Research Of Group Control Key Update In Mobile Ad Hoc Networks

With the rapid development of wireless communication technologies, A mobile ad hoc network (MANET) comes up as a new type of network. MANET is a multi-hop temporary autonomous system of mobile nodes with wireless transmitters and receivers without the aid of preestablished network infrastructure. In such an environment, it may be necessary for one mobile node, in order to communicate with another node, to depend on a chain of intermediate nodes forwarding packets, due to the limited propagation range of each mobile node.Along with the growing civil and military deployments of MANET, the security technology of the network receives increasing attention. Due to frequently changing topology and with no fixed infrastructure, so the security research for MANET will be confronted with many new issues. Group key management is essential in MANET security research, and it is also one of the hot areas in MANET research nowadays. In MANET, group key management has extensive applications. For example, the technologies of group key management can be applied to secure routing and secure group .communication. Actually secure routing problem can be treated as a secure group communication problem with all the nodes in the same group.By enough analyzing the requirements of MANET for security and some limitations of existing. work, we propose a novel distributed group key management framework (DGKMF) based on the threshold secret sharing mechanism. Since localized trust model is used and multiple nearby members can collaborate to generate a group key, the framework has good adaptability to frequent topoloty changes, robustness and scalability, also it advoids single point of failure. And the group key generation in the framework influenced a little by mobility of nodes and error-prone wireless channels. But, in the DGKMF, there exists a colluding problem for the leaving nodes. In other words, when there are over k-threshold group member nodes to leave from the group communication, they can collude to generate the Group Private Key and destroy group communication security. In the DGKMF, after enough researching of proactive secret sharing mechanism and the colluding problem, this dissertation proposes two Group Control Key Renewal Algorithms with proactive principle, and solves the colluding problem. The performances of the two algorithms are studied using network simulator (ns-2), and the simulation results demonstrate the effectiveness of these two algorithms in terms of GCK renewal success ratio and delay.