Trust-Based Routing for Mitigating Grayhole Attack in MANET

Abstract

MANET is a temporary network without having any pre-existing network setup. In this network, each node participating in the network act both as host and router. Due to the dynamicity and mobility of the network, connections in the network change frequently. Since each participating node in the MANETs is mobile and distributive and also the nodes are resource restricted, traditional networks security systems cannot be applied directly. Also, due to MANET various features like mobility, dynamicity, distributive, cooperative nature, MANETs are vulnerable to various attacks like blackhole, wormhole, grayhole, flooding. This paper explores trust and security challenges to improve security level for MANET. In this study, a new dynamic source routing protocol for MANET based on trust model is developed to mitigate grayhole attack. Trust is calculated based on trust function. Nodes are selected based on the values of trust function and threshold value. The modified DSR protocol can effectively detect the grayhole nodes and isolates them from taking part on routing.