Removal of Flooding Attacks in Ad Hoc Wireless Networks to Provide Security against Availability Security Service

Ad hoc wireless networks are infrastructure less networks and formed by mobile nodes. These networks are gaining popularity because of low cost mobiles devices and its ability to provide instant wireless networking capabilities. The communication in ad hoc wireless networks functions properly only if the participating nodes cooperate in routing without any malicious intention. But the ad hoc wireless networks are vulnerable to various attacks because of its features like continuous changing topology, resource constraints and unavailability of any centralized infrastructure. Many denial of service type of attacks are possible in ad hoc wireless networks and one of these types of attack is Flooding attack in which malicious node sends the useless packets to consume the valuable network resources. Flooding attack is possible in all almost all on demand routing protocols. Due to this flooding attack the interruption of the network is caused and hence availability of the network service is reduced. The current solutions for these types of attacks are mainly cryptographic, which suffer from heavy computational complexity. In this paper RREQ Flooding attack is detected based on Signal strength and time threshold is used to prevent the flooding attack. The performance of the proposed technique is tested in an On-Demand routing protocol(AODV).The results shows that the proposed techniques reduces the effect of the attack by increasing the packet deli vary ratio.