StarkWare Sessions #7 | Herodotus Cross-Chain Data

Sometimes, the frontier is at a crypto conference. We’re returning from our adventures in Tel Aviv with nine exclusive interviews with some of the key players in the StarkNet space. Wish you could make it to all the crypto conferences, but don't have the time? Don't worry, Bankless brings the frontier to you. Herodotus is a system for data interoperability across chains. The future is composable, and tools like Herodotus help move us in that direction. ------ 📣 MetaMask Learn https://bankless.cc/metamaskshow ------ 🚀 JOIN THE NATION: https://newsletter.banklesshq.com/subscribe ------ BANKLESS SPONSOR TOOLS: 🐙KRAKEN | MOST-TRUSTED CRYPTO EXCHANGE https://bankless.cc/kraken 🦄UNISWAP | ON-CHAIN MARKETPLACE https://bankless.cc/uniswap ⚖️ ARBITRUM | SCALING ETHEREUM https://bankless.cc/Arbitrum 🚁 EARNIFI | CLAIM YOUR UNCLAIMED AIRDROPS https://bankless.cc/earnifi 👻 PHANTOM | CROSS-CHAIN WALLET https://bankless.cc/phantom ------ Timestamps: 0:00 Intro 3:30 Herodotus 7:15 Use Cases 10:10 Storage Proofs 11:45 How it Works 15:00 The Future 18:30 Get Involved ----- Resources: Kacper Kozio https://twitter.com/kacperkozi Marcello Bardus https://twitter.com/0xmarcello Herodotus https://twitter.com/HerodotusDev StarkNet https://starkware.co/starknet/ ----- Not financial or tax advice. This channel is strictly educational and is not investment advice or a solicitation to buy or sell any assets or to make any financial decisions. This video is not tax advice. Talk to your accountant. Do your own research. Disclosure. From time-to-time I may add links in this newsletter to products I use. I may receive commission if you make a purchase through one of these links. Additionally, the Bankless writers hold crypto assets. See our investment disclosures here: https://www.bankless.com/disclosures

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:02David Hoffman?

  Welcome to Bankless, where we explore the frontier of internet money and internet finance. And sometimes, that frontier is at a conference. Like last weekend, where over 1,000 developers, founders, builders, and investors attended the Starkware Sessions in Tel Aviv in order to participate in growing the Starknet ecosystem. This is Bankless' Starkware Sessions series, which are nine bite-sized episodes interviewing the founders, builders, and ecosystem developers of Starknet. Every once in a while, in the crypto world, a conference happens, but not everyone is available to attend. Don't worry, Bankless has your back, because I go to basically every conference that's out on the frontier, and I bring an entire podcast studio in tow with me, in order to make sure that the Bankless nation stays on the frontier of what's happening in crypto.

• 0:45David Hoffman?

  In this interview, we are talking about Herodotus, and that is an interesting name, which will become self-evident as to how they named what they are working on, Herodotus, in this interview. Herodotus is a system for taking all of the very deep, rich data that we have across many, many chains, and allowing each of these chains to access the state across chains, both the current state and the historical state. So say, for example, Uniswap on Optimism wants to understand the average price of Ether on Arbitrum over a 30-day period, arbitrary-length period. Herodotus, by running all of these very deep archive nodes across all of these chains, can provide all of this data to cross all of these chains using ZK proofs, in order

• 1:30David Hoffman?

  to compress all of this data and prove it to the chain. It's an extremely useful thing to do, and the use cases for this are quite large, so I will let your imagination run wild as you listen to this episode. But first, before we get into this episode, a moment to talk about some of these fantastic sponsors that make this show possible. Kraken has been around for almost as long as crypto itself. As crazy as crypto is, Kraken has remained a rock for its clients, building out a platform designed to stand the test of time. Kraken is all about proof, not promises, which is why they've pioneered a proof of reserves, a system that lets Kraken's customers verify for themselves the solvency and responsibility of the Kraken exchange. And for this reason, and many more, we've chosen Kraken as Bankless' Strategic sponsor for 2023.

