Single chain past tense, multi-chain continuous tense, full chain Layer0 is the future? Decode the "new Holy Grail of Web3" zkOmnichain

康水跃

2023-02-15 18:00

Read this article in 16 Minutes

zkOmnichain, a full-chain interoperability protocol based on proof of zero knowledge, is the holy grail of blockchain and Web3.

Original title: zkOmnichain deserves More Attention than zkRollup

Shuiyue Kang is the founder of Fox Tech and Way Network and chairman of Danyang Investment

zkRollup is a Layer2 circuit designed to solve the Ethereum congestion problem. zkOmnichain belongs to the Layer0 circuit and aims to build the entire Web3 network. But because of the sheer volume of sound on the Ethereum system, the focus was on zkRollup and not zkOmnichain. zkOmnichain, a full-chain interoperability protocol based on proof of zero knowledge, is the holy grail of blockchain and Web3.

If Ethereum itself can maintain a 70% + market share for years, then Omnichain itself is a pseudo-concept. However, Ethereum can't maintain a 70% market share forever. The chart below shows the share trend of Ethereum TVL from August 2020 to February 2023. Ethereum's latest market share is 59.24%. Although the chain layer infrastructure of Web3 maintains the pattern of "one super many strong" for a long time, and Ethereum itself is constantly upgraded, with the traffic absorption of Layer2 of Ethereum like zkRollup and opRollup to Layer1, With the strong growth of challengers such as BNB Chain and Polygon, with the rapid rise of new public chains such as Atpos and Sui, and with the Cosmos system catching fire, we will see Ethereum itself below 50% market share for a long time after 2025.

Figure 1: Ethereum TVL share from August 2020 to February 2023, source: https://defillama.com

Almost all applications after DeFi Summer 2020 are implemented in a multi-chain state by deploying each of the original chains individually. This simple and crude approach not only brings a lot of trouble to developers in deployment and operation, but also leads to two major problems: the liquidity is severely divided in each chain, and the price difference between the same Token chains is huge.

In addition to the above original approach, there are three main paths for Application to achieve full chain coverage: The first path is also a common path of the first generation of cross-chain products, that is, Application interoperates with the start chain and the target chain through an intermediate consensus protocol. Appplicatio is usually not deployed on this intermediate chain. The typical representative of AppplicATIO is Cosmos and Polkadot, which are their own systems. Multichain, Celer, Wormhole, Thorchain, Axelar; The second path is to interoperate with the remaining chains through Optimistic mechanisms. A typical example of this type of path subdivision is Optimistic Verification

& The Fraud Proofs of Synapse, Nomad, Hyperlane, and the adoption of Optimistic Oracle & None Proofs of LayerZero, Across; The third path is that Application interoperates with other chains through zkOmnichain, a full-chain interoperable protocol based on zero-knowledge proof. The typical representative is Electron, Polymer, Succinct, which comes out from Cosmos system. Focus on the Overearlity of NFT across chains, as well as the Way Network dedicated to providing universal solutions.

Figure 2: Comparison of cross-chain protocols over time

Finally, there is a path where the Application deploys to a new smart contract public chain through which it interoperates with other chains, typically ZetaChain and Map Protocol. This is a heavy development and operational path. First of all, we need to solve the problem of book alignment when EVM public chains cross heterogeneous chains, which is the same as the first generation of products. Secondly, due to the overlap of functions with existing smart contract public chains, we must compete directly with them for Application resources. But no matter which path you take, you're doing the same thing, which is turning single-chain applications into full-chain applications.

In the first-generation intermediate chain (consensus protocol) mode, if there are too many verification nodes, it is slow, and if there are too few verification nodes, it is unsafe. Moreover, node operation is extremely heavy, which makes it difficult to assume the major role of Web3 Network Fabric. In this way, we can only focus on the non-intermediate chain (consensus protocol) model, focusing on the second generation product model opOmnichain and the third generation product model zkOmnichain.

Figure 3: Comparison of OP and ZK full chain interoperability protocols

Full-chain interoperability protocol Layer0 circuit, like Ethereum expansion scheme Layer2 circuit, forms OP and ZK solutions. Let's first look at the Optimistic Oracle submodel in the OP scenario, where LayerZero uses a Chainlink predictor, Chainlink has its own Cross-Chain Interoperability Protocol (CCIP), which makes them both partners and competitors. Across uses UMA as the predictor, and UMA and Across are two projects belonging to the same team.

Such schemes cannot realize decentralization in the true sense and do not have Shared Security. Shared Securit means that a particular Token or Application running on a given infrastructure is not free to choose its security model, but must comply with whatever security requirements the infrastructure provides. All Layer1 and Layer2 have Shared Security, and Layer0 should also have Shared Security, rather than Isolated Security, because only in this way can unified low-level security be provided for end users. And no matter what application they are using, no matter what the internal security policies of the application are. That's what the word "infrastructure" means.

