Secure routing in DSR to mitigate black hole attack

Mobile adhoc networks (MANETs) consist of mobile nodes with no fixed infrastructure. Dynamic Source Routing (DSR) which is on-demand routing protocol is a widely accepted mobile adhoc network routing protocol used to provide connectivity to mobile nodes. However, DSR and other on-demand routing protocols are vulnerable to different types of security attacks and black hole attack is one of them. In black hole attack, malicious node sends a fake route reply in response of route request to source node claiming for an optimal route to the destination. Thus, node which starts route discovery process establishes a path through malicious node and starts sending data packet on this route. Malicious node drops the data packet which reduces packet delivery ratio. To secure DSR, we propose a scheme which confirms the authenticity of route with the help of verification packet. This packet is generated by first intermediate hop in the route of route reply. Simulation results show improvement in packet delivery ratio and throughput.