Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey

TL;DR

This survey reviews physical layer security in multiuser wireless networks, covering foundational theories, transmission strategies, key generation, and interdisciplinary approaches, highlighting recent advances and future research directions.

Contribution

It provides a comprehensive overview of physical layer security techniques and their evolution in multiuser wireless networks, integrating diverse methods and identifying open challenges.

Findings

Overview of information-theoretic security foundations

Discussion of multiuser transmission strategies

Introduction to physical-layer key generation protocols

Abstract

This paper provides a comprehensive review of the domain of physical layer security in multiuser wireless networks. The essential premise of physical-layer security is to enable the exchange of confidential messages over a wireless medium in the presence of unauthorized eavesdroppers without relying on higher-layer encryption. This can be achieved primarily in two ways: without the need for a secret key by intelligently designing transmit coding strategies, or by exploiting the wireless communication medium to develop secret keys over public channels. The survey begins with an overview of the foundations dating back to the pioneering work of Shannon and Wyner on information-theoretic security. We then describe the evolution of secure transmission strategies from point-to-point channels to multiple-antenna systems, followed by generalizations to multiuser broadcast, multiple-access, interference, and relay networks. Secret-key generation and establishment protocols based on physical layer mechanisms are subsequently covered. Approaches for secrecy based on channel coding design are then examined, along with a description of inter-disciplinary approaches based on game theory and stochastic geometry. The associated problem of physical-layer message authentication is also introduced briefly. The survey concludes with observations on potential research directions in this area.