A robust key management scheme with strong connectivity for wireless sensor network

In a wireless sensor network (WSN), creating pairwise secure links between resource constrained sensor nodes is a major challenge. In this paper we point out three serious weaknesses, namely, lack of scalability, high memory requirements and vulnerability to node capture attacks in an earlier scheme for designing pair-wise key agreement between any pair of sensor nodes in a WSN proposed by Chien et al. [1]. We develop a new scheme based on Blom´s key agreement protocol [2] which is free from the weaknesses mentioned above. Compared to [1], our scheme not only achieves better resilience against the node capture attack, but also requires less memory and at the same time provides more secure accesses to the network. Furthermore, the computational efficiency of the new scheme is comparable to that of [1].