Discovering a Secure Path in MANET by Avoiding Black Hole Attack

In a mobile ad hoc network (MANET), a source node must rely on intermediate nodes to forward its packets along multi-hop routes to the destination node. Due to the lack of infrastructure in such networks, secure and reliable packet delivery is challenging. The performance of a Mobile Ad hoc Network (MANET) is closely related to the capability of the implemented routing protocol to adapt itself to unpredictable changes of topology network and link status. One of this routing protocol is OLSR [1] (Optimized Link State Routing Protocol) which assumes that all nodes are trusted. However, in hostile environnement, the OLSR is known to be vulnerable to various kinds of malicious attacks. This paper proposes a cooperative black hole attack against MANETs exploiting vulnerabilities of OLSR. In this attack, two attacking nodes cooperate in order to disrupt the topology discovery and prevent routes to a target node from being established in the network.