Comparison of zkEVM Solutions: Exploring the Path of Ethereum Scalability

The zkEVM technology is driving the large-scale application of Ethereum. With many options available, which solution stands out the most? This article will compare and analyze the major zkEVM solutions including Polygon zkEVM (and its 2.0 version), zkSync Era, Linea, Scroll, and Taiko, providing readers with a comprehensive zkEVM guide.

Introduction to zkEVM

zkEVM is a layer two network solution that handles transactions and sends proofs back to the Ethereum main chain. By combining zero-knowledge proof (ZK) technology and EVM compatibility, zkEVM significantly reduces the computational burden on the Ethereum mainnet, improves scalability, while maintaining security and decentralization.

However, there are differences among various zkEVM solutions. Ethereum founder Vitalik Buterin proposed a framework that categorizes zkEVM into different types, ranging from Ethereum equivalent (Type 1) to EVM compatible (Type 4). This classification reflects the trade-off between EVM compatibility and performance.

Comparison of Major zkEVM Solutions

Polygon 2.0 (zkEVM Validium)

In June 2023, Polygon Labs proposed upgrading Polygon PoS to zkEVM validium. Polygon PoS has a large ecosystem, including over $2 billion in locked value, tens of thousands of decentralized applications, and approximately 2.5 million daily transactions.

Migrating PoS to zkEVM validium can retain its network effects and low-cost advantages while not impacting the existing applications, user, and developer experience. Polygon 2.0, as a zkEVM validium, offers lower costs and higher throughput compared to the existing Polygon zkEVM Rollup.

The main difference between Validium and Rollup lies in the way they handle data availability. Validium stores transaction data off-chain, which reduces costs and increases scalability. However, this also brings challenges in ensuring the availability of off-chain data. The existing network of over 100 validators in Polygon PoS can provide strong assurance for data availability.

Polygon zkEVM

Polygon zkEVM is a Type 3 ZK-Rollup designed to achieve equivalence with the EVM. It retains compatibility with EVM opcodes, thereby providing greater scalability when collaborating with existing Ethereum tools and clients.

The Polygon zkEVM mainnet was launched in March 2023, and the current locked amount on the network is approximately $54 million. It complements Polygon 2.0: Polygon zkEVM (Rollup) has slightly higher fees and slightly lower throughput but offers the highest level of security, making it suitable for applications that handle high-value transactions (such as DeFi). On the other hand, Polygon 2.0 (zkEVM validium) offers the highest scalability, making it suitable for applications with high transaction volumes and low fee requirements (such as Web3 games and social platforms).

zkSync Era

zkSync Era is currently a Type 4 zkEVM developed by Matter Labs. Its mainnet went live in March 2023, with a current locked value of approximately $450 million and a transaction volume of 27 million in the past month.

The goal of zkSync Era is not to be fully equivalent to EVM, but to improve proof generation speed through its custom virtual machine (VM). It natively supports Ethereum cryptographic primitives, simplifies the testing process, and enhances user experience through native account abstraction.

zkSync Era uses the LLVM compiler to convert Solidity, Vyper, and Yul code into executable code on the zkSync VM, with plans to support Rust and C++ in the future. It also features a robust L1-L2 contract messaging system, making it easier for developers to transfer data between contracts on Ethereum and zkSync.

Linea

Linea, developed by ConsenSys (the creator of MetaMask, Truffle, and Infura), is currently a type 3 zkEVM. Its Alpha mainnet launched in July 2023 and has accumulated a locked value of 50 million USD. The uniqueness of Linea lies in its ability to execute unmodified native bytecode according to Ethereum Virtual Machine specifications.

Linea directly uses the bytecode compiled from Solidity to generate ZK proofs for smart contracts, reducing the risks of errors and hacking attacks. For users, this means they can achieve security similar to Ethereum, but with significantly lower transaction costs.

Scroll zkEVM

Scroll is a zk-Rollup on Ethereum, currently in the 3rd type of zkEVM, with plans to gradually transition to the 2nd and 1st types. Scroll's long-term goal is to prioritize EVM compatibility and decentralization, rather than pursuing rapid ZKP generation.

The current alpha test network of Scroll is the type 3 zkEVM, which is now open to the public. Successfully implementing the type 1 zkEVM will be the ultimate form of EVM compatibility, decentralization, and scalability, essentially replicating the functionality of Ethereum L1.

Taiko

Taiko is similar to Scroll, as it is a general-purpose zk-Rollup aimed at becoming a type-1 native zkEVM. Taiko takes a different approach from Scroll by prioritizing decentralization over speed from the very beginning.

The Taiko Type 1 testnet is now available. Unlike Scroll, which gradually enhances EVM compatibility and decentralizes its sequencer and prover at the time of mainnet launch, Taiko has been committed to the decentralization of these components from the very beginning while maximizing EVM compatibility, even though this may result in slower ZKP generation.

Summary

The development and application of Layer 2 networks are crucial for the future of Ethereum and are key to solving the scalability issues of blockchain. Each zkEVM solution has its unique advantages and challenges, but they all make significant contributions to building a more accessible Web3 ecosystem. With the continuous advancement of technology, we can expect to see more innovations and breakthroughs from these solutions in the future.