Optical information hiding based on speckle encoding with dual-multiplexing interferometry

Optical hiding schemes based on visual cryptography usually hide secret information in multiple visual keys. However, the traditional visual keys are usually Mosaic patterns, which are easy to attract the attention of attackers, and limit their randomness and security. And each visual key needs a corresponding transport carrier, leading to limited hiding capacity. To solve these problems, this paper proposes an optical information hiding method based on speckle encoding and dual-multiplexing interferometry. This method uses natural speckle with high randomness to partial replace traditional visual keys, realizing the combination application of natural speckle keys and artificial visual keys. The optical properties of wavelength and diffraction distance multiplexing interference can hide multiple visual keys in a single image, which improves the hiding capacity. Simulation and optical experiments show that the proposed method has high security, large hiding capacity, imperceptibility and robustness.