Group Key Agreement Protocols In Dynamic Peer Group

DPG (Dynamic Peer Group) is a kind of Ad Hoc group, whose peculiarity is symmetry, and the members in DPG are symmetrical and dynamic. None single part in the group can completely decide the generation of the group key and the membership events are frequent. So many applications in DPG are becoming increasing popular nowadays, such as multi-user games, video conference, chatting room and so on. These severices need system to provide the security very much. So in the group-oriented applications, it is important to establish the group key securely and efficiently.Secure communication depends on the security of key. Key establishment is one of the research topics of key management. On account of advantage of traditional encryption, it needs to share the same symmetrical session key in parties before the communication. It is an efficient method to establish the key agreement to generate the symmetrical session key.In this paper, we propose an efficient and authenticated key agreement scheme which can be applied to the DPG. The members in the DPG are divided into clusters. In the clusters the members perform the BD protocol to establish the cluster key and the TGDH protocol is performed between the clusters to generate the group key. This method can reduce the BD protocol's communication cost and avoid the weakness of AKA (Auxiliary Key Agreement) and it also reduces the computation cost in TGDH scheme. In theory, our scheme is more efficient than BD and TGDH. The members AKA (Auxiliary Key Agreement) and it also reduces the computation cost in TGDH scheme. In theory, our scheme is more efficient than BD and TGDH. The members have been authenticated based on identitise, so the scheme can prevent from the man-in-middle attack.In order to prevent the man-in-middle attack, we propose a signature algorithm which based on identity. We prove the security of this signature algorithm in the Random Oracle Model, which is existentially unforgeable under an adaptively chosen message attack.Furthermore, the communicational complexity and computational complexity of our scheme have also been analyzed carefully. The comparison among the three protocols of Ours, BD, and TGDH indicates that our scheme is the most efficient protocol. The analysis of the security shows that our protocol possesses of secure attributes of key independence, forward security, back security and no key control.Lastly, we use of the C++ compiled language to realize the system of our group key agreement protocol and the ID-Based signature algorithm. The experiment results demonstrate that the analysis is true and our protocol is feasible and efficient in practice.