A Reconfigurable Steganography Strategy Based on Multi‐Dimensional Optical Encryption Metasurface

Benefiting from their exceptional capability for manipulation of versatile light properties, metasurfaces have emerged as a promising platform for optical encryption. However, existing metasurface‐based encryption schemes are often constrained by limited concealment and a lack of post‐fabrication reconfigurability. Here, we propose a reconfigurable steganographic strategy that integrates metasurface‐enabled optical encryption with hidden cryptographic algorithms. In this scheme, chaotic encryption and steganographic algorithms are jointly employed to embed cryptographic ciphertexts and keys into four optically encoded meta‐images in a highly concealed manner. A single‐layer silicon metasurface independently encodes these meta‐images across multiple optical dimensions, including wavelength, polarization, and spatial distance (near‐ and far‐field), under white‐light and monochromatic illumination. Most importantly, the ciphertexts and keys as well as the choice of encryption algorithm are decoupled from the metasurface and can be flexibly updated via network control, enabling reconfigurable encryption without modifying the metasurface. Experiments confirm that secret images can only be recovered through the cooperative implementation of optical and algorithmic decryption. Our work has improved the security, concealment, and reconfigurability of metasurface‐based optical encryption, offering new opportunities for dynamic and interactive information‐security applications.