For Web3 to flourish as a new system that replaces the current Web2 status quo, there are advanced protocols and concepts that need to be applied, such as zero-knowledge proofs (ZKPs). Basically, ZKPs allow you to prove something without revealing any secrets, and when applied to Web3, it allows blockchain solutions to verify transactions without either party revealing more information about themselves. We have discussed the basics of ZKPs and their importance to Web3 in our previous blog.
Applying ZKPs on Web3 solutions will undoubtedly unlock various use cases of blockchain solutions and cryptocurrencies, but to do this, Web3 platforms rely on various protocols that implement this concept for real transactions. To understand how this works, particularly in the leading blockchain platform Ethereum, we need to review two underlying concepts: Zero-Knowledge Rolluos (ZK-rollups) and the Ethereum Virtual Machine (EVM).
How rollups scale Ethereum
Before we discuss ZK-rollups, we need to understand that there are two main directions toward which scaling solutions for Ethereum are being explored: on-chain scaling and off-chain scaling.
On-chain scaling requires changes to Layer 1 (L1) mainnet protocols like Ethereum. For a long time, sharding the blockchain, or the act of splitting the blockchain into discrete pieces (shards) to be verified by subsets of validators, was expected to scale Ethereum. This will require more drastic changes to Ethereum, and while the L1 protocol itself has undergone various changes for scaling purposes, many developers have leaned towards other solutions that are not as invasive.
Enter off-chain scaling, which involves solutions are meant to indirectly scale the primary L1 blockchain, in this case Ethereum, by adding more layers to process the transactions without using the actual core blockchain. A major example of off-chain scaling is the use of rollups.
Rollups bring the best of off-chain scaling solutions by creating a general-purpose solution while still having the security of a base layer like Ethereum. Rollups settle the transactions off-chain but post the compressed transaction data back to the base layer network and still derive its security from the base layer protocol. This design helps reduce the transaction fees and increase blockchain adoption.
Comparison of Popular Rollup Implementations
On Ethereum and a few other L1 protocols, there are two main rollup implementations:
Optimistic rollups are Layer 2 (L2) protocols designed to extend the throughput of Ethereum's base layer. They reduce computation on the main Ethereum chain by processing transactions off-chain, offering significant improvements in processing speeds. The most popular implementations are Optimism and Arbitrum.
Meanwhile, zero-knowledge rollups (ZK-rollups) bundle (or “roll up”) transactions into batches that are executed off-chain. Off-chain computation reduces the amount of data that has to be posted to the blockchain. ZK-rollup operators submit a summary of the changes required to represent all the transactions in a batch rather than sending each transaction individually. They also produce validity proofs to prove the correctness of their changes. The validity proof demonstrates with cryptographic certainty that the proposed changes to Ethereum's state are truly the end-result of executing all the transactions in the batch.
To better understand ZK-rollups, watch this video from Finematics:
ZK-rollups and EVM compatibility
**
**Many developers of ZK-rollups are building solutions that are meant to be compatible to the Ethereum Virtual Machine (EVM). To recap, the EVM is a runtime environment that executes smart contracts on the Ethereum blockchain, enabling decentralized applications (dApps) to run securely and deterministically. Fortunately, many in the Ethereum community, including founder Vitalik Buterin, support the implementation of ZKP on Ethereum itself.
Vitalik has been vocal about wanting to see zero-knowledge Ethereum Virtual Machines (zk-EVMs) built on Ethereum’s first layer to speed up the verification process on the base blockchain. A zkEVM is a significant upgrade to the underlying computational framework of EVM, enabling seamless integration with a highly efficient form of rollup that utilizes zero-knowledge proofs. The zkEVM is a hot research topic in the Ethereum ecosystem.
The integration of EVM-compatible ZK-rollups is anticipated to empower developers in harnessing the scalability and security benefits offered by zero-knowledge proofs. Furthermore, the compatibility with native Ethereum infrastructure enables developers to construct decentralized applications (dApps) that are compatible with zero-knowledge proofs, using well-established tools and programming languages that have been extensively tested and proven effective.
If you are interested in digging into zkEVM, don’t miss this article from Vitalik.
Who are building zkEVM?
Whether zkEVM becomes an actual part of Ethereum in its base level or not, there are several projects on making this a reality through ZK-rollups. Here are some projects working on zkEVM:
Polygon zkEVM is a decentralized ZK Rollup on the Ethereum mainnet working on a zero-knowledge Ethereum Virtual Machine (zkEVM) that executes Ethereum transactions in a transparent way, including smart contracts with zero-knowledge-proof validations.
ZKSync, now on its version 2.0,is an EVM-compatible ZK-ollup being built by Matter Labs, powered by its own zkEVM.
Linea is type 2 zkEVM that replicates an Ethereum environment by leveraging rollups. Linea’s users include Consensys.
Immutable zkEVM is the first of its kind - a chain for games that offers EVM compatibility, low cost, massive scale, and Ethereum security. The most cutting-edge technology in gaming with the largest ecosystem in web3.
Scroll is a tech-driven company working on building a native zkEVM Layer 2 Solution for Ethereum.
Taiko Taiko is a decentralized, Ethereum-equivalent ZK-rollup (a Type 1 ZK-EVM).
Closing thoughts
By unlocking the full potential of ZK-rollups, zkEVM is poised to revolutionize the blockchain landscape and empower the development of innovative decentralized applications.
ZKPs are often referred to as “moon math” because of their complexity. Developers need to make it understandable and accessible to people, so ZK-rollups are necessary to keep the Ethereum ecosystem “open and welcoming” to people without a mathematics degree.
Further Reading
https://vitalik.ca/general/2023/03/31/zkmulticlient.html
About Us
We are members of Artech Club, a group that is dedicated to building a leading Web3 education and media platform. Artech Club is committed to contributing educational and valuable stories about the blockchain ecosystem and Web3. Our goal is to deliver value and wisdom in this fascinating area .
Make Yourself Heard
We welcome everyone to discuss any related questions with us, leave us comments on the topics you would like us to focus on, or join us in creating content together. We believe that asking the right questions and finding solutions are equally important. Thank you for reading our latest article.