Abstract
Due to the inftastructure-less, dynamic and broadcast nature of radio transmissions, communications in mobile ad hoc networks (MANETs) are susceptible to malicious traffic analysis. After traffic analysis, an attacker determines a target node and conducts an intensive attack against it, called target-oriented attack. The traffic analysis and the target-oriented attacks are known as quite severe problems in MANETs, including position-based routing protocols, with respect to the degradation of both throughput and security of the routing. Also position information of routing nodes is very sensitive data in MANETs where even nodes not knowing either other establish a network temporarily. Therefore we propose a new position-based routing protocol which keeps routing nodes anonymous, thereby preventing possible traffic analysis. To this end, a time variant Temporary Identifier Temp ID is computed from time and position of a node and used for keeping the node anonymous. Only the position of a destination node is required for the route discovery, and Temp ID is used for establishing the route for sending data: a receiver hand shake scheme is designed for determining the next hop on-demand with use of the Temp ID. We evaluate the level of anonymity and performance of our scheme. The analysis shows that the proposed scheme ensures the anonymity of both route and nodes and the robustness against the target-oriented attack and several others. Also our scheme is applicable to networks with any density of nodes.