Impact of Node Misbehavior in Ad Hoc Networks, and Trust Based Routing

The dependability of the routing system in ad hoc networks inherently relies on node misbehavior. In order to support details the modeling process of various classes of misbehavior, most ad hoc routing algorithms assume well behaving nodes. However, in reality there may exist constrained, selfish or malicious nodes. In this paper we compare the DSR (Dynamic Source Routing) protocol in the presence of well behaved node, selfish or malicious node under security attack. We use a watchdog that identifies a misbehaving nodes and a pathrater that helps routing protocols avoids these misbehaving nodes. Another way is to build the trust relationship between the mobile nodes in the MANET and select routes based on the formed trust values. CONFIDANT is a dynamic feedback mechanism in which mobile nodes monitor the behavior of their neighbors and exchange first hand information about other nodes in the MANET and thus identify the misbehaved nodes. When these two techniques are used, the throughput increases by 17% in the presence of 40% misbehaving nodes, while the routing overhead increases to 17%. During extreme mobility, the network throughput increases. This thesis investigates solutions for selfish or malicious misbehavior in MANET, implements watchdog and pathrater and CONFIDANT protocol using ns2 as simulation environment, and evaluates the performance of throughput and CONFIDANT fortified DSR in the MANET where misbehaved nodes present.