Coin World News Report:
OP Succinct has pushed forward the process of Ethereum scalability by introducing zero-knowledge proofs (ZKP) into OP Stack, achieving the transition from optimistic verification to ZK Rollup.
By Ac-Core, YBB Capital Researcher
TL;DR
The main function provided by OP Succinct is to integrate ZKP into the modular architecture of OP Stack to transform OP Stack Rollup into fully verified ZK Rollup;
If the ultimate goal of Ethereum’s future expansion is to transform each Rollup into ZK Rollup, the purpose of OP Succinct is to combine Rust and SP1 to deploy Type-1 zkEVM (fully Ethereum equivalent) in OP Stack;
OP Succinct Proposer mainly accomplishes parallel proof generation and proof aggregation with verification;
The existing OP Stack system relies on a “7-day fraud prevention window”. If there is a dispute, the transaction verification will be postponed for one week. OP Succinct shortens the time required for transaction completion by using ZK proofs, eliminating the need for an extended fraud prevention window;
OP Succinct can greatly reduce transaction costs.
1. Recent Review: OP Mainnet Status and OP Stack vs OP Labs
Image source: Blockscout
1.1 Key Developments in OP Mainnet
According to the news on March 30, 2024, OP Labs released “fraud proofs” on the OP Sepoila testnet and officially launched the fraud proofs on the OP Mainnet on June 11, 2024, pushing decentralization to the first stage. It allows users to withdraw ETH and ERC-20 tokens from OP Mainnet and enables users to question and delete invalid withdrawals (including Base, Metal, Mode, and Zora) without the need for trusted third parties.
To ensure the security and trust of user assets, Optimism uses fraud proofs to improve the accuracy and effectiveness of on-chain transactions and prevent malicious behavior. The principles of fraud proofs include:
Data availability: Fraud proofs first ensure that all data on Layer-2 is accessible and can be verified by Layer-1;
Challenge period: Within a certain challenge period, anyone can dispute the data on Layer-2.
If someone finds inconsistencies between the data on Layer-2 and Layer-1, they can raise a challenge.
Proof submission: If there is a dispute, Layer-2 operators need to submit proofs to refute these disputes and prove the correctness of their data;
Finality: If there are no valid disputes during the challenge period, or if Layer-2 operators successfully refute the disputes, the transactions will be finally determined and considered valid.
1.2 The Relationship and Difference between OP Stack and OP Labs
OP Labs is the team or organization that develops the Optimism solution, while OP Stack is a technical framework for building and expanding Ethereum Layer-2 networks. The relationship between OP Labs and OP Stack can be understood as the relationship between developers and their development tools.
OP Labs:
OP Labs is the core contributor to the Optimism project, responsible for developing and maintaining the Optimism Layer-2 solution. It is a team or organization that focuses on building and improving technology tools related to Ethereum scalability, such as Optimistic Rollups. The main goal of OP Labs is to alleviate the burden on the Ethereum mainnet, reduce transaction costs, and increase transaction speed through Layer-2 scalability solutions. OP Labs also collaborates with other projects, such as Succinct Labs, to further advance Ethereum scalability technologies, such as OP Succinct, which focuses on optimizing zero-knowledge proofs.
OP Labs is the main team or organization that develops and maintains the Optimism network. Their goal is to build an efficient solution to scale Ethereum, focusing on reducing transaction fees and improving transaction speed. They are responsible not only for the development of Optimistic Rollups but also actively promote new technologies related to zero-knowledge proofs, such as OP Succinct, which is developed in collaboration with Succinct Labs.
OP Stack:
OP Stack is a modular architecture or technology stack used to build and expand Ethereum Layer-2 networks. It consists of multiple customizable components that allow developers to build their own Layer-2 chains based on specific requirements. It provides a standardized way for developers to quickly build Layer-2 scalability networks that meet specific conditions.
OP Stack is a set of modular frameworks developed by OP Labs. This framework provides the infrastructure for building Layer-2 networks, allowing developers to quickly build different scalability networks using OP Stack. Due to the modular design of OP Stack, it allows users to flexibly choose different verification mechanisms, such as Optimistic Rollups or ZK Rollups, to meet the needs of different projects.
OP Labs can be understood as the developer of OP Stack, and OP Stack is the technical tool provided by OP Labs to help developers build and expand Ethereum Layer-2 networks.
Before understanding OP Succinct, it is necessary to supplement the understanding of the four main components of each OP stack:
1. op-geth: Retrieves transactions from users and generates blocks and executes blocks with these transactions;
2. op-batcher: Batches user transactions and submits them to L1;
3. op-node: Reads batch processing data from L1 and drives op-geth for state transitions in non-sorter mode;
4. op-proposer: Periodically publishes output roots to L1 to capture L2 states, making it easier to process withdrawals.
2. Succinct Labs collaborates with OP Labs to inject ZK elements into OP Stack
Image source: Succinct Blog
2.1 OP Succinct Architecture Composition
Combining the content at the end of section 1.2 “Four main components of OP Stack,” OP Succinct is a lightweight upgrade of OP Stack that allows chains to use only ZK-verified blocks while keeping the other three components unchanged (op-geth, op-batcher, and op-node). OP Succinct mainly consists of the following four components:
Range Program: This is a program that executes batch blocks and is written in Rust. It is designed to be executed in zkVM;
Aggregation Program: Proof of the aggregated range program to reduce on-chain verification costs. This program is also written in Rust and is designed to be executed in zkVM;
OP Succinct L2 Output Oracle: A Solidity smart contract that contains an array of L2 state outputs, with each output being a submission to the L2 chain state. This contract already exists in the original Optimism system but has been modified to incorporate the verification proof as an authentication mechanism;
OP Succinct Proposer: Observes the transaction batches published on L1 and controls the proof of the range program and aggregation program.
