In wireless sensor networks (WSNs), localization is one of the most important topics because the location information is typically useful for many applications like target tracking, military applications and environmental monitoring. Anchor nodes are the nodes that know their current location. Neighboring nodes or non-anchor nodes calculate their location (or location reference) with the help of anchor nodes. The location information of anchor nodes may contain outliers that deviate from their true values. The existence of the outliers might make the estimated positions not accurate. Thus, it is important to detect and handle outliers in order to achieve high localization accuracy. Nowadays, it's a challenging task to identify the cheating anchor node or cheating node in a network. Even after finding out the location of the cheating anchor node, there is no assurance, that the identified node is legitimate or not. The aim of this research is to propose an algorithm to detect malicious beacon nodes based on trilateration algorithm to provide secure localization in wireless senor networks. We were able to attain a considerable reduction in the error achieved during localization. Extended simulation experiments indicate that the localization algorithm has relatively high precision and the location verification algorithm has relatively high accuracy. The communication overhead of these algorithms is relative low, and the whole set of reliable localization methods is practical as well as comprehensive.
Keywords: Localization, Security, Trilateration, Anchor nodes, Wireless Sensor Networks.