PaperlayerView exact revision on arXiv

Source-linked AI summary

Towards Multi-Functional 6G Wireless Networks: Integrating Sensing, Communication and Security

Zhongxiang Wei, Fan Liu, Christos Masouros, Nanchi Su, Athina P. Petropulu

arXiv:2107.07735v1eess.SP

TL;DR

ISAC must secure information-bearing sensing transmissions against eavesdropping while exploiting sensing to address weaknesses in physical-layer security. This overview examines sensing-aided secure designs, robust operation with imperfect knowledge, hardware-efficient architectures, and open research challenges. It concludes that sensing-aided secure ISAC offers a proactive direction for information security in robust, low-cost devices.

  • Problem

    ISAC embeds information in probing waveforms, allowing sensed targets to eavesdrop, while many physical-layer security methods require knowledge of eavesdropper channels or directions.

    Source: A. The Unique Security Challenges and… · p. 5

  • Method

    The paper surveys joint sensing–communication waveform fundamentals, sensing-aided secure transmission, robust designs under imperfect knowledge, and hardware-efficient secure ISAC architectures.

    Source: §I · p. 2, §V · p. 7

  • Results

    The overview identifies sensing-aided secure ISAC as a proactive approach and reviews low-cost designs using phase shifters or parasitic antennas instead of RF chains.

    Source: §I · p. 2, §V · p. 7

  • Takeaways & Limitations

    Sensing-aided secure ISAC supports information-security designs tailored to robust and hardware-constrained low-cost devices.

    Source: §V · p. 7

Abstract

from arXiv · show

Integrated sensing and communication (ISAC) has recently emerged as a candidate 6G technology, aiming to unify the two key operations of the future network in spectrum/energy/cost efficient way. ISAC involves communicating information to receivers and simultaneously sensing targets, while both operations use the same waveforms, the same transmitter and ultimately the same network infrastructure. Nevertheless, the inclusion of information signalling into the probing waveform for target sensing raises unique and difficult challenges from the perspective of information security. At the same time, the sensing capability incorporated in the ISAC transmission offers unique opportunities to design secure ISAC techniques. This overview paper discusses these unique challenges and opportunities for the next generation of ISAC networks. We first briefly discuss the fundamentals of waveform design for sensing and communication. Then, we detail the challenges and contradictory objectives involved in securing ISAC transmission, along with state-of-the-art approaches to address them. We then identify the new opportunity of using the sensing capability to obtain knowledge of the targets, as an enabling approach against known weaknesses of PHY security. Finally, we illustrate a low-cost secure ISAC architecture, followed by a series of open research topics. This family of sensing-aided secure ISAC techniques brings a new insight on providing information security, with an eye on robust and hardware-constrained designs tailored for low-cost ISAC devices.

I. INTRODUCTION

ISAC integrates sensing and communication through shared transmissions, devices, and infrastructure, improving efficiency while creating distinctive security challenges and motivating sensing-aided secure designs.

  • ISAC conveys information to communication users while simultaneously detecting targets through shared spectrum, hardware, signal processing, and network infrastructure.Source: §I · p. 1
  • The shared, broadcasting transmission can expose confidential messages to sensed targets, creating a trade-off between illuminating targets and limiting their useful received signal power.Source: §I · p. 1
  • Upper-layer cryptography faces secret-key management burdens, uncertain protection against computationally strong eavesdroppers, and difficulty detecting compromised keys.Source: §I · p. 1
  • Physical-layer security can avoid direct signal detectability at eavesdroppers without relying on cryptographic techniques or limited eavesdropper computation.Source: §I · p. 2
  • The article reviews sensing-aided secure waveform design, robust designs under imperfect knowledge, and hardware-efficient architectures based on directional modulation.Source: §I · p. 2

II. THE FUNDAMENTALS OF ISAC

ISAC extends spectrum-sharing approaches by jointly using communication and sensing functions across shared hardware platforms and network architectures.

  • Communication and radar spectrum sharing initially addressed spectrum sensing, dynamic access, and mutual interference mitigation between separate systems.Source: §II · p. 2
  • Unlike CRSS, ISAC supports shared use of spectrum, hardware platforms, and ultimately network architecture.Source: §II · p. 2

A. Sensing Basics

ISAC sensing extracts target information from reflected or scattered radio waves, supporting detection, estimation, and recognition while introducing performance objectives that differ from communication.

  • Sensing extracts information from radio waves reflected or scattered by targets, whereas communication recovers information delivered by the transmitter.Source: A. Sensing Basics · p. 2
  • Sensing tasks comprise detection of target presence, estimation of parameters such as range and velocity, and recognition of target identity.Source: A. Sensing Basics · p. 2
  • Detection and estimation rely mainly on physical-layer signal processing, while recognition draws on imaging and learning theories at the application layer.Source: A. Sensing Basics · p. 3
  • The article focuses on physical-layer sensing for secure waveform design and sets aside higher-layer sensing designs as future work.Source: A. Sensing Basics · p. 3
  • Different sensing and communication performance indicators create conflicting waveform-design objectives that must be balanced.Source: A. Sensing Basics · p. 3

B. Waveform Design for ISAC

ISAC waveform designs range from sensing-centric and communication-centric approaches to joint optimization, with joint design balancing ideal sensing beampatterns against communication quality.

