Multi-parameter Image Interference Encryption Technology

As a new encryption method,optical encryption technology has been rapidly developed in recent years.The ultimate goal of optical image encryption is to improve the practicality of the algorithm as much as possible,the same as the security.The more parameters of the encrypted image has,better security during tansmission.There is more scenes that you should transmit multiple images at the same time in daily life.Therefore,the multi-parameter and multi-image encryption method has become a research hotspot.In this paper,several typical image encryption methods are studied deeply.Combining the advantages of phase recovery algorithm and interferential encryption,multiple-image and multi-parameter encryption algorithms are discussed.First,the basic principle of the optical image encryption method is outlined.The basic principles of the Fresnel domain GS algorithm and fractional Fourier interference encryption system are analyzed.GS algorithm's encryption method is more flexible,the decryption process of fractional Fourier interference encryption algorithm is relatively simple,therefore an improved algorithm based on interference Fresnel domain GS encryption algorithm is proposed.The simulation of the single-image algorithm's security above was carried out.Secondly,due to the low security of the above algorithm,the Arnold transformation can be used to control the number of transformations in the process of transmission.We propose a new single image encryption algorithm : the interference-based Fresnel domain GS encryption algorithm combined with the Arnold transformation,which adds a key of scrambling.Then a multi-parameter fractional Fourier encryption algorithm was introduced,we use the new introduced one and a new multi-parameter single-image interference encryption algorithm was proposed,which adds periodic parameters and vector parameter keys,and extended fractional parameters to two dimensions.The single-image encryption algorithm greatly expands the key space and improves the security of the encryption process.Third,in order to improve the practicability of the algorithm,the algorithm is applied to multi-image encryption,and a new multi-image multi-parameter encryption algorithm is proposed.The Fresnel domain GS algorithm is improved to eliminate the crosstalk phenomenon in the multi-image restoration process.In addition,the introduction of chaotic Logistic maps adds two more keys than the Arnold scrambling.Further improve the security of the system.The experimental results show that the similarity between the restored image and the original image is close to 100%,and the lossless decryption is almost achieved.Therefore,the efficiency of the algorithm is high enough,and the key space is large enough.Finally,multi-image encryption algorithm is applied to the encryption of single color image.In order to improve the efficiency of the encryption algorithm,a new color image encryption method is proposed in combination with DCT compression and spectrum cutting.The Zigzag scanning sequence is used in spectrum cutting,and can be accurately scaled to each coefficient in cutting the low frequency components.This algorithm greatly saves the time greatly during the process of encryption and decryption,which means the real-time encryption and decryption of color image is realized.