 00:16:02.130 align:start position:0% technically we have to specify what it 00:16:02.130 --> 00:16:06.620 align:start position:0% technically we have to specify what it means<00:16:02.370> to<00:16:02.790> be<00:16:02.910> fresh<00:16:03.150> enough<00:16:03.860> and<00:16:05.360> the<00:16:06.360> most 00:16:06.620 --> 00:16:06.630 align:start position:0% means to be fresh enough and the most 00:16:06.630 --> 00:16:09.740 align:start position:0% means to be fresh enough and the most natural<00:16:07.340> strawman<00:16:08.340> kind<00:16:08.670> of<00:16:08.790> idea<00:16:09.120> is<00:16:09.330> to<00:16:09.510> say 00:16:09.740 --> 00:16:09.750 align:start position:0% natural strawman kind of idea is to say 00:16:09.750 --> 00:16:12.710 align:start position:0% natural strawman kind of idea is to say I<00:16:10.050> will<00:16:10.770> compare<00:16:11.250> the<00:16:11.400> parent<00:16:11.760> block<00:16:11.970> with<00:16:12.210> the 00:16:12.710 --> 00:16:12.720 align:start position:0% I will compare the parent block with the 00:16:12.720 --> 00:16:15.560 align:start position:0% I will compare the parent block with the freshest<00:16:13.200> notarized<00:16:13.590> chain<00:16:13.950> I've<00:16:14.700> seen<00:16:15.090> so 00:16:15.560 --> 00:16:15.570 align:start position:0% freshest notarized chain I've seen so 00:16:15.570 --> 00:16:18.890 align:start position:0% freshest notarized chain I've seen so far<00:16:15.600> and<00:16:16.020> I<00:16:16.770> want<00:16:17.070> that<00:16:17.430> the<00:16:17.610> parent<00:16:17.940> block<00:16:18.120> be 00:16:18.890 --> 00:16:18.900 align:start position:0% far and I want that the parent block be 00:16:18.900 --> 00:16:22.690 align:start position:0% far and I want that the parent block be at<00:16:19.110> least<00:16:19.410> as<00:16:19.680> fresh<00:16:20.510> so<00:16:21.510> this<00:16:21.720> almost<00:16:22.260> works 00:16:22.690 --> 00:16:22.700 align:start position:0% at least as fresh so this almost works 00:16:22.700 --> 00:16:26.690 align:start position:0% at least as fresh so this almost works but<00:16:23.700> not<00:16:23.880> quite<00:16:24.210> so<00:16:24.540> because<00:16:25.100> one<00:16:26.100> thing<00:16:26.460> is 00:16:26.690 --> 00:16:26.700 align:start position:0% but not quite so because one thing is 00:16:26.700 --> 00:16:29.870 align:start position:0% but not quite so because one thing is that<00:16:26.940> the<00:16:27.660> proposal<00:16:28.200> was<00:16:28.380> made<00:16:28.640> let's<00:16:29.640> say 00:16:29.870 --> 00:16:29.880 align:start position:0% that the proposal was made let's say 00:16:29.880 --> 00:16:32.570 align:start position:0% that the proposal was made let's say half<00:16:30.060> a<00:16:30.210> second<00:16:30.540> ago<00:16:30.780> right<00:16:31.530> and<00:16:32.310> if<00:16:32.460> I'm 00:16:32.570 --> 00:16:32.580 align:start position:0% half a second ago right and if I'm 00:16:32.580 --> 00:16:35.320 align:start position:0% half a second ago right and if I'm comparing<00:16:33.000> the<00:16:33.240> proposal<00:16:33.780> with<00:16:34.380> my<00:16:34.650> current 00:16:35.320 --> 00:16:35.330 align:start position:0% comparing the proposal with my current 00:16:35.330 --> 00:16:37.790 align:start position:0% comparing the proposal with my current freshest<00:16:36.330> notarized<00:16:36.720> chain<00:16:37.110> that's<00:16:37.470> kind<00:16:37.740> of 00:16:37.790 --> 00:16:37.800 align:start position:0% freshest notarized chain that's kind of 00:16:37.800 --> 00:16:40.670 align:start position:0% freshest notarized chain that's kind of unfair<00:16:38.220> to<00:16:38.250> the<00:16:38.520> proposal<00:16:38.970> because<00:16:39.210> a<00:16:39.420> lot<00:16:40.110> can 00:16:40.670 --> 00:16:40.680 align:start position:0% unfair to the proposal because a lot can 00:16:40.680 --> 00:16:42.470 align:start position:0% unfair to the proposal because a lot can have<00:16:40.890> happened<00:16:41.280> during<00:16:41.610> that<00:16:41.730> half<00:16:42.060> second 00:16:42.470 --> 00:16:42.480 align:start position:0% have happened during that half second 00:16:42.480 --> 00:16:44.480 align:start position:0% have happened during that half second right<00:16:42.750> I<00:16:42.780> could<00:16:43.050> have<00:16:43.080> seen<00:16:43.350> new<00:16:44.040> notarized 00:16:44.480 --> 00:16:44.490 align:start position:0% right I could have seen new notarized 00:16:44.490 --> 00:16:48.820 align:start position:0% right I could have seen new notarized blocks<00:16:44.730> during<00:16:45.090> that<00:16:45.210> half<00:16:45.300> second<00:16:47.150> so<00:16:48.150> what 00:16:48.820 --> 00:16:48.830 align:start position:0% blocks during that half second so what 00:16:48.830 --> 00:16:51.470 align:start position:0% blocks during that half second so what the<00:16:49.830> protocol<00:16:50.220> actually<00:16:50.640> does<00:16:50.850> is<00:16:51.090> to<00:16:51.270> have<00:16:51.450> a 00:16:51.470 --> 00:16:51.480 align:start position:0% the protocol actually does is to have a 00:16:51.480 --> 00:16:54.080 align:start position:0% the protocol actually does is to have a slightly<00:16:51.870> relaxed<00:16:52.650> condition<00:16:52.940> instead<00:16:53.940> of 00:16:54.080 --> 00:16:54.090 align:start position:0% slightly relaxed condition instead of 00:16:54.090 --> 00:16:56.060 align:start position:0% slightly relaxed condition instead of comparing<00:16:54.630> with<00:16:54.780> the<00:16:54.810> present<00:16:55.440> myself<00:16:55.590> I'm 00:16:56.060 --> 00:16:56.070 align:start position:0% comparing with the present myself I'm 00:16:56.070 --> 00:16:58.730 align:start position:0% comparing with the present myself I'm going<00:16:56.670> to<00:16:56.790> compare<00:16:57.330> the<00:16:57.480> parent<00:16:57.840> block<00:16:58.020> with 00:16:58.730 --> 00:16:58.740 align:start position:0% going to compare the parent block with 00:16:58.740 --> 00:17:02.720 align:start position:0% going to compare the parent block with myself<00:16:59.040> but<00:16:59.910> a<00:17:00.060> second<00:17:00.540> ago<00:17:00.860> so<00:17:01.860> the<00:17:01.980> second<00:17:02.580> is 00:17:02.720 --> 00:17:02.730 align:start position:0% myself but a second ago so the second is 00:17:02.730 --> 00:17:06.040 align:start position:0% myself but a second ago so the second is like<00:17:02.790> a<00:17:03.030> parameter<00:17:03.720> it<00:17:04.320> actually<00:17:04.940> captures 00:17:06.040 --> 00:17:06.050 align:start position:0% like a parameter it actually captures 00:17:06.050 --> 00:17:08.000 align:start position:0% like a parameter it actually captures attention<00:17:07.050> between<00:17:07.170> consistency<00:17:07.890> and 00:17:08.000 --> 00:17:08.010 align:start position:0% attention between consistency and 00:17:08.010 --> 00:17:10.640 align:start position:0% attention between consistency and lightness<00:17:08.370> and<00:17:09.300> the<00:17:09.360> actual<00:17:10.050> proof<00:17:10.260> to<00:17:10.500> show 00:17:10.640 --> 00:17:10.650 align:start position:0% lightness and the actual proof to show 00:17:10.650 --> 00:17:12.980 align:start position:0% lightness and the actual proof to show that<00:17:10.680> this<00:17:10.950> parameter<00:17:11.190> works<00:17:11.580> is<00:17:11.820> a<00:17:11.850> you<00:17:12.840> know 00:17:12.980 --> 00:17:12.990 align:start position:0% that this parameter works is a you know 00:17:12.990 --> 00:17:14.540 align:start position:0% that this parameter works is a you know just<00:17:13.260> it<00:17:13.380> needs<00:17:13.590> a<00:17:13.650> little<00:17:13.740> bit<00:17:13.890> more<00:17:14.130> work<00:17:14.310> and 