Volume 7, No. 3, May-June 2016 International Journal of Advanced Research in Computer Science REVIEW ARTICLE Available Online at www.ijarcs.info © 2015-19, IJARCS All Rights Reserved 249 A Review: Analysis of Various Attacks in VANET Shikha Sharma 1 & Er.Shivani Sharma 2 M.TECH Scholar 1 & Assistant Professor 2 Abstract: In Vehicular communication, the security of the system averse to the attacker is very essential part in vehicular technology. There are various types of attacks arises in the network. In this paper we will study about Sybil attack. Sybil attacks have been appraised as a significant security threat to ad-hoc networks. The Sybil attack in computer security is an attack where the original identity of a vehicle is distorted or stealing by an attacker to create multiple dummy identities. Detecting such type of attacker & the authentic vehicle is a provocation task in VANET. This survey paper briefly furnishes the Sybil attack in VANET. Keywords: Vehicular Ad-hoc Network (VANET), security, Sybil attack INTRODUCTION From the last few years, growth of wireless products on motorized vehicles involved remote keyless entrydevices, laptops, and mobile telephones, automotive industries have opened a huge change of prospect for both drivers and their passengers. Vehicular Adhoc Networks (VANETs) have engaged a lot of awareness in research section because of theirvaried value and services, namely vehicle security, automated toll payment, traffic management,improvement in navigation, location-based services for finding the nearest propellant stations, travel cottage or restaurants and simply access to the Internet.[6]Vehicular communication is specified as communication between the vehicles.[1] It is a subscription of MANET. It is an important and prominent area of research in the field of vehicular technology. Vanets are self-configuring systems where nodes are act as vehicles.Vanet is an Intelligent Transportation System in which vehicle act as sender, receiver & router to broadcast the information to the vehicular network. Its aim to provide timely information, security, & management of network. Vanets are dynamic in nature because connection between nodes is impermanent. It is designed for vehicle and vehicle and vehicle to infrastructure communication.[8] Due to accidents and road mortality increasing day by day, people are facing problem & need safety. so security in VANET is very essential, because the message sent by one vehicle might have important outcome such as accident prevention. Its main objective of exploiting vanet is to diminishing the level of accidents and provides safety to the passengers sitting in the vehicles.[8] Fig 1: Hierarchy of Wireless Ad-hoc Network[6] VANET OVERVIEW VANET ARCHITECTURE Vanet design largely composed of vehicles, road side units and infrastructure domain (I), communication is regulated largely by using wireless standards e.g. (IEEE 802.11p) .RSU act like a router and has high horizon than vehicle horizon.RoadSide Units (RSUs) arestands for fixed nodes provided along the path.On Board Unit (OBU)introducing to mobile nodes (i.e. vehicles) provisioned with some sort of radio interface that give the authority for communicating with other nodes in wireless manner.Vehicles are installed with on board unit for transmission. It is also installed with GPS for knowing its exact position as well as for tracking other vehicles. ELP is a electronic license plate is also set in the vehicle for recognition. A certificate authority (CA) service in the design for providing services and applications.[1] Intelligent transportation system It means that the vehicle itself proceed as a sender, receiver and router for distributing/disseminating the data information. It is a technique for transmitting information and provide communication facility to transport infrastructure and vehicles. It is based on IEEE 802.11p standard for (wave) wireless access for vehicular environment. ITS provides two types of communication in vanet. First is V2V mean vehicle to vehicle and second is vehicle to infrastructure (V2I). V2V communication uses multi-hop communication (multicasting/distributing) for communication of data.V2I communication composed of two type of communication. First Naive broadcasting which fabricate warning at systematic intervals and Intelligent broadcasting which generates messages on demand. V2I uses single hop communication.RSU transmit message to the vehicle in domain. It has a high bandwidth connection between the vehicles and the RSU’s.[1]