Research On Multiple-image Encryption Based On JTC And Fractional Fourier Transform

In the era of rapid development of modern information and communication technologies,the secure transmission and storage of images has become crucial.Multi-image encryption technology based on optical systems has the advantages of high-speed computation and high parallelism.By encrypting multiple parameters such as phase,amplitude,and wavelength of an image,the potential of multi-graph encryption can be excavated to a great extent,and the information security The field plays a key role.The research results of image encryption are widely used in commercial security,medical and military fields.The encryption technology based on optical theory is gradually maturing.This paper studies image encryption technology based on joint transform correlator and fractional Fourier transform.First,the related theory of image encryption is introduced in detail,including optical 4f system,joint transform correlator and fractional Fourier transform.The method of optical image encryption using joint transform correlator is analyzed.Second,the image encryption system is extended from the Fourier domain to the fractional Fourier domain,which expands the encryption space and makes it more secure.Before the input plane was obtained,a variety of scrambling techniques were studied.After analyzing its performance,chaos theory was used as the scrambling method of the original image.Combining chaotic scrambling technology with joint transform correlator and fractional Fourier transform makes the encryption system more secure and robust.In recent years,domestic and foreign scholars have proposed many algorithms for image encryption.The vast majority of them are aimed at single images.This can cause many difficulties when processing large amounts of image data,which seriously affects the efficiency of information transmission.In order to improve this situation,this paper finally proposes a multi-image encryption algorithm based on JTC,and realizes its feasibility through simulation.Based on the existing image encryption system,a single picture is encrypted and expanded to multiple pictures while being encrypted.Taking the discrete cosine transform as the theoretical basis,the low-frequency signal of the image is extracted by cutting the spectrum,and a plurality of images are spliced as the original image,and multipleimages are simultaneously encrypted.Through simulation experiments,the errors between the decrypted image and the original image of the 9 images and the 16 images were analyzed,and compared with the error after encryption and decryption of the single image,which proved the reliability and anti-attack ability of the system.