00:17:14.540 --> 00:17:14.550 align:start position:0% just it needs a little bit more work and 00:17:14.550 --> 00:17:17.780 align:start position:0% just it needs a little bit more work and but<00:17:15.300> for<00:17:15.930> the<00:17:16.020> talk<00:17:16.260> I'm<00:17:16.470> going<00:17:16.620> to<00:17:16.830> ask<00:17:17.340> you<00:17:17.640> to 00:17:17.780 --> 00:17:17.790 align:start position:0% but for the talk I'm going to ask you to 00:17:17.790 --> 00:17:19.610 align:start position:0% but for the talk I'm going to ask you to take<00:17:17.970> my<00:17:18.090> word<00:17:18.270> for<00:17:18.300> it<00:17:18.630> if<00:17:18.810> you<00:17:19.050> set<00:17:19.320> this<00:17:19.470> to 00:17:19.610 --> 00:17:19.620 align:start position:0% take my word for it if you set this to 00:17:19.620 --> 00:17:23.360 align:start position:0% take my word for it if you set this to be<00:17:19.650> one<00:17:19.860> second<00:17:20.220> it'll<00:17:20.400> all<00:17:20.580> work<00:17:22.310> okay<00:17:23.310> so 00:17:23.360 --> 00:17:23.370 align:start position:0% be one second it'll all work okay so 00:17:23.370 --> 00:17:25.610 align:start position:0% be one second it'll all work okay so that's<00:17:23.610> the<00:17:23.760> first<00:17:23.790> fix<00:17:24.270> and<00:17:24.810> we<00:17:25.350> are<00:17:25.440> almost 00:17:25.610 --> 00:17:25.620 align:start position:0% that's the first fix and we are almost 00:17:25.620 --> 00:17:26.240 align:start position:0% that's the first fix and we are almost there 00:17:26.240 --> 00:17:26.250 align:start position:0% there 00:17:26.250 --> 00:17:30.100 align:start position:0% there we<00:17:26.850> just<00:17:27.030> need<00:17:27.210> one<00:17:27.800> additional<00:17:28.800> minor<00:17:29.010> fix 00:17:30.100 --> 00:17:30.110 align:start position:0% we just need one additional minor fix 00:17:30.110 --> 00:17:33.110 align:start position:0% we just need one additional minor fix okay<00:17:31.110> and<00:17:31.530> I'm<00:17:31.740> going<00:17:32.040> to<00:17:32.100> use<00:17:32.310> exactly<00:17:32.580> the 00:17:33.110 --> 00:17:33.120 align:start position:0% okay and I'm going to use exactly the 00:17:33.120 --> 00:17:35.780 align:start position:0% okay and I'm going to use exactly the same<00:17:33.150> scenario<00:17:33.630> same<00:17:34.200> question<00:17:34.680> to<00:17:35.010> motivate 00:17:35.780 --> 00:17:35.790 align:start position:0% same scenario same question to motivate 00:17:35.790 --> 00:17:38.840 align:start position:0% same scenario same question to motivate the<00:17:35.940> second<00:17:36.330> fix<00:17:36.680> so<00:17:37.680> remember<00:17:38.100> what<00:17:38.280> we<00:17:38.310> asked 00:17:38.840 --> 00:17:38.850 align:start position:0% the second fix so remember what we asked 00:17:38.850 --> 00:17:41.720 align:start position:0% the second fix so remember what we asked is<00:17:39.330> why<00:17:40.200> does<00:17:40.470> the<00:17:40.590> block<00:17:40.800> number<00:17:40.950> 5<00:17:41.280> extend 00:17:41.720 --> 00:17:41.730 align:start position:0% is why does the block number 5 extend 00:17:41.730 --> 00:17:42.140 align:start position:0% is why does the block number 5 extend from 00:17:42.140 --> 00:17:42.150 align:start position:0% from 00:17:42.150 --> 00:17:45.260 align:start position:0% from and<00:17:42.360> not<00:17:42.510> four<00:17:42.780> and<00:17:43.760> earlier<00:17:44.760> we<00:17:44.910> said<00:17:45.120> you 00:17:45.260 --> 00:17:45.270 align:start position:0% and not four and earlier we said you 00:17:45.270 --> 00:17:46.610 align:start position:0% and not four and earlier we said you know<00:17:45.330> perhaps<00:17:45.570> the<00:17:45.870> proposer<00:17:46.170> five<00:17:46.440> is 00:17:46.610 --> 00:17:46.620 align:start position:0% know perhaps the proposer five is 00:17:46.620 --> 00:17:48.980 align:start position:0% know perhaps the proposer five is correct<00:17:46.980> now<00:17:47.850> I'm<00:17:48.090> going<00:17:48.360> to<00:17:48.480> ask<00:17:48.660> you<00:17:48.840> to 00:17:48.980 --> 00:17:48.990 align:start position:0% correct now I'm going to ask you to 00:17:48.990 --> 00:17:51.280 align:start position:0% correct now I'm going to ask you to erase<00:17:49.290> everything<00:17:49.680> from<00:17:50.370> your<00:17:50.520> your<00:17:50.940> mind 00:17:51.280 --> 00:17:51.290 align:start position:0% erase everything from your your mind 00:17:51.290 --> 00:17:53.980 align:start position:0% erase everything from your your mind forget<00:17:52.290> about<00:17:52.410> everything<00:17:52.770> I<00:17:52.980> explained<00:17:53.610> and 00:17:53.980 --> 00:17:53.990 align:start position:0% forget about everything I explained and 00:17:53.990 --> 00:17:57.260 align:start position:0% forget about everything I explained and let's<00:17:54.990> start<00:17:55.230> from<00:17:55.440> scratch<00:17:55.880> here's<00:17:56.880> another 00:17:57.260 --> 00:17:57.270 align:start position:0% let's start from scratch here's another 00:17:57.270 --> 00:18:00.560 align:start position:0% let's start from scratch here's another possible<00:17:57.810> explanation<00:17:58.970> it<00:17:59.970> actually<00:18:00.390> could 00:18:00.560 --> 00:18:00.570 align:start position:0% possible explanation it actually could 00:18:00.570 --> 00:18:02.090 align:start position:0% possible explanation it actually could be<00:18:00.720> the<00:18:00.810> case<00:18:00.990> that<00:18:01.170> proposed<00:18:01.500> a<00:18:01.620> five<00:18:01.830> is 00:18:02.090 --> 00:18:02.100 align:start position:0% be the case that proposed a five is 00:18:02.100 --> 00:18:05.270 align:start position:0% be the case that proposed a five is honest<00:18:02.520> and<00:18:02.700> it<00:18:03.330> is<00:18:03.450> proposal<00:18:04.050> for<00:18:04.320> who<00:18:05.130> is 00:18:05.270 --> 00:18:05.280 align:start position:0% honest and it is proposal for who is 00:18:05.280 --> 00:18:09.020 align:start position:0% honest and it is proposal for who is corrupt<00:18:05.610> and<00:18:07.010> this<00:18:08.010> scenario<00:18:08.430> can<00:18:08.580> also 00:18:09.020 --> 00:18:09.030 align:start position:0% corrupt and this scenario can also 00:18:09.030 --> 00:18:11.870 align:start position:0% corrupt and this scenario can also happen<00:18:09.660> when<00:18:10.110> proposal<00:18:10.710> for<00:18:11.070> is<00:18:11.280> the<00:18:11.460> bad<00:18:11.670> guy 00:18:11.870 --> 00:18:11.880 align:start position:0% happen when proposal for is the bad guy 00:18:11.880 --> 00:18:15.110 align:start position:0% happen when proposal for is the bad guy and<00:18:12.320> how<00:18:13.320> can<00:18:13.500> it<00:18:13.650> happen<00:18:13.940> here's<00:18:14.940> the 00:18:15.110 --> 00:18:15.120 align:start position:0% and how can it happen here's the 00:18:15.120 --> 00:18:18.110 align:start position:0% and how can it happen here's the concrete<00:18:15.510> attack<00:18:16.100> so<00:18:17.100> let's<00:18:17.310> say<00:18:17.430> Loki<00:18:17.820> is<00:18:17.940> our 00:18:18.110 --> 00:18:18.120 align:start position:0% concrete attack so let's say Loki is our 00:18:18.120 --> 00:18:20.900 align:start position:0% concrete attack so let's say Loki is our proposal<00:18:18.600> for<00:18:18.630> he<00:18:19.620> proposes<00:18:20.160> two<00:18:20.340> blocks<00:18:20.640> in 00:18:20.900 --> 00:18:20.910 align:start position:0% proposal for he proposes two blocks in 00:18:20.910 --> 00:18:23.690 align:start position:0% proposal for he proposes two blocks in epic<00:18:21.210> for<00:18:21.500> the<00:18:22.500> blue<00:18:22.680> block<00:18:22.950> to<00:18:23.190> the<00:18:23.310> blue<00:18:23.490> guys 