Smart handling of colluding black hole attacks in MANETs and wireless sensor networks using multipath routing

The open medium, dynamic topology and infrastructureless characteristics of MANETs and Sensor Networks, have found widespread military applications. However, the nature of these networks and the limited processing capabilities of the nodes make them vulnerable to malicious attacks. In this paper we address the problem of colluding and coordinated Black Hole attacks, one of the major security issues in MANET based defense applications. These attacks are caused by malicious nodes that advertise the availability of the shortest route to the intended destination, thereby exploiting the functioning of the AODV protocol and retaining the data packets. This leads to loss of critical and sensitive information being relayed across the network. We propose a technique that overcomes the shortcomings of this protocol, and makes it less vulnerable to such attacks by identifying the malicious nodes and isolating them from the network. We have developed a lightweight acknowledgement scheme with multipath routing for securing the protocol. The proposed technique can be extended to similar routing protocols and scenarios in MANETs.