Ethereum Foundation DevCon 6 - Layer 2s Track, 14 Oct 2022

Previous Meeting Next Meeting

⏯

youtube image

►

From YouTube: ENS Cross Chain Integration Strategy by Makoto Inoue | Devcon Bogotá

Description

Visit the https://archive.devcon.org/ to gain access to the entire library of Devcon talks with the ease of filtering, playlists, personalized suggestions, decentralized access on Swarm, IPFS and more.
https://archive.devcon.org/archive/watch/6/ens-cross-chain-integration-strategy/

In general, most cross chain use cases are “asset transfer” for bridges to cross tokens from one chain to another then each application deploys the exact copy from L1 to other chains. However, ENS (Ethereum Name Service) has a set of unique challenges because ENS functions as a “global address book” to resolve addresses on any chains from any wallets. We have received lots of requests from chains and dapp developers about how to integrate ENS into their chain of choice and I am going to explain

Speaker(s): Makoto Inoue
Skill level: Advanced
Track: Layer 2s
Keywords: ENS,L2,cross-chain

Follow us: https://twitter.com/efdevcon, https://twitter.com/ethereum
Learn more about devcon: https://www.devcon.org/
Learn more about ethereum: https://ethereum.org/

Devcon is the Ethereum conference for developers, researchers, thinkers, and makers.
Devcon 6 was held in Bogotá, Colombia on Oct 11 - 14, 2022.
Devcon is organized and presented by the Ethereum Foundation, with the support of our sponsors. To find out more, please visit https://ethereum.foundation/

A

A

Good okay, so uh my name is uh well. My name is Makoto by ens. Is my talking dog is how many people got this swag things great? Okay, so probably support someone with you. I was a man behind you know between the nice swag, and you know that you so like you know, just making sure you guys are cute alcohol and all that stuff, but uh I'm hope, hoping that now I don't really have to explain what the ens is.

A

So it's a basically Webster username, whether you go to uh Co-op or Instagram or openc or easy XYZ, it's all my token.is. So that's my name and so today I think this.

A

This room is mostly in a theme of a L2 track, so we are going to talk about kind of L2, of gen interchange, strategy on what ens is doing and we are actually been doing since kind of 2020 and there was a lot of talk and work going on, but people are not quite sure where we are at right now and it's actually some of the feature it's two and a halfway of the road map, but it's some of them are already available.

A

So first I was going to explain what kind of the Cross chain example already available to you. So this one doesn't really require any technology. Technical knowledge, then I go a bit deeper to the underhood. Definitely so probably I I show a bit of code so mostly for devs and therefore what's next section is yeah. What's going to happen in the probably a bit technical? Okay, so uh for some of you may know, uh coinbase I want the biggest exchange I recently announced that they decide to issue subdomain to all the users.

A

I think there's a couple from the coinbase I'm gonna raise the hands. Okay, thank you and it's great because, like whenever you go to, like you know, exchange that you change uh you get your fiatu coinbase, then you will not move into somewhere for the D5, then like passing struggle is like. Oh, what's how to send to you know same address in there. I think it's great that it's been uh ens is available available from the kind of assurance a new user got on board with crypto and uh I got.

A

You know when makoto.cb.id, because matokeo is already not available, unfortunately, but like if you go to your in a profile page, and another thing is so: coinbase has I think coinbase.ed eth, but they chose uh CB dot ID. Firstly, because it's a lot shorter and another thing is uh ens is just not just about dot eth. You can actually import the order. Your Internet domain as a ethereum name, so, like origin wallet, has a DOT XYZ and you can make or comment the stuff.

A

So they decide to use cb.id to import the DNS to kind of ens world then decided to issue subdomains. So once it's done, you can see my Q handwritten Avatar and yeah website and the email address, and if you look into this our ens manager, you can actually see the same thing. So it's the data which is stored in I. Think it's in a database in coinbase. It's processes route, uh basically same layer, one so that any doubts or like a well that can actually access the data.

A

And the great thing is uh the user hasn't paid any single gas and another exam interesting example. So I think coinbase cases was in a company of chain in the database. So lens is another kind of uh web3 social network which provide the user profile and how many people have lenses profile- okay, maybe half of it, and so this lens actually have a ens Association address, Associated and something you might not know is uh it's actually that's also a proxy to the uh you say: I'm L1 after ens and on layer one.

A

So if you actually look into it, you can actually see that on our EMS manager- and this is kind of recent uh release, but now uh beta mask supports so that like, if you try to send no one really has to send ease to study. You know if you want to you know you go to stanley.lens.xyz uh that that's already available, and this is another interesting things like so optimism.

A

uh There's some Community user, just posted on their our Forum, that hey, we created a name service and they actually just spoke the uh what we are doing and they create a kind of nft and they decided to issue some domain on their nft and it's actually available on optimism, which I didn't even know until he posted, which was kind of crazy and I. Do explain.

