Immuning Routing Protocols from the Wormhole Attack in Wireless Ad Hoc Networks

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 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 propose a scheme for the wormhole attack prevention in ad hoc networks. The scheme relies 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 network from the wormhole attack, the scheme provides a load balance among nodes to avoid exhausting nodes that are always cooperative in routing. In addition, a better network performance has been achieved in terms of traffic.