Design And Implementation Of Secure Email System

In the field of network security, the research and application is now focused on security of inner network, especially security of the Email system. This paper mainly does with the realization of a point-to-point Email secure agent, and the authentication for the Email system.This paper can be devided into three parts:In the first part, some popular standard and software are described, and then the algorithms, message structures, authentication and certificate structures are compared to see whether there are any disadvantages. Those algorithms that are suitable for Email application are described in detail.In the second part, a framework of secure Email system is proposed according to the S/MIME protocol. Further analyses are given to some important parts of the secure Email system, such as digital signature, encryption and decryption. The author also describes in detail how to realize them.In the third part, it is proposed to use LDAP server for distribution of the certificates and use SASL authentication in secure Email system to ensure information security. In the context of this part, the author gives out the reasons for choosing them and the details for realization.