Blockchain-based ciphertext access control for data sharing

Currently, with the continuous in-depth research and application of blockchain access control, security issues on the blockchain have become a focus of attention. Based on CPABE, this paper proposes a trusted and secure blockchain access control scheme based on ciphertext policy. Firstly, a decentralized attribute-based encryption algorithm (DABE) is adopted to achieve distributed calculation of user attribute private keys, effectively solving the problems of high trust cost and single point of failure caused by the key center generating private keys in traditional CPABE. At the same time, a private key consensus verification protocol based on zero-knowledge proof is designed to ensure the correctness and security of user attribute private keys without leaking private key information. Through the analysis of on-chain security and experimental simulation, the results show that this scheme has better performance while maintaining high security and is more suitable for distributed access control with large attribute scales.