LAUSR

Cognitive radio (CR) is a flexible wireless network that can solve the scarcity and underutilization problem of the spectrum by permitting unlicensed users to access licensed bands. The dynamic nature of CR makes it more vulnerable in terms of security. This paper’s emphasis is on the primary user emulation attack, which poses a severe threat to the spectrum sensing operation of CR. In this attack, a malicious user imitates the signal characteristics of a licensed user (primary user) to disguise its true identity. Although many survey papers enhance our knowledge of cognitive radio security, this paper is an attempt to culminate new findings with the old ones to keep up the pace of the research community. Finally, the paper summarizes with some recommendations and future strategies pertinent to energy-efficient and flexible security methods for next-generation wireless systems.