Panel I Cross-Chain & Interoperability | Pragma Istanbul 2023

[Music] up next I want to bring on our next three panelists we're going to talk about interoperability and how multi-chain universes are about to overlap so please join me in welcoming Dominic from definity tanang from polyedra and Brandon from Zeta chain we're seeing a lot of chains come up we're seeing a lot of specialization application specific items and uh this kind of leads us to being in a more interoperable multi-chain Centric world so the focus here is to learn about sort of how we can think about solving these problems and not put that burden on the user and I want to kind of start off with you Dominic just why don't you understand if you can give us an update on how the definity and the ICP ecosystem is going um what have kind of been things that you've been working on towards this goal and uh we'll kind of start off with some general updates there um it's going well um the big development in the community is uh the formation of something called ICP hubs over the last six months and they about 20 of them around the world now and uh some of them are growing quite big uh the Indian ICB Hub uh I think it's about 10,000 developers in a hackathon funnel right now uh we had a meet up in career with 800 people um and these these uh fundamentally independent so it's a kind of uh build locally scale globally Paradigm so that's going very well uh internet computer still chugging along uh currently processes about 200,000 eth equivalent transactions a second when you're looking at the actual number of virtual machine instructions being processed so it's I think the highest throughput chain in the world right now um and yeah awesome um I want to start off with you Brandon um could you give us an overview on what you've been working on and sort of why you decided to focus on this as a problem yeah so hi I'm Brandon I uh Zeta Shane and zet Shan's a new L1 focused on interoperability first what that means is you can deploy a spark contract on Zeta chain and that Spar contract has access to an interoperability layer to virtually any chain so you can read and write from Bitcoin in the same way you would read and write from ethereum or any other chain that lets developers build cross chain apps very easily uh you can you know deploy a uni Swap and it becomes a cross chain app in a few lines of code not you know a few months of development awesome and and finally to you tan Chang um tell us about what you've been working on and why you decided to focus on it as well uh uh so I was working on actually Z proof during my PhD area so after like 2021 and after the end of 2021 there had been many Bridge attacks uh happening and lost billions of dollars so at that moment we kind of thinking about this problem and we think we can use St proof to solve this problem we call we invented a protocol called DK bridge and then later on published papers and start this project so we submitted paper at 2022 May of 2022 and the project IM started at I think it's October or November and so the DK Bridge basically use the proof to prove the validity of the block header and messages so your transaction message uh sorry or your cross chain message is not secured by any kind of committee or intermediate layer but immediately secured by the by the by the general proof so it's kind of we removed every uh vulnerability every uh security assumption and trying to minimize the attx surface to only to the Circuit itself so yeah and yeah does that approach also prevent double spin because that's just proving the asset is correct on the communication side but yeah it prevent double spending because it pro basically proves that transaction is has been successfully included by the sender chain so there is no way to double spend it as long as the center CH don't Fork understood okay I misunderstood where the proof was it's not it's not the communication side it's on on on the Chain got it yeah only chance actually interesting so I mean Dominic I think you also have an interesting take on Bridges um how do you think about uh the need for Bridges to do cross chain transactions um I mean I I've been in crypto for a while you know I I transitioned to full-time work in crypto in 2013 you know um back in the day you know people were much more focused on uh the math and the security PRS and so on um gen generally speaking I think that blockchain um is about you know prably secure protocols and the moment we start processing assets that are wrapped and held in bridges um which don't provide the same security properties um we undermine the benefits of of blockchain and you know it we SE a lot of hacks Bridges um in the last few years I I forget what the number whereas it's it's in the billions it's in the billions yeah I think it's it certainly exceeds 2 billion it's probably Up 3 billion or something like that now so um you know the internet computer takes a different approach uh it supports something called chainkey cryptography and this enables the internet computer to create transactions on other blockchains so this far um the Network's been integrated with Bitcoin and support something called chy Bitcoin which is like a Bitcoin twin a trustless Bitcoin twin uh with one second finaly you can use it in defy social fire whatever you like and currently uh the defini Foundation uh we're working on eth integration but parts of this already work so for example uh there's something called the oyy wallet it's it's a wallet lless ethereum wallet it's in a web browser and uh uh you know what's happening is you're authenticating yourself in a crypto session to a ICP smart contract and that ICP smart contract creates an e EA add account for you and there's no private key but it can sign ethereum transactions so um you know you can open oy wallet