关键词: 安全邮件系统, 密钥托管缺陷, 无证书密码学, 基于身份的密码体系, 安全性分析

Abstract: Aiming at the inherent defects of identity-based cryptography in key escrow,one improved secure email system design architecture based on identity-based cryptography is proposed, which uses SM series algorithm as the core cipher algorithm,adopts Al-P certificateless public key encryption scheme, increases the user's selection of secret value to participate in the private key generation process, achieves the purpose that the trusted third party or the key generation center can not completely obtain the user private key,and solves the security defect that the trusted third party or the key generation center may obtain legitimate authorization for malicious behavior, effectively enhances the self security of the secure e-mail system. The security analysis shows that the system can not only solve the key escrow problem effectively, but also guarantee the confidentiality, integrity and authenticity of the data exchange.

Key words: secure email system, key escrow defect, certificateless cryptography, identity-based cryptography, security analysis