A certificate-based scheme to defend against worm hole attacks in multicast routing protocols for MANETs

Security issues are paramount in wireless networks even more so than in wired networks. A particularly devastating attack in wireless networks is the wormhole attack, where two or more malicious colluding nodes create a higher level virtual tunnel in the network, which is employed to transport packets between the tunnel end points. These tunnels emulate shorter links in the network in which adversary records transmitted packets at one location in the network, tunnels them to another location, and retransmits them into the network. Our focus in this paper is to analyze the performance of reactive multicast routing protocol Multicast Ad hoc On demand Distance Vector Protocol (MAODV) under the influence of worm hole nodes under different scenarios and design a Worm Hole Secure MAODV (WHS-MAODV) by applying certificate based authentication mechanism in the route discovery process. Our simulations show that the proposed technique can greatly improve the network performance in the presence of malicious nodes. WHS-MAODV is as effective as MAODV in discovering and maintaining routes in addition to providing the required security. The proposed protocol reduces the packet loss due to malicious nodes to a considerable extent thereby enhancing the performance.