Mitigating route request flooding attack in MANET using node reputation

An ad hoc network is an infrastructure-less, decentralized network, consisting of a group of mobile wireless nodes, moving around freely and cooperating with each other in routing and forwarding of packets. Due to the lack of any clear line of defense, MANET is accessible to both legitimate users and malicious attackers. Among various types of attacks, it is particularly vulnerable to various denial of service (DoS) attacks. Route request flooding attack is one such distributed DoS attack, launched by compromised nodes or intruders. This triggers an acute need of flooding attack prevention mechanisms for this highly vulnerable type of network. In this paper, a reputation based scheme is proposed to resist the impact of flooding attack in MANET. This scheme observes the behavior of a node in the network periodically and limits its route request sending rate accordingly.