Re-configurable Intelligent Surfaces (RIS) technology is increasingly becoming a potential component for next-generation wireless networks, offering enhanced performance in terms of throughput, spectral, and energy efficiency. However, the broadcast nature of RIS-assisted wireless communication makes it vulnerable to malicious attacks at the physical layer. At the same time, physical layer authentication is gaining popularity as a solution to secure wireless networks, thwarting different attacks such as cloning, spoofing, and impersonation by using the random features of the physical layer. In this paper, we investigate RIS-assisted wireless communication systems to unlock the potential of using RIS for physical layer authentication (PLA). In particular, we exploit two distinct features of the physical layer: pathloss and channel impulse response (CIR) for PLA in RIS-assisted wireless communication. We construct hypothesis tests for the estimated features and derive closed-form error expressions. Further, we consider the critical error, i.e., missed detection, as our objective function to minimize by optimizing the phase shift of the RIS pannel. We compare the performance of our proposed mechanisms with PLA schemes using the same features but with no RIS. Furthermore, we thoroughly evaluate our proposed schemes using performance metrics such as the probability of false alarm (PFA), the probability of missed detection (PMD), and the receiver operating characteristic (ROC) curves. The results demonstrate a clear positive impact of RIS on PLA, as it effectively reduces PMD values to zero when determining the optimal phase shift.

翻译：可重构智能超表面（RIS）技术正逐步成为下一代无线网络的关键组成部分，在吞吐量、频谱效率与能量效率方面展现出显著性能提升。然而，RIS辅助无线通信的广播特性使其在物理层易遭受恶意攻击。与此同时，物理层认证作为一种利用物理层随机特征来抵御克隆、欺骗及冒充等多种攻击的无线网络安全解决方案，日益受到关注。本文通过研究RIS辅助无线通信系统，探索将RIS用于物理层认证（PLA）的潜力。具体而言，我们利用物理层的两类独特特征——路径损耗与信道冲激响应（CIR）——来实现RIS辅助无线通信中的PLA。针对估计特征构建假设检验模型，并推导出闭式错误表达式。进一步地，我们将关键错误（即漏检概率）作为目标函数，通过优化RIS面板的相移进行最小化。在相同特征条件下，将所提机制与无RIS的PLA方案进行性能对比。此外，我们利用虚警概率（PFA）、漏检概率（PMD）及接收机工作特性（ROC）曲线等性能指标全面评估所提方案。结果表明，RIS对PLA具有显著的正向影响，在优化相移时能将PMD值有效降至零。