{"id":"0kaFloM9Qx4","title":"Whiteboard Series with NEAR | Ep: 12 James Prestwich from Summa |","description":"We had James Prestwich (  / _prestwich  ) from Summa (  / summa_one  ) join us for the Episode # 12 of our Whiteboard Series hosted by our Co-Founders Alex Skidanov (  / alexskidanov  ) & Illia Polosukhin (  / ilblackdragon  )\n\n\n\nMore details about Summa: https://summa.one/\n\nDownload the video here: https://near.ai/ecfiw\n\n------ About Whiteboard Series --------\n\nThe Whiteboard Series with NEAR is a set of video interviews with Founders who are building scalable solutions for Blockchain.  We deep dive into their story, what they're developing and how it is helping the ecosystem. \n\nFollow the latest from NEAR Protocol on, \n\nDiscord: https://near.ai/discord\nMedium: https://near.ai/medium\nTwitter: https://near.ai/twitter\nGitHub: https://near.ai/github\n\n\n#WhiteboardSeries #FutureIsNEAR #Blockchain","channel_name":"NEAR Protocol","published_at":"2019-03-25T00:00:00.000Z","thumbnail_url":"https://img.youtube.com/vi/0kaFloM9Qx4/hqdefault.jpg","transcript_text":"hi everybody this is Hylian alex from near and we are here with James from sumo he'll tell us about his project do you want to start with a little bit about yourself sure my name is James Prestwich I've been working full time on blockchain stuff for the last five years I co-founded a company called storage back in 2014 which is still going for a year in a bit now I've been working on Summa we're a design and implementation firm for cross-chain interoperability we work on markets that link Bitcoin and aetherium and other chains awesome that's I mean super interesting to learn how this actually works so let's dive in all right well like high level where do we want to start like there is there's a whole like history of interoperability solutions here there's like so many different approaches and nobody has written it down and nobody seems to know what the different approaches are and so we actually work on like five different broad tech categories for interoperability but explaining them is a little difficult sometimes you need a lot of background information so we can then let's just build it up from start right there you know yeah you have to change like what is their property Sony so we have these things called blockchain they seem to work fairly well so far but juries kind of still out there only ten years old I'm older than that so we have these things called block chains and they let's actually get the arrows going a better direction here right direction yes the right direction and it's a set of transactions and a block and they build up over time and we get this nice state out of them in Bitcoin and other UT x-bow chains that state is the UT Exocet which is the unspent transaction outputs in aetherium we have this nice state tree that's everything that is the state I don't know how to say it better than that that's like key Val store right and then you have hash yeah yeah it's a key value store encoded in a Merkel tree yeah that they call a Patricia tree because it's some like a special expanded Merkel tree so one of the like key differences between Bitcoin and aetherium is that in Bitcoin the UT Exocet is implicit it's something that you build up by traversing the history and you don't commit to anywhere whereas in aetherium each block commits to the current state route and in bitcoin you're building the UT x so said in aetherium you're building the state tree but a one of the super important things here is that bitcoins UT exo's progress from don't exist to exist to spend so unspent spent right whereas aetherium state can just be anything anytime whatever it feels like and so bitcoin has a much more constrained but also a much more predictable system Bitcoin UT exo's have what we call script pub keys a script pub key is basically a program that describes who owns it and when they're allowed to spend it whereas aetherium your account either has a pub key or a smart contract code or maybe both in really weird edge cases the only way to get both is like to to the 80 operations so it's really expensive okay so what we're trying to do is take these completely disparate state models on different chains that have completely different data formats and layouts really about the only thing they share is this blockchain structure and a signature scheme and we want to make those talk to each other in meaningful ways and we have a bunch of different tools for doing that that all have pros and cons any any questions so far no it looks let's get into the tools alright so there goes my marker cap I'm not going to worry about that cross chain communication we want to know something about Bitcoin from aetherium for example a lot of these can be generalized to any pair of chain sometimes there's really specific technical considerations here but generally we just want to know something about Bitcoin from aetherium we want this bit this etherion block to reference this Bitcoin block or some past Bitcoin block okay there's actually four different broad models of cross-chain communication that we've identified so far and we work on all of them as much as we can I'm gonna come over to your side of the board we have atomic SPV relay and merged okay so each of these has a very different mechanism you can actually like mix and match these so you can combine atomic with SPV or relay each of these has very different chain considerations so you can't use SPV with proof of stake chains at all you can only use it with proof-of-work chains we can get into that a little later if you want merged consensus you have to design the chain from the ground up with that in mind so these are things like etherium char earth to sharding may be near sharding polka dot cosmos and other kind of chain of chain ecosystems okay so relay is when we follow one chains consensus from within another chain so it's a one-way communication mechanism where we follow every Bitcoin block from aetherium or every tezo's block from near or something like that this is where there's an Oracle reading Bitcoin blocks and postings that material right right and because Bitcoin uses proof of work and proof of work is objective that Oracle could be anyone if we're tracking a proof of stake chain using relay we have to follow like the validator set changes over time which is doable it just can get a little weird and fuzzy sometimes and it depends on which consensus system we're trying to track okay so relays and merged consensus have been deployed in the wild BTC relay is a relay there have been designs for piece relay which is an eighth to east classic relay someone has talked about doing an EOS to eath relay but BTC relays the only one that's been deployed it turned out to be horrendously expensive and nobody used it and it's been dead since late 2017 basically like ethers picture of Bitcoin and BTC relay has just stopped updating you see three ATH relay costs 40% of the block well the BTC yeah it's it's really expensive and when we said relays one-way communication like eath can track Bitcoin but there's no way to make Bitcoin track eath anyways so we developed this is our contribution is SPV this is something that we invented back at eath Berlin that I don't think anyone else has ever worked on so instead of relaying every block we relay just the latest few blocks to prove something specific so in this case we want aetherium to inspect some specific event in bitcoins history and we have the etherium contract check the latest few blocks and that Bitcoin transaction so you take the transaction you put a merkel proof of inclusion and the Bitcoin header and then you put a bunch of headers on top of that to show that there's real work on top of it SPV is way cheaper than relay for any individual transaction for any individual user until you hit like several thousand regular users so with SPV though you don't get certainty you get an economic security parameter whereas with the relay you're tracking the whole consensus indefinitely with SPV you're only looking at a tiny slice of it and you only get that much security but no so just as an example right you just have pretty much just as an example all right you have like few blocks and you're checking them in so I would say we have this nice little T X out here right we have this T X and three blocks after it and after it yeah and so our aetherium chain is not sure like where the Bitcoin main chain is or what else is going on but it does know about this T X and these three blocks and it can determine how hard those blocks were to make how expensive they were by checking bitcoins proof of work and this is why SPV only works with proof of work chains is because we're actually looking at these blocks we're parsing the headers were examining the difficulty and we're totaling that across all the blocks and that gives us a pretty good economic idea of how expensive that proof was to make how to convert difficulty to actual money roughly and probabilistically you're not using some Bitcoin gas station now there's not like a real money Oracle involved here we're just saying I'll believe in anything that has at least this much work put into it so you get economic security out of that and you can adjust it if you want more security you ask for more work if you want less security which I'm not sure why you would want less security you can ask for less work but I mean there's a you know somewhat of money attached to this right right so it would be nice to have those the the rule of thumb right now is that six Bitcoin headers at the current difficulty is in the neighborhood of two hundred and fifty thousand dollars and so as long as this transactions not you know a million dollars six headers it's going to be more than enough and it's important to know that in SPV we're not doing a relay we're not tracking the whole state of the chain over time we're just getting tiny little insights into the chain and so while you can fake proofs it's very expensive to do so and if you want to fake a proof you're gonna spend a quarter million dollars faking it but if I'm an honest user the main chain is going to make it for me for free I'll pay nothing for it and if you have 10% of the hash rate it's going to take you ten hours to make six block headers but the main chain is going to make them for me the honest user for free in one hour so we have this nice economic and time based security to SPV so this is a lot of what we've been working on lately is implementing that and trying to tell people about it so but this is you takes oh right yeah this is you txl so well I mean let's work through a use case probably like what am I trying to do Liz's transaction the first thing that we're building is fast cross chain transactions so maybe I will sell ether and you will buy it with BTC and we can do that twice as fast as any other construction on chain so the way it works is you would commit to selling ether right yeah so you can clock it in a contract right you would lock it in a contract and specify your Bitcoin payment info and how much you want to be paid so you would commit to a transaction a partial Bitcoin transaction that pays you money to an address you control and anybody can come over here on Bitcoin and try to make this transaction and pay you that money so if you're selling 1/8 maybe you're asking for a point O to Bitcoin I'm not actually sure what ether is worth today it seems to change a lot so you've committed to selling your ether anybody can come in and pay you money on Bitcoin and whoever does that can build this nice proof here and submit it to the contract to get your ether and so all told this takes about an hour for each participant because you have to wait for some blocks to confirm it can be actually shorter than that and one of the supercool things is that anybody can try to buy your ether it doesn't have to be me like with an atomic swap anybody can come in look at your cell order and try to fill it so we get a nice cross chain market here all right interesting yeah and yeah like even if you span just you tick so somewhere here it doesn't matter because you actually kind of got it so the the really cool thing is that what you care about as the seller is that somebody paid you money at some point you don't care whether that money is still there because it was paid to you and you got it yeah so what are the rules on canceling disorder so that's a that's a really fun question because you is the seller cancel the order the same way anyone fills it now you just buy it out you just buy it yourself but you're the seller so you can buy it for nothing but the really important thing here is that if you could cancel this order the sell order on aetherium without touching this it breaks the security assumptions you could steal people's Bitcoin so you the seller you've locked up this eath and you've made it so that the eath is completely dependent on some transaction on some other chain and we can use that to you know like read any Bitcoin state that we want as long as it's a historical state and we don't care what happens after that point one of the really like fun tricks that we use in production this has been made net for four or five months now one of the really neat tricks that we use is this Bitcoin transaction