• 2:11David Hoffman?

  And once you're done using Kraken to get your dirty fiat money into pristine crypto assets, perhaps you should check out Arbitrum, where so much of the frontier of crypto innovation is taking place. Arbitrum just announced their Stylist Initiative, which is their brand-new programming environment that lets developers deploy apps using their favorite programming languages like Rust, C, C++ alongside regular old solidity EVM apps. Steps can use any coding language they like, and it simultaneously drops Layer 2 fees by an order of magnitude. It's a big deal. So many of your favorite TPI apps have already deployed to Arbitrum, like Uniswap. But did you know that Uniswap isn't just for ERC20 tokens anymore? Uniswap is also an NFT aggregator, too, to make sure that you are getting the best price on your NFC purchases. Uniswap gives NFT collectors and traders powerful tools,

• 2:54David Hoffman?

  all from the cozy, comfy Uniswap interface. By the way, it's also got a native fiat on-ramp. It's also deployed on, like, every Layer 2, and it's got this nifty, cool thing called a universal router that ensures that you always get the best price on your trades. Crypto protocols like Arbitrum and Uniswap are becoming super powerful. So make sure that you're also using a wallet that's equally as powerful, or else you'll be missing out. If you're looking to upgrade your wallet experience, check out Phantom, the number-one wallet of Solana, which has recently come to both Ethereum and Polygon. Phantom has native NFT support, giving you your own NFT gallery from inside the wallet. Phantom is both a browser extension and a mobile wallet, and is also the only wallet to span both the Solana and Ethereum ecosystems. Check it out at phantom.app. And now, let's get into the interview. And we're back in Tel Aviv for the Starkware Sessions,

• 3:39David Hoffman?

  and I'm talking with the Herodotus team. You guys want to introduce yourselves, and then we'll get into what you guys are building?

• 3:44Speaker 01

  Sure. I'm Cas Procosio. I am one of the co-founders of Herodotus.

• 3:49Speaker 02

  Marcelo? Yeah, Marcelo, also one of the co-founders of Herodotus. And yeah, I'm the technical guy.

• 3:56David Hoffman?

  And so, we're absolutely going to dive into Herodotus. But first, I want to ask you guys about why you decided to come all the way out to Tel Aviv for Starkware Sessions. What brought you here?

• 4:04Speaker 01

  Well, Starknet, the whole community over here is very vibrant. They're building a really interesting ecosystem with a lot of unique projects. We wanted to network with these projects and essentially explain to other projects how they can leverage storage proofs and advancements that we're building at Herodotus,

• 4:23Speaker 01

  and explore all the unique applications that these technologies unlock.

• 4:28Speaker 02

  Yeah, another reason. We use cryptography, we love cryptography. Many people over here also seem to like cryptography, so yeah, it just makes sense to come here and chat with the guys and yeah.

• 4:40David Hoffman?

  So you use the word "storage proofs", which tells me that this is going to be a very technical conversation, so fair warning to the Bankless Nation. How did you guys come up with the need for Herodotus? How did you guys come up with the need for Herodotus?

• 4:56Speaker 01

  Yes, so actually Herodotus is the father of history. That's what he's known for, but he's also the supposed creator of something called the Herodotus machine. Which, fun fact, the Herodotus machine was supposedly used to build pyramids in Cairo. So Cairo, Starknet, kind of the vibe, that's where the names came from. And yeah, and Herodotus, since he was a historian, our solutions unlock access to historical data for Ethereum and applications on it. And we thought that was an interesting fit. And yeah, it's a very technical product, so the target audience of that name is also quite niche, so it fits.

• 5:37David Hoffman?

  So when did the Herodotus project get started?

• 5:40Speaker 01

  So, Herodotus itself, we started building it in August of last year, August 2022. And since then, we have gone through a lot of research, a lot of experimentation that brought us to this point here. We have presented some of the concepts and some of the technologies that we have been building at several conferences last year. But only here at Starknet, Starkware Sessions in Tel Aviv, we have actually been able to demo a working API implementation of what, using these products, these solutions that we've been building will look like. And we're very excited to share them with the community.

