Abstract
In the recent years the number of mobile device have significantly increase and the high bandwidth have led to the demand for Mobile Ad hoc Network (MANET). The network offers mobile access to users with minimal configuration to operate. Nonetheless, such salient feature requires flexibility and cooperation between users, which increases the network's vulnerability to the Black hole attack. Therefore, an improved security approach is needed to maintain optimal network performance. The Black hole attack can severely threaten the network by exploiting the vulnerability of Route Request (RREQ) discovery process in the routing protocols such as Ad hoc On Demand Distance Vector (AODV). The intruders are able to utilise the loophole and carry out the malicious behaviours because the RREQ process is an essential mechanism within AODV. As a result, genuine RREQ packets are exploited and erroneously relayed to a false node(s). The on demand routing protocols, which act as the binding element in the networks, are a common target to such security attack. This paper presents a review of the Black hole attack on mobile nodes and subsequently proposes a new mechanism to alleviate the issue. The AODV routing protocol is chosen as the base protocol because it is inherently similar to other types of on demand routing protocol e. g. DSDV, DSR. In fact, any routing protocol which follows the request-reply method may utilise the scheme to mitigate the issue. It includes the proactive routing protocol such as OLSR. In the proposed scheme, each node is capable to detect and isolate the malicious node in their local region with appropriate implementation.