commits to an eighth address where the contract should deliver the ether so the contract when it sees this transaction can grab the Etha dress out of it and deliver the ether there and that ether dress can't be changed because this transaction is signed by the buyer so we get this like really neat we're using bitcoin state from aetherium and we're writing aetherium addresses and maybe eventually smart contract call info into bitcoin so what if somebody by mistake so like some of your uses transaction it did not include here so this is not sold right somebody made another buy transaction so what if there are two people trying to buy at the same time basically so normally this would be a race condition but we have tools in Bitcoin to make transactions mutually exclusive and so we can use a Bitcoin protocol feature that as far as I know nobody else has ever used called sig hash single anyone can pay and in a nutshell what this does is it lets you the seller create a one-time payment invoice where anybody can pay you those Bitcoin but only one person can do so as soon as one person is paid you everybody else's transactions trying to pay you will fail they'll become invalid so this is like you're creating you like a special address we're creating a you TXO that you the seller own basically what it looks like is Bitcoin transactions are a list of inputs and a list of outputs and they have to sum up to the same amount and so you as the seller are creating this transaction that sent that has like five hundred and fifty Satoshi tiny tiny little amounts of money less than a penny and it's going to send you point o2 out right so this is a validly formatted transaction but it can't go on chain because it doesn't balance and so anyone can come in and make it balance and submit it to the chain and making it balance pays you this money and so because we're including this tiny little dust input everyone who tries to make that TX balance and tries to submit it to the chain they are all mutually exclusive yeah like I soon as one gets included everything else everything else know that TJ's already yeah because it's already been spent so it is this transaction pretty much like part of the yeah it's very initial listing so you so the price is not like market right you're pretty much defines a price yeah yep we think that we can make it market price eventually but it's actually really complex yeah I mean if you're using this right you you kind of need to specify yeah and right on goal so the if we're using this we need to specify the end goal if we want to make it market based the alternative is that you don't specify what you're going to be paid but the smart contract refuses to dispense your ether to anyone who pays the wrong amount and in that case the buyer has some risk because they don't know whether they're paying the right amount and there's a whole like bunch of other problems to solve there but we think it's doable it might need one of the planned Bitcoin protocol upgrades which is something I'm not willing to wait for I'm not gonna like pin my hopes on Bitcoin upgrading things anytime soon what about video upgrading things well with earrings going to upgrade things too much hard fork every six months is quite a quite a lot to keep up with okay so this is a lot of what we're working on recently this is what's new that we've come up with these things have been kind of known for a while and the last thing we haven't covered is the atomic swap which is the most well known of these and was invented in 2014 by a Bitcoin talk user that goes by tier Nolan so we call it the tier Nolan swap a lot in the tier Nolan swap we're actually not communicating between the chains directly Bitcoin isn't gonna read aetherium state and aetherium is not going to read Bitcoin state but what we are gonna do is we're going to arrange so that both chains state is dependent on something else outside so in this case it's going to be a secret that we call K an awful lot for some reason so we're gonna start off this swap protocol and it's only useful for exchanging value there's very it can't actually exchange data at all we're gonna start this off where I know a secret it doesn't matter what it is as long as I know it and you don't it's gonna be some long like 32 byte random hex string and nobody cares right so I'm going to commit over here on Bitcoin I'm gonna commit to this I'm gonna make a transaction on chain and I'm going to pay in let's say 0.02 BTC and this is going to be payable to Ilya if k if you Lea knows the secret and James after time there we go that's probably completely illegible but here we are right so I'm gonna do this you're gonna see me do it and check my work and wait for it to confirm so it doesn't roll back and then once you're happy we're gonna go down here and you're gonna make the same commitment with your ether except instead you're gonna do it in Reverse you're gonna pay James if Kay Yuliya after time so each of these is you know kind of this nice symmetric contract right this one pays you if you know the secret and this one pays me if I reveal the secret so once both of these are set up we're in this nice atomic contract we call it atomic because either both things will happen you know will exchange or nothing will happen we'll get our funds back after the expert right so this has to end States once we've both escrowed one is that I reveal the secret and I take your ether and then you use the secret which is public on aetherium to get my Bitcoin right the other is that I don't reveal the secret and I just wait to get my Bitcoin back and you wait to get your ether back there's once we've both escrowed there's no other outcome well there's outcome where you reveal the secret and the time expires faster right all right so they say this is a super important thing I was gonna say it there's no other outcome apparently however on a blockchain time is all sorts of wibbly-wobbly time is actually set by miners and miners can influence how it progresses and so we have to set these timeouts very carefully so that your timeout always happens before mine yeah so mine has to go this long and yours has to be this long right so that ensures that I can't both get my refund and get your money however the lower the hash rate of the chain the more able I am to influence time by like using nice hash or something some hash rental service and if I can speed up time on this chain enough then the security assumptions broken and while it's unlikely time is probabilistic even in the best case so it might be you just get really unlucky that day and I get to scam you it's the other thing to know is we're both escrowed in here and so for this whole duration we can't use our money for anything right and I can decide because I know Kay and you don't I can decide when in this period I want to make the trade and so that leads to what we call the free option problem the trade happens at my choice so I'll just delay and see how the exchange rate goes yeah so a lot of thought gets put into fixing the free option problem in atomic constructions and I don't think anyone's come up with a great solution yet we've designed a few constructions where you can put in like a premium payment for that option and you can you know intend for it to be an option then it's no longer free some other people have put in multi-phase HT LCS where if I don't take it I will be penalized but that's not even the only problem with this basic atomic construction what if you just never escrow what if this just never happens down here now I've escrowed my funds and you just walk away and I'm just locked up and I get nothing and so you can liquidity do s me you can just throw me and convince me to lock up money for no reason yeah okay and so the other thing is that we we have to agree on all the terms in advance I can just never do this and then you'll never do anything and then we've just agreed on terms but you know we don't actually yeah there's no requirement after we've agreed on terms to go through with this and so the like standard atomic swap that everybody knows is actually kind of a pretty bad trade you get to troll me I get to take a free option from you and the whole thing takes like two to three confirmation cycles in the best-case yeah and if we're not on Bitcoin and aetherium it's not two or three hours it's like two or three weeks if you think about other proof-of-work chains most of them have very low hash rate yeah yeah I mean he sees what yeah two thousand four thousand dollars for up per our price so four thousand dollars per hour that means I can pay what $100,000 in reorganization and think about like the tiny coins like Virg Virg has like a few thousand dollars per day and was successfully 51% attacked recently so you almost can't do atomic constructions on Virg at all but you know we could do SPV but it would also require a lot of headers so actually the question of doing that is how much actually does it cost to verify like let's say it's a Bitcoin is helium how much was like six blocks of Bitcoin okay so for atomic stuff it's like super cheap to verify a few hundred gasps it's easy for SPV our current implementation does the verification in less than seven hundred thousand guess and so what this is doing is loading in a Bitcoin transaction a merkel proof which is going to be twelve or thirteen hashes so somewhere in the neighborhood of like four hundred bytes and then loads in usually five or six Bitcoin headers which is eight hundred I'm sorry four hundred or 480 bytes give or take it does 30 40 shots on all of that yeah most of it most of the expense right now is loading in the data and manipulating bytes getting the right byte strings together totally does not give you very good tools for slicing and concatenating bytes yeah but then if you want to do like eat like let's say cerium on EGC this way it will cost you it'll cost you an awful lot last I looked it did a blog for garage it won't this is something that Bitcoin actually does very well is because the block time is long we need many fewer headers if we want the same amount of security on aetherium we need something like 200 headers and then we have to do eath hash on each of those to check the work and eath hash in evm costs about 2.5 million gasps and so if you want to spend 500 million gasps that's how many blocks again each block is like 8 million yeah yeah so you know if you want to take like 65 blocks processing one proof like that's that's fine go ahead and and do that it doesn't seem very practical so remember I said earlier there's a bunch of like weird technical considerations this is one of them is actually it's going to be cheaper to do this for a Bitcoin than for basically any other chain because the blocks are slow yeah so pretty much if you want to do a thdhe you goes for Bitcoin yeah you can totally do that if you want to go from Earth to yose this kit this chain can be anything with SPV this chain has to be proof of work and actually bitcoin is the only chain we know of that we can do it with because of the long block time and another super important thing bitcoin uses sha-256 as its proof of work and if every other chain has shot yeah and so litecoin uses s crypt and z cache uses equi hash 209 and grin uses cucit rootin tootin something and beam uses equi hash 150 something and D cred uses Blake and like we've got all of these proof-of-work functions and solidity can't actually check any of those it can only check sha too but like if you if you're doing it here into EOS then your cos can check each hash but that's expensive and so it would almost be better to have a OS or it would almost certainly be better to have a OS checking Bitcoin and aetherium checking Bitcoin yeah unfortunately there's some limitations in what you can do because you have to encode data into Bitcoin somehow which means you have to have you know inbound communication to Bitcoin but we we think we have some solutions to that it's still a little we haven't like written it up or formalized it yet so I don't want to talk about it too much this is all of this is ongoing research everyone in East two is thinking about how to merge consensus we've had multiple relay designs that have failed to take off SPV is brand new we came up with it six months ago and atomic constructions I guess that are the oldest they've been around for five years but nobody's actually deployed a really good system using them so all of this is ongoing research we have no idea where it all ends up or what the most efficient way to do anything is and we keep discovering new things all the time do you think there's some merged one that is like let's say it is two different networks not not like sub charts is there something that can be done on like consensus layer like if one network is ready to change mm-hmm so I think you could probably patch that in after the fact if you willing to hard fork or maybe even soft fork one network mark freedom Bach wrote a really interesting paper about how you can soft fork anything into Bitcoin literally anything you could change the proof of work you could change the state model you could just do anything as a soft fork but nobody has really talked about patching this into chains that exists very much and it seems to us you know that nobody no-nobody like has