Reconfigurable Intelligent Surfaces: A Physical Layer Security Perspective

The conceptual design of the Sixth Generation (6G) wireless systems include, among others, Reconfigurable Intelligent Surfaces (RISs), arrays of elements that are capable of manipulating and reconfiguring the wireless propagation environment. Thereby, they are claimed to have advantages in different subjects, such as coverage, energy efficiency and localization. Therefore, this work discusses five use-cases of how RISs could contribute to Physical Layer Security (PhySec) concepts. By actively influencing the scattering, reflection and refraction characteristics of electromagnetic waves, beamforming and - splitting, as well as by adding individual information to the transmitted signals, they can increase the environmental wireless security. In addition to the description and discussion of the applicability of conceivable use-cases the RIS behaviour is demonstrated by full-wave simulations of the electric far-field.