SWAT: A Decentralized Self-healing Mechanism for Wormhole Attacks in Wireless Sensor Networks

This paper proposes and evaluates a decentralized self-healing mechanism that detects and recovers from wormhole attacks in wireless multi-hop sensor networks. Upon detecting a wormhole attack, the proposed mechanism, called SWAT, identifies the locations of malicious nodes (or wormhole nodes), isolates them from the network and recovers the routing structure distorted by them. SWAT is the first mechanism that performs both wormhole node isolation and routing structure recovery against wormhole attacks. Unlike many other wormhole detection mechanisms, SWAT does not require any extra networking facilities (e.g., timing analysis and localization facilities) as well as special hardware (e.g., GPS). Instead, it uses network connectivity information only in a decentralized manner. Simulation results show that SWAT yields 100% wormhole attack detection, 0% false detection, 100% wormhole node isolation and 0% false isolation in dense networks. The results also show that SWAT outperforms multi-path routing mechanisms in terms of control overhead and power consumption and outperforms another connectivity-based detection mechanism in terms of false isolation rate and recovery efficiency.