Modified AODV Protocol for Securing Moblie Adhoc Networks

Abstract

A Mobile Ad-hoc Network (MANET) is created by the independent mobile nodes that are able to communicate with each other without static infrastructure. Security is an essential service for mobile communication. Due to its dynamic topology MANETs are vulnerable to various types of security attacks. One of the attacks is the black hole attack in which the attackers can absorb the network traffic, injecting themselves into the path between the source and destination. This malicious node injects fault routing information to the network and leads all the data packets towards themselves, then destroy them all. In this paper, we discuss a solution to avoid the black hole and secure transmission of data packets. We propose a new protocol namely MAODV (Modified AODV), which enhances the security of the Ad-hoc on-demand routing Protocol to encounter the black hole attack. To transmit the data packets securely the ASCII codes of data packets are converted into Extended ASCII codes. This Extended ASCII codes are further encrypted using RSA algorithm. Later the encrypted data are decrypted into original data. Each node performs this encryption and decryption process individually and the malicious node cannot decrypt the original message. This provides the security of data being sent. Hence, the data can be securely transmitted and the malicious node can also be detected. The simulation results using the Network Simulator NS2 show that our protocol provides better security and better performance in terms of the packet delivery ratio than the MAODV routing protocol in the presence of one or multiple black hole Attacks with marginal rise in average end-to-end delay and normalized routing overhead.