TAGER: Trust-Aware Georouting Protocol for Wireless Sensor Networks

Security in Wireless Sensor Networks (WSNs) is a major requirement especially when these networks are used in hostile environments. In this paper, we present an efficient Trust-Aware GEographical Routing (TAGER) protocol which expands the simple and scalable position-based routing protocol and utilizes a trust strategy to safeguard routing behaviors and reduce the possibility of selecting the misbehaving nodes as forwarding nodes in WSNs. The algorithm is based on Greedy and Face routing strategies which are restricted in the trusted subminimal ellipses fixed by three points. Herein trust is characterized by the neighbors´ feedback suggestions which can be perceived and obtained from reactive acknowledgement. In proposed TAGER protocol scheme, the recommendations are parameterized as trust values, which are changed and updated repeatedly. If the node data forwarding is successful, its trust value would be improved; else its trust level would be decreased because misbehaving nodes have been used as forwarding nodes or forwarding is abnormal. Our simulation results show how our TAGER protocol alleviates the effect of malicious nodes, and improves the packets delivery rate in WSNs.