The Research And Simulation Of Ad Hoc Network Security

Recently, many people use the wireless Ad hoc network because of its convenience and flexibility. The demand for wireless Ad hoc network has been quickly rising in the military and commercial fields. With that, we must assure the service quality. Though the wireless Ad hoc network has been widely used, the security issues have become a tough problem. Therefore, under such a large scale of applications, how to ensure the security of data transmission also becomes the focus of many people. The routing protocol security is more important than other network security. Of course, the evaluation of the performance of the wireless Ad hoc network is also vital. An effective assessment scheme plays a positive role in improving Ad hoc network protocol.This paper focuses on the research of routing security issues with NS2. This paper selects the AODV routing protocol as the research object, aiming at finding some defects which need to be solved. The main work is the simulations of attacks with the AODV routing protocol and then proposing an appropriate defense policy to improve this protocol in wireless Ad hoc network.The means of attack used in this paper are the passive blackhole attack and the active balckhole attack. Then this paper analyzes the result under these two kinds of attack on network. This paper quotes the concept of network entropy so as to evaluate the attack’s level under these two blackhole attacks. This paper completes the above two kinds of blackhole attack, and analyses the network performance according to the calculation of network entropy value. After the analysis being completed, it shows how powerful the two kinds of blackhole attack on attacking the network. When there are several nodes like that in the network, it can even lead to the network crash.For these two kinds of blackhole attack, this paper puts forward a defense method based on the threshold values to prevent the attack from intrusion nodes. If the network finds suspicious nodes, it will shield these nodes and drop any messages from these nodes immediately. After running the improved AODV protocol, this paper also quotes the network entropy to evaluate the effects of the defense method. After using a defense scheme, the status of the network can be saved from almost paralyzed to intermediate or even minor level when it is under the two blackhole attacks. There is little difference between the AODV protocol and the improved AODV protocol. Compared with other methods, this method can protect the network better. The above points prove the validity of the defense scheme.