A Mobile Ad hoc Network (MANET) is a self governing network of mobile nodes connected through wireless links. Mobile ad hoc networks (MANET) are infrastructure less networks, dynamically formed by an autonomous system of mobile nodes that are connected via wireless links. Each node in MANET operates not only as a host but also as a router that has the task to forward data. Mobile nodes only can communicate directly via wireless link if they are within each other’s radio range otherwise, they depends on intermediate nodes to forward packets. The success of communication highly depends upon the cooperation of other nodes.
In MANET, data delivery is a major challenge. Due to unpredicted movement of mobile nodes topology of the network changes frequently. The primary goal of any routing protocol is establishing an optimal and efficient route between the communicating nodes. the past few years, much research efforts have been focused on this area and many different kinds of routing protocols have been put forward in the literature, such as Wireless Routing Protocol (WRP), Dynamic Source Routing protocol (DSR), Ad hoc On Demand Distance Vector protocol (AODV) and Location Aided Routing. However, from the beginning of its design, almost none of the routing protocols specify security measures.
To implement Security in MANETs is a complex issue. Nodes in the network are much more vulnerable to attacks compare to wired (traditional) networks due to the open medium, dynamically changing network topology, lack of centralized monitoring and management point, and lack of a clear line of defense. These factors have changed the battle field situations for the ad hoc wireless networks against the security threats. The ad hoc wireless networks the nodes communicate with each other on the basis of mutual trust without any a centralized administration. These characteristic makes ad hoc wireless networks more vulnerable to be exploited by an attacker inside the network. Wireless links also makes the ad hoc wireless networks more susceptible to attacks, which make it easier for the attacker to go inside the network and get access to the ongoing communication.