Across: Solving Cross-Chain UX Through Intents | Hart Lambur - Across Protocol

[Music] um and I don't think really anyone disagrees on this uh the question is all about how we get there and um there's sort of a model around what interop should look like uh people are modeling it after tcip uh they think that blockchains should talk to each other the way servers on the internet uh talk with each other uh it's cheap seamless don't even ever have to think about it and while I agree that this model is really appealing I'm not so certain that it's uh it's accurate or that's the way it's going to work um the the core thesis here is that people think bridging should be like message uh bridging should be like sending a message uh you have two blockchains blockchain A and blockchain B you want to move value between them or move a move an nft between them you just send a message right uh connect these two chains send a message you're done but the problem is that sending messages quickly cheaply and securely is basically impossible this is something people have been working on for a long time um and it hasn't worked Bridge hacks all sorts of cost issues it's problematic and if you step back and think about it it it makes sense it's like this tradeoff this trilemma between these three things uh intuitively makes some sense if you want to do something fast it's going to cost a lot if you want to do something securely it's going to either be slow or expensive um doing all all three of these things at once is just really challenging so the solution is just to stop sending messages uh that's that's the core idea from how a cross attempts to use intense and this intense architecture uh to communicate between blockchains so there's an observation we can make here uh tcpip is equivalent to moving bytes it's just moving messages between servers um but blockchains are really about moving value at least mostly mostly is in Brackets we can come back to this 95 5% of what people care about uh when they're interacting on blockchains involves some sort of value transfer it's a swap or a swap plus an action um from the interop space it's bridging an asset usually the same asset from one chain to another this is what people want to do and if we're trying to move value um at least most of the time the observation here is that value is fungible you don't care about how your money got somewhere you just care about the dollars actually getting there and this is our mental model of why this intent framework works so well the idea um in bridging with intents is that you don't actually send a message you don't send a message from blockchain A to blockchain B to move value between them rather you have a third party I call it a solver in a cross we often call it a relayer and this third party or this collection of third parties are watching block chain a for deposit transactions and when those happen they fill the user on blockchain B with their own Capital they send money to the user on blockchain B without sending a message and when you think about it okay this makes sense because we're moving value it's fungible we don't need to send a message we just need to fill the user and from a user's perspective this can be great because solvers can fill them very very very quickly um and that's that's the core idea with a cross-chain intent solvers are using their own capital and they're filling users quickly and cheaply and then getting repaid later and so um the cross view of what cross chain intense looks like um where it looks like a cake uh this comes from uh some some memes that the near foundation and the frontier research guys are doing um but the idea is that there's three layers to the stack there's three layers that users care about there's the top layer the intent layer what does the user want to do in this case it's usually move value from blockchain A to blockchain B swap an asset from blockchain A to blockchain B or swap plus do an action and at that intent layer users are going to uh articulate what their intent is we're going to talk about what that might look like in a second but they're going to articulate what their intent is and they're going to send it to some Source an RFQ system an aggregator some input source where then in the second layer solvers compete to fill them um they compete to fill them with their own Capital so they see this intent and they say hey user I'm going to fill you on blockchain B and do exactly what you want and I'm going to do this without sending a message I'm going to use my own Capital to fill you and execute you and complete your cross chain action and the second layer is maximally competitive and this is part of the reason why this is so cheap the solvers are all competing with each other to fill the user cheaply and quickly at this point the user's happy at this second layer they're filled they're done they move on with their day of course the solver though isn't yet happy they've made a loan and they haven't got paid back and that's the third layer what we're calling the settlement layer where the user funds on the origin chain are escrowed and they're held there until we verify that the intent was fulfilled and at that point in time we repay the user uh sorry repay the solver and send them back their money so it's worth going through why this intense framework uh works so well um intense can be really really fast and in according to our data um our the across Bridge average fill time is one to three orders of magnitude faster than message based bridging systems um in this chart I think you guys can see this uh I'm looking at at the median L2 to L2 fill times of across Stargate and cctp um across's median fill time is about 7 Seconds um and there's room for this to get a lot faster still um and we are just so much faster than message based systems because solvers are able to take on finality risk they can fill a user as quickly as they see the deposit transaction and they do not need to wait for the origin chain finality um unlike a message based protocol which simp cannnot send a message between chains until we have some origin chain finality so this intent framework allows solvers to compete on speed and actually assume some finality risk allowing for users to get much much faster fill times the second Advantage is related to security so this slide's a little text Heavy uh but the uh the important Concepts here is that in this framework where solvers are filling users with their own capital and getting repaid later what we've essentially done is we've separated the architecture between in two parts there's the Urgent part of getting the user their fast fill and then there's the complex part of doing the cross-chain messaging or figuring out if that fill actually happened and by separating these two parts into the Urgent part and the complex part um we're able to take our time and kind of expand the design space of how we do the hard part how we do the complex part and from our persp perspective this intense based bridging framework we can verify intense using any number of techniques we can use the canonical Bridges uh that rollups use to talk to uh ethereum layer one we could use ZK proofs which are expensive and take time to generate but it doesn't matter if we have time to to waste um or we can use optimistic systems which again have really elegant security um guarantees but take a lot of time to verify things and so the argument here is this intent framework can allow us to maximize security by separating this complex part from the Urgent part and the third Advantage here is intense can be really really cheap um and this is uh some data on the cost the average cost of a cross to move from uh ethereum layer one uh to a rollup uh versus Stargate and cctp these costs vary um