Association between nodes to combat blackhole attack in DSR based MANET

Mobile adhoc network (MANET) has become an exciting and important technology in recent years because of the rapid proliferation of wireless devices. MANET´s are highly vulnerable to attacks due to the open medium, dynamically changing network topology, cooperative algorithms, lack of centralized monitoring and management point, and lack of clear line defense. In this work we analyze the blackhole attack which is one of the possible and commonest attacks in adhoc networks. In this attack the malicious nodes advertise itself having the shortest path to the destination. In our approach we classify nodes in to 3 categories based on their behaviour. The extents of association between the nodes are used for the route selection. We have conducted extensive experiments using the network simulator-2 to validate our research.