Physical Layer Authentication for 5G Communications: Opportunities and Road Ahead

Resorting to the exploitation of physical attributes, physical-layer authentication (PLA) is a promising technology to supplement and enhance current cryptography-based security mechanisms in wireless communications. in the fifth-generation (5G) communications, many disruptive technologies spring up, such as millimeter-wave communication (mmWave), massive multiple-input and multiple-output (MiMO) and non-orthogonal- multiple-access (NOMA). PLA schemes in 5G networks are facing challenges while exposed to opportunities at the same time. This article seeks to identify the critical technology gaps as well as the feasible enablers in terms of the unique characteristics of 5G networks. The investigation consists of four hierarchical parts. in the first section, existing PLA schemes are reviewed, and the corresponding challenges are discussed in the next section. in the third section, we investigate potential enablers based on the unique characteristics of 5G networks and provide three corresponding PLA case studies. Open problems and research directions on PLA for 5G and beyond are discussed in the last section, including waveform design, feature learning, mobile users, and terahertz communications.

Introduction

Recent years have witnessed a spurt of progress in the fifth-generation (5G) communications. With the adoption of emerging 5G wireless communication technologies, such as millimeter wave (mmWave) communication, massive multiple-input and multiple-output (MIMO) and non-orthogonal access (NOMA), 5G networks are expected to provide reliable wireless communication with ultra-low delay and extremely high throughput. Meanwhile, the capability to ensure security, trust, identity, and privacy is of the utmost importance for 5G communications. In this regard, as a supplement and enhancement strategy, physical-layer authentication (PLA) is emerging as an effective approach to provide a high-security and low-complexity security solution utilizing the unique properties at the physical-layer in 5G networks [1], [2].