Performance optimization of region-based group key management in mobile ad hoc networks

We propose and analyse a scalable and efficient region-based group key management protocol for secure group communications in mobile ad hoc networks. For scalability and dynamic reconfigurability, we take a region-based approach by which group members are broken into region-based subgroups. Leaders in subgroups securely communicate with each other to agree on a group key in response to membership change and member mobility-induced events. We propose a novel approach to identify the optimal setting of the region-based key management protocol to maximize the performance of the system. We show that secrecy requirements for secure group communication are satisfied, and that there exists an optimal region size that minimizes the network traffic as a result of efficiently trading inter-regional vs. intra-regional group key management overheads. We compare the proposed region-based key management protocol with nonregion-based key management to demonstrate the effectiveness. Analytical results are validated by extensive simulation.