The Design of Secure Group Communication with Contributory Group Key Agreement Based on Mobile Ad Hoc Network

A Group Key Agreement (GKA) protocol is necessary for establishing a group key among all of the group members over a public network. The protocol presents a fundamental challenge in secure and efficient group communications. Without the disadvantages of centralized method, Contributory Group Key Agreement (CGKA) is more suitable for dynamic groups. Recently, a Dynamic Asymmetric Group Key Agreement (DASGKA) protocol is proposed base on CGKA. The protocol allows dynamic joining or leaving solution to enhance efficiency in ad hoc networks. In this paper, we focus on the problem of the establishment of the group key. We propose a secure contributory group key agreement protocol based on ring structure. As a member joining or leaving the group, there are more designs about secure transmission and precise verification. Moreover, the issues about passive attack, unknown key-share, key freshness, contributiveness, backward secrecy and forward secrecy were analyzed in this paper. The results of the paper show that our protocol provides more robust and secure group communication.