No abstract

Mobile ad hoc networks (MANET) refers to a network designed for special applications for which it is difficult to use a backbone network. In MANETs, applications are mostly involved with sensitive and secret information. Since MANET assumes a trusted environment for routing, security is a major issue. In this paper we analyze the vulnerabilities of a pro-active routing protocol called optimized link state routing (OLSR) against a specific type of denial-of-service (DOS) attack called node isolation attack. Analyzing the attack, we propose a mechanism called enhanced OLSR (EOLSR) protocol which is a trust based technique to secure the OLSR nodes against the attack. Our technique is capable of finding whether a node is advertising correct topology information or not by verifying its Hello packets, thus detecting node isolation attacks. The experiment results show that our protocol is able to achieve routing security with 45% increase in packet delivery ratio and 44% reduction in packet loss rate when compared to standard OLSR under node isolation attack. Our technique is light weight because it doesn't involve high computational complexity for securing the network.Index Terms: Ad hoc networks, denial-of-service (DOS) attack, node isolation attack, optimized link state routing (OLSR), routing protocols.

No abstract

Black hole attack which is a kind of Denial of Service (DOS) attack is one of the major problems in ad hoc network security. In this paper we propose a solution called Enhanced Dynamic Source Routing (EDSR) Protocol to detect black hole attack. Our technique is an ACKbased detection technique which is capable of finding whether data packets are reaching the destination or not, thus detecting black hole attacks. The experiment results show that our protocol is able to achieve routing security with 16% increase in packet delivery ratio and 31% reduction in packet loss rate when compared to standard DSR under black hole attack. Our technique is light weight because it does not involve high computational complexity and also scalable because it achieves better packet delivery ratio than standard DSR in a network size of 200 nodes.Keywords: black hole attack; DOS attack; DSR routing protocol; wireless ad hoc network.Reference to this paper should be made as follows: Mohanapriya, M. and Krishnamurthi, I. (2012) 'Enhanced dynamic source routing protocol for mitigating black hole attack', Int.

No abstract