Multi-image encryption based on interference of computer generated hologram

A multi-image encryption scheme based on interference of computer generated holograms (CGH) is proposed. The encrypted information can be divided into several parts and recorded by corresponding CGHs that distribute randomly. With interference of all CGHs, the original information can be reconstructed. So the multi-image encryption is achieved, and every hologram can be regarded as the key to the corresponding image. Multi-user authentication and storage of information is implemented by applying unique CGH to interfere the common CGH. Furthermore, the CGHs can be cascaded to implement classification of images. When images of different level are assigned to corresponding user, hierarchical encryption is completed successfully. Numerical simulation verifies the feasibility of the method, and demonstrates the security of the algorithm and the decryption characteristics. Flexibility and variability of scheme can be higher than the existing methods. There are a lot of scheme's details still to consider and fulfill in the future.