expressed a desire to do that yet a lot of chains are really tribal in their community and if you talk about merging aetherium consensus with tezo's consensus people get really like squirrelly about it for for us we like anything that promotes cross chain interoperability but we have to deal with a lot of partisans and a lot of maximalists and sometimes sometimes it's a little difficult and it actually does I think have a chilling effect on what research gets done I mean a lot of like the as you mentioned like polka dot cosmos into it like sharding and hub hubs of chains right they all kind of work within their own environment right there they require you to follow their oils their beacon chain they're too much yes I mean you can think of like it's something that's slower at blog producing and yeah defines validators across the board so in 8th - this is the beacon chain which selects all the committee's for each shard in cosmos this is the the main like atom tender mint consensus yeah that coordinates the IBC with everybody so what I mean that's an interesting question of like let's say you do have emerged consensus right is there actually like at which point you have the secure cross chain communication it's it's really interesting because everybody is going about this in different ways so far cosmos is all building around IBC and making it easy to spin up a new zone polkadot has their pair of chains eath 2 is eventually going to have these beacon to chard cross links but we're still years away from that everybody's taking different approaches nobody knows what the right model for crush shard or cross train communication in their ecosystem is what we like to focus on is you know when you don't have control over the system when you're working with deployed things that aren't going to change like Bitcoin and to a lesser extent aetherium is not going to change how can we get some of those benefits and we're also you know spinning up research about how to improve communication in merged systems how can we go eat to cross-train faster than for consensus cycles which you know sounds pretty for consensus cycles is like 25 minutes or so and eath - supposedly which sounds pretty good cross for treasured round-trip that's I mean so our I mean we are maybe on the other side but we believe that cross heart communication there's all of the communication pretty much like that because the more applications want to talk to each other and like controlling where applications live would be detrimental to the system because everybody will want to live on one shard for you waves that happens yeah you also you also can get some really weird incentive problems when that happens if maker is all on one everybody will want to live there yeah and also ether and die on other shards are worth less because they can't interact with the maker system yeah and it costs you to send it there in the first place and it takes time and time takes cost money and if I have a CDP and I need ether to rika lateral eyes I can use ether on my shard but I can't use ether on any other and that means that you know ether on my shirt is worth more to me at that moment so there's all kinds of these weird incentive things and we have to assume that crush our communication is going to be extremely important for like system composability and for users and so we're starting a lot more research into that and we think we have some good models to do it with economic security much faster but again this is something that I gotta write down and talk to protocol designers about and designing for East - is kind of a kind of a losing game right now anyway because it doesn't exist and we don't know what it will look like when it does exist we have a specification that changes regularly but do you think for crosswalk communication going through the beacon chain helps a lot like as as opposed to just sending directly the message between two charts so I think it makes it a lot simpler to reason about but I don't know that it makes it faster or more efficient but they're more secure does it make it more secure oh say say beacon chain has ultimate security to Metro forms right then hypothetically what's your what you're looking for is you know shard B to be certain of some passed state on sharda or some past event on shard a right we care about alternately you know state or state transitions if the beacon chain attest to that shard a state then we can be sure it's not going to fork and it's we can treat it on shared B as completely secure right but the beacon chain it couldn't be that the beacon chain was able to verify all the state transitions right so what the with the beacon chain is what we know from shard B is that the beacon chain validators have attested that the shard a validators have attested that this happened so instead short a believers could have directly yes right right right so this is something that we've been toying with as an idea eath to casper consensus is going to have validator committee look ahead so they're going to be known ahead of time yes you're going to be known ahead of time for a period of time and you can tell who's responsible for proposing the shard a block at height n and you could accept any block signed by that proposer that claims to be at that height because with economic security because either that's an honest block that was included in Sharda but not attested to by the beacon chain yet or that proposer will be slashed so that I think there's all sorts of really interesting things we can do here with Sharda proposers directly attesting to shard a state or history on shard B and we've started a toy with this design space but we don't know a lot about eath 2 yet yeah I mean what this would be a shell of what we're doing but what we're doing is we have a DFT consensus on shards which means that if you do have to search +1 signatures on the shard then yeah it's either if a final block or somebody actually attacks the shard and has more than one third in the shard then you can directly route it to another shirt and so then the the question is how to shard B track the canonical like validator set for sharda and that's where as a beacon chain comes in yeah that actually yep lets everybody know who is about interest in all the stores yeah ok that makes perfect sense we're talking about like hacking this into eath to after the fact which again ties back to my earlier point what we care about is adding interoperability where it wasn't designed you know in place and this always means anything communicating with Bitcoin Bitcoin was not designed for interim but at the same time Bitcoin has more than half of the liquidity in the space and so it wasn't designed for interrupts and interrupts with it is super important I got a research your BF to you more I mean one question I have and I don't know if you've looked at it at all but like if you do want to have an actual market place right it was actual like order and how like I mean there's actually I know a few people actually working on having like a separate to chain pretty much for doing the orders and doing this kind of communication like if you looked at that all we've looked at it a lot of it is it adds a lot of technical complexity because now we have to maintain in addition to cross links with Bitcoin and aetherium we have to maintain an entire chain we generally want to avoid doing that because it seems like an endless rabbit hole of design issues and what about something like I mean 0x or some other like relay or we have thought about it so with our current like SPV swap design there's an order book that lives on chain and etherium and everything is filled by id self matched so you look at this on chain contract you see what orders are available and you fill the ones you want they're all like a fixed price and a fixed size which is also kind of you're given an option sort of we we don't like usually call an order book or an option but you're posting things for sale and people can decide if they want to buy them or not sure so we want to eventually instead of making like one system that hosts all these order books make one client that accesses order books on many chains the user doesn't need a coordinating chain the user needs access to liquidity that's already out there they just need to figure out where the liquidity is and we can do that you know just as effectively by looking at many chains using like clients so our app today has a Bitcoin Mike client packaged in we rely on API for aetherium right now working on an aetherium like client if you guys make a great light client protocol let me know because I'm a little bit frustrated with etherium right now but a lot of the new chains like cosmos are designing with light clients in mind which really helps me well I mean this in the sharding world kind of everything is a light client yeah yep one of the nice things about shorting designs cool oh the last thing that we kind of add to this list sometimes is Federation's and I'm gonna separate that from the rest of the list because what we're going for with most of the things we work on is economic assumptions all of these rely on some someone loses some amount of money if they go wrong right and we have Economic Security Federation's rely on honesty instead which is not my favorite assumption so so this is more of a like just this would remove providing dates yeah Oracle's providing data some like group of custody people holding cross-chain assets like WBT see those we find less interesting but are still willing to think about do you think there's some so I mean like the one that we're yeah you have like a set of pretty much validators who like half maybe parts of the key to access some we we've thought really a lot about that the main question for us and something that we're actively thinking about and researching is can we make it so that those validators themselves you know these custodians holding BTC on someone's behalf can we make it so that they have risk of loss can we make it so that they will lose money if that BTC gets moved in appropriately and that converts it that's what you know convert from a federation - you know something else some combination of SPV and other stuff probably pretty much like if they move it incorrectly you can prove that right like providers keepers and so the the typical way that you know people move Federation's into economic assumptions you know they convert honesty to economics is bonds and slashing so that's that's kind of where our head is at right now we can potentially have something there but we don't know exactly what it will look like we're thinking about it a lot and we hope to have more announcements for it soon more public stuff soon questions more topics let's see this is I mean this is about like the general overview we can talk about transaction format in depth but I don't think that I don't think that's in scope so much yeah all right cool all right thanks everybody for tuning in I hope you learned a lot and leave some comments and check out some","transcript_synced_at":"2026-11-04T04:31:45.960Z","segments":[{"start_seconds":2,"text":"hi everybody this is Hylian alex from near and we are here with James from sumo he'll tell us about his project do","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2s"},{"start_seconds":10,"text":"you want to start with a little bit about yourself sure my name is James Prestwich I've been working full time on blockchain","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=10s"},{"start_seconds":18,"text":"stuff for the last five years I co-founded a company called storage back in 2014 which is still going for a year","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=18s"},{"start_seconds":26,"text":"in a bit now I've been working on Summa we're a design and implementation firm for cross-chain interoperability we work","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=26s"},{"start_seconds":34,"text":"on markets that link Bitcoin and aetherium and other chains awesome that's I mean super interesting to learn","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=34s"},{"start_seconds":42,"text":"how this actually works so let's dive in all right well like high level where do","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=42s"},{"start_seconds":49,"text":"we want to start like there is there's a whole like history of interoperability solutions here there's like so many","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=49s"},{"start_seconds":57,"text":"different approaches and nobody has written it down and nobody seems to know what the different approaches are and so","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=57s"},{"start_seconds":64,"text":"we actually work on like five different broad tech categories for interoperability but explaining them is","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=64s"},{"start_seconds":72,"text":"a little difficult sometimes you need a lot of background information so we can then let's just build it up from start","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=72s"},{"start_seconds":80,"text":"right there you know yeah you have to change like what is their property Sony so we have these things called blockchain","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=80s"},{"start_seconds":88,"text":"they