Dual-Security for Indoor OFDM-ISAC Systems via Temporal Artificial Noise

2026-07-17

AI Summary

This work addresses the dual security threats in indoor OFDM-based integrated sensing and communication (ISAC) systems—namely, authorized sensing users eavesdropping on communication data and authorized communication users performing unauthorized sensing—and proposes a time-domain artificial noise-based security enhancement scheme. The proposed approach is the first to jointly safeguard both communication and sensing functions: it injects carefully designed artificial noise in the time domain to disrupt eavesdroppers in the frequency domain, thereby preserving communication confidentiality, while simultaneously increasing sensing error in the time domain to suppress illicit sensing, all with minimal and controllable impact on legitimate users’ performance. Experimental results, leveraging standard OFDM receivers and SINR control mechanisms, demonstrate that the method effectively maintains authorized users’ communication and sensing capabilities while ensuring dual-function security.

Abstract

With the rapid development of integrated sensing and communication (ISAC) as a key enabler for future wireless networks, ensuring the security of both communication and sensing functions has become increasingly important. Current secure ISAC studies focus restrictively either on the communication or the sensing security, but not both. To bridge this gap, this paper investigates security for both, i.e., dual-security, in indoor orthogonal frequency division multiplexing (OFDM) based ISAC systems. Specifically, we consider a scenario in which a sensing user (SU) is authorised for sensing but may eavesdrop on communication data, while a communication user (CU) is authorised for communication but may perform unauthorised sensing. We chose this scenario as the pathological case where an authorised eavesdropper has more information and is more effective than an unauthorised one. To address this case, we propose the use of temporal artificial noise (AN) to prevent malicious CU sensing by enlarging its time-domain sensing error, and simultaneously degrade SU data eavesdropping by reducing its frequency-domain signal-to-noise-plus-interference ratio (SINR) with standard OFDM receiver processing. Meanwhile, our proposed scheme guarantees the sensing performance of the SU and the communication performance of the CU. We present numerical results that demonstrate AN can effectively provide dual protection for sensing and communication in OFDM-ISAC systems while guaranteeing the performance of legitimate users.

Problem

• dual-security
• ISAC
• OFDM
• eavesdropping
• unauthorized sensing

Innovation

• dual-security
• temporal artificial noise
• OFDM-ISAC
• integrated sensing and communication
• authorized eavesdropping