A secure e-mail protocol using ID-based FNS multicast mechanism

Electronic mail (e-mail) has been used to transfer various types of electronic data in Internet. Usually, a user has to send an e-mail to a specific group of users with a secure delivery mechanism. In this paper, a novel and feasible e-mail delivery mechanism using the secure multicast protocol with an ID-based factorial number structure (FNS) is proposed in the multicast system. In the proposed e-mail delivery mechanism, the e-mail is required to be encrypted before sending out in order to safeguard the message via a public channel, such as wire public switching communication links and wireless communication systems. Without loss generality, the public-key system is adopted in the proposed secure multicast system for a convenient and easy key management. The proposed scheme outperforms the existing methods for more easily to construct secure email system. Furthermore, the security of the proposed scheme is analyzed, including replay attack, sender impersonation attack, unknown key-share attack, forgery attack and insider attack. Finally, the computation complexities of the proposed mechanism are discussed. The result shows that the proposed scheme outperforms the CRT-based secure e-mail scheme.