Interception of Black- Hole Attacks in Mobile AD-HOC Networks

Mobile Ad-hoc network (MANET), is one of the ideal means for communication using mobile devices, as the devices here can configure themselves without a strict interference by the network administrators. Providing apt security for such networks is a challenging task and this area has proved itself as a vital field for researchers. MANET s are more susceptible to network attacks because of their dynamic network topology, absence of centralized monitoring, unavailability of sufficient resources to support their changing environment and restricted power supply. In this paper, we scrutinize one among the denial of service attacks known as the black hole attack. In this attack, a malicious node broadcasts a false route via itself as the most compact and valid path to the destination [ 1]. Using this fabricated route the malignant node schemes to intercept and consume all data packets intended for the destination node. An approach employing SAODV (secure ad-hoc on demand distance vector) routing algorithm is advocated in this paper to reveal and intercept black hole attacks in mobile networks. Here we use watchdog mechanism as an add-on in SAODV routing algorithm for detection and prevention of the black hole nodes in the MANET. The proposed methodology enhances the packet delivery ratio and performance in the presence of multiple black hole nodes in Mobile ad hoc networks.