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

TLDR

Physical layer security enables confidential wireless communication without higher‑layer encryption, achieved either by designing transmit coding strategies without secret keys or by generating secret keys over public channels, and also addresses message authentication. This paper reviews the field of physical layer security in multiuser wireless networks. The survey traces the evolution from Shannon–Wyner foundations to secure transmission strategies in point‑to‑point, multi‑antenna, broadcast, multiple‑access, interference, and relay networks, and discusses secret‑key generation, channel‑coding designs, and interdisciplinary game‑theoretic and stochastic‑geometry approaches. The authors highlight promising research directions for future work in physical layer security.

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 briefly introduced. The survey concludes with observations on potential research directions in this area.