Re-configurable Intelligent Surfaces (RIS) technology has proven itself a promising candidate for the next generation of wireless networks through its 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. On the other hand, physical layer authentication is an emerging area in the security domain to thwart 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). Specifically, 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 the closed-form errors' expressions. Further, we chose the critical error, i.e., missed detection as our objective function for minimization by optimizing the phase shift of the RIS pannel. We compare the performance of our proposed mechanisms with baseline mechanisms which are PLA schemes using the same features but with no RIS assistance. 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 the significant positive impact of RIS on PLA, as it effectively reduces PMD values to zero when determining the optimal phase shift.

翻译：可重构智能表面（RIS）技术通过提升吞吐量、频谱效率和能量效率，已被证明是下一代无线网络的有前景候选技术。然而，RIS辅助无线通信的广播特性使其在物理层易受恶意攻击。另一方面，物理层认证作为安全领域的新兴研究方向，通过利用物理层的随机特征来抵御克隆、欺骗和冒充等攻击。本文研究了RIS辅助无线通信系统，旨在挖掘RIS在物理层认证中的应用潜力。具体而言，我们利用物理层的两个独特特征——路径损耗和信道冲激响应（CIR）实现RIS辅助无线通信中的物理层认证。针对估计特征构建假设检验，并推导出闭式误差表达式。进一步，选择关键误差（即漏检概率）作为目标函数，通过优化RIS面板的相位偏移实现最小化。将所提机制的性能与采用相同特征但无RIS辅助的基线物理层认证方案进行对比。同时，使用虚警概率（PFA）、漏检概率（PMD）和接收器操作特性（ROC）曲线等性能指标对所提方案进行全面评估。结果表明，RIS对物理层认证具有显著积极影响——当确定最优相位偏移时，可有效将漏检概率降至零。