SECURE MULTICAST ROUTING IN MANETS BY MITIGATING PACKET DROPPING MISBEHAVIOUR

Abstract

In recent years the widespread availability of wireless communications, mobile computing and handheld devices has led to the growth and significance of wireless mobile ad hoc networks. The ability to establish communication without an infrastructure not with any kind ofcentral authority at very low cost and the capacity to communicate beyond the node's wireless transmission range embarks Mobile Ad hoc Networks (MANET) as the deployment ground for various fields such as wireless sensor networks, ubiquitous networks and peer-to-peer networks. Multicasting is very effective means of transmission in many applications of wireless networks by reducing transmission costs to a big extend. Security issues are paramount in such networks. Nodes in MANETs may launch various attacks or may become selfish to save their resources. These nodes can be termed as malicious. Mitigating the effects of such malicious nodes is critical to success of MANETs. Detecting malicious nodes in an open ad hoc network is more complicated than in traditional wired networks. Also, MANETs have several operational constraints like bandwidth, battery power, CPU, memory, signal strength, etc. Considering all these factors, developing a technique for detection of malicious nodes in MANETs is very challenging. A variety of techniques have been proposed but all of them have their limitations. The security issues in group communication are even more challenging. Here, we present a new dynamic trust mechanism for detection of malicious nodes. This technique detects and subsequently avoid the Black hole and Grey hole attacks. A node is blacklisted if its trust value falls below the threshold. This trust value is updated at regular intervals and hence it is dynamic. The proposed solution is tested by simulating it in QualNet. The results show that the solution works well and is able to find all the malicious nodes which contribute to the packet dropping misbehaviour