00:18:23.690 --> 00:18:23.700 align:start position:0% epic for the blue block to the blue guys 00:18:23.700 --> 00:18:27.710 align:start position:0% epic for the blue block to the blue guys and<00:18:24.000> the<00:18:24.510> red<00:18:24.660> block<00:18:24.870> to<00:18:25.050> the<00:18:25.140> red<00:18:25.290> guys<00:18:25.730> now<00:18:26.730> we 00:18:27.710 --> 00:18:27.720 align:start position:0% and the red block to the red guys now we 00:18:27.720 --> 00:18:30.260 align:start position:0% and the red block to the red guys now we have<00:18:27.900> six<00:18:28.140> and<00:18:28.500> people<00:18:29.460> on<00:18:29.610> the<00:18:29.700> committee<00:18:30.000> so 00:18:30.260 --> 00:18:30.270 align:start position:0% have six and people on the committee so 00:18:30.270 --> 00:18:32.390 align:start position:0% have six and people on the committee so you<00:18:30.930> need<00:18:31.260> like<00:18:31.440> four<00:18:31.740> votes<00:18:31.980> to<00:18:32.220> have<00:18:32.250> a 00:18:32.390 --> 00:18:32.400 align:start position:0% you need like four votes to have a 00:18:32.400 --> 00:18:34.460 align:start position:0% you need like four votes to have a notarization<00:18:33.000> right<00:18:33.360> in<00:18:33.750> this<00:18:33.990> case<00:18:34.200> if<00:18:34.380> you 00:18:34.460 --> 00:18:34.470 align:start position:0% notarization right in this case if you 00:18:34.470 --> 00:18:36.140 align:start position:0% notarization right in this case if you collect<00:18:34.800> all<00:18:35.010> of<00:18:35.100> the<00:18:35.370> honest<00:18:35.670> notes<00:18:35.880> votes 00:18:36.140 --> 00:18:36.150 align:start position:0% collect all of the honest notes votes 00:18:36.150 --> 00:18:39.290 align:start position:0% collect all of the honest notes votes it's<00:18:36.960> not<00:18:37.200> enough<00:18:37.620> to<00:18:37.830> make<00:18:38.580> a<00:18:38.610> notarize<00:18:39.060> issue 00:18:39.290 --> 00:18:39.300 align:start position:0% it's not enough to make a notarize issue 00:18:39.300 --> 00:18:40.610 align:start position:0% it's not enough to make a notarize issue for<00:18:39.480> either<00:18:39.600> the<00:18:39.840> blue<00:18:40.020> or<00:18:40.050> the<00:18:40.170> red<00:18:40.290> block 00:18:40.610 --> 00:18:40.620 align:start position:0% for either the blue or the red block 00:18:40.620 --> 00:18:42.830 align:start position:0% for either the blue or the red block because<00:18:41.550> we<00:18:41.700> have<00:18:41.850> three<00:18:42.090> for<00:18:42.300> blue<00:18:42.480> and<00:18:42.690> two 00:18:42.830 --> 00:18:42.840 align:start position:0% because we have three for blue and two 00:18:42.840 --> 00:18:47.540 align:start position:0% because we have three for blue and two for<00:18:43.080> red<00:18:44.360> but<00:18:45.360> remember<00:18:46.020> that<00:18:46.350> the<00:18:47.220> corrupt 00:18:47.540 --> 00:18:47.550 align:start position:0% for red but remember that the corrupt 00:18:47.550 --> 00:18:51.140 align:start position:0% for red but remember that the corrupt guy<00:18:47.730> also<00:18:47.970> has<00:18:48.090> a<00:18:48.270> vote<00:18:48.570> now<00:18:49.490> if<00:18:50.490> the<00:18:50.790> corrupt 00:18:51.140 --> 00:18:51.150 align:start position:0% guy also has a vote now if the corrupt 00:18:51.150 --> 00:18:54.080 align:start position:0% guy also has a vote now if the corrupt guy<00:18:51.390> votes<00:18:51.810> for<00:18:52.140> blue<00:18:52.460> he<00:18:53.460> can<00:18:53.730> have<00:18:53.940> an 00:18:54.080 --> 00:18:54.090 align:start position:0% guy votes for blue he can have an 00:18:54.090 --> 00:18:56.390 align:start position:0% guy votes for blue he can have an authorization<00:18:54.750> for<00:18:54.780> the<00:18:55.020> blue<00:18:55.200> block<00:18:55.470> and<00:18:55.800> the 00:18:56.390 --> 00:18:56.400 align:start position:0% authorization for the blue block and the 00:18:56.400 --> 00:18:59.030 align:start position:0% authorization for the blue block and the bad<00:18:56.640> thing<00:18:56.940> here<00:18:57.300> is<00:18:57.930> that<00:18:58.020> the<00:18:58.470> corrupt<00:18:58.830> guy 00:18:59.030 --> 00:18:59.040 align:start position:0% bad thing here is that the corrupt guy 00:18:59.040 --> 00:19:01.610 align:start position:0% bad thing here is that the corrupt guy is<00:18:59.520> the<00:18:59.790> only<00:19:00.180> guy<00:19:00.390> who<00:19:00.450> knows<00:19:01.380> an 00:19:01.610 --> 00:19:01.620 align:start position:0% is the only guy who knows an 00:19:01.620 --> 00:19:05.030 align:start position:0% is the only guy who knows an authorization<00:19:02.340> for<00:19:02.370> blue<00:19:02.880> and<00:19:03.740> no<00:19:04.740> one<00:19:04.890> else 00:19:05.030 --> 00:19:05.040 align:start position:0% authorization for blue and no one else 00:19:05.040 --> 00:19:07.340 align:start position:0% authorization for blue and no one else has<00:19:05.400> seen<00:19:05.670> an<00:19:06.180> authorization<00:19:06.750> for<00:19:06.780> blue<00:19:07.110> yet 00:19:07.340 --> 00:19:07.350 align:start position:0% has seen an authorization for blue yet 00:19:07.350 --> 00:19:09.860 align:start position:0% has seen an authorization for blue yet right<00:19:07.650> so<00:19:08.610> now<00:19:08.880> he<00:19:08.940> can<00:19:09.120> play<00:19:09.480> it<00:19:09.600> to<00:19:09.750> his 00:19:09.860 --> 00:19:09.870 align:start position:0% right so now he can play it to his 00:19:09.870 --> 00:19:12.470 align:start position:0% right so now he can play it to his advantage<00:19:10.020> in<00:19:11.010> particular<00:19:11.670> he<00:19:11.820> can<00:19:12.030> time<00:19:12.300> the 00:19:12.470 --> 00:19:12.480 align:start position:0% advantage in particular he can time the 00:19:12.480 --> 00:19:16.010 align:start position:0% advantage in particular he can time the release<00:19:12.830> he<00:19:13.830> can<00:19:14.070> let's<00:19:14.580> say<00:19:14.790> release<00:19:15.780> the 00:19:16.010 --> 00:19:16.020 align:start position:0% release he can let's say release the 00:19:16.020 --> 00:19:18.650 align:start position:0% release he can let's say release the last<00:19:16.260> vote<00:19:16.500> to<00:19:17.370> a<00:19:17.400> subset<00:19:17.820> of<00:19:17.880> the<00:19:18.120> notes<00:19:18.330> first 00:19:18.650 --> 00:19:18.660 align:start position:0% last vote to a subset of the notes first 00:19:18.660 --> 00:19:20.530 align:start position:0% last vote to a subset of the notes first so<00:19:19.320> some<00:19:19.530> of<00:19:19.560> the<00:19:19.830> people<00:19:20.010> will<00:19:20.250> see 00:19:20.530 --> 00:19:20.540 align:start position:0% so some of the people will see 00:19:20.540 --> 00:19:24.260 align:start position:0% so some of the people will see notarization<00:19:21.540> for<00:19:21.980> this<00:19:22.980> block<00:19:23.220> first<00:19:23.490> before 00:19:24.260 --> 00:19:24.270 align:start position:0% notarization for this block first before 00:19:24.270 --> 00:19:30.280 align:start position:0% notarization for this block first before others<00:19:24.570> see<00:19:24.780> it<00:19:25.430> okay<00:19:26.430> so<00:19:26.490> concretely<00:19:29.150> okay<00:19:30.150> so 00:19:30.280 --> 00:19:30.290 align:start position:0% others see it okay so concretely okay so 00:19:30.290 --> 00:19:32.420 align:start position:0% others see it okay so concretely okay so this<00:19:31.290> is<00:19:31.440> the<00:19:31.560> only<00:19:31.710> guy<00:19:31.920> who<00:19:31.980> knows<00:19:32.130> an 00:19:32.420 --> 00:19:32.430 align:start position:0% this is the only guy who knows an 00:19:32.430 --> 00:19:34.400 