2.2 What kind of Ethereum scalability narrative does OP Succinct tell?
As zkEVM Rollup is extremely difficult to build due to its deep cryptographic expertise, OP Labs has considered supporting proofs of various validity mechanisms when building the modular OP Stack and has created the open-source Kona (see extension link 1) to implement the state transition function STF (function logic of transaction state transition) under OP Stack Rollup using Rust.
And finally, by using Kona and SP1 programs to generate zero-knowledge proofs (ZKP) for OP Stack, it is theoretically possible to upgrade all chains of OP Stack and use ZKP.
The goal of SP1 (Succinct Processor 1) is to allow any developer to seamlessly integrate Type-1 zkEVM rollup using standard Rust code and seamlessly upgrade any existing OP Stack chain to Type-1 zkEVM rollup within only 1 hour through OP Succinct, providing high performance required by applications. The advantages obtained are as follows:
Fast confirmation of ZKP: Reduces proof latency to a few tens of minutes, “replacing” the 7-day fraud proof challenge period;
Cost reduction and efficiency improvement: Average cost per transaction reduced to a few cents;
Switching OP Stack to ZK: Only need to deploy a smart contract and start a lightweight OP Succinct proposal service (see below) to generate proofs through API calls, including batch processors/sorters, op-node, indexers, etc.;
Type-1 zkEVM: All tools and smart contracts compatible with OP Stack Rollup are applicable to OP Succinct Rollup;
Improved scalability: Customizable OP Succinct rollup allows the addition of new precompiles and modification of Rollup logic.
According to the official GitHub, the process only requires the installation of Rust, Foundry, and Docker. Any existing OP Stack rollup can be upgraded to Type-1 zkEVM rollup, and the process is simplified to two steps: 1. Deploy the ZK L2OutputOracle.sol contract; 2. Start the OP Succinct proposal service (process see GitHub extension link 2).
Upgrading OP Stack Rollup to ZK proofs, image source: Succinct Blog
2.3 Building Type-1 zkEVM with SP1 Reth
Succinct believes that the future of EVM Rollup is a maintainable zkEVM written in Rust, and currently, OP Rollup mainly faces three problems: a lengthy 7-day fraud-proof window, complex interoperability, and reliance on multiple sets of data instead of fraud-proof mechanisms in certain cases. In addition, creating zkEVM is a time-consuming process, so SP1 was developed to address these issues.
SP1 is a high-performance, 100% open-source, and fully customizable zkVM that can verify the execution of any Rust (or LLVM compiled language) program. According to public data, OP Succinct Stack has successfully run on OP Mainnet, OP Sepolia, and Base chains, achieving proof costs of 0.01-0.02 USD per Ethereum transaction (see extension link 3). And it is hoped that in the future, all blockchain infrastructure (including Rollups, bridges, coprocessors, etc.) will be written in Rust (or other LLVM compiled languages) and utilize ZKP.
Based on the summary of Succinct’s blog and open-source GitHub content, the performance differences between SP1 and other zkVMs are mainly caused by several key factors:
Precompile-centered architecture: SP1 supports a flexible precompile system that can significantly accelerate various operations (such as secp256k1 and ed25519 signature verification, sha256 and keccak256 hash functions), reducing the RISC-V cycle count by 5-10 times for many programs. Its design goal is to provide performance comparable to ZK circuits while maintaining the flexibility and good developer experience of zkVM;
Fully open-source: SP1 is 100% open-source, allowing teams to implement custom precompiles such as Argument and Scroll, significantly reducing cycle counts and accelerating proof generation time;
Industry standard: Since its launch, the concept of internal precompiles in zkVM has become an industry standard, integrated into projects such as RISC0, Valida, Nexus, and Jolt. SP1 is the only production-ready zkVM that widely supports precompiles for important cryptographic operations;
Efficient memory read and write: SP1 adopts an innovative memory proof method that uses a single challenge to achieve consistent memory proofs, avoiding the overhead of Merkleized memory;
Basic efficiency optimization: Lower detonation factor, new generation lookup parameters (such as LogUp based on logarithmic derivatives), and FRI variants in Plonky3 improve the utilization efficiency of the tracing area.
3. Can OP Succinct become the killer feature of OP Stack against ZK Stack?
Image source: @jtguibas
If we look at the short-term scalability solutions for Ethereum as OP and the long-term as ZK, OP Succinct, assuming it can succeed, will be seen as an important milestone in the development of the Ethereum roadmap. OP Succinct provides an upgrade path from ETH Rollups based on optimistic verification to zero-knowledge proofs, which not only reduces transaction costs and increases transaction speed but also preserves the security and anonymity properties of ZK rollups, bringing new possibilities for future application layer explosions.
Among the recognized four Layer-2 giants, from the perspective of the project’s ecosystem development at this stage, OP Stack is slightly superior to ZK Stack. In the future, the Matthew effect may further manifest, and with the addition of OP Succinct, it may also absorb some of the flow and potential of ZK Stack. If OP Succinct can be realized in the future, it may also have a certain impact on traditional zkEVM Rollups.
However, based on the currently publicly stated content, we can see from the operational logic of OP Succinct that we need to keep a long-term focus on how to ensure that developers can discover system-level risks caused by unknown vulnerabilities in a timely manner when modifying STF functions or adding new precompile functions.
Extension Links:
(1) https://github.com/anton-rs/kona?ref=blog.succinct.xyz
(2) https://github.com/succinctlabs/op-succinct
(3) https://blog.succinct.xyz/sp1-reth/
(4) https://blog.succinct.xyz/introducing-sp1/
