Integrating Communication, Sensing, and Security: Progress and Prospects of PLS in ISAC Systems

TL;DR

The paper addresses the challenge of securing integrated sensing and communication (ISAC) systems in 6G by framing physical-layer security (PLS) across three pillars: confidentiality, covertness, and authentication. It provides a foundational mathematical backdrop for ISAC and PLS, then delivers a system-oriented survey of state-of-the-art PLS techniques across MISO/MIMO, NOMA, RIS, and non-terrestrial networks, with emphasis on secrecy-rate optimization, robust beamforming, and RIS-enabled security. The work highlights practical challenges, including finite blocklength effects, sensing-eavesdropping, and active adversaries, and discusses emerging technologies (THz, OTFS) and AI-enabled approaches as avenues for future secure ISAC designs. Overall, the survey serves as both a taxonomy and a tutorial, offering theoretical tools and concrete design patterns to advance secure ISAC network architectures in 6G and beyond.

Abstract

The sixth generation of wireless networks defined several key performance indicators (KPIs) for assessing its networks, mainly in terms of reliability, coverage, and sensing. In this regard, remarkable attention has been paid recently to the integrated sensing and communication (ISAC) paradigm as an enabler for efficiently and jointly performing communication and sensing using the same spectrum and hardware resources. On the other hand, ensuring communication and data security has been an imperative requirement for wireless networks throughout their evolution. The physical-layer security (PLS) concept paved the way to catering to the security needs in wireless networks in a sustainable way while guaranteeing theoretically secure transmissions, independently of the computational capacity of adversaries. Therefore, it is of paramount importance to consider a balanced trade-off between communication reliability, sensing, and security in future networks, such as the 5G and beyond, and the 6G. In this paper, we provide a comprehensive and system-wise review of designed secure ISAC systems from a PLS point of view. In particular, the impact of various physical-layer techniques, schemes, and wireless technologies to ensure the sensing-security trade-off is studied from the surveyed work. Furthermore, the amalgamation of PLS and ISAC is analyzed in a broader impact by considering attacks targeting data confidentiality, communication covertness, and sensing spoofing. The paper also serves as a tutorial by presenting several theoretical foundations on ISAC and PLS, which represent a practical guide for readers to develop novel secure ISAC network designs.

Figures (13)

• Figure 1: An illustration of the interplay of ISAC use-cases with cutting-edge wireless technologies and techniques.
• Figure 2: Organizational Structure of Our Work
• Figure 3: Normalized beampattern gain plot. The figures illustrate the case of $L=3$ targets located at the directions $\theta=-\pi/4$, $-\pi/12$, and $\pi/12$, and $M=1$ communication user located at $\theta=\pi/4$ (As indicated by dashed vertical lines). MRT is adopted as an ISAC beamformer.
• Figure 4: Spatial power spectrum obtained by evaluating \ref{['rxechopower']} as a function of $\mathbf{w}(\theta)$ for varying $\theta$.
• Figure 5: Spatial power spectrum obtained by evaluating \ref{['rxechopower']} and \ref{['rxpowcapon']} as a function of $\mathbf{w}(\theta)$ for varying $\theta$ with $L=2$ and $N_t=N_r=10$.