SGM: A Subgroup Management Scheme Using K-Means Clustering in M2M Systems

Secure group key management is an important task to realize reliable machine-to-machine (M2M) systems. Although many group key management schemes have been proposed, most of them do not consider the communication cost and the number of keys held by each node. In this paper, we address these challenges by proposing a novel subgroup key management scheme, which we called SGM. SGM is a key tree hierarchy scheme which uses an alternative node to the key management server. Since the SGM node encrypts and distributes the group key during a rekeying process, the communication cost and the number of keys can be decreased. We also present a cost-efficient deployment method for the SGM node using a k-means clustering algorithm. Simulation results show that our proposed scheme can improve the energy efficiency of M2M networks, compared with the conventional scheme, logical key hierarchy (LKH).