Research And Design Anonymous Group Key Agreement Scheme

With the rapid development of network technology, a variety of new applications based on group communication come forth constantly. When a group of people want to communicate securely over an open network, they need a common conference key to encrypt their communication information, in order to prevent unauthorized users from getting any useful information about authorized services. The establishment of conference key plays an important role not only in theory of cryptography and information security, but also in promoting the development of communication network and new electronic application. In addition, research of anonymous communication technology is becoming more of a concern by more and more people. The anonymity and privacy protection has become a modern society running an indispensable mechanism. The group member's privacy protection has become another focus of user attention.So study of group key management scheme concentrated on improving of the robustness, scalability, provide proof of security and user privacy protection in four areas. Focusing on these focal of group key management, we establish a provably secure group anonymous authentication key agreement protocol. The new scheme ensures the security of group communication through the agreement and the dynamic update of the group key. Firstly, the scheme establishes a secure group key under the premise of authenticating group members. Secondly, for both internal and external group members the scheme achieves different degree of anonymity, that is, the external users can absolutely not learn any information about the internal membership structure, and the internal users only can find out the member composition but cannot recognize identity of the member. In order to achieve the forward security and backward security of group key, new scheme supports group members to renew their group key when the external nodes join the group or the internal members leave the group. At the same time, with computation complexity and storage cost substantially reduced, our scheme can establish the group session key though only one round.