摘要：A secure multicast communication is used to deliver encrypted messages from a sender to a group of authorized receivers. A practical approach is to use a common key only known by the authorized users to encrypt the transmitted messages. The common key must be renewed to ensure forward/backward secrecy when a group member joins/ leaves the group. In this case, the rekeying problem becomes a critical issue for secure multicast communication. Many researchers have focused on solving the rekeying problem. In 2010, Lin et al. proposed two multicast key management schemes without the rekeying process. However, the transmission size in their schemes is dependent on the number of group members. In this article, we adopt the time-bound concept to propose two new key management schemes without the rekeying process. The point is that the required transmission size in the proposed schemes is constant. Performance analysis is given to demonstrate that our schemes have better performance as compared with the recently proposed key management schemes in terms of transmission size and computational cost. Under several security assumptions, we prove that the proposed schemes are secure key management schemes for multicast communication.
关键词：Multicast; Key management; Group communication;Rekeying problem
