Defending Against Sybil Attacks in Sensor Networks using Pre-Distributed key

A wireless sensor network is a collaborative network in which nodes perform their sensing task in one hand, and function as relay for transferring the data of other nodes on the other hand if necessary. It consists of many inexpensive wireless nodes, each having sensing capability with some computational and communication power. As sensor networks are coming to be of wide-spread deployment, security issues become a central concern. A particularly harmful attack against sensor networks is Sybil attack, where a node illegitimately claims multiple identities. The Sybil attack can be exceedingly detrimental to many important functions of the sensor networks such as routing, resource allocation, misbehavior detection, etc. In this paper, we propose a novel protocol to defend against Sybil attack using pre-distributed keys. Our protocol uses symmetric keys (pre-distributed in sensor nodes) and nodes id to authenticate each other and protect a node to take on multiple identities.