Pairing based mutual healing in wireless sensor networks

Secure communication for information exchange in WSN requires the nodes to share some secret key within the network. One of the possible approaches used for this purpose is that a central authority broadcasts some keying material containing secret to a group of nodes. However, there is a possibility that a node misses out on one or more broadcast. Self-healing is incorporated to get such missing information wherein, using the recent broadcast keying material, a node extracts the key used in the previous sessions, if that node was an authorized member of the session. Furthermore, if the node misses out the recent broadcast, it seeks help of its neighboring nodes and obtains the missing key through mutual healing. The literature survey shows that a bi-linear pairing based protocol is so far the most secure approach for self-healing and mutual healing. In this paper, we propose a significant performance improvement over the existing self-healing protocol based on bi-linear pairing in terms of reduced storage and computation overhead for resource constrained sensor nodes. We also discuss the improved mutual healing protocol that provides mutual authentication and key confirmation without disclosing the node locations to the adversary. The security analysis with respect to active adversary shows that the performance improvement is achieved along with the existing security features such as forward and backward secrecy, resilience against node collusion, node revocation and resistance to impersonation.