Efficient Authenticated Key Agreement Protocol for Dynamic Groups

Group key management presents a fundamental challenge in secure dynamic group communications. In this paper, we propose an efficient group authenticated key agreement protocol (EGAKA), which is designed to be fully distributed and fault-tolerant, provides efficient dynamic group membership management, mutual authentication among group members and is secure against both passive and active attacks. The features of EGAKA are as follows: Firstly, EGAKA can be built on any general two-party key exchange protocol without relying on a particular one. EGAKA achieves scalability and robustness in heterogenous environments by allowing members to use any available two-party protocol in common and deliberately designed fault-tolerant mechanism in dynamic membership management. Secondly, EGAKA provides extremely efficient member join services in terms of both communication and computation costs which are constant to the group size. This is a very useful property in the scenarios with frequent member addition.