Efficient Self-Healing Key Distribution with Limited Group Membership for Communication-Constrained Networks

Self-healing key distribution enables users in a large and dynamic group to establish session keys for secure group communication over an unreliable network. The main property of self-healing key distribution is that the users are capable of recovering lost session keys on their own, without requesting additional transmissions from the group manager. In this paper, we propose an efficient self-healing key distribution scheme for unreliable networks with constrained communication resources. Our scheme has the limited group membership property that the number of members in the group is no more than t, where t is a scheme parameter. Under an appropriately defined security model, we show that our scheme achieves the optimal storage and communication overhead as compared to previous schemes. In addition, we propose a variant of the scheme which enables key recovery from a single broadcast message.