A modified algorithm to improve security and performance of AODV protocol against black hole attack

Ad Hoc network is a temporal network which is managed by autonomous nodes which have the ability to communicate with each other without having fixed network infrastructure or any central base station. Due to some reasons such as dynamic changes of the network topology, trusting the nodes to each other, lack of fixed substructure for the analysis of nodes’ behaviours and loss of specific offensive lines, this type of networks is not supportive against malicious nodes’ attacks. One of these attacks is black hole attack. In this attack, the malicious nodes absorb data packets and destroy them. Thus, it is essential to present an algorithm against the black hole attacks. This article suggests a new algorithm which enhances the security of AODV routing protocol to encounter the black hole attacks. This algorithm tries to identify malicious nodes according to nodes’ behaviours in an Ad Hoc network and delete them from routing. The suggested algorithm is simulated by NS2. The simulation results show some improvements in end-to-end delay and packet delivery rate in the suggested algorithm.