A

There's some Nuance on the difference on how you do she's doing and that what we could do in uh next chapter- and this is a really really crazy thing is like so we I'm saying like off chain, which can be anything so I showed like database example. I showed you. The lens is basically the polygon other ebm example. This is literally the Google Doc and someone put that kind of integration so that if you type the data into the Google spreadsheet, it actually updates, which is kind of crazy and yeah.

A

Some I only got to know because someone tweeted it so this is kind yeah. It's called sheets, though, is apparently, okay, so, and so current state is so these things we've been doing. It's not something you can. uh You can do it without any integration, so we actually talked to many partners and the integration Partners to integrate this thing first.

A

So if you adapt developer, if you want to have these like a coinbase sub domain or land sub domain or uh sheets subdomain, as long as your app has He suggests uh later than 560 or web3 Pi B6 or web3 JS b493, uh you already have the uh feature integrated and also I, think nowadays, people use framework kind of tool like wag me or used up they because they use esl.js, underneath that's already supported, yeah right away and for the wallet side.

A

There's a wallets like I'll, follow it uh urgent, metamask, Umbra, coinbase, trust, wallet, wallet, connect and it's a scan. They all uh integrate. So if you're using this, you can actually uh send money to basically study or like any coinbase user, who has CBI d sub domains if you want to and so yeah what's common across, oh yeah, I just realized I can just read that sorry, uh okay, so, what's coming across this example, is basically storage like no stick.

A

It can be the best polygon, optimistic optimism or Google spreadsheet and depends on the storage uh yeah. If it's in like a L2 or side chain, you might pay a little bit of gas if it's enough chain complete uh gasless and the interesting thing is like I think most of stuff I'm lucky. If you use different chain first things you have to do exactly you go to metamask and you know change the network ID and the stuff.

A

You don't have to do it because you don't want to know which chain these users data are and they're like I, don't want to know like you know where data is for the coinbase users or lens users, so that for the read-only purpose, data is all available through L1 and this one I will explain later. But we call it kind of trust, not minimized. You'll find out a bit more detail, okay, so under the hood.

A

uh So if there's any pretty much, all the things I'm going to say is in this docs ens.domains and there's a QR code. So if you you are interested, you can just you know, take a shot and sorry yeah, okay, four or five years and the basic model is. We have three well basically, two big components: one is called registry, where it's a big gigantic dictionary, key Value, Store and instead of registry. Hence the value we return.

A

So, for example, in this example, uh you ask: uh what's the user says, what's the uh food or is has in example, it returns x1234, which is some another smart contract called resolver and the resolver is a one. If you ask that resolver, what's the address of food.edh that Returns the actual ECM address, so that kind of two ways right- and the reason we did is- is the flexibility that uh once you kind of change, it's very difficult to change smart contract. Once you deployed to ask everybody to change point to the new one.

A

So, but if you have a resolver, each user or each name owner, this is important to understand, is a can, swap the resolver and have their own custom uh logic or if we release a new feature, you can upgrade to the new feature or by uh by each user by each domain. Okay.

A

So this is a basic and, with this in mind, uh what we do with this new interchange of across chain uh thing is something called ccip read, also known as eip3668 uh secure of chain data retrievable, and what I'm going to explain is it's going to the instead of the two-step model of the existing resolver. It's a three-step model and.

A

Request and a verify okay, so what it does for the first time is like, for example, if you go ask for the uh data on the resolver uh instead of returning the data, it actually throw the exception called off chain lookup, and so like this error message came from I.

A

Think solidity, eight point something, and this interesting thing is like a basically: it returns a different kind of a data type by calling the same function, so that, like you, don't have to client, doesn't have to know whether the function call is towards L1 or L2 other place. It's just like you uh e reverts and it catches. And then, once you revert, you catch the revert message. It has the information about uh this address, which is a resolver.

A

Then it has something called URL, which is we call a Gateway server and plus the core data which you know you send for the function. Call and of gem is over Reservoir. So this is I, think the function type of the uh function which you're gonna call once again, once the Gateway returns up results and what the code is a bit old.

A

So there might be some consistency that so step one revert and that's solidity code and the once that's done uh so this is a web service that URL, you know you just catch in a revert. You call this uh web services and the uh things it does is uh fast line is the Salvador. Art is just like a function: uh ccipv server, Library offers like any or any of the web services. You have you can kind of chuckle in this uh capability easily. Then, what you do is you basically query the data from somewhere?

A

It could be database, it could be of a side chain, it could be Google spreadsheet, then, after that we basically ask the gateway to sign the data and it returns uh back to the client and once it's returned uh again, this is in L1 that uh it basically calls this function to, and you decode this signature and you check like if we verified and if you it's verified by the Gateway, it was specified in revert. We say: okay, we trust this Gateway service so like.

A

Hence we return the data so bye by using smart contract to be kind of proxy yeah user can retrieve the off-chain data without switching metamask or not knowing any other information. But all these things are kind of encapsulated, especially using esos.js. So most data use- you don't actually even see it, but if we want to do directly with the interactive smart contract, you kind of have to know yeah, and so once the basic logic of the of generated redrubal is explained.

