Research On Rekeying Schemes Of Secure Multicast

Multicast is widely applied in one-to-many and many-to-many communications nowadays. Secure multicast needs to satisfy: group secrecy, forward access confidentiality, backward access confidentiality. That is only the current group members have the newest group key to encrypt and decrypt the transmission messages. Hence whenever an individual joins or leaves the group, redistribution of the group key is necessary.For the significant status of rekeying, during recent years, there has been much research on improving the performance of rekeying. The important work of LKH approach has reduced the complexity of rekey operation fromΟ(N) toΟ(logN), where N is the number of group members.If no efficient auxiliary measures are taken while group members leave or join in batches, even the scalable Logical Key Hierarchy (LKH) approach will pose a bottleneck after frequent individual rekeying. Instead of organizing members randomly and unorderly in the leaf nodes, we propose an optimal LKH scheme firstly utilizing the similar attributes and internal correlation of group members that have an impact on batch removal as Rekeying Influence Factors (RIF), to cluster group members and further construct an optimization logic key tree. In our approach, the members with higher correlation degree according to the RIF distribute more centralized in the logic key tree. We present intact construction algorithm and key management strategies for our optimization tree. Furthermore, we analyze the rekeying performance for batch leaving of our approach by comparing with that in traditional LKH on worst-case and average-case, make simulation, and show our scheme is very efficient and effective for dependent batch removal with respect to redistribution and bandwidth usage as well.