Robust Range-based Secure Localization in Wireless Sensor Networks

Geotagging of sensor data in a wireless sensor network is important in many applications. It may not always be possible to record locations of the sensor nodes during deployment. Localization techniques provide the node location information, however most of these techniques rely on the neighboring nodes for localization. Thus it is essential that the information from neighbors be trustworthy and/or the localization techniques be robust to some of the nodes turning malicious. In this paper, we address the scenario where the malicious node(s) attempt to disrupt the localization process of a target node in an uncoordinated manner. We propose a secure localization technique, called the weighted least square (WLS) localization, in a network with one or more compromised anchor nodes (nodes with known positions are referred to as anchor nodes). The WLS technique assigns larger weights to the anchor nodes that are closer to the target node and is shown to offer significant advantages over existing techniques. The Cramer-Rao lower bound (CRLB) on the root mean square error (RMSE) of the position estimate for the uncoordinated attack is also derived. The proposed technique is shown to provide better localization accuracy than existing algorithms.