Behavioural Investigation of Blackhole and Sinkhole Attacks using AODV Routing Protocol in VANET

Abstract

A Vehicular Ad-hoc Network (VANET) enables communication between vehicles (V2V) and roadside infrastructure (V2I). This technology aims to enhance road safety, traffic efficiency, and passenger comfort by sharing real-time information, such as hazard warnings, forming the backbone of Intelligent Transportation Systems (ITS) and autonomous driving. Within these environments, the Ad-hoc On-Demand Distance Vector (AODV) routing protocol is frequently employed. AODV discovers paths on-demand using route requests and replies in VANETs, this allows for efficient adaptation to high vehicle mobility by establishing fresh routes only when communication is required. However, the dynamic and open nature of VANETs makes them vulnerable to security threat i.e. malicious actors can deploy Blackhole and Sinkhole attacks to disrupt the network, causing severe performance degradation including packet loss, increased latency, and reduced throughput which can lead to significant traffic risks in modern transportation system. This research aims to simulate Blackhole and Sinkhole attacks using the AODV routing protocol in a VANET. The methodology involves simulating these attacks within a controlled environment using NS-2, SUMO and OpenStreetMap to generate realistic traffic scenarios. The performance of AODV protocol is assessed by analysing key metrics, which is throughput, end-to-end delay (EED), packet delivery ratio (PDR), and routing overhead (RO). Findings indicate that both Blackhole and Sinkhole attacks significantly degrade VANET performance, with sinkhole attacks causing the most severe impact at high node densities. At a density of 100 nodes, a Sinkhole attack reduces throughput by 31% (from 62.21 to 42.99 kbps) and the PDR by 5.4% (from 83.23% to 78.73%) compared to normal traffic conditions. Meanwhile, Blackhole attacks increase routing overhead by 29% (from 7.21 to 9.28) and delay by 23% at moderate densities. Furthermore, variations in packet size amplify these disruptions. These results underscore the urgent need for adaptive, attack-resistant routing protocols to maintain traffic efficiency and reliability.