Reconfigurable Metasurface‐Driven Pixel‐Wise Visual Cryptography for High‐Security Dynamic Encryption

ABSTRACT In an era characterized by exponential digital growth and escalating cybersecurity threats, traditional encryption methods grapple with issues such as quantum vulnerability and static electromagnetic limitations. This paper introduces a transformative reconfigurable metasurfacebased pixel‐wise visual cryptography (VC) framework. By integrating field‐programmable gate arrays (FPGAs), the system dynamically encodes secrets into noise‐like visual keys (VKs), which unveil content solely through electromagnetic superposition. Treating each 2 × 2 pixel as an independent encryption unit, it enables fine‐grained control and real‐time key reconfiguration, emulating the “one‐time pad” principle to resist brute‐force, machine‐learning, and replay attacks. The pixel‐wise encoding overcomes the coarse resolution constraints of traditional visual secret sharing, facilitating high‐fidelity encoding of complex content, including alphanumeric text and high‐resolution images. Experimental results demonstrate its robust performance, exhibiting notable tolerance to phase noise and reliable decryption even in the presence of partial hologram damage. This framework ensures information‐theoretic security by eliminating statistical correlations between encryption cycles, outperforming traditional visual secret sharing (VSS) in resisting partial key interception.