Wormhole and Sybil attack in WSN: A review

With the increasing popularity of mobile devices, recent developments in wireless communication and the deployment of wireless sensor networks in the hostile environment makes it the popular field of interest from research perspective. Sensor networks consist of `smart nodes' communicating wirelessly which are resources constrained in terms of memory, energy, computation power. The design of these networks must encounter all factors including fault tolerance capability, scalability, costs of production, operating environment, hardware constraints etc. However, due to wireless nature of these networks and no tamper-resistant hardware these are vulnerable to various types of attacks. In this paper, various types of attacks have been studied and defensive techniques of one of the severe attacks i.e. wormhole and Sybil are surveyed in major detail with the comparison of merits and demerits of several techniques.