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Node revocation and key update protocol in wireless sensor networks

Wireless Sensor Network (WSN) consisting of a large number of tiny sensor nodes deployed in unattended hostile environment is vulnerable to various attacks including node capture. An attacker may physically capture, reprogram and redeploy a node in the network. A node, that is victim of capture attack, must be revoked from the network to avoid further insider attacks. In this paper, we present a node revocation and key update protocol in a clustered network setup. The proposed protocol considers that the communication in a clustered network is secured using a common group secret which is distributed by the respective cluster head only to the authorized nodes in the cluster. The protocol uses Chinese remainder theorem based group key broadcast to revoke the victim node and update the group key for remaining valid nodes. The proposed protocol provides secure node revocation, along with forward and backward secrecy, resistance to node collusion, impersonation and replay attacks, in an efficient manner with significantly less communication, computation and storage overhead as compared to the existing node revocation and key update protocols.