Abstract: To solve the key distribution problems in the BF-IBE scheme, this paper proposes a new key distribution protocol based on Merkle simple key distribution protocol and Diffie-Hellman key exchange, which improves the BF-IBE scheme. A new secure E-mail scheme based on Identity-Based Cryptosystems(IBC) is designed with the combination of the improved BF-IBE scheme, GDH group signatures and key exchange protocols. It ensures not only the confidentiality, integrity and authenticity, but also the non-repudiation and tracing of the e-mail owing to the improved PKG. The new scheme is compatible with the existing mail protocols and has some practicability as well as application prospects.

Key words: Identity-Based Cryptosystem(IBC), secure E-mail, Identity-Based Encryption(IBE), GDH group signature

摘要： 针对当前BF-IBE方案中的密钥分发问题，设计基于Merkle简单密钥分配协议和Diffie-Hellman密码交换的密钥分发协议，实现对BF-IBE方案的改进。将改进方案与GDH群身份签名技术、密钥交换协议相结合，提出一种基于身份密码体制(IBC)的安全电子邮件解决方案，可保证邮件的机密性、完整性和可认证性。由于对PKG功能的扩展，还能实现邮件的不可抵赖性和可追踪性。新方案与现有的邮件协议/系统兼容，具有一定实用性和应用前景。

关键词: 基于身份的密码体制, 安全电子邮件, 基于身份加密, GDH群签名

CLC Number: 

• TP393.08