ON DISRUPTION OF EXISTING ROUTING PROTOCOLS BY SYBIL ATTACK ON VEHICLE TO VEHICLE COMMUNICATION IN VEHICULAR AD HOC NETWORKS

Moving vehicles mounted with On Board Unit (OBU) when come in each other's radio transmission range form a Vehicular Ad hoc Network (VANET). The two modes of communication in VANET are Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I). Being a unique category of ad hoc networks, there always persist few inbuilt challenges, consequently making VANETs open to various types of attacks. Among these attacks, VANETs, like other types of ad hoc networks, also seem to be prone to Sybil attack. In this attack, a malicious vehicle enters the network illicitly, fabricates virtual vehicle(s) either one after another in some intervals of time or all vehicles simultaneously, and thus initiating disruption or malfunction of the network services. This may destroy the sole rationale behind VANETs, ultimately making such networks unsuitable for deployment. Sybil attack is sustainable only in V2V communication where vehicles communicate among themselves in a peer to peer manner, with no centralized authority in place. Whereas, in V2I communication, the deployment of infrastructure with the Road Side Units (RSUs), Sybil attack may not be able to sustain itself and is likely to be detected and made ineffective sooner than later. In V2V communication, there exists a plethora of routing protocols to be used selectively under different scenarios for efficient outcomes. The authors thought it to be interesting to explore the vulnerability of these set of protocols to the Sybil attack as there existed a strong possibility of Sybil vehicle(s) compromising the working of these routing protocols and disrupting the normal functioning of the VANET. In such a scenario with applications having time constraints, delays in communication can lead to the failure of the network. Thus, in this paper, we have explored the vulnerability to Sybil attack of all the five identified categories and their subcategories of routing protocols designed for VANET: Ad hoc/ Topology Based, Position Based, Geocast Based, Cluster Based, Broadcast Based protocols. This work has been elucidated with significant illustrations in each category showing how every single routing protocol in each specific category is liable to be affected by the Sybil attack. This paper is an attempt, first of its kind that has shown disruption by the Sybil attack on all categories of routing protocols in VANET.