A zkEVM rollup is a zero-knowledge Ethereum Virtual Machine¹. It aims to replicate the Ethereum environment as a rollup, allowing developers to build on it just like they would on Ethereum¹. It is an EVM-compatible rollup that is secured by a Zero-Knowledge Proof (ZKP), giving it the enhanced functionality of some of the Optimistic Rollup solutions that are EVM-compatible while also giving it the security of earlier zk-Rollup options that didn’t offer compatibility with Ethereum’s EVM².

Zero-knowledge rollups (ZK-rollups) bundle (or ‘roll up’) transactions into batches that are executed off-chain³. Off-chain computation reduces the amount of data that has to be posted to the blockchain³. ZK-rollup operators submit a summary of the changes required to represent all the transactions in a batch rather than sending each transaction individually³. They also produce validity proofs to prove the correctness of their changes³.

The ZK-rollup’s state is maintained by a smart contract deployed on the Ethereum network³. To update this state, ZK-rollup nodes must submit a validity proof for verification³. As mentioned, the validity proof is a cryptographic assurance that the state-change proposed by the rollup is really the result of executing the given batch of transactions³.

Polygon zkEVM Beta is an example of a leading ZK scaling solution that is equivalent to Ethereum Virtual Machine⁴. The vast majority of existing smart contracts, developer tools and wallets work seamlessly with it⁴.