A Novel Solution for Grayhole Attack in AODV Based MANETs

Security plays a vital role to provide protected data transmission in Mobile Ad-hoc Networks (MANETs). Mobile nodes communicate in multi-hop way via routing protocols that work in physically insecure environment. MANETs are susceptible to various Denial-of-Service (DoS) attacks on network layer due to their unique characteristics such as unclear line of defense, limited communication resources, lack of centralized monitoring, wireless radio communication and varying topology. Grayhole attack is a major DoS attack that disrupts data transmission in the network by sending false routing information. To keep the communication route free from such attacks, it is imperative to design a secure and efficient protocol. In this paper, we provide a modification of Ad-hoc On-demand Distance Vector (AODV) protocol to prevent Grayhole attack in which a node sending bogus routing information is detected and recorded by the node receiving it. To avoid the use of extra control packets, default routing packets are given additional responsibility to pass information about malicious nodes. The simulation results in ns-2 show that the solution is reliable against multiple attackers and gives significant improvement in packet delivery ratio with negligible difference in end-to-end delay and routing overhead.