Detection and defense mechanisms against wormhole attacks in wireless sensor networks

Wireless ad hoc and sensor networks applications are deployed in hostile environments. This leads to emergence of security as a primary requirement. Here, in this paper, a severe attack, wormhole attack is introduced which is challenging to defend. Attackers even without compromising any node can launch wormhole attacks and this can be done even in networks providing authenticity and confidentiality. An attacker record bits from one network location, tunnels them selectively to a varied location and replays them into the network. The nodes placed closer to the attacker are not provided any alternative routes and all routes are directed to the wormholes. If wormhole is launched in optimized link state routing protocols, wrong link information is spread throughout the network. Thus a proper wormhole detection and defense mechanism is discussed based on location information and time synchronization between nodes in the network. Here we also discuss packet leashes for wormhole attacks detection and defense.