A collusion attack detection method for OLSR-based MANETS employing scruple packets

Collusion Attack is an attack against Mobile Ad hoc Networks (MANETs) exploiting vulnerabilities of the Optimised Link State Routing (OLSR) protocol. In this attack, two attacker nodes work together to prevent routes to the targeted node from being established in the network. Consequences of this attack can be severe, as Packet Delivery Ratio (PDR) for the victim node drops to 0% for neighbor nodes at a distance of three-hops or more. In this paper, we propose a detection method called Scruple for this attack. In the proposed method, discovery packets called ScruplePackets are injected to probe the routes from victim node to its three-hop neighbors. Based on the acquired information, a node checks if it is a victim of some Collusion Attack. In this paper, we describe Scruple, its implementation and analysis of effectiveness of this technique through experimental simulations using network simulator ns-3.