Reconfigurable Intelligent Surface (RIS)-Assisted Physical Layer Authentication

Physical Layer Authentication (PLA) is an emerging area in the security domain where physical layer characteristics are exploited for security purposes. With networks continuing to evolve and support increasingly diverse applications and services, the need for robust security mechanisms at the physical layer becomes paramount. However, traditional PLA techniques may face challenges in effectively addressing security threats in these advanced networks. In this thesis, we introduce a promising new approach to innovate and assist PLA methodologies based on Reconfigurable Intelligent Surfaces (RIS) technology. RIS is considered a key enabler for 6G systems and a potential solution to enhance the performance of PLA in traditional wireless communication systems. Our proposed RIS-assisted PLA model utilizes two key physical layer characteristics, i.e., Pathloss and Channel Impulse Response (CIR). By comparing our model with (traditional) non-RIS PLA schemes, we demonstrate the effectiveness of using RIS on PLA. We employ binary hypothesis testing based on the considered physical layer attributes to distinguish between legitimate and malicious nodes. Furthermore, we thoroughly evaluate our proposed models using performance metrics such as Probability of False Alarm (PFA), Probability of Missed Detection (PMD), and Receiver Operating Characteristic (ROC) curve. The results demonstrate the significant positive effect of RIS on PLA, as it effectively reduces PMD values to zero when determining the optimal phase shift.