Revised Variable Length Interval Batch Rekeying with Balanced Key Tree Management for Secure Multicast Communications

Summary With the evolution of the Internet, multicast communications seem particularly well adapted for large scale commercial distribution applications, for example, the pay TV channels and secure videoconferencing. A key tree approach has been proposed by other authors to distribute the multicast group key in such a way that the rekeying cost scales with the logarithm of the group size for a join or depart request. The efficiency of this key tree approach critically depends on whether the key tree remains balanced over time as members join or depart. So the researchers try to create a balanced tree by applying merging algorithms for batch join requests and to handle the batch depart request they extended and created a batch balanced algorithm. But we found that the algorithm works well only if the number of joining members is greater than the number of departing members. In this paper we analyzed various strategies and extended the Batch balanced algorithm further by utilizing variable length batch rekeying interval. This paper analyses the efficiency of the proposed scheme with the existing schemes and the comparison shows that the proposed scheme performs better than the existing schemes in terms of balanced key tree generation and minimizing the number of key update messages.