Smart primary user emulation in cognitive radio networks: Defence strategies against radio-aware attacks and robust spectrum sensing

Cognitive radio (CR), which provides dynamic spectrum access to combat spectrum scarcity, imposes some emerging threats to the network. One of the common threats in CR is primary user emulation (PUE) attack, in which some malicious users try to mimic primary signal and deceive CR users to prevent them from accessing the vacant frequency bands. In this paper, we propose a smart radio-aware PUE attacker that is equipped with spectrum sensing and consumes malicious resources in a way that causes more destruction on CR performance than always present PUE attackers. We first analyse and formulate the destructive effect such an attacker imposes to the CR network, and then, we derive robust cooperative spectrum sensing rules for energy detection spectrum sensing under PUE attacks. Moreover, using a weighting vector at fusion centre of the CRs, we propose a scheme to combat fake signals by maximising the average cognitive signal to interference plus noise ratio. We combine proposed method with two widely used energy detection scheme, Neyman-Pearson and minimum probability of error criterion. Numerical results show the superiority and robustness of our proposed method in the presence of smart attackers compared with conventional methods. In this paper, we analyze and formulate the destructive effect primary user emulation (PUE) attacker imposes to the CR network, and then, we derive robust cooperative spectrum sensing rules for energy detection spectrum sensing under PUE attacks. We propose a scheme to combat fake signals by maximizing the average cognitive signal to interference plus noise ratio. Numerical results show the superiority and robustness of our proposed method in the presence of smart attackers compared with conventional methods.