Sensing-Centric Design

  • Sensing-centric designs embed communication messages into sensing waveforms using pulse intervals, index modulation, or generalized spatial modulation.Source: B. Waveform Design for ISAC · p. 3
  • Multipath communication distorts mainlobe-based schemes because dispersed non-line-of-sight signals make sidelobe and mainlobe power contribute comparably.Source: B. Waveform Design for ISAC · p. 4

Communication-Centric Design

  • Communication-centric designs reuse standardized communication waveforms, protocols, and architectures, including pilots and frame preambles, for sensing.Source: B. Waveform Design for ISAC · p. 4

Joint Design

III. FROM DUAL-FUNCTIONAL TO MULTI-FUNCTIONAL: INTEGRATING SECURITY INTO ISAC

This section examines how ISAC’s sensing functionality can be deliberately used to support information security, extending ISAC beyond sensing and communication.

  • Sensing functionality is judiciously utilized to benefit information security in ISAC systems.Source: §III · p. 4

A. The Unique Security Challenges and Opportunities of ISAC

ISAC creates a security trade-off because sensing requires power directed toward targets, which can increase their ability to intercept confidential signals. Sensing-derived target information can nevertheless support secure waveform design under joint sensing, communication, and secrecy objectives.

B. Robust Secure ISAC Waveform Design

Robust secure ISAC waveform design addresses imperfect target localization and legitimate-user channel knowledge. It widens or adapts the sensing beam while suppressing target reception SINR across uncertain locations.

C. Hardware Efficient Secure ISAC Design

Hardware-efficient secure ISAC designs address the cost and power demands of fully digital implementations by reducing or removing RF-chain and DAC requirements. Directional modulation further uses antenna-level symbol shaping to favor legitimate users and degrade Eve’s constellation reception.

IV. OPEN CHALLENGES AND FUTURE WORKS

Future work must extend secure ISAC beyond current performance metrics and address privacy, compatibility, network-level analysis, and hardware-efficient designs. These challenges include aligning security with stringent 5G/6G requirements while preserving practical feasibility.

Open Challenges

  • Secure ISAC remains broadly open, with unresolved challenges spanning privacy, compatibility, performance analysis, and design requirements.The paper identifies these areas as future research directions rather than settled capabilities.Source: §IV · pp. 6–7

Radar Location and Identity Privacy-Preserving Design

  • Parameter sharing between radar and communication units can expose radar location or identity, creating a privacy-preserving design challenge.A curious communication transmitter may infer radar parameters or location from exchanged waveform-related information.Source: §IV · p. 6

Secure ISAC Design for 5G/6G KPIs

  • Existing secure ISAC evaluations commonly use SINR or end-to-end throughput, but practical applications also require latency, reliability, massive access, and short-packet metrics.Future techniques must align with these stringent requirements while maintaining low complexity and overhead.Source: §IV · pp. 6–7

Low-Cost Secure ISAC

  • Figure 4 illustrates a low-cost antenna-level design that shifts legitimate-user symbols into constructive-interference regions and eavesdropper signals into destructive regions.The approach uses driven elements or parasitic antennas and produces high eavesdropper symbol error rates.Source: Figure 4 · p. 7

On Compatibility of Secure ISAC and 5G NR

  • Compatibility between secure ISAC and standardized 5G NR waveforms and adaptive wireless-interface configurations remains unresolved.The challenge concerns diverse communication environments and specific performance requirements.Source: §IV · p. 7

Network Level ISAC Design and Secure Performance Analysis

  • Network-level secure ISAC analysis is needed to support system-wide planning and engineering design beyond generic communication-system analyses.Existing network studies analyze metrics such as SINR, convergence probability, outage probability, and ergodic system capacity.Source: §IV · p. 7

V. CONCLUSIONS

The paper reviews sensing-aided secure ISAC techniques and hardware-efficient architectures. It presents proactive sensing-based protection as a direction for preserving information security in future low-cost ISAC systems.

Conclusions

  • The article examines sensing-aided secure ISAC techniques that prevent confidential signals embedded in probing waveforms from being eavesdropped by sensing targets.This is presented as a central focus of the article’s security discussion.Source: §V · p. 7
  • The review covers energy- and hardware-efficient ISAC designs that replace RF chains with phase shifters or parasitic antennas.These architectures target reduced power consumption and hardware cost.Source: §V · p. 7
  • Sensing-aided secure ISAC design offers a broad research direction for proactive information-security preservation.The paper identifies this direction as relevant to future robust and hardware-constrained ISAC designs.Source: §V · p. 7

Related papers

Loading 2107.07735v1…