Based On The Calculation Of Holographic Optical Key Research

This paper described the development and current status of the image optical encryption technology. Brief introduced the development and application of optical holography and computer generated hologram, the basic theory of CGH, spatial filtering, Fresnel diffraction and Fraunhofer Wo Fei diffraction, computer generated hologram coding. This paper Studied in detail the theoretical basis of the double random phase image encryption technology of the 4f system based on CGH, the advantages and disadvantages was Analysed, new encryption methods was proposed according to the classic encryption system. In New optical encryption methods the CGH was introduced for the first time, which was the way to solve the problem of record the complex-valued encrypted image, and the new methods contact the optical image with the computer algorithm which give convenience for the growing digital image encryption and transmission. besides the new methods not only was easy access to the conjugate image needed in decryption, but also greatly improves the security of image encryption, This paper, the performance of these methods is analyzed, compared with traditional methods, computer simulation of image encryption and decryption experiments to verify the technical feasibility and practicality. And through in-depth research, this paper was Focused on the principles and realization of the methods of image encryption, three random phase plates, the Fresnel diffraction double random phase encryption and color image encryption and decryption principle based on CGH by the computer MATLAB simulation, analysis, comparison the pros and cons of new methods and classic methods.In this paper, four new image optical encryption methods based on the calculation of the holographic was proposed:(1) Double random phase image encryption technology the 4f system based on the CGH. (2) Three double random phase image encryption technology the 4f system based on the CGH. (3) Double random phase image encryption technology the Fresnel diffraction system based on the CGH. (4) Double random phase color image encryption technology the 4f system based on the CGH. Theoretical analysis, computer simulation was Conducted which show that:a) Calculate the hologram as a key element of the image processing system is feasible, its unique image recording method, making it’s reproduced spectrum has special spectral efficiency, so that the decryption keys are unique; b) The CGH key make the random phase plate encryption technology possible, which is the breakthrough of the classic double random phase encryption technology. The new image encryption technology further improved the security of image encryption and transmission, and enhanced the shear capacity of image encryption and noise immunity. The new methods can be widely used in optical image security, image secure transmission, confidential files encrypted stored and other fields.