seem to work fairly well so far but juries kind of still out there only ten years old I'm older than that so we have","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=88s"},{"start_seconds":97,"text":"these things called block chains and they let's actually get the arrows going a better direction here right direction","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=97s"},{"start_seconds":104,"text":"yes the right direction and it's a set of transactions and a block and they build up over time and we get this nice","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=104s"},{"start_seconds":114,"text":"state out of them in Bitcoin and other UT x-bow chains that state is the UT Exocet which is the unspent transaction","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=114s"},{"start_seconds":122,"text":"outputs in aetherium we have this nice state tree that's everything that is the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=122s"},{"start_seconds":130,"text":"state I don't know how to say it better than that that's like key Val store right and then you have hash yeah yeah it's a key value store encoded in a","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=130s"},{"start_seconds":138,"text":"Merkel tree yeah that they call a Patricia tree because it's some like a special expanded Merkel tree so one of","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=138s"},{"start_seconds":146,"text":"the like key differences between Bitcoin and aetherium is that in Bitcoin the UT Exocet is implicit it's something that you build up by traversing the history","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=146s"},{"start_seconds":155,"text":"and you don't commit to anywhere whereas in aetherium each block commits to the current state route and in bitcoin","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=155s"},{"start_seconds":163,"text":"you're building the UT x so said in aetherium you're building the state tree but a one of the super important things","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=163s"},{"start_seconds":171,"text":"here is that bitcoins UT exo's progress from don't exist to exist to spend so unspent spent right whereas aetherium","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=171s"},{"start_seconds":180,"text":"state can just be anything anytime whatever it feels like and so bitcoin has a much more constrained but also a","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=180s"},{"start_seconds":186,"text":"much more predictable system Bitcoin UT exo's have what we call script pub keys","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=186s"},{"start_seconds":193,"text":"a script pub key is basically a program that describes who owns it and when they're allowed to spend it","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=193s"},{"start_seconds":201,"text":"whereas aetherium your account either has a pub key or a smart contract code or maybe both in really weird edge cases","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=201s"},{"start_seconds":211,"text":"the only way to get both is like to to the 80 operations so it's really expensive okay so what we're trying to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=211s"},{"start_seconds":220,"text":"do is take these completely disparate state models on different chains that have completely different data formats and layouts really about the only thing","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=220s"},{"start_seconds":229,"text":"they share is this blockchain structure and a signature scheme and we want to make those talk to each other in meaningful ways and we have a bunch of","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=229s"},{"start_seconds":238,"text":"different tools for doing that that all have pros and cons any any questions so far no it looks let's get into the tools","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=238s"},{"start_seconds":247,"text":"alright so there goes my marker cap I'm not going to worry about that cross","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=247s"},{"start_seconds":257,"text":"chain communication we want to know something about Bitcoin from aetherium for example a lot of these can be","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=257s"},{"start_seconds":265,"text":"generalized to any pair of chain sometimes there's really specific technical considerations here but","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=265s"},{"start_seconds":273,"text":"generally we just want to know something about Bitcoin from aetherium we want this bit this etherion block to reference this Bitcoin block or some","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=273s"},{"start_seconds":282,"text":"past Bitcoin block okay there's actually four different broad models of","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=282s"},{"start_seconds":290,"text":"cross-chain communication that we've identified so far and we work on all of them as much as we can I'm gonna come","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=290s"},{"start_seconds":297,"text":"over to your side of the board we have","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=297s"},{"start_seconds":301,"text":"atomic SPV relay and merged okay so each","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=301s"},{"start_seconds":318,"text":"of these has a very different mechanism you can actually like mix and match these so you can combine atomic with SPV","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=318s"},{"start_seconds":326,"text":"or relay each of these has very different chain considerations so you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=326s"},{"start_seconds":334,"text":"can't use SPV with proof of stake chains at all you can only use it with proof-of-work chains we can get into","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=334s"},{"start_seconds":343,"text":"that a little later if you want merged consensus you have to design the chain from the ground up with that in mind so","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=343s"},{"start_seconds":351,"text":"these are things like etherium char earth to sharding may be near sharding polka dot cosmos and other kind of chain","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=351s"},{"start_seconds":360,"text":"of chain ecosystems okay so relay is when we follow one","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=360s"},{"start_seconds":371,"text":"chains consensus from within another chain so it's a one-way communication mechanism where we follow every Bitcoin","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=371s"},{"start_seconds":379,"text":"block from aetherium or every tezo's block from near or something like that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=379s"},{"start_seconds":387,"text":"this is where there's an Oracle reading Bitcoin blocks and postings that material right right and because Bitcoin","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=387s"},{"start_seconds":395,"text":"uses proof of work and proof of work is objective that Oracle could be anyone if we're tracking a proof of stake chain","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=395s"},{"start_seconds":403,"text":"using relay we have to follow like the validator set changes over time which is","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=403s"},{"start_seconds":410,"text":"doable it just can get a little weird and fuzzy sometimes and it depends on which consensus system we're trying to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=410s"},{"start_seconds":419,"text":"track okay so relays and merged consensus have been deployed in the wild","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=419s"},{"start_seconds":428,"text":"BTC relay is a relay there have been designs for piece relay which is an eighth to east classic relay someone has","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=428s"},{"start_seconds":437,"text":"talked about doing an EOS to eath relay but BTC relays the only one that's been deployed it turned out to be horrendously expensive and nobody used","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=437s"},{"start_seconds":446,"text":"it and it's been dead since late 2017 basically like ethers picture of Bitcoin","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=446s"},{"start_seconds":453,"text":"and BTC relay has just stopped updating you see three ATH relay costs 40% of the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=453s"},{"start_seconds":461,"text":"block well the BTC yeah it's it's really expensive and when we said relays","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=461s"},{"start_seconds":469,"text":"one-way communication like eath can track Bitcoin but there's no way to make Bitcoin track eath anyways so we","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=469s"},{"start_seconds":477,"text":"developed this is our contribution is SPV this is something that we invented","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=477s"},{"start_seconds":484,"text":"back at eath Berlin that I don't think anyone else has ever worked on so instead of relaying every block we relay","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=484s"},{"start_seconds":493,"text":"just the latest few blocks to prove something specific so in this case we want aetherium to inspect some specific","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=493s"},{"start_seconds":502,"text":"event in bitcoins history and we have the etherium contract check the latest few blocks and that Bitcoin transaction","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=502s"},{"start_seconds":510,"text":"so you take the transaction you put a merkel proof of inclusion and the Bitcoin header and then you put a bunch of headers on top of that to show that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=510s"},{"start_seconds":517,"text":"there's real work on top of it SPV is way cheaper than relay for any individual transaction for any","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=517s"},{"start_seconds":527,"text":"individual user until you hit like several thousand regular users","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=527s"},{"start_seconds":534,"text":"so with SPV though you don't get certainty you get an economic security parameter whereas with the relay you're","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=534s"},{"start_seconds":543,"text":"tracking the whole consensus indefinitely with SPV you're only looking at a tiny slice of it and you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=543s"},{"start_seconds":550,"text":"only get that much security but no so just as an example right you just have pretty much just as an","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=550s"},{"start_seconds":557,"text":"example all right you have like few blocks and you're checking them in so I would say we have this nice little T X out here right we have this T X and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=557s"},{"start_seconds":566,"text":"three blocks after it and after it yeah and so our aetherium chain is not sure like where the Bitcoin main chain is or","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=566s"},{"start_seconds":575,"text":"what else is going on but it does know about this T X and these three blocks and it can determine how hard those","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=575s"},{"start_seconds":583,"text":"blocks were to make how expensive they were by checking bitcoins proof of work and this is why SPV only works with","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=583s"},{"start_seconds":591,"text":"proof of work chains is because we're actually looking at these blocks we're parsing the headers were examining the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=591s"},{"start_seconds":599,"text":"difficulty and we're totaling that across all the blocks and that gives us a pretty good economic idea of how","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=599s"},{"start_seconds":607,"text":"expensive that proof was to make how to convert difficulty to actual money","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=607s"},{"start_seconds":613,"text":"roughly and probabilistically you're not using some Bitcoin gas station now","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=613s"},{"start_seconds":622,"text":"there's not like a real money Oracle involved here we're just saying I'll believe in anything that has at least","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=622s"},{"start_seconds":630,"text":"this much work put into it so you get economic security out of that and you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=630s"},{"start_seconds":638,"text":"can adjust it if you want more security you ask for more work if you want less security which I'm not sure why you would want less security you can ask for","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=638s"},{"start_seconds":646,"text":"less work but I mean there's a you know somewhat of money attached to this right right so it would be nice to have