Research On Image Encryption Technology Based On Light Field Modulation

Optical image encryption is an information security technology that protects image data by optical information processing means,which has wide application due to high capacity,efficient information storage,fast processing speed and high parallelity.The combination of light field modulation technology and image encryption technology can design the parameters of light such as wavelength,spatial frequency,polarization state,and orbital angular momentum as the encryption key,which greatly improve the key space and security of the optical image encryption system.This work studies the image encryption technology based on light field modulation,mainly from the three aspects of image encryption system security,encryption capacity and encryption efficiency.The specific contents include:1.The basic knowledge and research status of existing optical image encryption technology and light field modulation technology are summarized.This work discusses typical optical image encryption methods,such as using double random phase encoding,optical parameter multiplexing,compressive sensing,holography to realize image encryption.The research results and applications of light field modulation devices,hologram coding methods,complex amplitude control methods and vector light field generation systems are summarized.2.Theoretical and experimental research on vector beam modulation system based on spatial light modulator and 4F system is carried out.The optical path structure,generation principle,and modulation mechanism of the full-light modulation vector beam system are analyzed.The results of simulation of vector beams under different light field parameters were simulated by MATLAB.The experimental system produced by the full-optical regulation vector beam was built,and the single mode,dual mode and complex pattern vector beams were obtained.Through comparative analysis of simulation and experimental results,we have verified the effectiveness and feasibility of the experimental system for precise modulation of optical parameters.3.A multi-image asymmetric polarization optical encryption method based on light field modulation and frequency shift is proposed.This method can realize parallel encryption of multiple images,and utilize the incompatible polarization state of the human eye as a key,greatly improves the security of the optical image encryption system.In addition,multiple images encrypts the single amplitude type ciphertext image for storage and transmission,the encryption efficiency of the encryption system is greatly improved.The simulation experiment verifies the validity and feasibility of the multi-image encryption scheme.The experimental results show that the method has high security,noise immunity,shear resistance ability,and anti-chosen-plaintext attack,has certain application value in the optical information security.4.A multi-image encryption method based on light field modulation and orbital angular momentum holography is proposed.This method encrypts and stores multiple images to be encrypted as an optical holographic image.Decrypting the vortex beam of a specific topology to acquire a plurality of decryption images by decryption system.The method is used as a key with the number of topological mats of the vortex beam,which greatly improves the security and encryption capacity of the optical image encryption system.Simulation experiments have verified the effectiveness and feasibility of the multi image encryption scheme.The experimental results show that the method has high security,noise immunity,and shear resistance.