A

Next thing you also have to know is another EIP called ensip10, so wild card resolution for issue sub domain is like one thing you need to know in the case of. We are talking about biggest use case as a issue in sub-domains and when it goes to, uh for example, cbe.id cbd.id does have a resolver contract on the L1, which basically acts as a Gateway too of chain, but use the subdomain actually doesn't have any data on L1 and what it does is this isn't just another rule.

A

We Define in a client level that if I I have a let's say my token in this example, it says eth and the IFA dot matokeo.eth it doesn't exist. No one doesn't have a resolver at the client library on asked to the parent. In that case, matokundo is to say, do you know anything about your child, then that child goes to LT or of chain and get data? So that's how uh China allows you to issue subdomains, which is gas free, because it doesn't exist on L1.

A

And so the consequence of this approach is fast, so no unchain event for issuing subdomain or records. So quite often when you build adapts nowadays, you kind of rely heavily on like something like subgraph to retrieve data with information uh in current specification, which don't have that. So in our case, we kind of hard coding, like you know, especially if you have done any coding on the ens, for example, text record a key value store, which key has been uh said. We actually are, or which coin type has been said.

A

We actually retrieve from the subgraph the graph sub graphs and because it, the graph information, doesn't exist. We actually basically hardcore and if you look into the ens manager and if you look into the subdomain of the cbd.id or lens or XYZ, you actually see like it doesn't exist because that whole thing doesn't exist on L1 and another.

A

So this is specific to the uh the ccip protocol itself. But another thing what we are doing right now is it's actually kind of halfway through going to our what we really want to do and currently because we are rely on this kind of centralized Gateway model to sign the keys. So if you find a key which Gateway is has is compromised, the Mauritius actor could potentially. Basically we point all the sub domain address to my address, so they all the money so protecting the Gateway.

A

It has some security concern and for that reason, if you have a gate where you you have to deploy Gateway by yourself, you can't let other people to deploy it Gateway and use their own. So that's kind of limitation. Current approach, however, it it's here and it's working so another uh photo time- is that if you want to try out this approach into uad app, this is a QR code to take a photo with me, smiling, thank you and so what's next, and so we are kind of yeah.

A

As I said it's kind of halfway, and so we did the off-chain data, retrieval ticked and basic library and wallets integrated, checked and so there's three other things we kind of have to solve to to go to where we really want to achieve go, and the first thing is I call CC.

A

Sorry, a ccwdp, AKA eip559 is called cross chain right deferral protocol, but I think it's the joint uh EIP with I, think coinbase and then Nick Johnson I think is basically so far. You saw that uh all the data can be retrieved on L1 so that you don't need to switch Network to read the data, but once the next step is actually you want to let users to update the data and currently I think uh in case of lens lens have its own interpersonal L2.

A

So, like you have to know that you have to update on lens in case of a coinbase, you have to know that you have to do in a coinbase, uh basically extension, but this one kind of uses similar approach to ccip reads to return the like, where uh you need to kind of be points to your end point or like a URL to update the data. So this is kind of fresh, oh, no, it's June! So it's been there, but I only get to know like cycle that this existed.

A

So uh it's fresh but like there's already draft, so you can take a look and uh next so yeah trust, minimize, resolver, Eco uh Roll-Ups, so that so far I was talking about quite kind of centralized approach like you have to trust the Gateway. Well, we uh have design is going uh so yeah.

A

One of the stuff of the Roll Up is the fact that, like you most of the roll up, whether it's a kind of uh optimistic or DK, that their basic principle is to batch right, uh L2 data to periodically in a battery data into L1. That means you can actually uh verify the state or belt too.

A

On L1, using L1 Contra, uh so yeah optimistic uh roll up, uses, Cloud proof and a DK user validity proof, and once and my understanding is that uh optimism or like stock, where all these companies listed, they do have a basic function.

A

So once we have that function, what we're gonna do I explain how do I here so here it's uh just like retrieving the data and signing the uh message, but what you can do on the L2 rollup is like you can get basically get the proof: data with the proof and uh yeah you construct the Marco R3 and on this uh verify station on a smart contract, you can basically call uh I forgot the name of the optimism code.

A

Do you remember verify was State commitment, something called a function to verify and by doing the, uh even if a Gateway returns just data. Oh, my time is already up. Okay, uh you can uh you don't have to trust. So that's. Are you gonna? It's a complete app of another five minutes. Okay, so uh I think I already mentioned and there's a demo which we did two years ago for the optimism so optimism.

A

We know like how it works and we are right in the middle of updating to the latest version and yeah I'll skip that order and all the end. You know this now YouTube my old photo. So sorry, so the QR code, so you should refer to and the more important things is yeah. We have a set of ens by Nick Johnson for salty uh so yeah. That's it.