A Simulation Model to Secure the Routing Protocol AODV against Black-Hole Attack in MANET

An ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. In mobile ad hoc network, each mobile node acts as a host as well as a router. These nodes communicate to each other by hop-to-hop communication. A number of routing protocols like Ad Hoc On-Demand Distance Vector Routing (AODV), Dynamic Source Routing (DSR), Destination-Sequenced Distance-Vector (DSDV) and Temporally Ordered Routing Algorithm (TORA) have been implemented. AODV is a prominent on-demand reactive routing protocol for mobile ad hoc networks. But in existing AODV, there is no security provision against a well-known "Black Hole" attack. Black hole nodes are those malicious nodes that agree to forward packet to destination but do not forward packet intentionally. These black hole nodes participate in the network actively and degrade the performance of network eventually. This thesis proposes watchdog mechanism to detect the blackhole nodes in a MANET. This method first detects a black hole attack and then gives a new route bypassing this node. In this thesis an attempt has been made to compare the performance of original AODV and modified AODV in the presence of multiple black hole nodes on the basis of throughput and packet delivery ratio. With this new protocol, throughput increases 10-18% in the presence of 10% black hole nodes for different pause times.