Research on batch rekeying strategy in multicast communication

In order to offer security for multicast applications,the group key has to be changed whenever a user joins or leaves the group.Batch rekeying alleviates the problems of inefficient and out-of-sync which are brought by individual rekeying.But the batch re-keying ignores the change probability of members.Even in an update cycle,no membership changes or some members change only in a sub-tree,the group manager must update all the keys,therefore will increase the overhead of group rekeying and communication costs.The paper proposes the triggered batch re-keying based on the six-probabilityoptimization key-tree which is constructed according to the users'change probabilities.The paper also proves that this approach further reduces the overhead of group re-keying and communication costs,improves scalability of group members and adapts better to the dynamic changes in multicast group membership through performance analysis and simulation experiments.