Tag-based Physical-Layer Authentication Against Message Interference

2026-04-08

AI Summary

This work addresses the performance degradation and suboptimal threshold issues in conventional tag-based physical-layer authentication, which stem from error-prone message decoding. To overcome these limitations, the paper proposes two novel schemes: Tag-Based Challenge-Response (TBCR) and Series Cancellation Authentication (SCA). Both methods enable direct tag estimation without requiring message decoding by leveraging challenge-response signal superposition and successive interference cancellation. SCA achieves near-ideal detection performance, while TBCR enhances security with reduced key consumption at high signal-to-noise ratios. Theoretical analysis and simulations demonstrate that the proposed approaches significantly outperform existing techniques, offering substantially improved detection probability and lower time complexity. Moreover, closed-form expressions for the optimal authentication threshold and detection performance are derived.

Abstract

Tag-based Physical-Layer Authentication (PLA) has attracted significant attention in recent years due to its low complexity, high security, and low latency. Traditional tag-based PLA schemes typically estimate tags by decoding the message and then subtracting the estimation of the message from the received signal. However, these approaches suffer from two main limitations. First, decoding errors introduce message interference that degrades authentication performance. Second, the analytical complexity of decoding errors leads to sub-optimal threshold settings, thereby limiting detection probability. To address these limitations, this paper proposes a Tag-Based Challenge-Response (TBCR) scheme and a Series Cancellation Authentication (SCA) scheme. Specifically, in the TBCR scheme, the tags are superimposed on a forwarded challenge signal, enabling the receiver to estimate tags by removing the known challenge signal rather than relying on decoding. However, the challenge-response mechanism introduces extra noise. Here, we propose the SCA scheme without the noise interference, where both the series signal generation and cancellation modules are well-designed to generate authentication signals and estimate tags, respectively. Furthermore, we derive the closed-form expressions to evaluate the robustness and security of both proposed schemes. Notably, on one hand, the optimal threshold and detection probability are derived, which theoretically reveal that the SCA scheme always achieves the ideal detection performance, while the TBCR scheme does so in the absence of noise at Alice. On the other hand, the TBCR scheme provides enhanced security at high Signal-to-Noise Ratio (SNR) regions with fewer keys. Theoretical analysis and simulation demonstrate that both proposed schemes significantly outperform the benchmarks in detection probability with reduced time complexity.

Problem

• Tag-based Physical-Layer Authentication
• message interference
• decoding errors
• authentication performance
• threshold setting

Innovation

• Physical-Layer Authentication
• Tag-based PLA
• Challenge-Response
• Series Cancellation
• Detection Probability