those","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=646s"},{"start_seconds":653,"text":"the the rule of thumb right now is that six Bitcoin headers at the current difficulty is in the neighborhood of two","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=653s"},{"start_seconds":660,"text":"hundred and fifty thousand dollars and so as long as this transactions not you know a million dollars six headers it's going","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=660s"},{"start_seconds":668,"text":"to be more than enough and it's important to know that in SPV we're not","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=668s"},{"start_seconds":676,"text":"doing a relay we're not tracking the whole state of the chain over time we're just getting tiny little insights into","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=676s"},{"start_seconds":683,"text":"the chain and so while you can fake proofs it's very expensive to do so and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=683s"},{"start_seconds":691,"text":"if you want to fake a proof you're gonna spend a quarter million dollars faking it but if I'm an honest user the main","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=691s"},{"start_seconds":699,"text":"chain is going to make it for me for free I'll pay nothing for it and if you have 10% of the hash rate it's going to take","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=699s"},{"start_seconds":706,"text":"you ten hours to make six block headers but the main chain is going to make them for me the honest user for free in one hour so we have this nice economic and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=706s"},{"start_seconds":715,"text":"time based security to SPV so this is a lot of what we've been working on lately is implementing that and trying to tell","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=715s"},{"start_seconds":723,"text":"people about it so but this is you takes oh right yeah this is you txl so well I mean let's work through a use case","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=723s"},{"start_seconds":730,"text":"probably like what am I trying to do Liz's transaction the first thing that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=730s"},{"start_seconds":739,"text":"we're building is fast cross chain transactions so maybe I will sell ether","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=739s"},{"start_seconds":746,"text":"and you will buy it with BTC and we can do that twice as fast as any other construction on chain so the way it","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=746s"},{"start_seconds":755,"text":"works is you would commit to selling ether right yeah so you can clock it in","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=755s"},{"start_seconds":764,"text":"a contract right you would lock it in a contract and specify your Bitcoin payment info and how much you want to be","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=764s"},{"start_seconds":772,"text":"paid so you would commit to a transaction a partial Bitcoin transaction that pays you money to an","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=772s"},{"start_seconds":779,"text":"address you control and anybody can come over here on Bitcoin and try to make this transaction and pay you that money","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=779s"},{"start_seconds":787,"text":"so if you're selling 1/8 maybe you're asking for a point O to Bitcoin I'm not actually sure what ether is worth today","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=787s"},{"start_seconds":796,"text":"it seems to change a lot so you've committed to selling your ether anybody","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=796s"},{"start_seconds":804,"text":"can come in and pay you money on Bitcoin and whoever does that can build this nice proof here and submit it to the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=804s"},{"start_seconds":814,"text":"contract to get your ether and so all told this takes about an hour for each","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=814s"},{"start_seconds":821,"text":"participant because you have to wait for some blocks to confirm it can be actually shorter than that and one of","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=821s"},{"start_seconds":830,"text":"the supercool things is that anybody can try to buy your ether it doesn't have to be me like with an atomic swap anybody","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=830s"},{"start_seconds":838,"text":"can come in look at your cell order and try to fill it so we get a nice cross chain market here all right interesting","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=838s"},{"start_seconds":847,"text":"yeah and yeah like even if you span just you tick so somewhere here it doesn't","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=847s"},{"start_seconds":855,"text":"matter because you actually kind of got it so the the really cool thing is that what you care about as the seller is","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=855s"},{"start_seconds":863,"text":"that somebody paid you money at some point you don't care whether that money is still there because it was paid to you and you got it yeah so what are the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=863s"},{"start_seconds":872,"text":"rules on canceling disorder so that's a that's a really fun question because you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=872s"},{"start_seconds":880,"text":"is the seller cancel the order the same way anyone fills it now you just buy it out you just buy it yourself but you're","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=880s"},{"start_seconds":887,"text":"the seller so you can buy it for nothing but the really important thing here is that if you could cancel this order the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=887s"},{"start_seconds":895,"text":"sell order on aetherium without touching this it breaks the security assumptions you could steal people's Bitcoin so you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=895s"},{"start_seconds":905,"text":"the seller you've locked up this eath and you've made it so that the eath is completely dependent on some transaction","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=905s"},{"start_seconds":912,"text":"on some other chain and we can use that to you know like read any Bitcoin state","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=912s"},{"start_seconds":919,"text":"that we want as long as it's a historical state and we don't care what happens after that point one of the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=919s"},{"start_seconds":927,"text":"really like fun tricks that we use in production this has been made net for four or five months now one","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=927s"},{"start_seconds":935,"text":"of the really neat tricks that we use is this Bitcoin transaction commits to an eighth address where the contract should","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=935s"},{"start_seconds":943,"text":"deliver the ether so the contract when it sees this transaction can grab the Etha dress out of it and deliver the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=943s"},{"start_seconds":952,"text":"ether there and that ether dress can't be changed because this transaction is signed by the buyer so we get this like","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=952s"},{"start_seconds":960,"text":"really neat we're using bitcoin state from aetherium and we're writing aetherium addresses and maybe eventually","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=960s"},{"start_seconds":969,"text":"smart contract call info into bitcoin so what if somebody by mistake so like some","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=969s"},{"start_seconds":978,"text":"of your uses transaction it did not include here so this is not sold right somebody made another buy transaction so","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=978s"},{"start_seconds":988,"text":"what if there are two people trying to buy at the same time basically so normally this would be a race condition","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=988s"},{"start_seconds":994,"text":"but we have tools in Bitcoin to make transactions mutually exclusive and so","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=994s"},{"start_seconds":1001,"text":"we can use a Bitcoin protocol feature that as far as I know nobody else has ever used called sig hash single anyone","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1001s"},{"start_seconds":1011,"text":"can pay and in a nutshell what this does is it lets you the seller create a","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1011s"},{"start_seconds":1017,"text":"one-time payment invoice where anybody can pay you those Bitcoin but only one person can do so as soon as one person","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1017s"},{"start_seconds":1026,"text":"is paid you everybody else's transactions trying to pay you will fail they'll become invalid so this is like you're creating you like a special","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1026s"},{"start_seconds":1035,"text":"address we're creating a you TXO that you the seller own basically what it","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1035s"},{"start_seconds":1043,"text":"looks like is Bitcoin transactions are a list of inputs and a list of outputs and they have to sum up to the same amount and so you as the seller are creating","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1043s"},{"start_seconds":1052,"text":"this transaction that sent that has like five hundred and fifty Satoshi tiny tiny","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1052s"},{"start_seconds":1060,"text":"little amounts of money less than a penny and it's going to send you point o2 out","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1060s"},{"start_seconds":1067,"text":"right so this is a validly formatted transaction but it can't go on chain because it doesn't balance and so anyone","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1067s"},{"start_seconds":1077,"text":"can come in and make it balance and submit it to the chain and making it balance pays you this money and so","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1077s"},{"start_seconds":1087,"text":"because we're including this tiny little dust input everyone who tries to make that TX balance and tries to submit it","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1087s"},{"start_seconds":1096,"text":"to the chain they are all mutually exclusive yeah like I soon as one gets included everything else everything else know that TJ's already yeah because it's","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1096s"},{"start_seconds":1105,"text":"already been spent so it is this transaction pretty much like part of the yeah it's very initial listing so you so","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1105s"},{"start_seconds":1112,"text":"the price is not like market right you're pretty much defines a price yeah yep we think that we can make it market","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1112s"},{"start_seconds":1121,"text":"price eventually but it's actually really complex yeah I mean if you're using this right you you kind of need to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1121s"},{"start_seconds":1129,"text":"specify yeah and right on goal so the if we're using this we need to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1129s"},{"start_seconds":1139,"text":"specify the end goal if we want to make it market based the alternative is that you don't specify what you're going to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1139s"},{"start_seconds":1146,"text":"be paid but the smart contract refuses to dispense your ether to anyone who pays the wrong amount and in that case","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1146s"},{"start_seconds":1153,"text":"the buyer has some risk because they don't know whether they're paying the right amount and there's a whole like","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1153s"},{"start_seconds":1160,"text":"bunch of other problems to solve there but we think it's doable it might need one of the planned Bitcoin protocol","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1160s"},{"start_seconds":1167,"text":"upgrades which is something I'm not willing to wait for I'm not gonna like pin my hopes on Bitcoin upgrading things","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1167s"},{"start_seconds":1176,"text":"anytime soon what about video upgrading things well with earrings going to upgrade things too much hard fork every six months is","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1176s"},{"start_seconds":1185,"text":"quite a quite a lot to keep up with okay so this is a lot of what we're","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1185s"},{"start_seconds":1194,"text":"working on recently this is what's new that we've come up with these things have been kind of known for a while