Distributed cooperative algorithm to mitigate hello flood attack in cognitive radio ad hoc networks (CRAHNs)

Abstract

Cognitive radio technology was first introduced by J. Mitola in 1999 to solve the problem of spectrum scarcity for wireless communication. A Cognitive Radio Ad hoc Network (CRAHN) is one of the cognitive radio-based architectures in which wireless unlicensed nodes communicate in infrastructureless environment. Each node in CRAHN has the cognitive capability of sensing the surrounding radio environment for accessing the underutilized licensed spectrum in an opportunistic manner. But those unlicensed users (secondary users) should not make any interference to the communication of licensed users (primary users). In CRAHNs, each node operates as an end system and also as a router to forward packets for multi-hop communication. Due to the dynamic topology, time and space-varying spectrum availability and lack of centralized system, CRAHNs are vulnerable to various security attacks. Hello flood attack is a network layer attack in CRAHNs which can drain off the limited resources of CRAHN nodes by making excessive flooding of hello messages in the network. The proposed distributed cooperative algorithm mitigates the hello flood attack in CRAHNs.