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Unformatted text preview: FEEPVR: First End-to-End protocol to Secure Ad hoc Networks with variable ranges against Wormhole Attacks Sandhya Khurana Department of Computer Science, University of Delhi [email protected] Neelima Gupta Department of Computer Science, University of Delhi [email protected] Abstract In this paper, we present a very simple and efficient end- to-end algorithm to handle wormhole attacks on ad hoc net- works with variable ranges of communication. Most of the existing approaches focus on the prevention of wormholes between neighbors that trust each other. The known end-to- end mechanisms assume that all the nodes of the network have same communication range. To the best of our knowl- edge this is the first attempt to handle variable ranges of the nodes in an ad hoc network where only the source and the destination are assumed to trust each other. We pro- vide a lower bound on the minimum number of hops on a good route. Any path showing lesser hop-counts is shown to be under attack. Our algorithm requires every node to know its location. With very accurate GPS available, this assumption is not unreasonable. Since our protocol does not require speed or time, we do not need clock synchro- nization. In the absence of any error in the location, there are no false alarms i.e. no good paths are discarded. We have shown that the effect of error in the location informa- tion is negligible and can be ignored most of the times. The storage and computation overhead is low. For a path of length l , it takes only O ( l ) space and time. 1 Introduction Ad-hoc networks have been proposed to support scenar- ios where no wired infrastructure exists. Several types of attacks on ad hoc networks have been discussed in literature. Some of these (blackhole or grey holes attack, rushing attack, wormhole attacks) cripple the network by disrupting the route of the legitimate packets while others (flooding attack) inject too many extra pack- ets in the system thereby consuming system resources like bandwidth, memory/computational power of nodes. In this paper, we address the problem of detecting worm- hole attacks in ad hoc networks. Since the mobile devices use a wireless medium to transmit information, the mali- cious nodes can eavesdrop the packets, tunnel them to an- other location in the network and retransmit them at the other end. Attackers may use out of band channel, high power transmission, packet relay or encapsulation tech- nique to tunnel packets to colluding nodes. The tunnel so created forms a wormhole. The tunneling procedure gener- ates an illusion that the two nodes more than one hop away are in the neighborhood of each other. We call the two nodes as the victim nodes. Since most of the routing protocols maintain a neighborhood set at each node, false information about a node’s neighbor can severely affect the discovered route. If the routing protocol uses the number of hop-counts to compute the shortest path, it prevents the routes longer than three hops to be discovered between the victim nodes.than three hops to be discovered between the victim nodes....
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- Spring '12
- Computer Science