TRIUMF: Trust-Based Routing Protocol with controlled degree of Selfishness for Securing MANET against Packet Dropping Attack

In a m obile ad-hoc network, nodes cannot rely on a ny fixed infrastructure for routing purposes. Rather, they have to cooperate to achieve this objective. H owever, performing network functions consumes energy and other resources. Therefore, some network nodes may decide against cooperating with others; selfish nodes. Also security issues are more paramount in such networks even more so than in wired networks. In particular these networks are extremely under threat to insider; malicious nodes; especially through packet dropping attacks. Selfish and malicious nodes are termed as misbehaving nodes. Giving the selfish nodes the incentive to cooperate, while isolating the malicious nodes have been an active research area recently. In this paper, we design a n ovel secure reactive routing protocol for Mobile ad hoc networks (MANETs), called TRIUMF (Trust-Based Routing Protocol with controlled degree of Selfishness for Securing MANET against Packet Dropping Attack). In the proposed protocol trust among nodes is represented by trust value, which consists of cooperation score, direct trust and indirect trust. The proposed trust routing allows controlled degree of selfishness to give an incentive to the selfish nodes to declare its selfishness behavior to its neighbor nodes, which reduce the searching time of misbehaving nodes to search for the malicious nodes only. In the proposed routing protocol two node-disjoint routes between the source and destination nodes are selected based on their path trust values, one marked as primary and the other as secondary. We use both DLL-ACK and endto-end TCP-ACK as monitoring tools to monitor the behavior of routing path nodes: if the data packet successfully transmitted, then the path nodes trust value are updated positively; otherwise, if a malicious behavior is detected then the path searching tool starts to identify the malicious nodes and isolate them from the routing path and the network. Finally our scheme reduces the searching time of malicious nodes, and the routing protocol avoids the isolated misbehaving node from sharing in all future routes, which improves the overall network throughput. Keyword: Ad Hoc Network, Trust-Based routing, Secure Routing Protocol, network security.