Secure Node Localization in Clustered Sensor Networks with Effective Key Revocation

Abstract

Wireless sensor networks are deployed in unattended and hostile environment for many applications such as battlefield surveillance. The WSN applications may require knowing the locations of the node in the network to assist in neighbour discovery, selective information sharing and so on. The trivial approach to node localization is to equip each node with GPS. However, the cost and size of GPS enabled nodes make it impractical for resource-constrained, low cost WSNs. GPS-free node localization has been addressed using two different approaches - Beacon Based (BB) and Without Beacon Based (WBB). In BB approach, few nodes aware of their locations serve as beacons to help other nodes in the network localize themselves. In WBB approach, nodes need to localize themselves with the help of their neighbours only. Although, knowledge of nodes' location within network is desirable, exposure of node location information to adversary may lead to undesirable consequences, such as ease of planning for node capture attack, and hence the need of secure localization. The BB approach has been studied extensively under adversarial model and many algorithms based on BB approach have been proposed in literature in order to localize nodes in a secure manner. In contrast, WBB approach for node localization under adversarial model has not received substantial attention from researchers. In this chapter, we discuss static and dynamic key settings for node localization using WBB for node localization under adversarial model. We consider the Localized Combinatorial Keying (LEAP) and Localized Encryption and Authentication Protocol (LEAP) as the building block and propose a protocol for pair-wise key establishment and key revocation to facilitate secure node localization without using beacon nodes in mobile sensor networks, aiming at providing resilience against node impersonation attack and thus minimizing the impact of node capture threats. We provide a comparison of the improved protocol with other related protocols. We show that the improved protocol provides effective node localization in a secure manner with minimal node capture threats.