Secure Multicast Key Protocol for E-Mail System Using Factorial Number Structure

Electronic mail (e-mail) system are widely are used in Internet. A user usually needs to send an e-mail to a specific group of users via a secure delivery mechanism. In this paper, a new e-mail delivery mechanism using secure multicast key protocol with ID-based factorial number structure (ID-based FNS) is proposed in an encryption multicast system. In the e-mail delivery mechanism, the message of e-mail is required to encrypt first before sending out in order to safeguard the secrecy of the message on a public channel, such as wire-lined public switching communication links and wireless communication systems. Without loss generality, the public-key system is usually adopted in the multicast environment for the convenience at the easy key management need. As a manner of fact, the mechanism is having analyzed the space occupation; our scheme outperforms the existed methods in the way of magnitude order of reconstructing secure command key. Besides, the extraction of direct secure command key associated each intended receiver is fast operated to succeed the subsequent e-mail message recovery. Therefore, we provide a new and feasible solution for e-mail message encryption multicast in network system.