A Novel Defense Scheme against Flooding Attack in Mobile Adhoc Networks

Background: Mobile Adhoc NETwork (MANET) is a self-configurable network consisting of mobile nodes connected by wireless links according to recent patents. The inherent features of MANETs like- dynamic topology, limited resources and lack of centralized trusted authority make it more vulnerable to attacks than wired networks. Reactive protocols that involve broadcasting of route request (RREQ) messages to their one hop neighbors are prone to RREQ flooding attack. We have revised the patents relating to flooding attack in MANET. Objective: An attempt is made to propose a secure route from source to destination in presence of RREQ flooding attack and effectiveness of proposed scheme is validated using NS-2. Methods: We proposed an efficient and lightweight detection algorithm, which is capable of not only mitigating useless RREQs packets caused by malicious nodes but also detecting and isolating them. The cache of a node purges after a fixed interval of time to account for better memory utilization of mobile nodes. Results: Simulation results show significant improvement in packet delivery fraction in the presence of RREQ Flooding nodes with marginal rise in average end to end delay and routing load thus indicating the closeness to the Adhoc On-Demand Distance-Vector (AODV) routing protocol. Conclusion: Our proposed algorithm detects and isolates multiple RREQ Flooding nodes without sending any additional control packets. Benign nodes in the network work in cooperation for detecting and penalizing attacker nodes by blocking routing and data packets originated from it.