Rotation based secure multicast key management for batch rekeying operations

Many emerging security-rich network applications such as pay-per-view, video broadcasting, video on demand and videoconferencing are based on multicast communication. Thus, securing multicast communications is an important Internet design issue in most of the network applications. In such a scenario providing high security for multicast group members using a common group key is a challenging task. Most of the previous literature describes key tree approaches to distribute the multicast group key in which the rekeying cost is high for batch joining or leaving operations. The marking algorithms proposed in the past focus on batch join and batch leave requests. However, merging and batch balanced algorithms consider batch join more and do not focus much on batch leave operations. In this paper, we present rotation based key tree algorithms to make the tree balanced even when batch leave requests are more than batch joins operations. These proposed algorithms not only maintain a balanced key tree, but also reduce the rekeying costs in comparison with the existing algorithms when batch leave operation is higher than batch join operation (JM < LM). Our simulation result shows that this proposed scheme reduces 20%–30% rekeying cost compared to the existing approaches.