Multiple color images encryption by triplets recombination combining the phase retrieval technique and Arnold transform

We propose a new method for multiple color images encryption by using triplets recombination. In this proposed technique, triplet (R, G and B) components of the secret color image are recorded simultaneously as a real and positive gray image exploiting parallel multi-wavelength recording technology. Arnold transform and phase retrieval algorithm adapted to Fresnel transform domain are used to encode the parallel hybrid result. By using of the proposed technique, each color image is encrypted into a pure phase distribution and combined by superposition. Phase modulation is introduced to eliminate the cross-talk caused by multiple images superposition. The wavelength and transform parameters are provided as keys to enhance the system security. In addition, computer simulations are performed and numerical results are presented to show the validity and efficiency of the proposed method.