• 6:23Speaker 01

  The developers that build on top of this, essentially...

• 6:29Speaker 01

  Can build really cool things and I'd love to give you some examples of how others are using and exploring our technologies. And yeah.

• 6:38David Hoffman?

  First, I'd like to ask what's broken about the state of all of these blockchains that we're using, the state of Web3? Because Herodotus doesn't exist. What's broken about the world right now?

• 6:47Speaker 02

  Yeah, so first of all, I would say that nowadays we live in a 2D world. Why? Because if you build a smart contract, this smart contract can access its own storage and to some limited scope, the storage of other contracts. And we want to enable some other dimensions, one of them being, hey, let's see what's happening on other rollups and other layers of Ethereum. And another dimension, which is probably the most important one, is time. And yeah, that's our mission to essentially enable these two dimensions.

• 7:16David Hoffman?

  So where should we get started diving into Herodotus? Where should we leave?

• 7:20Speaker 01

  I think the best way to kind of get started is to go over some use cases, give some intuition as to where this technology fits in. And then maybe later on, we can kind of cover some more of the like the technical stuff of how we actually make this happen. And where do we see Herodotus fitting in in the future? So as of right now, I'd say that our most flagship integration is with, is for governance, it's Snapshot X. And essentially what Snapshot X allows you to do is it allows you, well, how they use Herodotus is they leverage Herodotus storage proofs to allow you to prove ownership of L1 assets on Starknet. So essentially you're able to prove that you are the rightful owner of an asset on an L2. And reap the utility of this asset. And this is very powerful.

• 8:06Speaker 01

  Because you're able to keep the security of keeping your assets on this main chain. And essentially eliminate the need for bridging. And I think that's one of the main takeaways from from storage proofs in general. They unlock a lot of use cases. And while I agree that there's a big shift over the recent months to, well, years, to bridging assets between various chains, storage proofs actually eliminate the need for bridging in many circumstances. That said, it is possible to build a bridge on top of Stark's proofs. However, the general like. Possibilities of what you can build on top of them are quite limitless. And yeah, so Snapshot is one of a very interesting example because users normally are kind of restricted to voting on the L1,

• 8:50Speaker 01

  which of course is pretty expensive. And if we want to have DAO adoption governance becoming much more used, we want to make sure it's accessible to all the people who might not want to pay $16 for transaction fee, etc. Is there anything you want to add?

• 9:08Speaker 02

  No, I think that was a great explanation.

• 9:10David Hoffman?

  I think that's a use case that a lot of people in the Bankless Nation probably pretty easily wrap their heads around. I mean, how many times has there been a Snapshot vote that has been relevant to a DeFi app or DAO that you are a part of, but your assets are somewhere else and you haven't really, you just can't vote. And so what do you do? Do you go retrieve your assets to go Snapshot vote? Or do you just skip the vote? You probably skip the vote.

• 9:33Speaker 01

  Yeah, especially when gas fees go through the roof and not much you can do about that at that time. So yeah, so governance is one example, but there's a lot more you can build with this. So I personally am always excited with most of the financial applications of what's possible to build on this. And one of the examples is lending. Cross-chain lending is quite interesting because you're able to essentially do something like locking your assets on an L1 and taking out a loan on an L2 based on storage proof. This allows you to keep your assets on a chain that you find secure, which is L1, you trust it, and get exposure for, let's say, cross-chain arbitrage, etc.

• 10:13David Hoffman?

  I want to unpack that one really quick because I think that's really, really cool. Okay, so like, say I have an AVE position on Optimism, and I would like to borrow USDC on Optimism, but I don't have any ETH on Optimism. All my ETH is on the Layer 1. And so using, what are they called?

• 10:31David Hoffman?

