Biblio

Mobile Ad hoc Network has a wide range of applications in military and civilian domains. It is generally assumed that the nodes are trustworthy and cooperative in routing protocols of MANETs viz. AODV, DSR etc. This assumption makes wireless ad hoc network more prone to interception and manipulation which further open possibilities of various types of Denial of Service (DoS) attacks. In order to mitigate the effect of malicious nodes, a reputation based secure routing protocol is proposed in this paper. The basic idea of the proposed scheme is organize the network with 25 nodes which are deployed in a 5×5 grid structure. Each normal node in the network has a specific prime number, which acts as Node identity. A Backbone Network (BBN) is deployed in a 5×5 grid structure. The proposed scheme uses legitimacy value table and reputation level table maintained by backbone network in the network. These tables are used to provide best path selection after avoiding malicious nodes during path discovery. Based on the values collected in their legitimacy table & reputation level table backbone nodes separate and avoid the malicious nodes while making path between source and destination.

Rapid advances in wireless ad hoc networks lead to increase their applications in real life. Since wireless ad hoc networks have no centralized infrastructure and management, they are vulnerable to several security threats. Malicious packet dropping is a serious attack against these networks. In this attack, an adversary node tries to drop all or partial received packets instead of forwarding them to the next hop through the path. A dangerous type of this attack is called black hole. In this attack, after absorbing network traffic by the malicious node, it drops all received packets to form a denial of service (DOS) attack. In this paper, a dynamic trust model to defend network against this attack is proposed. In this approach, a node trusts all immediate neighbors initially. Getting feedback from neighbors' behaviors, a node updates the corresponding trust value. The simulation results by NS-2 show that the attack is detected successfully with low false positive probability.