一种前向安全的电子邮件协议

Towards a Secure E-mail Protocol with Perfect Forward Secrecy

电子邮件已成为Internet环境中传送通讯数据的一个重要应用.为了安全有效地传递电子邮件协议数据,目前很多研究者从电子邮件协议的基本安全性以及可认证电子邮件协议等方面提出了一些安全方案.但这些方案仅仅解决了电子邮件协议的某些安全需求,并不能从实用安全电子邮件协议的角度来提供完整的安全解决方案.本文首次给出了一个安全电子邮件的定义,提出了一个前向安全的电子邮件协议.该协议利用短期密钥来加密协议消息,并且使用Diffie-Hellman算法进行短期密钥协商.安全分析表明该协议不仅保证了协议的基本安全性,而且确保了协议的前向安全性.另外,该协议还提供了安全电子邮件协议中所需要的可认证性,时效性和敏感性.

E-mail has been an important application to transfer the data of communication on Internet.In order to securely and efficiently transfer the E-mail message,many researchers focus on the issues of providing basic encryption function for E-mail protocol or certified E-mail schemes.However,these schemes only meet part of the security requirements for a secure E-mail protocol,and fail to provide a complete solution from the view of a practical secure E-mail protocol.A secure E-mail protocol is defined and proposed for the first time in this paper.In this protocol,the message is encrypted by the short-term encryption keys which are negotiated by the Diffie-Hellman algorithm.The security analysis shows that the scheme not only provides the basic security mechanism but also guarantees the perfect forward secrecy.In addition,this protocol resolves the problems of certification,timeliness and sensitivity,which are strongly needed by a secure E-mail protocol.