Color Code Encryption Based On Optical Image Encryption

With the progress of times,the field of information security has attracted more and more attention.Image information security and encryption are very important components among the field.Image encryption can not only be realized by computer methods,but also by optical methods.In this paper,we give a brief introduction to the theoretical knowledge and development of optical image encryption technology first,and on this basis,we propose two color code encryption systems combining optical image encryption technology.Color code is a new kind of barcode technology,which is different from the quick response(QR)code that shows as black and white.It has beautiful colors,better visual experience,more capacity,and also has a good application prospect.Since the information of the original image is completely stored in the color code,the original image can be completely recovered from the ciphertext when the color code is used as the input image for optical encryption.In this paper,we propose a coding method to convert image into color code first,The binary information of the original image is encoded in the color code,and the image can be recovered from the color code.Then,two color code encryption systems which use the color code as the input image of optical image encryption technology are proposed.The first kind of encryption system is a combination of double random polarization encryption technology and exclusive-OR(XOR)operation.Firstly,the original image is encoded as a color code,then the color code is encrypted with XOR operation,finally,the encrypted color code is used as the input image for double random polarization encryption.The key is the random polarization masks and the four-bit binary number used in XOR operation.Double random polarization encryption method was originally designed for binary image,but in this paper,the encryption method can be used for color code encryption,and the XOR operation can improve the effectiveness and security of the system.The second kind of encryption system combines color code with phase-only optical encryption method and Arnold transformation,and the key is the random phase mask used in encryption process and scrambling times.We simulate and analyze the above two encryption systems,and the results show that both of them have good encryption effect.Since the color code is used as the input image of optical image encryption technology,the above two encryption systems have a good recovery effect.However,when the key is wrong or the ciphertext is tampered or cut,the image cannot be recovered.