ZK-BFT: A Zero-knowledge and Byzantine Fault Tolerant Consensus for Permissioned Blockchain Networks
Wanxin Li, Collin Meese, Mark Nejad, Hao Guo · 2023
Consensus algorithms play an essential role in blockchains, directly impacting their performance. These algorithms involve validating and ordering pending transactions into new blocks, a process that exposes data to consensus nodes, raising privacy concerns. While existing consensus algorithms focus on network security and performance, data privacy within the consensus layer has received limited attention. This study introduces ZK-BFT, a zero-knowledge and Byzantine fault-tolerant consensus algorithm for permissioned blockchains. ZK-BFT verifies transactions without disclosing original information to consensus nodes, enhancing data privacy within the consensus layer while maintaining Byzantine fault tolerance. Our experiments, using the Hyperledger Ursa cryptographic library and Hyperledger Fabric permissioned blockchain, demonstrate ZK-BFT’s potential for integration into existing permissioned blockchain systems that require privacy-by-design and Byzantine fault tolerance.