Double-Validation Metasurface Holographic Encryption Based on XOR Algorithm

Electromagnetic metasurfaces have garnered widespread attention due to their capability for arbitrary wavefront manipulation of electromagnetic waves. In the field of information encryption, electromagnetic metasurfaces are also playing an increasingly important role. This article proposes a one-time dual-authentication encryption scheme for metasurfaces based on the XOR algorithm. Compared to traditional metasurface encryption, we do not store information solely in a single degree of freedom of the electromagnetic wave, thus avoiding decryption by indiscriminate attacks from adversaries. By employing the XOR algorithm of digital systems, we divide the information to be encrypted into multiple parts, which are held by several individuals, with each part containing no useful information on its own. To decrypt the information, the collaboration of all participants is required to successfully decode the encrypted message. On this basis, we have also designed a dual-authentication decryption method that requires two layers of decryption to break the final encrypted information. The first layer of decryption not only confuses attackers but also provides a key for the second layer of decryption, achieving a dual anti-counterfeiting purpose. Moreover, due to the theoretically unbreakable nature of the one-time pad (OTP), our scheme offers extremely strong security. To validate the theoretical concept, we improved the traditional G-S algorithm, using metasurface holography as a bridge, designed theoretical simulations at the 8-GHz electromagnetic band, and conducted microwave experiments. The experimental results highly correspond with the simulation outcomes, confirming the feasibility of the concept.