Practical implementation of secure email system based on IBE, DNS and proxy service

Now a days, email has become the most widely used communication system in daily life. To improve security and efficiency of email system, most of the current email system adopts S/MIME or PGP as the mechanism implement security. But these systems are not efficient because of the high cost for public key certificate management and the problem on credential trust management. This paper presents a complete implementation of a practical secure email system based on Identity Based Encryption (IBE) which uses DNS as the infrastructure for public key exchange, a proxy service for encryption/decryption on behalf of user and a secure key token or fingerprint authentication system for user authentication.