in a web page um and now you can use wallet connect to link that to you SW at another web page um and you know essentially conduct ethereum transactions without an the wet so that gives you an idea the kind of capabilities but that same functionality um can be used to link different blockchains so in principle using chain key um it would be possible for for example you know a small contract on ethereum to call directly into a smart contract on salana it's not even just about moving tokens and there's no intermediary you can actually get the the networks nodes talking directly to each other or alternatively use your user experience to move transactions across but this there's no trusted intermediates um relying entirely on um cryptography and provable math um in that first example of uh the the wallet that you talked about does somebody still need to execute that transaction to broadcast it and and somebody takes on that risk of maybe never broadcasting it to to theum yeah so that that's where the complexity lies with the uh internet computer ethereum integration you know um but with the bcoin um integration internet computer nodes talk to um Bitcoin nodes and you know there's a certain level of Rony and you know if the transaction's not seen there some loads will resend the transaction and things like that so it's taking that responsibility away from the developer what they Us in um interestingly Brandon you're also doing a multi-chain Bitcoin um through Zeta chain uh could you tell us about how that works um what's going to happen so far and and sort of uh specifically what it enables compar comp to other um kind of bridges we've seen for for Bitcoin yeah so I think pretty aligned with uh ICP in we aren't or we're trying to minimize new wrapped assets uh so in an ideal world even if you are transacting across many different chains you start with a native asset or like you're you're on bitcoin and you settle also on uh another native asset you're not creating a new wrapped asset every time you're making a chain pair um specifically for Bitcoin I think I mean it's kind of a Trope now that a lot of people say you know all of this liquidity all these users are on bitcoin Network Grandma and Grandpa they have Bitcoin in a wallet somewhere but have no idea how to use it uh in many ways because there's no actual route to use it unless you're bridging it to uh ethereum or some other blockchain uh so for us we're very focused both on developer experience and user experience where uh again for this Bitcoin example you never have to leave Bitcoin Network or leave your Bitcoin wallet to call a contract that interacts with many different chains so you can just send a transaction uh just an OP return or memo on that transaction and that can specify what contract you're going to call metadata whatever so uh everything you're doing in this space with Zeta chain is one step you're never having to really change that work unless you know there are Ed cases where you need to or may want to but if you want to just stay in your like safe Ledger Bitcoin wallet you can do that and also settle natively um that is all done uh I think in a similar architecture to chain key uh Bitcoin for my understanding probably some nuances but uh yeah that's kind of where we're at also awesome um and then uh kind of maybe so I want to zoom back a little bit and just actually talk about what the problems are before we kind of go into how we're solving them uh so uh Tang my question for you is um could you give us like a slightly more detailed version of what the problems are with Bridges right now um we kind of just hear about they got hacked but let's understand why the common reasons uh these things happen but um yeah so it be great to just kind of get that context and uh or can I answer that from the bridging site but then I'd like um Brandon and Dominic to comment on the cross and communication piece on some of these vulnerabilities uh so you are asking the data hacks right just generally what are security considerations or common things that go wrong with Bridges okay previous Bridges like most hacks happens on the smart contract level where you this is specifically the bridge contract interfacing with a different chain yes okay uh the bridge contract and the S of the application contract so in our side we first the bridge contract is just a z proof verifier it doesn't it doesn't do anything uh except for the verification so we basically moved the vulnerability from the contract side to the offchain uh circuit side and secondly we actually we we are more focused on uh the the connectivity so we don't actually do asset transfer or nft transfer we only do is data transfer where you transfer bites between uh different chains so this is basically decompos the application layer and the transport layer so for our company we are kind of more focused on the transport layer implementation so this can be uh things can be more simplified for our side and we also do some um as a transfer or uh lft Bridges as a demo or demonstration uh application so that part can be further uh dedicated to to more specialized team in in the field yeah so kind of we are first we are trying to uh minimize this DX surface second we trying to decouple the work into different specialized teams yeah so so um make sure just just make sure smart contract hacks don't happen yeah yeah um even in the case of kind of getting rid of bridges do we still have the smart contract on the integration side kind of being potentially vulnerable like how do you kind of in a way minimize that risk of the contract that is in charge of communicating what that state change would be on the other side well um there's there's sort of two different levels to think about the issue with Bridges um the first is you've got three parties so