Abstract:

Traditional conditional broadcast proxy re-encryption data sharing approaches over-rely on untrustworthy third-party proxy servers,which leads to issues of a low efficiency,data security and privacy leaks.To address the above problems,this paper proposes an information security protection scheme that combines conditional broadcast proxy re-encryption with blockchain consensus mechanisms.First,to solve the single point of failure and collusion attacks of individual proxy servers,this scheme uses blockchain nodes to take turns to act as proxy servers.At the same time,it selects high-credibility proxy servers to participate in re-encryption through the Delegated Proof of Stake(DPoS) consensus algorithm that integrates credibility mechanisms,greatly reducing the risks of the single point of failure and collusion attacks.Second,to address the high permission issue of proxy servers using re-encryption keys,this paper introduces the threshold cryptosystem concept and splits the re-encryption key into multiple fragments distributed across different proxy servers.In this way,any single proxy server is unable to decrypt data independently,thus effectively improving the security of the re-encryption process.Finally,through the analysis of the security,correctness and credibility of the scheme,it is demonstrated that this scheme can effectively solve security vulnerabilities in traditional schemes.Related simulation experimental results also prove that compared with existing data sharing schemes,this scheme has significant advantages in ensuring data security while having lower computational costs.

Key words: conditional broadcast proxy re-encryption, threshold key, blockchain, consensus mechanism