Abstract: MANET provides a flexible framework for the wireless communication which does not requires infrastructure or centralized controlling, because of the these abilities the MANET has great applicability in the applications where the other system cannot be deployed such as remote sensing, disaster management and military applications. However such flexibility comes with the cost of a number of limitations which can be exploited to compromise the security of the system. This paper we are presents an adaptive and enhanced trust based mechanism to detect and remove the malicious nodes from the network. In the proposed technique each node observes the packets transmission around it, and analyse it on the bases of trust estimation function which relates the RREQ, RREP and DATA packets. Furthermore these individual trust ratings are shared with other nodes to make it a collaborative system which provides much reliable detection of malicious nodes and minimizes the false detection probabilities. The proposed technique can also be integrated into MANET protocols with minimum efforts and it also have minimal impact of traffic overheads. The experimental result verifies that the proposed technique can successfully counter the black hole attack, selfish attack, collaborative attacks etc.
Keywords: Intrusion detection technique (IDS), Mobile Ad-Hoc Network (MANET).