for example if you had a canister smart contract or the internet computer and it wants to instruct uh an ethereum SM contract um you know there are two block chains involved um ideally you wouldn't introduce a third party the bridge in the middle because the more parties that you have the higher risks something goes wrong right um that's the first problem the second problem is that um you know bridg isn't a blockchain so it has it has completely different properties uh you know many of the bigger bridges are just like a handful of nodes run by a bunch of insiders no one even knows what source code runs on them essentially they're wrapping um they're wrapping tokens so uh we saw this you know with the um well with Wormhole e for example you know um I think the Avalanche Bridge has five nodes and no one seen the source code so essentially when you're using that bridge you're you're entrusting your crypto to whoever is running and you know um bridging is a pretty diverse field and some bridges are more secure than others and some are more centralized than others and so on and so forth but um there are two levels of problems there should just be two parties like it's one blockchain talking to another blockchain why do you need a third party in the middle um and we know from you know Satoshi back in the day that the whole purpose of a blockchain is to remove intermediaries a bridge is an intermet so we shouldn't want the bridge um but it's actually worse than just introducing an unnecessary intermediary that you know these bridges on blockchains they're insecure and you have to trust people and the whole point about blockchain is that you don't have to trust people so um you they're bad things so on the internet computer um you know you have a smart contract and it it can create a for example an ear account it's just a keeper um but although there's a public key created that the small contract can manage it doesn't have the private key and in fact there isn't a private key um the chain uh the chain has to sign for that public key itself using this chain key Arrangement and um you know obviously threshold cryptographers involved but that's a gross simplification there's actually a lot of lot of things you have to do to um make make these change cryptography Frameworks work um but but essentially uh you know a small contract on the internet computer can create transactions on ethereum salana Avalanche whatever it needs to um currently um you know we've kind of completed the integration pretty much with with with Bitcoin um ethereum Works ongoing allba you can already do amazing things like like I've been showing people here the oy wallet which is just a web page just an ethereum wallet um that integrates with all the existing ethereum Defi and I'm sure all of you have like used metamask on your phone right you open the metamask wallet takes 30 seconds to open or something and then you have to press the web browser and you get a sub web browser inside the metamask application um it's completely game game not as easy it could be experience is gamechanging because now you just have this page and and there are your assets and you from that page you can send assets and um you can link it to any ethereum defi service you like and there's no app there's nothing that can be blocked there's no centralization it's all gone um so that's working and uh but but what's coming next is the network level integration so internet computer nodes will talk to ethereum nodes in the same way that they talk to well they already do but in the same way they talk to bitcoin nodes and uh you know there'll be apis within the C to small contracts that allow you to do this kind of thing awesome um and by the way please feel free to add on anything this is not meant to be one by one type of thing um I think the the thing that is super interesting to me is that effectively every time somebody talks about bridging acrossing communication they're kind of largely stuck at let's just transfer assets from one place to another and uh granted that's a super majority of those use cases uh it's not really kind how the space is moving forward which is we're getting a lot more application specific use cases destinations people are focused on hey let's if you have a heavy compute workload go here if you have this specific surgy requirement go here um and that to me is like the core use case for multi-chain worlds um my kind of question is in that world how do you think about kind of separation of compute versus assets and largely is that the same to to the service like are we just still passing bytes and it doesn't matter or is there something better or something that we need to add or improve to what we have right now um well I mean ec20 is implemented with a smart contract right so uh you know why not generalize it and allow smart contracts to talk to Smart contracts and you know different chains provide different properties they specialized for different purposes and so on um ethereum has an architecture which makes D5 very straightforward because you just have a single public key and TH or balances and you you be on one app you can see your assets you can go to another app and you also see your same balances um it's it's a synchronous one transaction at a time architecture internet computer is um a very different kind of architecture um small contracts and software actors they run in parallel a single smart contract can have 96 gigabytes of persistent memory Pages inside along with the web assembly B code internet computer smart contracts can process HTTP and uh deliver user experiences directly to browsers and things like that so um you know the integration integration of the small contract level will allow uh you know ethereum daps to leverage all of those kind of things that you go on the insn