A Comprehensive Approach for Secure Key Extraction in NOMA Networks with RIS: Defending Against Internal Eavesdropping

The Non-Orthogonal Multiple Access (NOMA) and Reconfigurable Intelligent Surface (RIS) technologies enhance spectral efficiency by permitting multiple users to share similar resources. However, resource sharing can introduce security risks in NOMA systems with internal users. Security-enhancing techniques for NOMA with eavesdroppers have been proposed to address these concerns. One such approach is the Artificial Noise- Beamforming and Power Allocation (ABPA) methodology, which incorporates noise and power management to enhance security. Additionally, using a reflecting surface and channel fuzziness enables the extraction of a secret key for reliable encrypted data transmission while also introducing intentional interference and confusing potential eavesdroppers. The intelligent control of reflections by the RIS further enhances security by creating complex interference patterns that are challenging to decipher. These frameworks provide promising solutions for mitigating the risks posed by internal eavesdroppers in NOMA systems, leveraging advanced signal manipulation techniques.