and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1194s"},{"start_seconds":1202,"text":"the last thing we haven't covered is the atomic swap which is the most well known of these and was invented in 2014 by a","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1202s"},{"start_seconds":1210,"text":"Bitcoin talk user that goes by tier Nolan so we call it the tier Nolan swap a lot in the tier Nolan swap we're","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1210s"},{"start_seconds":1219,"text":"actually not communicating between the chains directly Bitcoin isn't gonna read aetherium state and aetherium is not","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1219s"},{"start_seconds":1228,"text":"going to read Bitcoin state but what we are gonna do is we're going to arrange","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1228s"},{"start_seconds":1239,"text":"so that both chains state is dependent on something else outside so in this","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1239s"},{"start_seconds":1248,"text":"case it's going to be a secret that we call K an awful lot for some reason so we're gonna start off this swap protocol","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1248s"},{"start_seconds":1257,"text":"and it's only useful for exchanging value there's very it can't actually","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1257s"},{"start_seconds":1263,"text":"exchange data at all we're gonna start this off where I know a secret it doesn't matter what it is as long as I","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1263s"},{"start_seconds":1271,"text":"know it and you don't it's gonna be some long like 32 byte random hex string and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1271s"},{"start_seconds":1280,"text":"nobody cares right so I'm going to commit over here on Bitcoin I'm gonna commit to this I'm","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1280s"},{"start_seconds":1291,"text":"gonna make a transaction on chain and I'm going to pay in let's say 0.02 BTC","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1291s"},{"start_seconds":1297,"text":"and this is going to be payable to Ilya if k if you Lea knows the secret and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1297s"},{"start_seconds":1307,"text":"James after time there we go that's probably completely illegible but","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1307s"},{"start_seconds":1316,"text":"here we are right so I'm gonna do this you're gonna see me do it and check my work and wait for it to confirm","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1316s"},{"start_seconds":1323,"text":"so it doesn't roll back and then once you're happy we're gonna go down here and you're gonna make the same","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1323s"},{"start_seconds":1331,"text":"commitment with your ether except instead you're gonna do it in Reverse","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1331s"},{"start_seconds":1340,"text":"you're gonna pay James if Kay Yuliya after time so each of these is you know","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1340s"},{"start_seconds":1350,"text":"kind of this nice symmetric contract right this one pays you if you know the secret and this one pays me if I reveal","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1350s"},{"start_seconds":1358,"text":"the secret so once both of these are set up we're in this nice atomic contract we call it atomic because either both things will","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1358s"},{"start_seconds":1368,"text":"happen you know will exchange or nothing will happen we'll get our funds back after the expert right so this has to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1368s"},{"start_seconds":1379,"text":"end States once we've both escrowed one is that I reveal the secret and I take your ether and then you use the secret","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1379s"},{"start_seconds":1387,"text":"which is public on aetherium to get my Bitcoin right the other is that I don't reveal the secret and I just wait to get","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1387s"},{"start_seconds":1396,"text":"my Bitcoin back and you wait to get your ether back there's once we've both","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1396s"},{"start_seconds":1403,"text":"escrowed there's no other outcome well there's outcome where you reveal the secret and the time expires faster right","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1403s"},{"start_seconds":1411,"text":"all right so they say this is a super important thing I was gonna say it there's no other outcome apparently","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1411s"},{"start_seconds":1419,"text":"however on a blockchain time is all sorts of wibbly-wobbly time is actually","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1419s"},{"start_seconds":1428,"text":"set by miners and miners can influence how it progresses and so we have to set","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1428s"},{"start_seconds":1436,"text":"these timeouts very carefully so that your timeout always happens before mine","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1436s"},{"start_seconds":1443,"text":"yeah so mine has to go this long and yours has to be this long right so that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1443s"},{"start_seconds":1450,"text":"ensures that I can't both get my refund and get your money however the lower the hash rate of the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1450s"},{"start_seconds":1459,"text":"chain the more able I am to influence time by like using nice hash or something some hash rental service and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1459s"},{"start_seconds":1468,"text":"if I can speed up time on this chain enough then the security assumptions broken and while it's unlikely time is","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1468s"},{"start_seconds":1477,"text":"probabilistic even in the best case so it might be you just get really unlucky that day and I get to scam you it's the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1477s"},{"start_seconds":1486,"text":"other thing to know is we're both escrowed in here and so for this whole duration we can't use our money for","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1486s"},{"start_seconds":1493,"text":"anything right and I can decide because I know Kay and you don't I can decide","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1493s"},{"start_seconds":1501,"text":"when in this period I want to make the trade and so that leads to what we call the free option problem the trade","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1501s"},{"start_seconds":1508,"text":"happens at my choice so I'll just delay and see how the exchange rate goes yeah","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1508s"},{"start_seconds":1515,"text":"so a lot of thought gets put into fixing the free option problem in atomic","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1515s"},{"start_seconds":1522,"text":"constructions and I don't think anyone's come up with a great solution yet we've","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1522s"},{"start_seconds":1530,"text":"designed a few constructions where you can put in like a premium payment for that option and you can you know intend for it to be an option then it's no","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1530s"},{"start_seconds":1538,"text":"longer free some other people have put in multi-phase HT LCS where if I don't","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1538s"},{"start_seconds":1545,"text":"take it I will be penalized but that's not even the only problem with this","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1545s"},{"start_seconds":1553,"text":"basic atomic construction what if you just never escrow what if this just","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1553s"},{"start_seconds":1560,"text":"never happens down here now I've escrowed my funds and you just walk away and I'm just locked up and I get nothing","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1560s"},{"start_seconds":1569,"text":"and so you can liquidity do s me you can just throw me and convince me to lock up","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1569s"},{"start_seconds":1577,"text":"money for no reason yeah okay and so the other thing is that we we have to agree","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1577s"},{"start_seconds":1584,"text":"on all the terms in advance I can just never do this and then you'll never do anything and then we've just agreed on terms but you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1584s"},{"start_seconds":1593,"text":"know we don't actually yeah there's no requirement after we've agreed on terms to go through with this","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1593s"},{"start_seconds":1600,"text":"and so the like standard atomic swap that everybody knows is actually kind of a pretty bad trade you get to troll me I","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1600s"},{"start_seconds":1610,"text":"get to take a free option from you and the whole thing takes like two to three confirmation cycles in the best-case","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1610s"},{"start_seconds":1618,"text":"yeah and if we're not on Bitcoin and aetherium it's not two or three hours it's like two or three weeks if you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1618s"},{"start_seconds":1627,"text":"think about other proof-of-work chains most of them have very low hash rate yeah yeah I mean he sees what yeah two","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1627s"},{"start_seconds":1634,"text":"thousand four thousand dollars for up per our price so four thousand dollars","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1634s"},{"start_seconds":1640,"text":"per hour that means I can pay what","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1640s"},{"start_seconds":1645,"text":"$100,000 in reorganization and think","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1645s"},{"start_seconds":1656,"text":"about like the tiny coins like Virg Virg has like a few thousand dollars per day and was successfully 51% attacked","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1656s"},{"start_seconds":1664,"text":"recently so you almost can't do atomic constructions on Virg at all but you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1664s"},{"start_seconds":1672,"text":"know we could do SPV but it would also require a lot of headers so actually the question of doing that is how much actually does it cost to verify like","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1672s"},{"start_seconds":1680,"text":"let's say it's a Bitcoin is helium how much was like six blocks of Bitcoin okay so for atomic stuff it's like super","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1680s"},{"start_seconds":1689,"text":"cheap to verify a few hundred gasps it's easy for SPV our current implementation does the verification in less than seven","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1689s"},{"start_seconds":1698,"text":"hundred thousand guess and so what this is doing is loading in a Bitcoin transaction a merkel proof which is","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1698s"},{"start_seconds":1707,"text":"going to be twelve or thirteen hashes so somewhere in the neighborhood of like four hundred bytes and then loads in","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1707s"},{"start_seconds":1714,"text":"usually five or six Bitcoin headers which is eight hundred I'm sorry four hundred","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1714s"},{"start_seconds":1721,"text":"or 480 bytes give or take it does 30 40","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1721s"},{"start_seconds":1728,"text":"shots on all of that yeah most of it most of the expense right now is loading","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1728s"},{"start_seconds":1736,"text":"in the data and manipulating bytes getting the right byte strings together totally does not give you very good","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1736s"},{"start_seconds":1743,"text":"tools for slicing and concatenating bytes yeah but then if you want to do like eat","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1743s"},{"start_seconds":1751,"text":"like let's say cerium on EGC this way it will cost you it'll cost you an awful","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1751s"},{"start_seconds":1758,"text":"lot last I looked it did a blog for garage it won't this is something that Bitcoin actually does very well is because the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1758s"},{"start_seconds":1767,"text":"block time is long we need many fewer headers if we want the same amount of security on aetherium we need something","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1767s"},{"start_seconds":1775,"text":"like 200 headers and then we have to do eath hash on each of those to check