Sybil-Free Hybrid Localization Scheme in Wireless Sensor Networks

Abstract

Applications of wireless sensor networks such as target tracking, estimating the location of the fire in forests, tracking the enemy tanks in the battlefield and geographical routing require the location of sensor nodes. There are various existing range-free localization approaches to localize the sensor nodes like APIT, DV-hop, centroid method, etc. But because of the wireless transmission medium of sensor networks, security threats like Sybil attack, wormhole attack, selective forwarding, sinkhole attack, etc., could happen more easily. Sybil attack is the most common and vital security threat in WSN. Sybil attack-affected node can have multiple identities which can affect the localization process and increase localization error. Recently, Sybil-free localization scheme SF-APIT has been proposed to detect Sybil attack but because of the exclusion of suspected nodes in the localization process, the number of blind nodes or unresolved sensor nodes is increased significantly. In this paper, we have proposed a novel lightweight secure hybrid localization scheme against Sybil attack, named Sybil-Free Hybrid Localization Scheme (SFHL), to address Sybil attack more efficiently and to localize blind or ghost nodes using a hybrid approach. Firstly, the Sybil attack is detected while using the APIT localization scheme, and then, Sybil nodes and blind nodes are identified. At last, unresolved nodes are localized using a hybrid localization scheme. Simulation results depict that SFHL performed better than existing localization approaches in the presence of Sybil attack, in terms of minimizing the number of blind nodes and localization error.