An Efficient and variable interval Rekeying for Dynamic Ad Hoc Multicast Group using Key Path Reduction

Key distribution is one of the major issues in secure ad hoc multicast group communication. There has been an extensive research on rekeying, to reduce cost. In this study, we propose an efficient and scalable batch rekeying for dynamic ad hoc multicast group, with variable interval and key path reduction techniques. The proposed scheme overcomes the major existing issues like inefficiency in using the keys that are generated and distributed, the sync issue in which a user tries to decrypt a data using an irrelevant key, imbalance in network traffic and latency in the key server response to the user request, for leaving and joining at once. Generally, a central key server is used to govern all the above issues. The proposed scheme excludes the usage of a central key server by generating the group key in the individual nodes, which minimizes the communication overhead and the number of keys that each user possesses. The proposed scheme also reduces the depth of the tree very effectively, when a user joins or leaves the group, using key path reduction technique and ensures forward and backward secrecy. The simulation result shows better performance when compared to individual, regular batch and periodic rekeying.