the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1775s"},{"start_seconds":1781,"text":"work and eath hash in evm costs about 2.5 million gasps and so if you want to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1781s"},{"start_seconds":1790,"text":"spend 500 million gasps that's how many blocks again each block is like 8","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1790s"},{"start_seconds":1797,"text":"million yeah yeah so you know if you want to take like 65 blocks processing one proof like that's that's","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1797s"},{"start_seconds":1804,"text":"fine go ahead and and do that it doesn't seem very practical so remember I said earlier there's a bunch of like weird","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1804s"},{"start_seconds":1813,"text":"technical considerations this is one of them is actually it's going to be cheaper to do this for a Bitcoin than for basically any other chain because","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1813s"},{"start_seconds":1821,"text":"the blocks are slow yeah so pretty much if you want to do a thdhe you goes for Bitcoin yeah you can totally do that if","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1821s"},{"start_seconds":1831,"text":"you want to go from Earth to yose this kit this chain can be anything with SPV","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1831s"},{"start_seconds":1838,"text":"this chain has to be proof of work and actually bitcoin is the only chain we know of that we can do it with because","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1838s"},{"start_seconds":1846,"text":"of the long block time and another super important thing bitcoin uses sha-256 as its proof of work and if","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1846s"},{"start_seconds":1854,"text":"every other chain has shot yeah and so litecoin uses s crypt and z cache uses","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1854s"},{"start_seconds":1861,"text":"equi hash 209 and grin uses cucit rootin tootin something and beam uses equi hash","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1861s"},{"start_seconds":1871,"text":"150 something and D cred uses Blake and like we've got all of these proof-of-work functions and solidity","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1871s"},{"start_seconds":1880,"text":"can't actually check any of those it can only check sha too but like if you if you're doing it here into EOS then your","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1880s"},{"start_seconds":1889,"text":"cos can check each hash but that's expensive and so it would almost be better to have a OS or it would almost","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1889s"},{"start_seconds":1897,"text":"certainly be better to have a OS checking Bitcoin and aetherium checking Bitcoin yeah unfortunately there's some","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1897s"},{"start_seconds":1905,"text":"limitations in what you can do because you have to encode data into Bitcoin somehow which means you have to have you know inbound communication to Bitcoin","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1905s"},{"start_seconds":1913,"text":"but we we think we have some solutions to that it's still a little we haven't","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1913s"},{"start_seconds":1922,"text":"like written it up or formalized it yet so I don't want to talk about it too much this is all of this is ongoing","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1922s"},{"start_seconds":1930,"text":"research everyone in East two is thinking about how to merge consensus we've had multiple relay designs that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1930s"},{"start_seconds":1938,"text":"have failed to take off SPV is brand new we came up with it six months ago and atomic constructions I guess that are","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1938s"},{"start_seconds":1947,"text":"the oldest they've been around for five years but nobody's actually deployed a really good system using them so all of","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1947s"},{"start_seconds":1958,"text":"this is ongoing research we have no idea where it all ends up or what the most efficient way to do anything is and we keep discovering new things all the time","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1958s"},{"start_seconds":1965,"text":"do you think there's some merged one that is like let's say it is two","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1965s"},{"start_seconds":1973,"text":"different networks not not like sub charts is there something that can be done on like consensus layer like if one","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1973s"},{"start_seconds":1981,"text":"network is ready to change mm-hmm so I think you could probably patch that in after the fact if you willing to hard fork or maybe even soft","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1981s"},{"start_seconds":1990,"text":"fork one network mark freedom Bach wrote a really interesting paper about how you can soft fork anything into Bitcoin","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1990s"},{"start_seconds":1999,"text":"literally anything you could change the proof of work you could change the state model you could just do anything as a","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=1999s"},{"start_seconds":2006,"text":"soft fork but nobody has really talked about patching this into chains that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2006s"},{"start_seconds":2013,"text":"exists very much and it seems to us you know that nobody no-nobody like has","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2013s"},{"start_seconds":2021,"text":"expressed a desire to do that yet a lot of chains are really tribal in their community and if you talk about merging","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2021s"},{"start_seconds":2028,"text":"aetherium consensus with tezo's consensus people get really like squirrelly about it for for us we like","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2028s"},{"start_seconds":2036,"text":"anything that promotes cross chain interoperability but we have to deal with a lot of partisans and a lot of","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2036s"},{"start_seconds":2042,"text":"maximalists and sometimes sometimes it's a little difficult and it actually does","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2042s"},{"start_seconds":2050,"text":"I think have a chilling effect on what research gets done I mean a lot of like the as you mentioned like polka dot","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2050s"},{"start_seconds":2058,"text":"cosmos into it like sharding and hub hubs of chains right they all kind of","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2058s"},{"start_seconds":2065,"text":"work within their own environment right there they require you to follow their oils their beacon chain they're too much","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2065s"},{"start_seconds":2073,"text":"yes I mean you can think of like it's something that's slower at blog producing and yeah defines validators","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2073s"},{"start_seconds":2081,"text":"across the board so in 8th - this is the beacon chain which selects all the committee's for each shard in cosmos","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2081s"},{"start_seconds":2090,"text":"this is the the main like atom tender mint consensus yeah that coordinates the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2090s"},{"start_seconds":2097,"text":"IBC with everybody so what I mean that's an interesting question of like let's say you do have emerged consensus right","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2097s"},{"start_seconds":2105,"text":"is there actually like at which point you have the secure cross chain","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2105s"},{"start_seconds":2112,"text":"communication it's it's really interesting because everybody is going about this in different ways so far","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2112s"},{"start_seconds":2119,"text":"cosmos is all building around IBC and making it easy to spin up a new zone polkadot has their pair of chains eath 2","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2119s"},{"start_seconds":2127,"text":"is eventually going to have these beacon to chard cross links but we're still","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2127s"},{"start_seconds":2133,"text":"years away from that everybody's taking different approaches nobody knows what","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2133s"},{"start_seconds":2140,"text":"the right model for crush shard or cross train communication in their ecosystem is what we like to focus on is you know","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2140s"},{"start_seconds":2149,"text":"when you don't have control over the system when you're working with deployed things that aren't going to change like Bitcoin and to a lesser extent aetherium","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2149s"},{"start_seconds":2157,"text":"is not going to change how can we get some of those benefits and we're also you know spinning up research about how","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2157s"},{"start_seconds":2166,"text":"to improve communication in merged systems how can we go eat to cross-train","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2166s"},{"start_seconds":2173,"text":"faster than for consensus cycles which you know sounds pretty for consensus","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2173s"},{"start_seconds":2182,"text":"cycles is like 25 minutes or so and eath - supposedly which sounds pretty good","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2182s"},{"start_seconds":2191,"text":"cross for treasured round-trip that's I mean so our I mean we are maybe on the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2191s"},{"start_seconds":2199,"text":"other side but we believe that cross heart communication there's all of the communication pretty much like that because the more applications want to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2199s"},{"start_seconds":2206,"text":"talk to each other and like controlling where applications live would be detrimental to the system because","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2206s"},{"start_seconds":2214,"text":"everybody will want to live on one shard for you waves that happens yeah you also you also can get some really weird incentive","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2214s"},{"start_seconds":2223,"text":"problems when that happens if maker is all on one everybody will want to live there yeah and also ether and die on","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2223s"},{"start_seconds":2232,"text":"other shards are worth less because they can't interact with the maker system yeah and it costs you to send it there in the first place and it takes time and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2232s"},{"start_seconds":2240,"text":"time takes cost money and if I have a CDP and I need ether to rika lateral eyes I can use ether on my shard but I","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2240s"},{"start_seconds":2249,"text":"can't use ether on any other and that means that you know ether on my shirt is worth more to me at that moment so there's all kinds of these weird","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2249s"},{"start_seconds":2257,"text":"incentive things and we have to assume that crush our communication is going to be extremely important for like system","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2257s"},{"start_seconds":2265,"text":"composability and for users and so we're starting a lot more research into that and we think we have some good models to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2265s"},{"start_seconds":2272,"text":"do it with economic security much faster but again this is something that I gotta write down and talk to protocol","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2272s"},{"start_seconds":2282,"text":"designers about and designing for East - is kind of a kind of a losing game right now anyway because it doesn't exist and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2282s"},{"start_seconds":2291,"text":"we don't know what it will look like when it does exist we have a specification that changes regularly but do you think for crosswalk communication","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2291s"},{"start_seconds":2299,"text":"going through the beacon chain helps a lot like as as opposed to just sending directly the message between two charts","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2299s"},{"start_seconds":2306,"text":"so I think it makes it a lot simpler to reason about but I don't know that it makes it faster or more efficient but","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2306s"},{"start_seconds":2315,"text":"they're more secure