Efficient Secure Multicast with Well-Populated Multicast Key Trees

• Authors: M. Moharrum;R. Mukkamala;M. Eltoweissy
• Venue: ICPADS '04 Proceedings of the Parallel and Distributed Systems, Tenth International Conference
• Year: 2004

Secure group communications is the basis for many recent multimedia and web technologies.In order to maintain secure and efficient communications within a dynamic group, it isessential that the generation and management of group key(s) be secure and efficient with real-time response. Typically, a logical key hierarchy is used for distribution of group keys to users so that whenever users leave or join the group, newkeys are generated and distributed using the key hierarchy. In this paper, we propose Well-Populated Multicast Key Tree (WPMKT), a new efficient technique to handle group dynamics in the key tree and maintain the tree balanced withminimal cost. In WPKT, sub-trees are swapped in a way that keeps the key tree balanced and well populated. At the same time, rekeying overhead due to reorganization is kept at aminimum. Another advantage of WPKT is that rebalancing has no effect on the internal keystructure of the swapped sub-trees Results from simulation studies show that under random user deletion, our approach achieves one order of magnitude in overhead less than existingapproaches. Under clustered sequential user deletion, our approach achieves almost a lineargrowth with tree size under individual rebalancing. For periodic rebalancing, weachieved almost half the overhead introduced by other approaches.