Circumventing Sinkholes and Wormholes in Wireless Sensor Networks

Sensor networks are formed with the help of a large number of wireless nodes, generally with limited energy, computation and transmission powers. Each node helps every other node in the network by forwarding their packets. All is well if such an altruistic attitude is upheld by all participating nodes. However, as these nodes often operate in a physically insecure environment, they are vulnerable to capture and compromise. In addition, the communication medium being wireless, restricts enforcement of rigourous node memberships and so a number of malicious nodes also participate in the network. These nodes, in order to snoop or sabotage, can carry out a variety of attacks against the network including sinkhole and wormhole attacks. In this paper, we present a novel trust-based scheme for identifying and isolating malicious nodes, which launch these two types of attacks in a sensor network.