Sixth-generation (6G) networks pose substantial security risks because confidential information is transmitted over wireless channels with a broadcast nature, and various attack vectors emerge. Physical layer security (PLS) exploits the dynamic characteristics of wireless environments to provide secure communications, while reconfigurable intelligent surfaces (RISs) can facilitate PLS by controlling wireless transmissions. With RIS-aided PLS, a lightweight security solution can be designed for low-end Internet of Things (IoT) devices, depending on the design scenario and communication objective. This article discusses RIS-aided PLS designs for 6G-IoT networks against eavesdropping and jamming attacks. The theoretical background and literature review of RIS-aided PLS are discussed, and design solutions related to resource allocation, beamforming, artificial noise, and cooperative communication are presented. We provide simulation results to show the effectiveness of RIS in terms of PLS. In addition, we examine the research issues and possible solutions for RIS modeling, channel modeling and estimation, optimization, and machine learning. Finally, we discuss recent advances, including STAR-RIS and malicious RIS.

翻译：第六代（6G）网络因机密信息通过具有广播特性的无线信道传输且面临多种攻击向量而存在重大安全风险。物理层安全（PLS）利用无线环境的动态特性实现安全通信，而可重构智能表面（RIS）可通过控制无线传输促进PLS的实现。借助RIS辅助的PLS，可根据设计场景和通信目标为低端物联网（IoT）设备设计轻量级安全解决方案。本文探讨了面向6G-IoT网络中窃听与干扰攻击的RIS辅助PLS设计方案。首先论述RIS辅助PLS的理论基础与文献综述，继而提出资源分配、波束赋形、人工噪声及协作通信等设计解决方案。通过仿真结果展示RIS在PLS中的有效性。此外，本文剖析了RIS建模、信道建模与估计、优化及机器学习等方面的研究问题与可行方案。最后，讨论近期进展，包括STAR-RIS与恶意RIS。