with gas fees but the overall point here this is the 90day data set overall point here is a cross is cheap um it's really cheap well-being faster than these other Solutions and there's a fair bit of complexity here around all the optimizations we do to make this cheap uh but at a high level what across is able to do in this intent framework is to batch the verification that these intents occurred so rather than than verifying each individual transfer we can batch them over a 1-hour period and be like all these intents did in fact occur um over that period and then we can optimistically verify those intents which allows us to maintain high security guarantees while also very cheaply verifying uh what happened the trade-off here with the intent framework is that these solvers are making short-term loans these solvers are fronting their own Capital to the end user uh which is how it gets to be so fast um and so what we really need to do if we're going to do a proper kind of cost analysis is we have to look at all the cost savings we achieve by reducing messaging uh against the cost of the loan that the solver is making so this is just a sort of theoretical example here where Let's Pretend We're bridging $50 million in volume over 25,00 transactions so an average transaction size of about $5,000 um this is something that across uses today we're doe 50 million of volume relatively routinely uh volumes have been going up um and uh we can just do a comparison against a message based uh system like Stargate not picking on Stargate just an example here and in both designs we are going to have the user there's there's no way we get around the user making a deposit transaction and uh the protocol or the solver making a fill transaction on the destination side so there are gas costs coming in and out that are simply unavoidable but what we can compare is the difference in verifying um how those verifying those fills and in the intent bridge that across has we have solvers extending loans for about an hour and if you think about the cost of a 1hour loan on $50 million uh at a 10% % annualized interest rate that's $500 it's a very small amount of money to make a loan for that short a period of time and then because of the way across batches things we only need to send one message every hour period this is hypothetical but we're really sending like a handful of messages every day to support this $50 million of volume and so those messages we're using canonical message Bridges to pass those messages from ethereum mainnet Back to the spokes um a and our cost here I'm estimating at about a thousand bucks of total verification costs for this entire $50 million uh spread over 25,000 transactions meanwhile if you were to compare that to a message based design like a Stargate or most other Bridges out there for each one of those 25,000 messages we have some verification cost there's some cost of verifying of sending that message or and making sure that message was Secure um um and here I'm estimating that cost at um at $2 uh it's hard to know but it's it's something nonzero and it adds up to a real amount of money um and so this intent framework really by minimizing messaging is able to have far cheaper costs even though we have this cost of a loan of solvers extending uh extending a loan so the tldr here is that a cross functioning as this settlement layer for cross chain intense can can scale to transfer uh a billion dollars a day of cross-chain interop while only sending on the order of 100 messages per day so huge volume huge number of transactions very very few messages sent meanwhile the other way of thinking about cross chain interop if I'm sending a message for every transaction you know sending a billion dollars of value is going to cost me on the order of 10,000 10 million messages and to me that just seems expensive Ive that seems like something that's going to cost a lot so what's what's the idea here what's the vision so going back to our our stack our three layers of this cake um across thinks about the intent layer at the top um as where user intents are ingested where user order flow comes from um and there should be auction or RFQ systems that exist to have solvers compete for the right to fill user order so one of the things the directions we're going in is helping build an ecosystem of efficient RFQ and intent aggregation systems that are going to allow users to get the best price and speed for their order the second layer of the system is the solver layer where we want the deepest most efficient network of offchain liquidity of solvers or relays or Searchers or or fillers whatever word you want to use for them um we we want these solvers to be competing to profit from that user order and this is a high this is a super competitive PBP layer where everyone is trying to uh maximize their profits and that competition is all in service of the user getting the best fill the bottom layer here is what we think of is the settlement layer so this is where user assets are escrowed when the user makes their deposit transaction and they're only released back to the solver after we verified their intent was fulfilled and this is really actually what we think across does today across is this settlement layer for crossan intents uh kind of masquerading as a bridge and bridging in our mind the future of bridging looks like these settlement layers it looks like it's going to be uh uh this intent framework where user assets are escro um and only release back to solvers after we verified their fill so yeah our stack the future of interop the way we see this playing out is these three layers intent solver settlement working together to emphasize competition to best fill the user um with fast speeds and minimal messaging so our our version of the future here is the actual number of messages sent uh per day is on the order of thousands not Millions or tens of millions and a thousand messages a day in this framework can support billions of dollars of interupt um and that's all because this settlement layer does this batch repayment um only when needed to uh to minimize the messaging costs while maximizing security um so one more thing as I wrap this up um when we go back to thinking about the solver layer here uh the way we think we can maximize competition is by developing standards standards for what a cross-chain intent looks like um and the idea of that standard is that if we could have a user write an order ticket for what they want to do and I I mentally model this literally as an order ticket where user saying uh I have asset a on chain one and I want asset B on chain two uh and then they sign that if we can develop a standard for that order ticket we can standardize what the auction systems look like uh to have users or have solvers compete to fill those transactions and we can maximize solver competition by having all the solvers understand what this common order standard looks like and so our version of the future is that we do want to uh uh coales around what a standard for cross chain intents could look like here's uh a proposal for something we're putting together um and to leak a little Alpha uh this is something we're going to be working on with uh a number of other partners in the ecosystem to attempt to establish the standard for cross chain intents since we think it will make interop and cross chain ux better for everyone and so guys that's uh that's my presentation um you can follow me on Twitter at h201 uh also on farcaster trying to do a little bit more there uh at heart um and uh follow along with a cross protocol uh we are currently the fastest cheapest and most secure Bridge uh in the evm space and uh we're looking to push further into this intent-based bridging framework thank you very much