Group Key Distribution with Self-healing Property for Unreliable and Communication-constrained Networks

The most common solution for implementing access control into a dynamic group is to use a group key unknown to all but the users in the group. The group key (i.e., session key) is updated for every session throughout the lifetime of the group with the procedure of group key distribution. In this paper, we propose a group key distribution scheme with self-healing property that enables users in a dynamic group to establish session keys over an unreliable network with constrained bandwidth resources. To achieve this, our scheme also has the limited group membership property that there exists an upper bound on the number of users in the group. Through modeling and analysis, we show that our scheme has a better tradeoff between storage and communication overhead as compared to previous work. In addition, we propose a variant of the scheme which enables key recovery from a single broadcast message.