Research On Network Security In Cognitive Radio

With the rapid development of wireless communication currently, the problem of shortage of wireless spectrum is increasingly serious. As a matter of fact, too much load is depending on some of frequency bands in the current network, but still so many spectrums have fewer efficiency of utility. In the light of this situation, people considered and proposed the concept of Cognitive Radio (CR). The appearance of this technology could solve the shortage of wireless spectrum resources. Through allowing' secondary users to access to the free spectrum resources which are allocated for the primary user, the utilization rate of the wireless spectrum can be improved.Spectrum sensing is the key technology of Cognitive Radio Network. It perceives the wireless environment and detects spectrum holes whenever necessary. IEEE 802.22 proposed in 2004 is the world's first Cognitive Radio air-interface Standard, which is also significant for the coexistence and collaboration between CR network and other communication network. The key of the Cognitive Radio is to let secondary users utilize the free spectrum without impacting on the primary users. So under this kind of policy of priority difference, as well as the technology characteristic of the spectrum sensing, there are not only traditional network security problems in Cognitive Radio Network, but CR brings some new network danger. Attackers can compete for the network spectrum viciously; occupy amount of network resources which will interfere with the spectrum management environment. As one of the wireless communication technology, with the increasing of information value, especially some confidential information in the special industries, the research for the Cognitive Radio Network security will be more and more popular and emphasized.Based on the analysis of Cognitive Radio Network and the PUEA in this paper, we proposed an improved encryption and displacement based scheme by utilizing ID bonding, encryption matching and information displacement to authenticate the security of the network users, which solves the problem of air interception that traditional method cannot settled. According to the secondary BS network, some malicious users employ massive volumes of useless or unsafe traffic to occupy all the spectrum resources that should have served legitimate users. This paper proposed a new scheme of setting up dedicated node and detecting signal characteristic in the dedicated channel for overcoming malicious users, which can protect the network resources for legitimate users effectively. The simulation result by NS2 indicates the feasibility and validity of these two schemes.