Securing Mobile Ad Hoc Networks Against Packet Dropping Attack

Need of infrastructure less, self operating, self configuring, communication networks have resulted in the formation of mobile ad hoc networks (MANET). MANET has proved very useful over traditional networks in disastrous conditions. In MANET all mobile devices work cooperatively for route discovery and data transmission. Due to its broadcast nature of transmission, and cooperative model of working, routing the traffic is a tedious task in MANET. Routing protocols are constantly targeted by attackers to cause damage to network. Routing protocols in MANET needs to be robust against various security threats. Ad hoc on-demand distance vector routing (AODV) protocol is widely used and studied in the area of mobile ad hoc networks. In this work, we present a secure AODV protocol to mitigate Black Hole Attack. In black hole attack a node maliciously diverts the data to route through it, and then drops the data packets, which results in lower packet delivery ratio. For this we have introduced a decision module in routing algorithm, which scans the RREP messages coming from a node before forwarding them towards the sender. Decision module has been build to exploit the black hole attack model. We check for the freshness and the path length mentioned in the reply message. Depending upon these values we decide whether to forward this reply or not. Thus eliminating the false replies. We simulated this proposed scheme to measure its effectiveness using NS-3. The results shows that our proposed algorithm shows better performance in terms of higher packet delivery ratio