Paper 2011/216

Provably Secure Group Key Management Approach Based upon Hyper-sphere

Shaohua Tang and Lingling Xu and Niu Liu and Jintai Ding and Zhiming Yang

Abstract

Secure group communication systems become more and more important in many emerging network applications. For a secure group communication system, an efficient and robust group key management approach is essential. In this paper, a new group key management approach with a group controller GC using the theory of hyper-sphere is developed, where a hyper-sphere is constructed for a group and each member in the group corresponds to a point on the hyper-sphere, which is called the member's private point. The GC computes the central point of the hyper-sphere, intuitively, whose ``distance" from each member's private point is identical. The central point is published and each member can compute a common group key via a function invoking each member's private point and the central point of the hyper-sphere. This approach is provably secure under the pseudo-random function (PRF) assumption. The performance of our approach is analyzed to demonstrate its advantages in comparison with others, which include: 1) it requires both small memory and little computations for each group member; 2) it can handle massive membership change efficiently with only two re-keying messages, i.e., the central point of the hyper-sphere and a random number; 3) it is very efficient and very scalable for large-size groups. Our experiments confirm these advantages and the implementation of our prototype presents very satisfactory performance for large-size groups.