align:start position:0% this is the only guy who knows an authorization<00:19:32.970> for<00:19:33.000> the<00:19:33.210> blue<00:19:33.360> block<00:19:33.600> so 00:19:34.400 --> 00:19:34.410 align:start position:0% authorization for the blue block so 00:19:34.410 --> 00:19:37.160 align:start position:0% authorization for the blue block so concretely<00:19:34.860> he's<00:19:35.160> going<00:19:35.340> to<00:19:35.460> exploit<00:19:36.170> this 00:19:37.160 --> 00:19:37.170 align:start position:0% concretely he's going to exploit this 00:19:37.170 --> 00:19:39.980 align:start position:0% concretely he's going to exploit this advantage<00:19:37.680> in<00:19:38.310> the<00:19:38.520> following<00:19:38.820> way<00:19:39.090> so<00:19:39.840> at 00:19:39.980 --> 00:19:39.990 align:start position:0% advantage in the following way so at 00:19:39.990 --> 00:19:44.120 align:start position:0% advantage in the following way so at some<00:19:40.200> instant<00:19:41.180> the<00:19:42.180> bad<00:19:42.390> guy<00:19:42.830> chooses<00:19:43.830> one 00:19:44.120 --> 00:19:44.130 align:start position:0% some instant the bad guy chooses one 00:19:44.130 --> 00:19:47.480 align:start position:0% some instant the bad guy chooses one victim<00:19:44.910> in<00:19:45.180> this<00:19:45.390> case<00:19:45.740> spider-man<00:19:46.740> and<00:19:46.950> it's 00:19:47.480 --> 00:19:47.490 align:start position:0% victim in this case spider-man and it's 00:19:47.490 --> 00:19:48.650 align:start position:0% victim in this case spider-man and it's going<00:19:47.640> to<00:19:47.760> tell<00:19:47.940> spider-man<00:19:48.510> an 00:19:48.650 --> 00:19:48.660 align:start position:0% going to tell spider-man an 00:19:48.660 --> 00:19:51.370 align:start position:0% going to tell spider-man an authorization<00:19:49.320> for<00:19:49.350> the<00:19:49.620> the<00:19:50.100> fourth<00:19:50.340> block 00:19:51.370 --> 00:19:51.380 align:start position:0% authorization for the the fourth block 00:19:51.380 --> 00:19:53.100 align:start position:0% authorization for the the fourth block okay 00:19:53.100 --> 00:19:53.110 align:start position:0% okay 00:19:53.110 --> 00:19:57.600 align:start position:0% okay at<00:19:53.230> the<00:19:53.470> same<00:19:53.710> instant<00:19:55.260> everyone<00:19:56.260> else<00:19:56.610> hasn't 00:19:57.600 --> 00:19:57.610 align:start position:0% at the same instant everyone else hasn't 00:19:57.610 --> 00:19:59.940 align:start position:0% at the same instant everyone else hasn't seen<00:19:57.850> another<00:19:58.150> ization<00:19:58.540> 4/4<00:19:59.080> yet<00:19:59.260> they've 00:19:59.940 --> 00:19:59.950 align:start position:0% seen another ization 4/4 yet they've 00:19:59.950 --> 00:20:02.490 align:start position:0% seen another ization 4/4 yet they've only<00:20:00.160> seen<00:20:00.400> notarization<00:20:01.000> for<00:20:01.870> the<00:20:01.960> prefix<00:20:02.350> up 00:20:02.490 --> 00:20:02.500 align:start position:0% only seen notarization for the prefix up 00:20:02.500 --> 00:20:04.920 align:start position:0% only seen notarization for the prefix up to<00:20:02.650> three<00:20:02.860> so<00:20:03.730> now<00:20:03.910> what's<00:20:04.210> going<00:20:04.450> to<00:20:04.510> happen 00:20:04.920 --> 00:20:04.930 align:start position:0% to three so now what's going to happen 00:20:04.930 --> 00:20:07.080 align:start position:0% to three so now what's going to happen is<00:20:05.740> that<00:20:05.950> these<00:20:06.190> guys<00:20:06.400> are<00:20:06.640> going<00:20:06.730> to<00:20:06.850> vote<00:20:07.030> for 00:20:07.080 --> 00:20:07.090 align:start position:0% is that these guys are going to vote for 00:20:07.090 --> 00:20:10.080 align:start position:0% is that these guys are going to vote for the<00:20:07.360> block<00:20:07.540> 5<00:20:07.810> and<00:20:08.140> because<00:20:09.130> the<00:20:09.460> you<00:20:09.760> know<00:20:09.820> the 00:20:10.080 --> 00:20:10.090 align:start position:0% the block 5 and because the you know the 00:20:10.090 --> 00:20:13.290 align:start position:0% the block 5 and because the you know the fifth<00:20:10.270> proposer<00:20:10.720> is<00:20:11.620> honest<00:20:12.130> and<00:20:12.340> he<00:20:13.120> hasn't 00:20:13.290 --> 00:20:13.300 align:start position:0% fifth proposer is honest and he hasn't 00:20:13.300 --> 00:20:16.410 align:start position:0% fifth proposer is honest and he hasn't seen<00:20:13.600> notarization<00:20:14.170> 4/4<00:20:14.830> yet<00:20:15.030> so<00:20:16.030> he's<00:20:16.210> going 00:20:16.410 --> 00:20:16.420 align:start position:0% seen notarization 4/4 yet so he's going 00:20:16.420 --> 00:20:21.510 align:start position:0% seen notarization 4/4 yet so he's going to<00:20:16.890> build<00:20:17.890> this<00:20:18.700> block<00:20:19.030> from<00:20:19.570> 3<00:20:19.900> and<00:20:20.340> then<00:20:21.340> this 00:20:21.510 --> 00:20:21.520 align:start position:0% to build this block from 3 and then this 00:20:21.520 --> 00:20:23.640 align:start position:0% to build this block from 3 and then this block<00:20:21.760> can<00:20:21.790> take<00:20:22.120> notarization<00:20:22.630> in<00:20:22.960> this<00:20:23.110> very 00:20:23.640 --> 00:20:23.650 align:start position:0% block can take notarization in this very 00:20:23.650 --> 00:20:28.980 align:start position:0% block can take notarization in this very instant<00:20:24.690> okay<00:20:26.850> so<00:20:27.850> what<00:20:28.030> is<00:20:28.150> problematic 00:20:28.980 --> 00:20:28.990 align:start position:0% instant okay so what is problematic 00:20:28.990 --> 00:20:33.390 align:start position:0% instant okay so what is problematic about<00:20:29.410> the<00:20:29.530> scenario<00:20:31.380> the<00:20:32.380> problem<00:20:32.830> here<00:20:33.220> is 00:20:33.390 --> 00:20:33.400 align:start position:0% about the scenario the problem here is 00:20:33.400 --> 00:20:37.260 align:start position:0% about the scenario the problem here is that<00:20:33.510> suppose<00:20:34.560> and<00:20:35.560> at<00:20:36.400> the<00:20:36.640> instant<00:20:36.910> when 00:20:37.260 --> 00:20:37.270 align:start position:0% that suppose and at the instant when 00:20:37.270 --> 00:20:40.350 align:start position:0% that suppose and at the instant when spider-man<00:20:37.720> sees<00:20:38.110> notarization<00:20:38.650> 4/4<00:20:39.280> if<00:20:40.000> he 00:20:40.350 --> 00:20:40.360 align:start position:0% spider-man sees notarization 4/4 if he 00:20:40.360 --> 00:20:43.020 align:start position:0% spider-man sees notarization 4/4 if he hastily<00:20:40.960> confirms<00:20:41.530> plot<00:20:41.830> for<00:20:42.100> that<00:20:42.670> he's<00:20:42.850> in 00:20:43.020 --> 00:20:43.030 align:start position:0% hastily confirms plot for that he's in 00:20:43.030 --> 00:20:45.270 align:start position:0% hastily confirms plot for that he's in trouble<00:20:43.210> because<00:20:43.720> at<00:20:44.470> the<00:20:44.620> end<00:20:44.650> of<00:20:44.890> the<00:20:45.070> time 00:20:45.270 --> 00:20:45.280 align:start position:0% trouble because at the end of the time 00:20:45.280 --> 00:20:48.870 align:start position:0% trouble because at the end of the time he'll<00:20:46.030> live<00:20:46.270> to<00:20:46.300> discover<00:20:46.840> that<00:20:47.140> in<00:20:48.070> fact<00:20:48.400> this 00:20:48.870 --> 00:20:48.880 align:start position:0% he'll live to discover that in fact this 00:20:48.880 --> 00:20:51.120 align:start position:0% he'll live to discover that in fact this other<00:20:49.150> fork<00:20:49.510> survived<00:20:50.320> to<00:20:50.500> the<00:20:50.620> end<00:20:50.770> of<00:20:50.890> time 00:20:51.120 --> 00:20:51.130 align:start position:0% other fork survived to the end of time 00:20:51.130 --> 00:20:54.570 align:start position:0% other fork survived to the end of time and<00:20:51.310> 4<00:20:52.120> is<00:20:52.270> abandoned<00:20:52.810> right<00:20:53.710> so<00:20:53.980> he<00:20:54.250> risks 00:20:54.570 --> 00:20:54.580 align:start position:0% and 4 is abandoned right so he risks 00:20:54.580 --> 00:20:57.090 align:start position:0% and 4 is abandoned right so he risks inconsistency<00:20:55.330> with<00:20:55.480> the<00:20:55.570> rest<00:20:55.720> of<00:20:55.930> the<00:20:56.140> notes 00:20:57.090 --> 00:20:57.100 align:start position:0% inconsistency with the rest of the notes 00:20:57.100 --> 00:21:02.700 align:start position:0% inconsistency with the rest of the notes at<00:20:57.430> the<00:20:57.520> end<00:20:57.640> of<00:20:57.880> time<00:20:59.370> okay<00:21:00.370> so<00:21:01.350> what<00:21:02.350> do<00:21:02.440> we<00:21:02.500> do 00:21:02.700 --> 00:21:02.710 align:start position:0% at the end of time okay so what do we do 00:21:02.710 --> 00:21:06.560 align:start position:0% at the end of time okay so what do we do now<00:21:04.080> well<00:21:05.080> the<00:21:05.230> moral<00:21:05.440> of<00:21:05.680> the<00:21:05.800> story<00:21:05.830> is<00:21:06.280> that 00:21:06.560 --> 00:21:06.570 align:start position:0% now well the moral of the story is that 00:21:06.570 --> 00:21:09.240 align:start position:0% now well the moral of the story is that like<00:21:07.570> perhaps<00:21:07.900> I<00:21:08.110> shouldn't<00:21:08.440> confirm<00:21:08.860> a<00:21:08.890> block 00:21:09.240 --> 00:21:09.250 align:start position:0% like perhaps I shouldn't confirm a block 00:21:09.250 --> 00:21:14.040 align:start position:0% like perhaps I shouldn't confirm a block the<00:21:09.850> moment<00:21:10.240> I<00:21:10.390> cease<00:21:10.660> an<00:21:10.810> authorization<00:21:13.050> form 00:21:14.040 --> 00:21:14.050 align:start position:0% the moment I cease an authorization form 00:21:14.050 --> 00:21:17.460 align:start position:0% the moment I cease an authorization form for<00:21:14.530> me<00:21:14.650> to<00:21:14.800> confirm<00:21:15.190> the<00:21:15.370> block<00:21:15.750> not<00:21:16.750> only<00:21:17.140> do 00:21:17.460 --> 00:21:17.470 align:start position:0% for me to confirm the block not only do 00:21:17.470 --> 00:21:19.260 align:start position:0% for me to confirm the block not only do I<00:21:17.530> want<00:21:17.650> to<00:21:18.040> see<00:21:18.220> an<00:21:18.340> authorization<00:21:19.000> for<00:21:19.180> the 00:21:19.260 --> 00:21:19.270 align:start position:0% I want to see an authorization for the 00:21:19.270 --> 00:21:21.630 align:start position:0% I want to see an authorization for the block<00:21:19.450> I<00:21:19.690> also<00:21:20.200> want<00:21:20.470> to<00:21:20.530> note<00:21:20.770> that<00:21:20.800> many 00:21:21.630 --> 00:21:21.640 align:start position:0% block I also want to note that many 00:21:21.640 --> 00:21:23.310 align:start position:0% block I also want to note that many other<00:21:21.910> people<00:21:22.300> have<00:21:22.420> seen<00:21:22.600> an<00:21:22.780> authorization 00:21:23.310 --> 00:21:23.320 align:start position:0% other people have seen an authorization 00:21:23.320 --> 00:21:26.490 align:start position:0% other people have seen an authorization for<00:21:23.470> the<00:21:23.560> block<00:21:23.800> -<00:21:24.010> so<00:21:24.940> I<00:21:24.970> want<00:21:25.510> like<00:21:26.080> a<00:21:26.110> higher 00:21:26.490 --> 00:21:26.500 align:start position:0% for the block - so I want like a higher 00:21:26.500 --> 00:21:31.370 align:start position:0% for the block - so I want like a higher degree<00:21:26.770> of<00:21:26.980> confidence<00:21:28.020> okay<00:21:29.310> so<00:21:30.310> now<00:21:30.550> to 00:21:31.370 --> 00:21:31.380 align:start position:0% degree of confidence okay so now to 00:21:31.380 --> 00:21:34.020 align:start position:0% degree of confidence okay so now to implement<00:21:32.380> this<00:21:32.710> idea<00:21:32.890> the<00:21:33.460> question<00:21:33.820> we<00:21:33.910> have 00:21:34.020 --> 00:21:34.030 align:start position:0% implement this idea the question we have 00:21:34.030 --> 00:21:37.680 align:start position:0% implement this idea the question we have to<00:21:34.180> answer<00:21:34.500> is<00:21:35.580> how<00:21:36.580> do<00:21:36.640> I<00:21:36.850> know<00:21:36.970> that<00:21:37.510> many 00:21:37.680 --> 00:21:37.690 align:start position:0% to answer is how do I know that many 00:21:37.690 --> 00:21:39.120 align:start position:0% to answer is how do I know that many other<00:21:37.930> people<00:21:38.020> have<00:21:38.320> seen<00:21:38.500> the<00:21:38.650> notarization 00:21:39.120 --> 00:21:39.130 align:start position:0% other people have seen the notarization 00:21:39.130 --> 00:21:41.220 align:start position:0% other people have seen the notarization right<00:21:39.490> I<00:21:39.640> know<00:21:39.700> when<00:21:40.090> I<00:21:40.270> see<00:21:40.600> the<00:21:40.720> notarization 00:21:41.220 --> 00:21:41.230 align:start position:0% right I know when I see the notarization 00:21:41.230 --> 00:21:43.170 align:start position:0% right I know when I see the notarization but<00:21:41.800> how<00:21:41.920> can<00:21:41.980> I<00:21:42.220> tell<00:21:42.490> that<00:21:42.520> you<00:21:42.790> guys<00:21:43.000> have 00:21:43.170 --> 00:21:43.180 align:start position:0% but how can I tell that you guys have 00:21:43.180 --> 00:21:47.640 align:start position:0% but how can I tell that you guys have seen<00:21:43.330> the<00:21:43.450> notarization<00:21:43.930> -<00:21:45.300> in<00:21:46.300> fact<00:21:46.570> we<00:21:47.410> can't 00:21:47.640 --> 00:21:47.650 align:start position:0% seen the notarization - in fact we can't 00:21:47.650 --> 00:21:52.140 align:start position:0% seen the notarization - in fact we can't do<00:21:47.860> this<00:21:47.980> also<00:21:48.340> very<00:21:48.640> simply<00:21:49.060> so<00:21:50.820> imagine<00:21:51.820> we 00:21:52.140 --> 00:21:52.150 align:start position:0% do this also very simply so imagine we 00:21:52.150 --> 00:21:54.060 align:start position:0% do this also very simply so imagine we have<00:21:52.300> two<00:21:52.330> consecutive<00:21:52.870> blocks<00:21:53.260> in<00:21:53.680> this<00:21:53.860> case 00:21:54.060 --> 00:21:54.070 align:start position:0% have two consecutive blocks in this case 00:21:54.070 --> 00:21:56.850 align:start position:0% have two consecutive blocks in this case 3<00:21:54.340> &<00:21:54.490> 4<00:21:54.730> and<00:21:55.060> I've<00:21:55.930> seen<00:21:56.170> both<00:21:56.530> of<00:21:56.680> them 00:21:56.850 --> 00:21:56.860 align:start position:0% 3 & 4 and I've seen both of them 00:21:56.860 --> 00:22:01.230 align:start position:0% 3 & 4 and I've seen both of them notarized<00:21:58.470> so<00:21:59.470> remember<00:22:00.010> the<00:22:00.700> honest<00:22:01.060> notes 00:22:01.230 --> 00:22:01.240 align:start position:0% notarized so remember the honest notes 00:22:01.240 --> 00:22:03.480 align:start position:0% notarized so remember the honest notes are<00:22:01.420> only<00:22:01.600> going<00:22:01.900> to<00:22:02.110> vote<00:22:02.260> for<00:22:02.320> block<00:22:02.830> 4<00:22:03.190> if 00:22:03.480 --> 00:22:03.490 align:start position:0% are only going to vote for block 4 if 00:22:03.490 --> 00:22:05.820 align:start position:0% are only going to vote for block 4 if they<00:22:03.940> have<00:22:04.150> seen<00:22:04.420> notarization<00:22:04.990> for<00:22:05.320> 3<00:22:05.500> right 00:22:05.820 --> 00:22:05.830 align:start position:0% they have seen notarization for 3 right 00:22:05.830 --> 00:22:06.220 align:start position:0% they have seen notarization for 3 right I'm 00:22:06.220 --> 00:22:06.230 align:start position:0% I'm 00:22:06.230 --> 00:22:07.659 align:start position:0% I'm see<00:22:06.500> the<00:22:06.559> notarization<00:22:07.040> for<00:22:07.309> the<00:22:07.370> parent 00:22:07.659 --> 00:22:07.669 align:start position:0% see the notarization for the parent 00:22:07.669 --> 00:22:09.549 align:start position:0% see the notarization for the parent before<00:22:07.910> I<00:22:07.940> vote<00:22:08.090> for<00:22:08.240> the<00:22:08.360> block<00:22:08.510> so<00:22:09.380> this 00:22:09.549 --> 00:22:09.559 align:start position:0% before I vote for the block so this 00:22:09.559 --> 00:22:11.590 align:start position:0% before I vote for the block so this means<00:22:09.799> by<00:22:10.010> voting<00:22:10.250> for<00:22:10.400> four<00:22:10.760> I'm<00:22:11.000> also 00:22:11.590 --> 00:22:11.600 align:start position:0% means by voting for four I'm also 00:22:11.600 --> 00:22:13.200 align:start position:0% means by voting for four I'm also attesting<00:22:12.200> to<00:22:12.260> the<00:22:12.350> fact<00:22:12.470> that<00:22:12.799> I've<00:22:12.950> seen 00:22:13.200 --> 00:22:13.210 align:start position:0% attesting to the fact that I've seen 00:22:13.210 --> 00:22:18.340 align:start position:0% attesting to the fact that I've seen notarization<00:22:14.210> for<00:22:14.570> three<00:22:14.900> in<00:22:15.650> epic<00:22:16.100> form<00:22:17.350> so 00:22:18.340 --> 00:22:18.350 align:start position:0% notarization for three in epic form so 00:22:18.350 --> 00:22:20.230 align:start position:0% notarization for three in epic form so whenever<00:22:18.650> I<00:22:18.799> see<00:22:19.100> this<00:22:19.280> pattern<00:22:19.549> two 00:22:20.230 --> 00:22:20.240 align:start position:0% whenever I see this pattern two 00:22:20.240 --> 00:22:21.909 align:start position:0% whenever I see this pattern two consecutive<00:22:20.630> blocks<00:22:20.960> get<00:22:21.320> both<00:22:21.559> getting 00:22:21.909 --> 00:22:21.919 align:start position:0% consecutive blocks get both getting 00:22:21.919 --> 00:22:24.640 align:start position:0% consecutive blocks get both getting authorized<00:22:22.280> I<00:22:22.690> can<00:22:23.690> draw<00:22:23.929> the<00:22:23.990> conclusion 00:22:24.640 --> 00:22:24.650 align:start position:0% authorized I can draw the conclusion 00:22:24.650 --> 00:22:28.659 align:start position:0% authorized I can draw the conclusion that<00:22:25.960> many<00:22:26.960> honest<00:22:27.440> people<00:22:27.650> must<00:22:28.250> have<00:22:28.460> seen 00:22:28.659 --> 00:22:28.669 align:start position:0% that many honest people must have seen 00:22:28.669 --> 00:22:31.270 align:start position:0% that many honest people must have seen an<00:22:28.850> authorization<00:22:29.570> for<00:22:29.600> three<00:22:29.960> in<00:22:30.559> their<00:22:30.860> epic 00:22:31.270 --> 00:22:31.280 align:start position:0% an authorization for three in their epic 00:22:31.280 --> 00:22:33.549 align:start position:0% an authorization for three in their epic form<00:22:31.750> not<00:22:32.750> only<00:22:32.990> have<00:22:33.169> they<00:22:33.320> seen<00:22:33.500> the 00:22:33.549 --> 00:22:33.559 align:start position:0% form not only have they seen the 00:22:33.559 --> 00:22:35.230 align:start position:0% form not only have they seen the notarization<00:22:34.070> they<00:22:34.309> see<00:22:34.460> it<00:22:34.549> very<00:22:34.730> fast 00:22:35.230 --> 00:22:35.240 align:start position:0% notarization they see it very fast 00:22:35.240 --> 00:22:37.990 align:start position:0% notarization they see it very fast the<00:22:35.390> seating<00:22:35.750> I<00:22:36.020> pick<00:22:36.500> four<00:22:36.770> so<00:22:37.460> this<00:22:37.640> is<00:22:37.790> very 00:22:37.990 --> 00:22:38.000 align:start position:0% the seating I pick four so this is very 00:22:38.000 --> 00:22:43.090 align:start position:0% the seating I pick four so this is very nice<00:22:38.440> because<00:22:39.440> for<00:22:40.040> any<00:22:40.190> future<00:22:40.580> block<00:22:42.100> many 00:22:43.090 --> 00:22:43.100 align:start position:0% nice because for any future block many 00:22:43.100 --> 00:22:44.799 align:start position:0% nice because for any future block many since<00:22:43.460> many<00:22:43.640> people<00:22:43.940> have<00:22:44.059> seen<00:22:44.210> notarization 00:22:44.799 --> 00:22:44.809 align:start position:0% since many people have seen notarization 00:22:44.809 --> 00:22:47.710 align:start position:0% since many people have seen notarization for<00:22:45.710> three<00:22:45.950> very<00:22:46.370> quickly<00:22:46.640> they're<00:22:47.270> going<00:22:47.299> to 00:22:47.710 --> 00:22:47.720 align:start position:0% for three very quickly they're going to 00:22:47.720 --> 00:22:52.030 align:start position:0% for three very quickly they're going to insist<00:22:48.140> on<00:22:48.549> the<00:22:49.549> prefix<00:22:50.059> ending<00:22:50.870> as<00:22:51.049> three<00:22:51.320> be 00:22:52.030 --> 00:22:52.040 align:start position:0% insist on the prefix ending as three be 00:22:52.040 --> 00:22:54.760 align:start position:0% insist on the prefix ending as three be included<00:22:52.790> in<00:22:52.880> any<00:22:53.150> future<00:22:53.270> chain<00:22:53.870> and<00:22:54.110> that's 00:22:54.760 --> 00:22:54.770 align:start position:0% included in any future chain and that's 00:22:54.770 --> 00:22:56.020 align:start position:0% included in any future chain and that's how<00:22:54.919> the<00:22:54.980> block<00:22:55.309> is<00:22:55.460> going<00:22:55.640> to<00:22:55.760> stick<00:22:56.000> around 00:22:56.020 --> 00:22:56.030 align:start position:0% how the block is going to stick around 00:22:56.030 --> 00:22:59.340 align:start position:0% how the block is going to stick around and<00:22:56.450> not<00:22:56.600> be<00:22:56.630> lost<00:22:56.990> right<00:22:57.260> so<00:22:57.740> for<00:22:57.919> instance<00:22:58.270> I 00:22:59.340 --> 00:22:59.350 align:start position:0% and not be lost right so for instance I 00:22:59.350 --> 00:23:04.000 align:start position:0% and not be lost right so for instance I put<00:23:00.350> five<00:23:00.559> for<00:23:00.799> any<00:23:01.040> future<00:23:01.730> epic<00:23:02.590> if<00:23:03.590> anyone 00:23:04.000 --> 00:23:04.010 align:start position:0% put five for any future epic if anyone 00:23:04.010 --> 00:23:06.669 align:start position:0% put five for any future epic if anyone makes<00:23:04.220> a<00:23:04.340> proposal<00:23:05.049> this<00:23:06.049> proposal<00:23:06.559> must 00:23:06.669 --> 00:23:06.679 align:start position:0% makes a proposal this proposal must 00:23:06.679 --> 00:23:09.270 align:start position:0% makes a proposal this proposal must include<00:23:07.070> the<00:23:07.850> prefix<00:23:08.270> ending<00:23:08.840> as<00:23:08.960> three 00:23:09.270 --> 00:23:09.280 align:start position:0% include the prefix ending as three 00:23:09.280 --> 00:23:11.080 align:start position:0% include the prefix ending as three otherwise<00:23:10.280> people<00:23:10.549> are<00:23:10.700> just<00:23:10.880> going<00:23:10.970> to 00:23:11.080 --> 00:23:11.090 align:start position:0% otherwise people are just going to 00:23:11.090 --> 00:23:13.120 align:start position:0% otherwise people are just going to refuse<00:23:11.419> to<00:23:11.600> vote<00:23:11.750> on<00:23:11.990> it<00:23:12.169> right<00:23:12.380> remember 00:23:13.120 --> 00:23:13.130 align:start