computer so uh you know smart contracts can all of a sudden store and process gigabytes of data if that's that's what they want to do all of a sudden smart contracts can directly serve Dynamic interactive user experiences directly into browsers um and that's it oh and coming soon on the internet computer you know uh AI you know there's already um large language models running SM contracts on internet computer so you know that's going to be an interesting world yeah so uh you know uh with with with smart contract level integration um all kinds of really cool things come possible so I think you know even you know people talk about tokens it's easy to do um but look ec20 is a small contract already of course we should generalize it and it should be you know we should have all of these chains be able to um have Smart contracts that can call into each other Brandon do you have any uh kind of comments on how you're thinking about yeah so I I agree with a lot of what DC said where like to your question of do we just need asset transfer do we need something more um I I think with current kind of like the side Guist of interoperability that is like a couple years in and being adopted now is is this cross shade messaging pie where you're essentially I mean you're passing bites to another chain uh in simple terms uh that sort of like you know I I would call it asynchronous where you you like you have one contract that calls to another if you're managing across 10 chains and you need a synchronized State you have to broadcast a bunch of messages and and do that whole thing it gets very complex uh if you have something that is more synchronous where you have a programmability layer you can orchestrate not only assets but data so uh if you you know have an onchain game or social network or whatever that is uh you can take the best parts of uh a high compute chain do whatever compute you need to do there or data storage and then you also have access in the same app or in the same logic piece to you know bring Bitcoin liquidity in or bring value in where kind of like meeting users where they're at so I I mean I think there's a space for both sides definitely uh just have few question for uh definity yeah so I'm not familiar with the internet computer is this just a consensus of among a lot of committee members well so uh a big question but internet computers um you know runs on dedicated Hardware so you have people no providers that run things called No machines and um so it's more similar to Bitcoin in that sense it runs on softare Hardware not on cloud and the as a governance system and it organizes these node machines into subnets um and because of the way cheny cryptography works it combine these subnets into a single small contract environment so there's no partitions there no real concept to um you know like a like a power chain or something like that and every smart contract can directly call into every other smart contract um and but but but it's an a synchronous environment in the sense that these contracts are running in parallel um the actors at the lower level this message deterministic message passing but the messages of course a smart contract implications and smart contract results if that makes sense yeah uh I don't have a further comment um maybe for all three of you um how important is evm compatibility in this world and uh and is that in a way essential or does that mean it's just it just could just be componentized and modularized so that you can swap it with anym um what's kind of the general thinking around this evm as a as a runtime there well it depends where your your you know your application is right so I um look I mean I I was you know I working on blockchain theory for a very long time and I was involved with ethereum uh early on and and you know got enamored with the S of a world computer but my interpretation of the world computer vision is that eventually there'll be a sort of blockchain singularity in the sense that you know most backend systems and services you know will run on blockchain and if you want to get there then you need a different kind of V VM uh that's more performant you need to be able to run small contracts in parallel and uh you know in the case of the internet computer um rather than like a Patricia state tree you have persist of memory pages that you know WM B code that youve credit with rust with Toco uh typescript run runs within and it's very very efficient and you know um I mean actually earlier was you know I think you said he was 8,000 times more efficient than ethereum cheaper for call data yes I think the internet computer is a million times more efficient it uses same called DET terministic decentralizations or reduce replication by um looking at the node providers the data centers the geographies of the data centers the jurisdictions of the data centers all kinds of stuff and you know it's it's it's conceived as a small contract Cloud um upon which you can really build anything but you know if you're looking at um defi there are huge advantages to having a much simpler model where you know you have one account um and all of your balances are associated with that and it sort of follows you as you go between different defy apps similarly you know synchronous uh calls um great simplify certain aspects of defi so internet computers small project is run in parallel actually it's a privacy preserving system so um you certainly don't have one private key every every uh uh is a different stud so I I think that um so you know horses for courses right but um however someone uh there's a project called B affinity and they've implemented an evm on the internet computer and uh is that just a runtime as a as a contract or is it a bridge what exactly is it yeah so each internet computer smart contract uh can have