A Broadcast-Encryption-Based Key Management Scheme for Dynamic Multicast Communications

Broadcast encryption is an efficient and secure method to allow a user to be able to communicate securely with multiple receivers in an insecure broadcast environment. Previously, scholars usually applied tree structures to design multicast key management schemes, in which the distributed key was used to encrypt the transmitted message. However, in order to achieve forward secrecy and backward secrecy, previous tree-structure-based approaches had to conduct the rekeying process when a member joined or left a multicast group. However, the rekeying process usually requires that other members change their cryptographic keys. Consequently, this proved to be inconvenient and impractical. In this paper, we propose an efficient multicast key management scheme to solve this problem. Compared with previous tree-structure-based multicast key management schemes, the benefits of our scheme include eliminating the rekeying process and reducing the required key storage for each member.