does it make it more secure oh say say beacon chain has ultimate security to Metro forms right","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2315s"},{"start_seconds":2322,"text":"then hypothetically what's your what you're looking for is you know shard B to be certain of some","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2322s"},{"start_seconds":2330,"text":"passed state on sharda or some past event on shard a right we care about alternately you know state or state","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2330s"},{"start_seconds":2338,"text":"transitions if the beacon chain attest to that shard a state then we can be","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2338s"},{"start_seconds":2346,"text":"sure it's not going to fork and it's we can treat it on shared B as completely secure right but the beacon chain it","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2346s"},{"start_seconds":2355,"text":"couldn't be that the beacon chain was able to verify all the state transitions right so what the with the beacon chain","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2355s"},{"start_seconds":2361,"text":"is what we know from shard B is that the beacon chain validators have attested that the shard a validators have","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2361s"},{"start_seconds":2369,"text":"attested that this happened so instead short a believers could have directly yes right right right so this is something that we've been","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2369s"},{"start_seconds":2376,"text":"toying with as an idea eath to casper consensus is going to have validator committee look ahead","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2376s"},{"start_seconds":2385,"text":"so they're going to be known ahead of time yes you're going to be known ahead of time for a period of time and you can tell who's responsible for proposing the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2385s"},{"start_seconds":2394,"text":"shard a block at height n and you could accept any block signed by that proposer that claims to be at that height because","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2394s"},{"start_seconds":2402,"text":"with economic security because either that's an honest block that was included in Sharda but not attested to by the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2402s"},{"start_seconds":2410,"text":"beacon chain yet or that proposer will be slashed so that I think there's all sorts of really interesting things we","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2410s"},{"start_seconds":2417,"text":"can do here with Sharda proposers directly attesting to shard a state or history on shard B and we've started a","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2417s"},{"start_seconds":2425,"text":"toy with this design space but we don't know a lot about eath 2 yet yeah I mean what this would be a shell of what we're","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2425s"},{"start_seconds":2434,"text":"doing but what we're doing is we have a DFT consensus on shards which means that if you do have to search +1 signatures","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2434s"},{"start_seconds":2442,"text":"on the shard then yeah it's either if a final block or somebody actually attacks","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2442s"},{"start_seconds":2449,"text":"the shard and has more than one third in the shard then you can directly route it to another shirt and so then the the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2449s"},{"start_seconds":2456,"text":"question is how to shard B track the canonical like validator set for sharda and that's where as a beacon chain comes in yeah that actually yep lets everybody","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2456s"},{"start_seconds":2466,"text":"know who is about interest in all the stores yeah ok that makes perfect sense we're talking about like hacking this","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2466s"},{"start_seconds":2474,"text":"into eath to after the fact which again ties back to my earlier point what we care about is adding interoperability","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2474s"},{"start_seconds":2482,"text":"where it wasn't designed you know in place and this always means anything communicating with Bitcoin Bitcoin was","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2482s"},{"start_seconds":2491,"text":"not designed for interim but at the same time Bitcoin has more than half of the liquidity in the space and so it wasn't","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2491s"},{"start_seconds":2499,"text":"designed for interrupts and interrupts with it is super important I got a research your BF to you more I","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2499s"},{"start_seconds":2508,"text":"mean one question I have and I don't know if you've looked at it at all but like if you do want to have an actual market place right it was actual like","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2508s"},{"start_seconds":2517,"text":"order and how like I mean there's actually I know a few people actually working on","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2517s"},{"start_seconds":2525,"text":"having like a separate to chain pretty much for doing the orders and doing this kind of communication like if you looked","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2525s"},{"start_seconds":2531,"text":"at that all we've looked at it a lot of it is it adds a lot of technical","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2531s"},{"start_seconds":2541,"text":"complexity because now we have to maintain in addition to cross links with","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2541s"},{"start_seconds":2548,"text":"Bitcoin and aetherium we have to maintain an entire chain we generally","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2548s"},{"start_seconds":2555,"text":"want to avoid doing that because it seems like an endless rabbit hole of design issues and what about something","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2555s"},{"start_seconds":2564,"text":"like I mean 0x or some other like relay or we have thought about it so with our","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2564s"},{"start_seconds":2571,"text":"current like SPV swap design there's an order book that lives on chain and etherium and everything is filled by id","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2571s"},{"start_seconds":2578,"text":"self matched so you look at this on chain contract you see what orders are available and you fill the ones you want","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2578s"},{"start_seconds":2586,"text":"they're all like a fixed price and a fixed size which is also kind of you're given an option sort of we we don't like","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2586s"},{"start_seconds":2595,"text":"usually call an order book or an option but you're posting things for sale and people can decide if they want to buy","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2595s"},{"start_seconds":2603,"text":"them or not sure so we want to","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2603s"},{"start_seconds":2610,"text":"eventually instead of making like one system that hosts all these order books make one client that accesses order","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2610s"},{"start_seconds":2620,"text":"books on many chains the user doesn't need a coordinating chain the user needs","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2620s"},{"start_seconds":2629,"text":"access to liquidity that's already out there they just need to figure out where the liquidity is and we can do that you","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2629s"},{"start_seconds":2637,"text":"know just as effectively by looking at many chains using like clients so our app today has a Bitcoin Mike client","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2637s"},{"start_seconds":2645,"text":"packaged in we rely on API for aetherium right now working on an aetherium like client if you guys make a great light client","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2645s"},{"start_seconds":2654,"text":"protocol let me know because I'm a little bit frustrated with etherium right now but a lot of the new chains","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2654s"},{"start_seconds":2662,"text":"like cosmos are designing with light clients in mind which really helps me well I mean this in the sharding world","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2662s"},{"start_seconds":2670,"text":"kind of everything is a light client yeah yep one of the nice things about","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2670s"},{"start_seconds":2676,"text":"shorting designs cool oh the last thing that we kind of add to this list","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2676s"},{"start_seconds":2684,"text":"sometimes is Federation's and I'm gonna separate that from the rest of the list","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2684s"},{"start_seconds":2692,"text":"because what we're going for with most of the things we work on is economic","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2692s"},{"start_seconds":2698,"text":"assumptions all of these rely on some someone loses some amount of money if","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2698s"},{"start_seconds":2704,"text":"they go wrong right and we have Economic Security Federation's rely on honesty instead which is not my favorite","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2704s"},{"start_seconds":2714,"text":"assumption so so this is more of a like just this would remove providing dates","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2714s"},{"start_seconds":2720,"text":"yeah Oracle's providing data some like group of custody people holding cross-chain assets like WBT see those we","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2720s"},{"start_seconds":2730,"text":"find less interesting but are still willing to think about do you think there's some so I mean like the one that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2730s"},{"start_seconds":2740,"text":"we're yeah you have like a set of pretty much validators who like half maybe","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2740s"},{"start_seconds":2746,"text":"parts of the key to access some we we've thought really a lot about that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2746s"},{"start_seconds":2754,"text":"the main question for us and something that we're actively thinking about and researching is can we make it so that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2754s"},{"start_seconds":2762,"text":"those validators themselves you know these custodians holding BTC on someone's behalf can we make it so that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2762s"},{"start_seconds":2771,"text":"they have risk of loss can we make it so that they will lose money if that BTC gets moved in appropriately and that","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2771s"},{"start_seconds":2780,"text":"converts it that's what you know convert from a federation - you know something else some combination of SPV and other","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2780s"},{"start_seconds":2790,"text":"stuff probably pretty much like if they move it incorrectly you can prove that right like providers keepers and so the","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2790s"},{"start_seconds":2799,"text":"the typical way that you know people move Federation's into economic assumptions you know they convert","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2799s"},{"start_seconds":2806,"text":"honesty to economics is bonds and slashing so that's that's kind of where","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2806s"},{"start_seconds":2813,"text":"our head is at right now we can potentially have something there but we don't know exactly what it will look like we're thinking about it a lot and","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2813s"},{"start_seconds":2821,"text":"we hope to have more announcements for it soon more public stuff soon questions","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2821s"},{"start_seconds":2833,"text":"more topics let's see this is I mean","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2833s"},{"start_seconds":2840,"text":"this is about like the general overview we can talk about transaction format in depth but I don't think that I don't","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2840s"},{"start_seconds":2848,"text":"think that's in scope so much yeah all right cool all right thanks everybody","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2848s"},{"start_seconds":2856,"text":"for tuning in I hope you learned a lot and leave some comments and check out some","url":"https://www.youtube.com/watch?v=0kaFloM9Qx4&t=2856s"}],"youtube_url":"https://youtube.com/watch?v=0kaFloM9Qx4","url":"https://near-pedia.xyz/videos/0kaFloM9Qx4"}