position:0% refuse to vote on it right remember 00:23:13.130 --> 00:23:16.690 align:start position:0% refuse to vote on it right remember people<00:23:13.280> check<00:23:13.640> that<00:23:14.630> the<00:23:14.750> parent<00:23:15.370> block<00:23:16.370> must 00:23:16.690 --> 00:23:16.700 align:start position:0% people check that the parent block must 00:23:16.700 --> 00:23:20.280 align:start position:0% people check that the parent block must be<00:23:16.880> fresh<00:23:17.120> enough<00:23:17.620> when<00:23:18.620> they<00:23:18.799> cast<00:23:19.070> the<00:23:19.250> vote 00:23:20.280 --> 00:23:20.290 align:start position:0% be fresh enough when they cast the vote 00:23:20.290 --> 00:23:27.460 align:start position:0% be fresh enough when they cast the vote okay<00:23:22.570> so<00:23:24.700> essentially<00:23:25.700> this<00:23:26.140> motivates<00:23:27.140> the 00:23:27.460 --> 00:23:27.470 align:start position:0% okay so essentially this motivates the 00:23:27.470 --> 00:23:30.820 align:start position:0% okay so essentially this motivates the second<00:23:27.890> very<00:23:28.460> simple<00:23:28.880> fix<00:23:29.059> and<00:23:29.559> all<00:23:30.559> we<00:23:30.679> need 00:23:30.820 --> 00:23:30.830 align:start position:0% second very simple fix and all we need 00:23:30.830 --> 00:23:35.080 align:start position:0% second very simple fix and all we need to<00:23:30.980> do<00:23:31.400> is<00:23:31.820> to<00:23:32.120> add<00:23:33.940> the<00:23:34.940> following 00:23:35.080 --> 00:23:35.090 align:start position:0% to do is to add the following 00:23:35.090 --> 00:23:37.210 align:start position:0% to do is to add the following modification<00:23:36.020> to<00:23:36.140> finalization<00:23:36.919> right<00:23:37.100> so 00:23:37.210 --> 00:23:37.220 align:start position:0% modification to finalization right so 00:23:37.220 --> 00:23:39.220 align:start position:0% modification to finalization right so remember<00:23:37.309> in<00:23:37.760> Bitcoin<00:23:38.210> whenever<00:23:38.660> we<00:23:38.990> see<00:23:39.200> a 00:23:39.220 --> 00:23:39.230 align:start position:0% remember in Bitcoin whenever we see a 00:23:39.230 --> 00:23:41.409 align:start position:0% remember in Bitcoin whenever we see a chain<00:23:39.590> we<00:23:40.130> don't<00:23:40.340> output<00:23:40.760> we<00:23:40.940> don't<00:23:41.120> confirm 00:23:41.409 --> 00:23:41.419 align:start position:0% chain we don't output we don't confirm 00:23:41.419 --> 00:23:44.049 align:start position:0% chain we don't output we don't confirm the<00:23:41.570> whole<00:23:41.720> chain<00:23:42.020> we<00:23:42.620> chop<00:23:43.280> off<00:23:43.429> the<00:23:43.700> trailing 00:23:44.049 --> 00:23:44.059 align:start position:0% the whole chain we chop off the trailing 00:23:44.059 --> 00:23:46.750 align:start position:0% the whole chain we chop off the trailing six<00:23:44.390> blocks<00:23:44.660> the<00:23:45.590> trailing<00:23:46.040> six<00:23:46.370> blocks<00:23:46.610> are 00:23:46.750 --> 00:23:46.760 align:start position:0% six blocks the trailing six blocks are 00:23:46.760 --> 00:23:48.700 align:start position:0% six blocks the trailing six blocks are not<00:23:46.790> stable<00:23:47.299> yet<00:23:47.450> and<00:23:47.720> here<00:23:48.290> it's<00:23:48.470> a<00:23:48.650> little 00:23:48.700 --> 00:23:48.710 align:start position:0% not stable yet and here it's a little 00:23:48.710 --> 00:23:51.760 align:start position:0% not stable yet and here it's a little bit<00:23:49.040> similar<00:23:49.390> except<00:23:50.390> that<00:23:50.600> we<00:23:51.230> don't<00:23:51.350> chop<00:23:51.590> up 00:23:51.760 --> 00:23:51.770 align:start position:0% bit similar except that we don't chop up 00:23:51.770 --> 00:23:53.440 align:start position:0% bit similar except that we don't chop up six<00:23:52.010> blocks<00:23:52.250> right<00:23:52.490> whenever<00:23:52.730> I<00:23:52.880> see<00:23:53.179> a 00:23:53.440 --> 00:23:53.450 align:start position:0% six blocks right whenever I see a 00:23:53.450 --> 00:23:55.539 align:start position:0% six blocks right whenever I see a notarized<00:23:54.230> chain<00:23:54.559> and<00:23:54.799> let's<00:23:55.280> say<00:23:55.429> the 00:23:55.539 --> 00:23:55.549 align:start position:0% notarized chain and let's say the 00:23:55.549 --> 00:23:58.980 align:start position:0% notarized chain and let's say the notarized<00:23:56.000> chain<00:23:56.240> and<00:23:56.500> at<00:23:57.500> a<00:23:57.830> streak<00:23:58.640> of 00:23:58.980 --> 00:23:58.990 align:start position:0% notarized chain and at a streak of 00:23:58.990 --> 00:24:01.690 align:start position:0% notarized chain and at a streak of consecutively<00:23:59.990> notarized<00:24:00.470> blocks<00:24:00.740> so 00:24:01.690 --> 00:24:01.700 align:start position:0% consecutively notarized blocks so 00:24:01.700 --> 00:24:03.760 align:start position:0% consecutively notarized blocks so basically<00:24:02.059> everything<00:24:02.660> except<00:24:03.470> the<00:24:03.590> last 00:24:03.760 --> 00:24:03.770 align:start position:0% basically everything except the last 00:24:03.770 --> 00:24:08.169 align:start position:0% basically everything except the last block<00:24:04.130> is<00:24:04.370> by<00:24:04.580> now<00:24:04.929> so<00:24:05.929> if<00:24:06.080> any<00:24:06.830> time<00:24:07.190> I<00:24:07.429> see<00:24:08.150> a 00:24:08.169 --> 00:24:08.179 align:start position:0% block is by now so if any time I see a 00:24:08.179 --> 00:24:11.520 align:start position:0% block is by now so if any time I see a notarized<00:24:08.780> chain<00:24:09.280> ending<00:24:10.280> at<00:24:10.549> a<00:24:10.610> streak<00:24:11.150> of 00:24:11.520 --> 00:24:11.530 align:start position:0% notarized chain ending at a streak of 00:24:11.530 --> 00:24:15.430 align:start position:0% notarized chain ending at a streak of consecutively<00:24:12.530> notarized<00:24:13.040> blocks<00:24:13.340> I<00:24:14.440> only 00:24:15.430 --> 00:24:15.440 align:start position:0% consecutively notarized blocks I only 00:24:15.440 --> 00:24:17.200 align:start position:0% consecutively notarized blocks I only have<00:24:15.679> to<00:24:15.799> chop<00:24:15.980> off<00:24:16.159> the<00:24:16.280> last<00:24:16.429> one<00:24:16.669> and<00:24:16.850> then 00:24:17.200 --> 00:24:17.210 align:start position:0% have to chop off the last one and then 00:24:17.210 --> 00:24:18.549 align:start position:0% have to chop off the last one and then the<00:24:17.299> prefix<00:24:17.690> is<00:24:17.900> notarized 00:24:18.549 --> 00:24:18.559 align:start position:0% the prefix is notarized 00:24:18.559 --> 00:24:19.880 align:start position:0% the prefix is notarized but<00:24:18.710> the<00:24:18.799> prefix<00:24:19.159> is<00:24:19.280> final 00:24:19.880 --> 00:24:19.890 align:start position:0% but the prefix is final 00:24:19.890 --> 00:24:24.950 align:start position:0% but the prefix is final okay<00:24:21.440> so<00:24:22.440> that's<00:24:22.590> basically<00:24:23.100> it<00:24:23.370> and<00:24:23.840> just<00:24:24.840> to 00:24:24.950 --> 00:24:24.960 align:start position:0% okay so that's basically it and just to 00:24:24.960 --> 00:24:27.470 align:start position:0% okay so that's basically it and just to quickly<00:24:25.049> recap<00:24:25.910> the<00:24:26.910> protocol<00:24:27.360> is<00:24:27.450> very 00:24:27.470 --> 00:24:27.480 align:start position:0% quickly recap the protocol is very 00:24:27.480 --> 00:24:29.390 align:start position:0% quickly recap the protocol is very simple<00:24:28.049> you<00:24:28.080> go<00:24:28.290> by<00:24:28.470> proposed<00:24:28.830> vote<00:24:29.040> proposed 