The physical layer authentication (PLA) is a promising technology which can enhance the access security of a massive number of devices in the near future. In this paper, we propose a reconfigurable intelligent surface (RIS)-assisted PLA system, in which the legitimate transmitter can customize the channel fingerprints during PLA by controlling the ON-OFF state of the RIS. Without loss of generality, we use the received signal strength (RSS) based spoofing detection approach to analyze the feasibility of the proposed architecture. Specifically, based on the RSS, we derive the statistical properties of PLA and give some interesting insights, which showcase that the RIS-assisted PLA is theoretically feasible. Then, we derive the optimal detection threshold to maximize the performance in the context of the presented performance metrics. Next, the actual feasibility of the proposed system is verified via proof-of-concept experiments on a RIS-assisted PLA prototype platform. The experiment results show that there are 3.5% and 76% performance improvements when the transmission sources are at different locations and at the same location, respectively.

翻译：物理层认证（PLA）是一种前景广阔的技术，可在不久的将来增强海量设备的接入安全性。本文提出了一种可重构智能表面（RIS）辅助的PLA系统，其中合法发射器通过控制RIS的开关状态，可在PLA过程中定制信道指纹。不失一般性，我们采用基于接收信号强度（RSS）的欺骗检测方法来分析所提架构的可行性。具体而言，我们基于RSS推导了PLA的统计特性，给出了若干有趣见解，表明RIS辅助PLA在理论上可行。随后，在所呈现性能指标的背景下，我们推导了最优检测阈值以最大化性能。接着，通过基于RIS辅助PLA原型平台的原理验证实验，验证了所提系统的实际可行性。实验结果表明，当传输源位于不同位置和同一位置时，性能分别提升了3.5%和76%。