Hybrid image cryptosystem based on dyadic phase displacement in the frequency domain

Image dyadic displacements can be considered a unique pixel address permutation. This property can be exploited to obtain perfect decryption when encrypting an image. This work presents a hybrid image cryptosystem based on the holographic interference and dyadic permutations. First, the phase and amplitude of the Fourier transform of an input image are recorded as the intensity information via the holographic interference. The extracted phase is then processed via dyadic permutations by applying the exclusive-OR (XOR) operations to a. user key and phase information addresses. Decryption uses an asymmetric process to recover the original image. Simulation results are provided to verify the proposed cryptosystem, and demonstrate that it is robust to additional noise. (C) 2004 Elsevier B.V. All rights reserved.