  Uh, bridge, um... Storage proofs. Storage proofs, excuse me, using storage proofs. I can lock up my assets on the layer one and then prove that to AVE on layer two.

• 10:43Speaker 02

  Yep.

• 10:43Speaker 01

  Yes, but that's something that can be built on top of Herodotus. I want to clarify that our infrastructure unlocks these use cases, but it's up to the actual end developers to build these solutions on top of them.

• 10:57David Hoffman?

  Strictly theoretical use cases.

• 10:59Speaker 01

  Correct. All the examples I'm going to list right now are simply things that projects we have been discussing with entering into partnership agreements with are exploring and we've heard of. Another really cool example that I'm sure if someone has listened to our Starknet workshop presented by Maciej Sulewski, is essentially proving that your nonce in an account abstraction wallet has not changed in over a year. And at that point, you could essentially write account abstraction wallets that allow you to do fund recovery that is based on like a dead man's switch, for example. So you can prove that there was no activity for over a year, which makes it a reasonable assumption you maybe lost your keys. And at that point, you could delegate ownership of that wallet or transfer funds based on that proof.

• 11:40Speaker 02

  That can also work for EOAs that are part of, let's say, a multi-sig.

• 11:45David Hoffman?

  Okay, so how does the magic come about? What's the magic under the hood that really enables this to happen?

• 11:51Speaker 02

  Okay, so that's my part. So essentially, the way how we think about blockchain is essentially it's a list, right? A list of blocks. And there is a very nice cryptographic relation between them. Essentially, one block header refers to its parent, right? In a cryptographic manner, because the hashes just match. And we essentially embrace that relation. We just process the whole chain. We prove it, so we know that whatever we come up with is valid. And then on top of that, we can access the state roots. And the state roots are just a root of a tree that contains everything was ever committed on the blockchain at this specific block. And essentially by just leveraging cryptographic proofs, we are able to access whatever was present at any time on any chain.

• 12:34David Hoffman?

  Okay, and so where does the role of just like nodes come into play? Like, because this is all based off of archive nodes, right?

• 12:41Speaker 01

  Yes, so to kind of expand on like, storage proofs in general, they're very complex to work with, and they have pretty high hardware like requirements and all know-how requirements. You need to have archive nodes, and you need to maintain them. You need to benchmark the different proving systems that can be used to essentially generate these proofs. And on every single chain, this will vary. This is pretty complex, and we believe that developers, it doesn't give a developer a very easy integration experience. If we want to see storage proofs mainstream and essentially see them being adopted in the increased amount of projects, we want to simplify that as much as possible. We want to take this very complex topic and make it easy to integrate into your app.

• 13:22Speaker 01

  So for example, let's say I want to have an options protocol that settles based on, let's say, historical, historical yield of, let's say, an AVE, on AVE. We could take that feed from essentially Herodotus by essentially sampling historical points in time through, from the blockchain, and computing something we call a verifiable data feed. That's an interesting use case as well.

• 13:51Speaker 01

  What else? And yeah, so essentially, we're abstracting the complexity of working with storage proofs and giving them to developers in an easy-to-use API.

• 14:00David Hoffman?

  So let me try and repeat a bunch of stuff to make sure I check my understanding here. So like, there are some ways for data to go into our DeFi apps, that DeFi app might actually be able to look on-chain at historical data and then come up with its own data feed about using native smart contracts on Ethereum, but that's probably going to be really computationally intensive and probably extremely expensive, and on the L1, probably so expensive that it's not even possible, and it's just a theoretical conversation because of how expensive it is. What you guys are doing is operating archive nodes, taking that same data that exists on Ethereum or other Layer 2s or whatever, and then generating a proof of that data, which then you can prove to a smart contract about the data that's going into it, and

• 14:45David Hoffman?

  you can also prove that it's valid, and that smart contract can receive that same data, but rather than that smart contract processing Ethereum history, you guys are just feeding it externally, but you don't have any trust assumptions because it's a proof.

• 14:57Speaker 01

  Exactly. Correct, yes.

