Lightweight key management for wireless sensor networks

Given the growing number of applications of wireless sensor networks, some recent research has focused on managing secure wireless communications in such networks. When a large group of sensors that typically are constrained in energy, computation and communication resource are deployed, efficient key management becomes critical. In this paper, we propose a new hierarchical key management scheme for wireless sensor networks based on a combinatorial optimization of the group key management problem. Our solution uses symmetric encryption and re-keying to support current, forward and backward secrecy. An important contribution of our solution is that it yields optimal results for the number of administrative keys per network granule and the number of re-key messages. We also present a mechanism for recovery from a node failure or compromise.