Wireless physical layer security [Guest Editorial]

The ongoing paradigm shift from classical centralized wireless technologies toward distributed large-scale networks such as the Internet of Things has introduced new security challenges that cannot be fully handled via traditional cryptographic means. In emerging wireless environments, devices have limited capabilities and are not controlled by a central control center; thus, the implementation of computationally expensive cryptographic techniques can be challenging. Motivated by this paradigm shift, substantial recent research has been investigating the use of the physical layer as a means to develop low-complexity and effective wireless security mechanisms. Such techniques are grouped under the umbrella of physical layer security. These techniques range from information-theoretic security, which exploits channel advantages to thwart eavesdropping, to physical layer fi ngerprinting techniques that exploit physical layer features for device identifi cation. In this context, providing state-of-the-art tutorials on the various approaches to physical layer security is of considerable interest. This Feature Topic gathers together tutorial-style and survey articles that provide an in-depth overview of the broad spectrum of security opportunities brought forward by physical layer security.