up to 96 gigabytes of memory pages so you can f a lot of a lot of evm State trees in inside so um that obviously doesn't scale out though because you can only have one Hardware thread inside a ICP small contract at a time so what you can do is you can create different EVMS on different subnets that's was how to behind the scenes you know is transparent to the contracts themselves and I I know one of the I think there been quite a bit of interest in it um and one of the advantages is you can for example use chainy Bitcoin and things like that so all of this will work seamlessly so that's not a inter know that's not the internet computer per se that's a project that's being built on top of the internet computer and I think it's going to be exciting to see how that works especially with the ethereum integration um uh yeah see what happens and um for for you I think you're also leveraging coso SDK so that already required a second level of uh kind of extra work to make it evm compatible could you talk us about that process and sort of the decision framework there yeah so yeah it was a very active decision CA blome evm uh and as I mentioned before like one of our guiding principles is just improving the experience for users and developers and uh going evm compatible at least for our V1 is uh just a way to make it very easy and low barrier entry for the existing developer community so the majority of smart contract developers are experienced in solidity building on evm we let you basically bring any app you have on an existing evm and deploy that and bring it cross but does that mean that's the final decision you've made or you can support any other runtime in the future because designed to be that that modular yeah so it's designed to be modular I would say probably not in the near term we would go to Cosmos or some other VM but um the way it works is the interoperability layer is uh kind of like a threshold signature scheme validators can read and write from other chains smart contracts on our evm have access to that read and write so uh in the same way you could add in a km wasum run time where those contracts can also read and write in the same way uh but as I said for now we think evm is sufficient or more than sufficient to achieve a lot of the the things that developers want to achieve uh you know it it's not necessarily just bringing you know compound off a unisoft onto Zeta chain but also building with this new mechanism you know a Bitcoin back stable coin that sort of thing that just isn't really possible right now but is something that people understand how to build in evm land uh so our technology actually don't care whether it's a evm or not or whether you are ler two or not we only care about the consensus algorithm itself and can we implement the consensus algorithm in the Z proof so that's all we care about so we kind of compatible with all kind of chains of course acceptable sonana their consensus rely on referable delay function where too many hashes for us needed to compute the consensus uh only this exception other chance we seems working on where well yeah I mean one thing that I'm noticing here is that we're all kind of trying a small tweak to the things that in a way couple of you already doing obviously not all three of you are doing the same thing uh in terms of the just solving cross communication um what are kind of your opinions on standardization and and does that mean we got to just potentially agree on something to not repeat the things or is just my way better until it works and and hope that others adopt it uh at least for the sake of people's money what perspective should we have on on standarization for these types of things I me it's a good question I think um you know um things kind of get standardized um all on their own I mean like evm is a huge standard right uh I don't know how many evm implementations throughout the day it seems to be a new one popping up daily um look what's the most fun what's the most fundamental standard in crypto would you say today year20 no something more basic ecdsa right E I see think about it I probably the um just public private key generation it's very yeah Ana power and you can keep Bitcoin ether whatever so uh you know that that's a standard um cheny cryptography supports eastsa um small contracts can create e ecdsa signatures without having private keys in their possession um so that means you know if you have a chain that supports chain key you can now create transactions on any other blockchain um so I I guess you know that's an example you know if you go down the stack and you look at the you'll see something that's common yeah the most basic thing you know the foundational standard that we all use is you know the the signature schemes that authenticate transactions so you know if you support doing that in a multichain way you can integrate anything and and then that allows people room to innovate on the higher LS so you know if if if if an internet computer smart contract an ICB smart contract wants to credit a transaction on ethereum it doesn't matter what the format of the transaction is all it's got to do is sign a message right same for salana same for Avalanche and so on so um I think sometimes it's important to you know think about what level standards exist and um the danger is if we set create standards too high in the stack when something changes lower in the stack then it'll kind of goes to hell anyway but the other one by the way is HTTP that's another really fundamental status so that's internet computer contracts process HTTP but we do actually look I mean the you know the internet computer has uh you got internet identity it's not it's a it's a crypto session based model rather than a wallet based model so you know front ends are creating lots of transactions