Intelligent Reflecting Surface-Aided Visible Light Communications for Granting Indoor Secrecy

The newly emerging concept of intelligent reflecting surfaces (IRSs) is changing how we think about the optical wireless propagation channel. Through controlling the light propagation within indoor settings, it becomes feasible to influence the optical channel characteristics in order for visible light communications (VLC) systems to attain specific key performance metrics. In this paper, we propose a novel physical layer security (PLS) mechanism for IRS-assisted VLC systems based on utilising a secret IRS activation pattern that is only shared with the legitimate users. We show that our approach can enhance the secrecy performance of the system without the need to acquire information about the locations of the eavesdropper, which is a major practical limitation to many PLS techniques.