Chaotic information metasurface for direct physical-layer secure communication.

Wireless information security has garnered significant attention with the ever-increasingly widespread adoption of broadcast wireless communication systems. The utilization of chaotic systems for secure communication methods has become a prominent area of research, given their inherent advantages of high randomness and sensitivity to initial conditions. However, existing chaos-based approaches usually require legitimate receivers to have access to the chaotic system's parameters as decryption keys, often involving complex operations at the digital level. In this study, we present a novel physical-layer secure communication scheme that relies on an information metasurface whose local reflection properties are dynamically modulated by chaotic patterns. Our approach introduces a "one-time" mixed-pattern generation method that concurrently ensures communication security and transmission efficiency. More importantly, our proposed scheme removes the stringent requirement for decryption operations, enabling the legitimate receiver to directly access the original data while illegitimate receivers receive chaotically encrypted signals. This approach demonstrates significant merits, encompassing high security, a streamlined architecture, and intrinsic backward compatibility. Our innovative strategy provides a renewed perspective for advancing next-generation secure wireless communication systems.