Thwarting the Sybil Attack in Wireless Ad Hoc Networks

The present document is essentially a summarized version of the dissertation that will be developed within the scope of an MSc degree in Communication Networks, in the area of security in wireless ad hoc network. Wireless ad hoc networking is a technology that allows fast, easy, and inexpensive network deployment. Unfortunately, these advantages also make the task of an attacker simpler, as it is also easier to deploy a malicious node in the environment. To make the ad hoc network secure, one has often to use Byzantine fault-tolerance techniques, which typically rely on quorum based security protocols. However, quorums may be easily defeated if a single adversary can participate in the network with multiple identities, a behavior known as the Sybil Attack. This work addresses the problem of preventing the Sybil Attack in wireless ad hoc networks. It studies and compares different techniques that have been previously presented in the literature, and proposes a technique applicable to a broader range of networks.