In addition, the above Optimistic Oracle has strict trust assumptions, and the end user must trust that Oracle will not be randomly validated. At this point, Oracle is A Third Trusted Party in this mode. Users must trust that Oracle and Relayer are not conspiring to steal their assets. Moreover, such schemes would not produce any Fraud Proofs or Validity Proofs Proofs, nor could there be any on-chain verification proofs. All kinds of disadvantages and problems, L2BEAT, Nomad, Way Network and other teams have written pointed out, no longer discussed here.

Next, let's look at the Optimistic Verification sub-model in OP scheme, which is more rigorous and prudent than the Optimistic Oracle above, and may generate Fraud Proofs. Messages are optimistically signed on the source chain, and a network of validators below the chain is responsible for submitting proof of fraud to the target chain during the enforced Optimistic Window (Timeout Period). During this window, fraudulent messages may be challenged. If any errors are noticed, the Validator can examine and reject the message and prohibit any fraudulent transactions. Optimistic Verification relies on the single honest verifier hypothesis, while the external verification network of first-generation products relies on the honest majority hypothesis. Optimistic validation only requires an honest Validator that initiates Change to secure the system. But Tradeoff is precisely the delay that comes with this window. Fortunately, this Latency is not as long as opRollup, and instead of waiting seven days, you wait tens of minutes, as Nomad, for example, has a 30-minute Timeout Period.

Let's turn finally to the most important one, zkOmnichain. This model is Zero-Knowledge Verification, so it has a better Robustness. zkOmnichain, just like zkRollup, will also have Validity Proofs. One of the important links is to call the sum-Check Protocol module, do proof (Sum) in the chain, do verification (Check) on the chain. Through this very rigorous mathematical and cryptographic verification, to achieve Completeness and fairness Soundness. As for Succinctness, Groth16 can be used to further compress the Proof Size. For example, the original Proof Size produced by Way Network's zkSpark is about 100KB, but it can be reduced to 130B after being compressed by Groth16.

Figure 4: zkPark Sum-Check Protocol of the Way Network

It is with zkOmnichain, a "strong cryptography" full chain interoperability protocol, that we can finally achieve the highest standard of infrastructure products, that is, the de-trusted Trustless of any third party trusted body, and the Decentralized decentralized of any central privilege body. With zkOmnichain, we finally see the possibility of moving from a "chain" to a "network" and the possibility of building an infrastructure called Layer0 that can support the deployment of large-scale full-chain applications to various smart contract public chains.

基于 zkOmnichain 的全链应用会带来哪些变化？首先是去掉了第一代跨链产品里头的居间链 Intermediate Chain，消减了昂贵验证节点运营成本；其次是去掉了 Intermediate Token 居间 Token 以及 Wrapped/Pegged Token 衍生Token，用户无需信这些 Token 就可以完成 Native Token 跨链交易。最后是去掉了第三方受信主体 Oracle 预言机，这一举措的意义有助于提高全链网络的韧性。基于 zkOmnichain 的全链应用，既不依赖于居间链，又不依赖于预言机，同时也没有居间 Token 与衍生 Token 。它以严密的数学、密码学进行有效性证明，并在链上做验证的方式来实现去中心化 Decentralized 和去信任化 Trustless 的目标，实现像比特币网络一样的 peer-to-peer 全链通讯。

From Singlechain to Multichain to Omnichain, this is the basic trend of the Web3 wave, where full-chain applications will not be as sparse as they are now, but ubiquitous. Zkomnichain-based applications have higher cross-chain security, lower communication costs, and faster communication speeds, so they are more likely to succeed.

Figure 5: Full-chain application based on zkOmnichain

In the past few years, there has been a proliferation of full-chain interoperability protocols aimed at connecting the various blockchains into a veritable Web3. Compared with the context of Web2, Cosmos is equivalent to the construction of a Local Area Network (LAN), while Way Network is dedicated to the construction of a Wide Area Network (WAN) and even the Internet. The criterion to judge the quality of such products lies not in the number of chains or other things that can be accessed by this agreement, but in whether the access methods are Decentralized and Trustless, i.e., the consensus of Satoshi Nakamoto, because this is "1" and others are "0", without 1, no amount of 0 is useless.

Conclusion: The Interoperability Protocol of the zkOmnichain Interoperability Protocol is a key technical tool and infrastructure in order to interoperability Web3 applications, which will gradually replace single-chain/multi-chain applications as the dominant deployment mode in the next three years. Soon, we'll see Zkomnichain-based full-chain AMM applications, full-chain Lending applications, full-chain SocialFi, full-chain NFT, and so on.