Abstract: Wireless sensor networks are vulnerable to the node clone, and several distributed protocols have been proposed to detect this attack. However, they require too strong assumptions to be practical for large-scale, randomly deployed sensor networks. In this paper, we propose two novel node clone detection protocols with different tradeoffs on network conditions and performance. The first one is based on a distributed hash table (DHT), by which a fully decentralized, key-based caching and checking system is constructed to catch cloned nodes effectively. The protocol performance on efficient storage consumption and high security level is theoretically deducted through a probability model, and the resulting equations, with necessary adjustments for real application, are supported by the simulations. Although the DHT-based protocol incurs similar communication cost as previous approaches, it may be considered a little high for some scenarios. To address this concern, our second distributed detection protocol, named randomly directed exploration, presents good communication performance for dense sensor networks, by a probabilistic directed forwarding technique along with random initial direction and border determination. The simulation results uphold the protocol design and show its efficiency on communication overhead and satisfactory detection probability.

Keywords: Wireless sensor networks, Distributed hash table, key-based caching, clone detection.