A general and efficient redactable blockchain scheme based on voting committee

Abstract In recent years, blockchain technologies have attracted widespread attention and research in academia and industry. The immutable characteristic of a blockchain guarantees the reliability of data on the blockchain, but the characteristic also leads to the consequence that the harmful or erroneous or privacy data of blockchain cannot be redacted. For the purpose of eliminating harmful data, protecting privacy, updating erroneous data, etc., it is necessary to delete and update the data on blockchains in a safe and controlled way. In this paper, we propose a general and efficient redactable blockchain scheme based on the voting committee selection. Our scheme achieves controllable redactions because a redaction request can be executed only when enough committee members agree to the request. We use a distributed key generation scheme and a threshold signature scheme to significantly decrease the redaction proof size, which results in small running overheads. Our scheme is compatible with various consensus mechanisms and network environments, supports publicly verifiability and fast redactions, and has a good scalability. We also formally prove that our scheme satisfies the necessary security properties. Finally, we develop a proof-of-concept implementation for our scheme, and the experiment results show that the scheme is efficient and practical.