Cryptography Metasurface for One‐Time‐Pad Encryption and Massive Data Storage

Abstract Compared with traditional encryption methods, one‐time‐pad encryption shows theoretically unbreakable characteristics in cryptography owing to the randomness of the generated keys which are generally the same length as the target message. Here, a novel one‐time‐pad encryption strategy is proposed for combining one‐time‐pad keys storage and associated information authentication in metasurface platform. In the concept, visual secret sharing protocol is used to generated one‐time‐pad key by encoding each pixel of secret to two shared sub‐pixels, while each share reveals no information about original image. Then instead of overlaying the two shares to retrieve the secret, the two shares are further encoded to two random polarization key sequences of horizontal and vertical polarization states in an anisotropic metasurface for encryption. In decryption, a single anisotropic metasurface is adopted as the ciphertext to reconstruct target image combined with the doubly‐encrypted polarization keys. By replacing the conventional multichannel metasurface‐based encryption methods with the digital‐based one‐time‐pad encryption, this work enables the reusability of the metasurface and paves the way toward a new methodology for massive data storage.