Exclusion of Denial of Service Attack using Graph Theory in MANETS

1PG Student, Department of CSE, PDA College of Engineering, Kalaburagi, Karnataka, India. [email protected] 2Assistant Professor, Department of CSE, PDA College of Engineering, Kalaburagi, Karnataka, India. ---------------------------------------------------------------------***--------------------------------------------------------------------Abstract -Mobile ad hoc networks (MANET) are wireless, multi-hop, infrastructure less collection of self organizing mobile devices that form a temporary cooperative network without any base station. Sending packets from one device to another is done via chain of intermediate nodes. Because of dynamic topology node can enter or leave network at any time, during this, malicious node can enter and harm the network. The main focus of research in routing protocols for Mobile Ad-Hoc Networks (MANET) geared towards routing efficiency, the resulting protocols tend to be insecure to various attacks such as Denial of service (DoS )attack .One of the major DoS attack against the Optimized Link State Routing protocol (OLSR) known as the node isolation attack occurs when topological knowledge of the network is exploited by an attacker who is able to isolate the victim from the rest of the network and subsequently deny communication services to the victim. Different solutions have been proposed to eliminate the dos attack, however, these solutions often compromise routing efficiency or network overhead. Here a novel method has been focused on detection and prevention of DoS attack using trust based mechanism which is based on the graph theory, where the trust value is obtained based on the behaviors and activity information of each node to secure the routing protocol because it has a better performance rather than cryptography method. Results show that secured transmission is done in the nodes by overcoming the DoS attack, where the data travels in the honest route by mitigating the DoS attack.