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

This work presents an optical encryption process for various types of information related to 3D worlds (scenes) or 2D images, utilizing Computer-Generated Holograms (CGHs). It also introduces a modification to the Dual Random Phase Encoding (DRPE) encryption algorithm by incorporating pixel shuffling. This proposal enables the use of either a single key for both pixel shuffling and phase mask definition or two independent keys. The latter option is particularly advantageous in applications that require the involvement of two independent agents to retrieve the original plaintext. The dimension of the CGHs determines the size of the keys based on the random generation of values by cryptographically secure algorithms, so the use of arithmetic encryption is proposed for data compression. However, this proposal allows the use of other algorithms described in the literature to generate the shuffle and phase matrices. The complete workflow is described starting from the synthesis of a 3D scene, defined by a mesh of triangles with shape and appearance modeling, or 2D images of any level of geometric or visual complexity using computer graphics; its storage in a CGH, the encryption and decryption process, and finally, the results obtained in the laboratory and by simulation are shown. The similarity between different encryption levels is measured by the Pearson Coefficient to evaluate the results obtained.