• 14:59David Hoffman?

  Nice, alright, okay. Uh, that sounds so generalizable that you can unlock almost anything with that.

• 15:07Speaker 01

  Yes, there's a lot more use cases that I can probably think of. I'd kind of like to explain as to how we actually got here. And um, how we ended up in a situation where this data access is sharded essentially amongst all these other chains. Um, Layer 2s have done a lot for Ethereum. They increased transaction throughput, etc. Um, however, in itself, in like the very early days of Ethereum, if you were a smart contract, you had access to pretty much all the data. You, it was all in this one chain. And as we wanted to increase this transaction throughput on Ethereum, Layer 2s managed to increase this transaction throughput, but in itself, they sharded this data access. So if you were that smart contract, you would, you no longer had access

• 15:50Speaker 01

  to all the data because it became isolated within your Layer 2. Um, and uh, and with Herodotus and our APIs and uh, and the solutions that we're building, what we want to enable you to do is we want to enable developers to once again be able to access data between these Layer 2s in a trustless manner. Relying on uh, on these cryptographic properties that secure the blockchain itself, uh, without introducing unnecessary trust assumptions.

• 16:18David Hoffman?

  So what's the roadmap like? Like, what are you guys building first? I think you guys, you talked about Snapshot. Uh, it sounds like that's coming first. What's coming second? What's coming third? What are the ways that people are going to be impacted by this the most?

• 16:28Speaker 01

  Yes, so our first uh, first integrations are essentially with Starknet. Uh, we have a Starknet Ethereum connection built. We define these as connections, meaning that when there's two chains between there, there's a need for data access, uh, we define that as a connection. Um, and this connection can be one directional or bidirectional. And in this case, the first connection that we have built and we have successfully Benchmark, etc., and we will be releasing access for the public for with API keys, etc., in the future, is this connection allows you to read Ethereum data from Starknet. So it's a one-directional connection. In this case, this was more of a decision that it's very expensive to do it the other way around. In the future, this is something we're going to explore as well. And now that we have done this Starknet Ethereum connection, the next ones that we're

• 17:11Speaker 01

  going to be exploring are going to be EVM to EVM. We haven't yet finally finalized a decision as to which roll-up we're going to go for, but this is going to come out sometime in the next two to three months.

• 17:24Speaker 02

  Maybe to add on top of that, we also allow to access state from Polygon, Optimism, and Arbitrum on Starknet.

• 17:31David Hoffman?

  So my intuition tells me that this just works across any blockchain, and the fact that a Layer 1, or a Layer 2, or a side-chain, or an alternative Layer 1 is actually a detail that does not matter for what you guys are building?

• 17:44Speaker 01

  Yes, in a way, right now, we're simply focusing on making it EVM-compatible, and the chains that we deploy it on later is a later decision. We have not picked one yet.

• 17:57Speaker 02

  Maybe to add on top of that, we firstly are focused on doing like L2 to L2 communication, L1 to L2. We are not looking at L1 to L1 yet, because it's a completely different type of problem. Many things are in common, but it's still not on the roadmap yet.

• 18:13Speaker 01

  Not for anytime soon.

• 18:15David Hoffman?

  So how big is the team?

• 18:16Speaker 01

  Currently, there's nine of us, and there's a few part-time people. But yeah, the team's growing, and we're building, there's results, and things are moving very nicely.

• 18:29David Hoffman?

  Beautiful. If people want to learn more, where should they go?

• 18:34Speaker 01

  HerodotusDev, the Twitter, or herodotus.dev, the website, is probably the best resource. And yeah, that's where we post updates, etc.

• 18:43David Hoffman?

  Awesome. And at the end of this interview, at the end of this conversation, the naming "Father of Modern History" definitely checks out. I understand how that came to be.

• 18:52Speaker 01

  Happy to hear that.

• 18:53David Hoffman?

  Cheers, guys. Thank you so much.

• 18:55Speaker 01

  Thanks. Thank you.