Research On Multicast Key Management System Based On IPv6

Secure multicast is a research hotspot of multicast technology; its core issue is the multicast key management. Multicast key management is proposed mainly to solve forward and backward security difficulties in secure multicast. The difficulties are that legal group member cannot receive multicast data after they leav the group, and that new members cannot receive the multicast data before they join the group. To solve these difficulties, it will be need to update members'encryption key of the multicast data when there is dynamic changes occurred, to make unqualified members cannot decrypt data, and to achieve safety requirements. How to reduce the resource load of key updated has become a research hotspot of multicast system.In view of the current existing multicast key management protocols, multicast security needs and IPv6 multicast technology concepts are firstly discussed in the thesis, various group key management architectures and key updating strategies are analyzed. How to reduce the resource load brought by key updating is deeply researched in this thesis. Main jobs and achievements in this thesis are described as the following:Firstly, the existing multicast key management architectures, such as centralized architecture, subgroup hierarchy, and distributed multicast group key management solutions, are expatiated. The types of multicast management advantages are compared and analyzed. Then, the key updated algorithm that are the immediate and batch rekey strategy is introduced, the advantages and disadvantages of each rekey algorithm are analyzed, the IPv6 multicast technology is studied.Secondly, by the analysis of members'behavior patterns, an adaptive key updated algorithm based on group state is proposed in this thesis. The concept and the use of related calculation formula are defined. Algorithm is combined with immediate rekey and batch rekey's advantages, and the combination maximizes the communication security with intelligence, effectively balances the load, and solves the issues on key management resources security. Simulation experiments results indicate that the algorithm is identical with theoretical derivation, and that the algorithms are superior on safety and resource load to traditional algorithms in particular the consistent multicast application.Thirdly, on the basis of deeply analyzing on logic LKH tree, how to adjust LKH tree on the adaptive algorithm of group members'joining or leaving is studied. The adjustment and optimization is researched in detail, the optimal key tree structure is analyzed. Time complexity and space complexity of the adaptive algorithm, and their comparison with traditional algorithm, are given. Simulation experiments results support the theory.Finally, based on the adaptive algorithm, the group key management system framework in IPv6 environment is proposed, it can dynamic adopt key updating algorithm according to the behavior patterns of the user groups, and can let the user to adjust the values of the algorithm parameters for fitting the special requirements. Simulation results indicate that the system secure multicast communication can accurately work.