Security threats, detection, and countermeasures for physical layer in cognitive radio networks: A survey

Cyber-security threats and issues have been exponentially increasing over the last two decades, including in cognitive radio networks. These attacks and vulnerabilities negatively impact the normal functioning of these networks. Investigating these vulnerabilities and their countermeasures is a necessary step toward securing the cognitive radio based networks. Although there have numerous survey papers on cognitive radio security, a few papers related to the security issues over the physical layer which has a primordial role in establishing radio communications. Thus, an up to date overview of the ongoing research about the threats, detection, and countermeasures techniques over the physical layer is necessary. In this paper, different attacks targeting the physical layer are described and analyzed. Detection methods and countermeasures corresponding to each attack are also discussed and compared. Challenges and future directions are presented as well. (C) 2020 Elsevier B.V. All rights reserved.