Preventing wormhole attack in wireless ad hoc networks using cost-based schemes

Ad hoc networks can be rapidly deployed and reconfigured. Hence, they are very appealing as they can be tailored to lots of applications. Due to their features, they are vulnerable to many attacks. A particularly severe security attack, called the wormhole attack, has been introduced in the context of ad-hoc networks. During the attack a malicious node captures packets from one location in the network, and tunnels them to another malicious node at a distant point, which replays them locally. In this paper we explain the wormhole attack modes and propose two schemes for the wormhole attack prevention in ad hoc networks. The schemes rely on the idea that usually the wormhole nodes participate in the routing in a repeated way as they attract most of the traffic. Therefore, each node will be assigned a cost depending in its participation in routing. The cost function is chosen to be exponential in powers of two such that to rapidly increase the cost of already used nodes. Besides preventing the wormhole attack, these schemes provide a load balance among nodes to avoid exhausting a node that is always cooperative in routing.