The Key Technologies Of Spectrum Sensing Security In Cognitive Radio Networks

Along with the wireless communication technology's development and the widespread application, the limited spectrum and the static spectrum allocation policy which is shown to be inefficient has resulted in the shortage of spectrum resources. Cognitive radio (CR) which is implemented based on the software-defined radio provides mechanisms for intelligent spectrum sensing to detect available spectrum resource. CR can change its transmitter parameters based on interaction with environment in which it operates, and access the spectrum hole without interfering with licensed users. CR provides a new idea to improve the efficiency of spectrum utilization, realize the coexistence of different kinds of standards, and supply general access and self-management of network.The current research work of cognitive radio networks focuses on spectrum sensing, management and access. Because of the open communication characteristics of the radio and dynamic variety of spectrum environment, the secure spectrum sensing and accessing have become an important forward-looking research. In this paper, the basic characters of CR, including sensing ability, adaptive, reasoning, learning and so on, will be discussed. We then analyze the potential security problems from the perspective of attacker. After that, two representative attacks will be researched based on the analysis of inherent reliability about CR networks, including Primary User Emulation Attack (PUEA) and false sensing information attack.Spectrum sensing is an essential mechanism in CR networks. But there is no appropriate scheme to realize secure sensing in untrustworthy environments. PUEA which is a typical attack in the process of spectrum sensing would impact the network performance seriously. In this paper, we propose a mechanism based on Energy Fingerprint (EF) matching to address PUEA. Based on the distribution of positions, the secondary users can create PU's EF which is used as an identification of PU to analyze the spectrum accessing modes of different users. Comparing with the existing mechanism, this program can detect PUEA effectively while keeping the probability of missing the return of the PU low. At the same time, it does not need the PU-related information (such as physical location, signal modulation, etc.)This paper proposes a trust model based cooperative sensing mechanism to suppress the false sensing information attack, and finally realize the security cooperation in the detection process. First of all, analysis models of anomalous behavior are devised to identify the malicious users. Then we employ PID like controller to calculate the credit values of nodes, which is used as the weight of WBD to make spectrum decision. Theoretical analysis and simulation results demonstrate that, comparing with the existing methods, the proposed scheme performs better especially in the case that there exist a large number of malicious nodes. The research can provide an important basis for security and survivability design of cognitive radio networks, and have an important role in the development of CR networks.