Multiple-image authentication scheme based on the phase-only holograms

A multiple-image cryptographic authentication scheme based on phase-only holograms is proposed in this paper. First, computer-generated holograms of original images to be authenticated are encoded to phase-only holograms using the Floyd-Steinberg error diffusion algorithm. Second, each phase-only hologram image is randomly sampled as the sparse representation with the help of its random binary mask. Finally, the phase-only ciphertext containing the information of original images is obtained by integrating all sparse representations using their binary masks. The existence of each original image can be verified by calculating the nonlinear correlation map between it and its corresponding decrypted result. High security level of this cryptosystem can be achieved by considering random binary masks as secret keys. This work provides an effective alternative for the related research based on computer-generated holograms.