transparently in these crypto sessions um and we're adding uh properties to internet as entity um but we're using the web three Consortium credential standards so we you know which is great yeah yeah yeah you know I think so standards are very important but you know um sometimes we miss that it's really fundamental things that unite us and the most fundamental thing probably in crypto is just the public Keys skips fair enough uh well you are talking about standardization so of bridges so what do brid do actually think about this it's doing uh transmission of data between blockchains so this think about this standard standardization of of data transmission is actually has been standardized before right there is IP uh tcpip protocol where it handles every single internet uh trans data transmission where but underlying Hardware can be different so I think in in the human history same standardization process it has happened and we can basically follow that route um we can have a standardized format of data transfer but application on top of it like ASA transfer or nft transfer can be diversed yeah yeah I I think I like to use the analogy of countries a lot where it it may apply to blockchains more directly where you like you know there has been a lot of consolidation of countries or reconsolidation of countries over time there are larger players ethereum Bitcoin but there are is a space for more specialized chains uh whether it's like a something da focused or storage compute uh and I I think the same goes for these interrup Solutions um there is you know the parallel of TCP IP where there is some way of communicating that everyone has kind of agreed on because it now is standardized and I might equate that to something like boats for like Freight transfer uh I I think there are a lot of flavors of boats in the same way there could be a space for many different types of messaging protocols but I I think there's also some uh standardization and the more like global way of doing things something like Swift how like countries would do crossb payments through one single sort of agreed upon system uh I think there's probably space for a few of those as the Great Space grows and uh kind of what I imagine the the standard being is not necessarily A protocol but more of like an application or uh like a specific system that has been built to do things so um Swift is an example for like cross shap border transfer yeah I guess because effectively you're talking about in this case the application being let me give you the interface for how do we talk so which is like the erc20 analogy in this case where we know this is what the standard is how to represent this type of asset yeah but we're not talking about fundamental networking layer standardization uh maybe one one quick open last question to to any one of you uh if if you were to do a call for what's missing at least on the developer tooling side uh what are some things that would make working with cross chain blockchains and just can actually do those applications a lot easier is there something obvious that comes to mind something that you think is missing or we just don't think somebody has paid enough attention to these types of toolings uh what's out there that we can instruct developers to kind of Open Source or work on um I mean bridges are pigs they create a terrible user experience and they're insecure so um just remove bridges have blockchains talking to each other directly and and everything will be much better and simpl okay me okay so GK Bridge actually is built on the general proof where our proof system actually need a lot of help like we need a compiler for our proof system from high level language to our aration we call it circuit but it's different from uh plunk circuit or gross circuit so actually uh we do need the compiler people anyone anyone here works on a compiler anyway and secondly we since we are we are we are using proofs to generate uh to to to secure Bridges we need a high very high performance Computing uh code so any Cuda people RM people metal people here we can also have Conn uh contact here um basically we need in in general we need to BU to build a a full stack of computing basically the compiler execution environment uh well that's all about our future steps it's kind of missing because this with this thing we can further bring the cost of bridging down from maybe currently we are we are we are have we are several cent of US dollar maybe in the future we can 0.1 cent of US dollar per transaction yeah which this help yeah for for me top of Mind very recently looking at Bitcoin tooling there is is not much uh around compared to evm ecosystem and some that's by Design it's it's it's simpler in nature but even things like node access all of that for developers is not very robust uh at least from what I've seen the other side is I think developers have a lot of choice right now there are a lot of chains to deploy on a lot of messaging Solutions uh and committing to one is a very tall ask for a developer right now a lot of people people will maybe just default to going to whoever will give them the largest Grant not necessarily what chain is bringing the right value to their app like whether that is performance or security uh so at least what we want to build for developers is a way to build something that is future proof or agnostic in a way where you can deploy and even if there are new chains that you want access to whether it's for liquidity or some other small component you you have access to that going forward as we add chain support so it's not like you are deploying something that is going to be tied to this one Sil ecosystem for the future awesome well I want to thank all three of you for an amazing conversation and uh really appreciate your time thanks thank [Applause]