00:24:29.390 --> 00:24:29.400 align:start position:0% simple you go by proposed vote proposed 00:24:29.400 --> 00:24:32.150 align:start position:0% simple you go by proposed vote proposed vote<00:24:29.670> and<00:24:30.000> you<00:24:30.840> you<00:24:31.290> need<00:24:31.440> to<00:24:31.559> check<00:24:31.830> a<00:24:32.010> couple 00:24:32.150 --> 00:24:32.160 align:start position:0% vote and you you need to check a couple 00:24:32.160 --> 00:24:35.510 align:start position:0% vote and you you need to check a couple of<00:24:32.340> things<00:24:32.520> when<00:24:33.480> you<00:24:33.630> vote<00:24:33.870> and<00:24:34.309> then<00:24:35.309> this 00:24:35.510 --> 00:24:35.520 align:start position:0% of things when you vote and then this 00:24:35.520 --> 00:24:38.120 align:start position:0% of things when you vote and then this very<00:24:35.730> simple<00:24:36.150> proposed<00:24:36.570> vote<00:24:36.809> based<00:24:37.590> protocol 00:24:38.120 --> 00:24:38.130 align:start position:0% very simple proposed vote based protocol 00:24:38.130 --> 00:24:42.230 align:start position:0% very simple proposed vote based protocol combined<00:24:39.090> with<00:24:40.340> finalization<00:24:41.340> rule<00:24:41.549> actually 00:24:42.230 --> 00:24:42.240 align:start position:0% combined with finalization rule actually 00:24:42.240 --> 00:24:44.870 align:start position:0% combined with finalization rule actually gives<00:24:42.750> you<00:24:42.870> approval<00:24:43.410> a<00:24:43.500> correct<00:24:43.890> consensus 00:24:44.870 --> 00:24:44.880 align:start position:0% gives you approval a correct consensus 00:24:44.880 --> 00:24:49.580 align:start position:0% gives you approval a correct consensus protocol<00:24:46.130> I'm<00:24:47.130> not<00:24:47.309> going<00:24:47.490> to<00:24:48.230> go<00:24:49.230> through<00:24:49.410> the 00:24:49.580 --> 00:24:49.590 align:start position:0% protocol I'm not going to go through the 00:24:49.590 --> 00:24:53.840 align:start position:0% protocol I'm not going to go through the proof<00:24:50.000> and<00:24:51.000> to<00:24:51.210> quickly<00:24:51.540> conclude<00:24:52.790> in<00:24:53.790> this 00:24:53.840 --> 00:24:53.850 align:start position:0% proof and to quickly conclude in this 00:24:53.850 --> 00:24:57.260 align:start position:0% proof and to quickly conclude in this talk<00:24:54.240> I<00:24:54.590> talked<00:24:55.590> about<00:24:55.830> a<00:24:56.270> synchronous 00:24:57.260 --> 00:24:57.270 align:start position:0% talk I talked about a synchronous 00:24:57.270 --> 00:24:59.570 align:start position:0% talk I talked about a synchronous protocol<00:24:57.690> that<00:24:57.840> tolerates<00:24:58.580> one-third 00:24:59.570 --> 00:24:59.580 align:start position:0% protocol that tolerates one-third 00:24:59.580 --> 00:25:04.820 align:start position:0% protocol that tolerates one-third corruptions<00:25:00.150> right<00:25:02.270> for<00:25:03.270> Santa's<00:25:03.690> new<00:25:04.530> fast 00:25:04.820 --> 00:25:04.830 align:start position:0% corruptions right for Santa's new fast 00:25:04.830 --> 00:25:07.730 align:start position:0% corruptions right for Santa's new fast pad<00:25:05.100> consensus<00:25:05.900> it's<00:25:06.900> not<00:25:07.110> too<00:25:07.260> difficult<00:25:07.470> to 00:25:07.730 --> 00:25:07.740 align:start position:0% pad consensus it's not too difficult to 00:25:07.740 --> 00:25:09.350 align:start position:0% pad consensus it's not too difficult to extend<00:25:08.010> this<00:25:08.190> protocol<00:25:08.549> to<00:25:08.790> the<00:25:09.030> paschal 00:25:09.350 --> 00:25:09.360 align:start position:0% extend this protocol to the paschal 00:25:09.360 --> 00:25:12.860 align:start position:0% extend this protocol to the paschal asynchronous<00:25:09.870> setting<00:25:10.200> and<00:25:11.360> as<00:25:12.360> I<00:25:12.510> said<00:25:12.750> the 00:25:12.860 --> 00:25:12.870 align:start position:0% asynchronous setting and as I said the 00:25:12.870 --> 00:25:14.480 align:start position:0% asynchronous setting and as I said the protocol<00:25:13.290> is<00:25:13.380> extremely<00:25:13.890> simple<00:25:14.130> it's<00:25:14.429> like 00:25:14.480 --> 00:25:14.490 align:start position:0% protocol is extremely simple it's like 00:25:14.490 --> 00:25:16.100 align:start position:0% protocol is extremely simple it's like almost<00:25:14.880> the<00:25:15.000> most<00:25:15.240> natural<00:25:15.690> protocol 00:25:16.100 --> 00:25:16.110 align:start position:0% almost the most natural protocol 00:25:16.110 --> 00:25:18.230 align:start position:0% almost the most natural protocol combined<00:25:16.890> with<00:25:17.130> the<00:25:17.309> you<00:25:17.490> know<00:25:17.640> a<00:25:17.790> carefully 00:25:18.230 --> 00:25:18.240 align:start position:0% combined with the you know a carefully 00:25:18.240 --> 00:25:18.730 align:start position:0% combined with the you know a carefully thought-out 00:25:18.730 --> 00:25:18.740 align:start position:0% thought-out 00:25:18.740 --> 00:25:22.280 align:start position:0% thought-out finalization<00:25:19.740> rule<00:25:20.150> and<00:25:21.150> what's<00:25:22.020> cool<00:25:22.260> about 00:25:22.280 --> 00:25:22.290 align:start position:0% finalization rule and what's cool about 00:25:22.290 --> 00:25:23.930 align:start position:0% finalization rule and what's cool about this<00:25:22.679> protocol<00:25:23.100> is<00:25:23.220> every<00:25:23.490> block<00:25:23.730> requires 00:25:23.930 --> 00:25:23.940 align:start position:0% this protocol is every block requires 00:25:23.940 --> 00:25:33.340 align:start position:0% this protocol is every block requires only<00:25:24.360> a<00:25:24.510> single<00:25:24.990> round<00:25:25.169> of<00:25:25.320> voting<00:25:25.440> to<00:25:25.799> confirm 00:25:33.340 --> 00:25:33.350 align:start position:0% 00:25:33.350 --> 00:25:38.020 align:start position:0% okay<00:25:34.350> so<00:25:34.799> let<00:25:35.250> me<00:25:35.370> just<00:25:35.520> quickly<00:25:36.049> conclude<00:25:37.049> and 00:25:38.020 --> 00:25:38.030 align:start position:0% okay so let me just quickly conclude and 00:25:38.030 --> 00:25:41.450 align:start position:0% okay so let me just quickly conclude and try<00:25:39.030> out<00:25:39.210> our<00:25:39.240> test<00:25:39.720> net<00:25:39.900> and<00:25:40.140> also<00:25:40.440> sander<00:25:41.280> is 00:25:41.450 --> 00:25:41.460 align:start position:0% try out our test net and also sander is 00:25:41.460 --> 00:25:43.130 align:start position:0% try out our test net and also sander is currently<00:25:42.030> hiring<00:25:42.240> and<00:25:42.570> we<00:25:42.660> have<00:25:42.840> all<00:25:42.990> sorts 00:25:43.130 --> 00:25:43.140 align:start position:0% currently hiring and we have all sorts 00:25:43.140 --> 00:25:45.200 align:start position:0% currently hiring and we have all sorts of<00:25:43.290> positions<00:25:43.710> including<00:25:44.400> executive<00:25:44.669> level 00:25:45.200 --> 00:25:45.210 align:start position:0% of positions including executive level 00:25:45.210 --> 00:25:48.440 align:start position:0% of positions including executive level positions<00:25:45.390> like<00:25:46.200> CMO<00:25:46.650> and<00:25:46.830> CRO<00:25:47.130> and<00:25:47.490> contact 00:25:48.440 --> 00:25:48.450 align:start position:0% positions like CMO and CRO and contact 00:25:48.450 --> 00:26:00.520 align:start position:0% positions like CMO and CRO and contact me<00:25:48.570> if<00:25:48.720> you<00:25:48.809> are<00:25:48.900> interested<00:25:49.410> thanks 00:26:00.520 --> 00:26:00.530 align:start position:0% 00:26:00.530 --> 00:26:02.590 align:start position:0% you