Advancement of the DPRE Encryption Algorithm for Phase CGHs by Random Pixel Shuffling

Optical encryption of information using Computer Generated Holograms (CGH) is a well-known discipline based on the modification of the phase pattern obtained from the calculation of the hologram from a scene. This paper presents an evolution of this technique adding random pixel permutation. The complete workflow is described starting from the synthesis of a 3D scene by Computer Graphics, its storage in a CGH, the encryption and decryption process, showing results obtained in the laboratory and by simulation. Special emphasis is given to the proposals related to the encryption phase, allowing the use, if desired, of a single key in the pixel permutation and phase modification processes to generate the encrypted CGH. The similarity between different encryption levels is used as a metric to evaluate the results obtained.