Abstract:
The basic characteristic of MANET's is that nodes depend on their neighbouring nodes for routing and forwarding. Because of this nature and its other characteristic like dynamic topology, no central authority etc., manet is vulnerable to many security attacks. The wormhole attack is one of the most severe security attacks in wireless ad hoc networks, in which two or more colluding attacker's tunnel packets from one place to another. From this tunneling they falsely claim to other nodes that they have shorter routes to intercept packets.
bases
In this thesis, we have proposed 2 methodspn Optimized Linked State Routing Protocol. An
important effect of wormhole attack is packet dropping. To address this problem we propose a method 1 that correlates the packet sent and receive ratio to find the attacker node and to avoid paths through it. But a wormhole attacker can do more than just packet dropping as
described _` • I . in method 2. We detect such node based on analysis that frequency of using wormhole link is very high compared to other routes. For avoiding such attacker nodes we generate a special type of control packet for suspicious links and detect whether there is a wormhole link based on packet sent and acknowledgement receive timings. Once wormhole nodes are detected, the traffic through wormhole nodes is effectively avoided and throughput of network is maintained.
The proposed technique has been simulated on the java based JiST-Swans simulator using various scenarios
