GNB-AODV: Guard Node Based –AODV to Mitigate Black Hole Attack in MANET

In multi-hop wireless ad hoc network, the packets are transmitted through intermediate nodes to reach the destination. In this topological structure, there is no centralized co-ordinating, monitoring or control point. Due to this type of network environment, an intermediate node can act as either selfish or malicious to drop packets. The primary objective of such an untrustworthy behavior of the node is to preserve its own resource such as energy. In this paper, Guard Node Based Ad hoc On Demand Distance Vector Routing scheme has been proposed to detect and prevent the black hole attack on AODV, in Mobile Ad hoc networks. A black hole attack refers to an attack by a malicious node, which forcibly acquire the route from a source to a destination by the falsification of the sequence number and hop count of the routing message. In the proposed system, fixed guard nodes are deployed in the network environment to mitigate black hole attack. These guard nodes are set in promiscuous mode to listen about the transmission within its transmission range. This also calculates the Trust Value of a node, depending upon the abnormal difference between the routing packets transmitted from the node. If the trust value falls below the specified range, guard node will broadcast an alert message, informing all the nodes in the network to isolate the malicious node. The performance and effectiveness of the proposed system outperform the existing protocol in terms of Packet Delivery Ratio, Throughput and Delay.