Research Of Group Key Management In Mobile Ad HoC Networks

A mobile Ad Hoc network has become the most favorite area in wireless networks and mobile computing. Group communication is its important communication method, in which a feasible and effective group key management mechanism is the key precondition for security. The group key management problems this thesis studies mainly include energy-saving multicast key distribution, secure and efficient group rekeying, and key pre-distribution. Firstly, the thesis introduced the basic concepts, features, applications, security requirements and security threats, as well as the key management of mobile ad hoc networks. Secondly, for the reason of energy-constrained nodes in mobile ad hoc networks, the thesis indicated the study difference of multicast key distribution scheme between wired networks and mobile ad hoc networks, and analyzed that the consideration of the physical location and routing information is critical for developing energy-saving key distribution schemes. Based on routing information, a Routing Branch Clustering Algorithm was proposed and applied to multicast key distribution scheme. The simulation Studies demonstrate that our scheme can decrease the communication energy consumption in mobile ad hoc networks. Thirdly, on the basis of the analysis of group rekeying problems, the thesis proposed a new symmetric-key based group rekeying scheme for secure and efficient group rekeying, which used multiple key pools in key pre-distribution phase and combines identity-based cryptographic technology with it. Finally, three classes of key management, namely key distribution, key agreement and key pre-distribution, were analyzed for comparison, and the current development and some important evaluation metrics of key pre-distribution were introduced. After that Latin squares were used to construct t-packing designs, which have cover-free families properties and were adopted in key pre-distribution phase, on which a new group rekeying scheme was built. The security and performance analysis demonstrate that the new scheme improves the collusion-resilience of the networks, and enhances the key-sharing connectivity of nodes which makes key management more efficient.