STUDY OF BLACKHOLE ATTACK AND WORMHOLE ATTACK IN VANET ENVIRONMENT AND THEIR COUNTERMEASURE

Vehicular Ad-hoc Networks (VANETs) are being designed with the goal of avoiding vehicular crashes. VANETs, however, offer a challenging environment for efficient and reliable message transmission due to its high dynamic mobility of vehicles (nodes) leading to frequent disconnections, which makes topology-based routing protocol not suitable for this type of application. Position-based routing protocols, on the other hand are more suitable for this type of environment. Firstly, we focus on the performance evaluation of the network layer by implementing the cross-layer, weighted, position-based routing (CLWPR) protocol and evaluating its performance in real-world scenarios. We compare the performance of CLWPR to another position-based routing protocol, the Greedy Perimeter Stateless Routing (GPSR) to demonstrate its superiority. We also evaluate the effect of radio channel modeling on the network performance. Since VANET carries various safety and non-safety information, data security is one of the most delicate issues in VANET. There are several types of attacks carried out by the attackers to compromise safety critical information. In this work, we implemented the blackhole attack and the wormhole attack in a VANET environment to check the performance of the routing protocol in this critical environment. In blackhole attack, the malicious node drops the packet before sending it to the destination. This attack is extremely dangerous because the data packets containing safety information is lost permanently in the attack during its transmission to the destination. In wormhole attack, the attacker reroutes the data packets to the destination through a malicious intermediate node. The malicious node may modify or falsify the content of data packet. This is also extremely dangerous as it can affect the safety of the vehicle. Thus, it is extremely important to study the effect of these attacks in VANET environment. The implementation of blackhole attack and wormhole attack is done using position-based routing protocols such as GPSR and CLWPR. Additionally, we checked the performance of the protocol using performance evaluation parameters such as packet delivery ratio, average time delay, and throughput before and after the attack. After analyzing both the attacks, we formulated and proposed a solution for the detection and prevention of each attack. The simulation results demonstrated that our proposed solution techniques are able to restore the normal performance of the routing protocols after the attack is detected and controlled