Abstract: A mobile ad hoc network (MANET) is an accumulation of wireless mobile nodes which are having the capability for communicating with one another with having no central base station and network infrastructure. Whenever the source node sends the messages of route request in the network the node which is malicious after getting the request of message creates a route reply to the source. In this novel approach is presented in which black hole attack is prevented by using NTP method. Firstly nodes are deployed in the network and the source node sends route request to the destination node and after those first two replies are selected by source and compares them and if sequence number is very high, the node will be considered as malicious node. In this research work, fact considered is that the black hole never sends the message of route request in the network. The number of request packets that are forwarded will be zero. As source node gets many replies from the nodes and it will compare the time. As the time of black hole is less than all other nodes and number of forwarded request packets is zero also, so that malicious path will not be chosen by source node.

Keywords: MANETs, RREP, RREQ, black hole, AODV, NTP.