3.1 Overview

ZK Rollup represents a groundbreaking advancement in blockchain technology, including scalability, security, and efficiency. This cutting-edge solution addresses the pressing need for enhanced transaction throughput while maintaining robust security measures inherent to blockchain networks. However, directly utilizing zk rollup to build DApps comes with very high development requirements, which hinders the development of the ecosystem, so ZK EVM has emerged. ZK EVM constructs all EVM instructions with zero-knowledge proofs. As long as the compiled bytecode of the contract is inputted, verifiable zero-knowledge proofs can be generated based on the contract execution process. This completes the entire process from ordinary Solidity program to generating execution process proofs. Developers in the Ethereum ecosystem can easily migrate old applications and develop new ones. NERO provides the ZK Rollup Execution engine including fine-tuned ZK EVM based on Plonk system of ZK-SNARK. It comprises several key components essential for its optimal performance and functionality within the ecosystem. The core component is the zero-knowledge protocol module. This allows for the construction of ZK proofs for all EVM instructions, ensuring that transactions and smart contract executions remain private and confidential. Additionally, NERO incorporates a robust ZK proof generation engine. This engine is responsible for creating verifiable zero-knowledge proofs based on the execution process of smart contracts. These proofs serve as cryptographic evidence of the correctness and validity of transactions and contract executions, enabling efficient verification by the settlement layer. Furthermore, NERO includes comprehensive developer tools like bytecode compiler etc. These tools provide developers with the necessary resources and support to leverage the privacy and scalability benefits offered by ZK EVM.

Figure 3: Execution process in Execution Layer