Reconfigurable Intelligent Surface for Physical Layer Key Generation: Constructive or Destructive?

Physical layer key generation (PKG) is a promising means to provide on-the-fly shared secret keys by exploiting the intrinsic randomness of radio channel. However, performance PKG highly dependent on propagation environments. Due its feature controlling wireless environment, reconfigurable intelligent surface (RIS) appealing be applied in PKG. In this article, contrast existing literature, we investigate both constructive and destructive effects RIS scheme. For aspect, have identified static wave-blockage environments as two RIS-empowered-PKG applications future systems. particular, our experimental results environment showed that can enhance entropy key, achieving rate (KGR) 97.39 bit/s with bit disagreement (BDR) 0.083. multi-user systems where some remote users are worse channel conditions, proposed RIS-assisted algorithm improves sum more than 2 dB, compared literature. Furthermore, point out could utilized an attacker perform new jamming leakage attacks give countermeasures, respectively. Finally, outline research directions for light RIS.