Eliminating Selective Dropping Attack in Mobile Ad Hoc Network

In this paper, we propose a new reputation approach, called I-WG (improved Watchdog). The aims is to eliminate selective dropping attack that occurs when malicious nodes drop packets at low rate to damage the network, while at the same time to avoid to be detected. The proposed approach is structured around four modules. The monitoring module overhears the forwarding activities of neighbors nodes using the promiscuous mode. The reputation module evaluates the nodes reputation values. We have have proposed a new reputation method that enable nodes to evaluate their neighbors in multiple monitoring sessions. Thus, the computed reputation value is used to determine the increment and decrement reputation rate. The exclusion module is responsible for excluding nodes with reputation values below the reputation threshold. The route selection module make restriction about discovered forwarding routes. Only forwarding routes satisfying the route incorporation threshold are accepted. The simulation results demonstrate that I-WG improves the success rate and reduces the number of packets dropped by malicious nodes, while increases the end-to-end delay.