Image Frequency Domain Encryption And Compression Encryption Based On Digital Chaos

In the era of rapid development of information technology,the popularity of smart phones and the improvement of media technologies have led to the rapid development of image streaming and video streaming services.However,as an important information carrier,digital images face huge security risks during network transmission.During the transmission process,digital images may be attacked,causing the image information to be stolen and tampered.Therefore,the security issues of digital images are becoming increasingly serious and becoming the focus of attention.Because image data has its own unique data characteristics,for example,there is a strong correlation between the pixels of the image,which makes the image data have a lot of data redundancy,and the amount of image data is generally very large,requiring large storage space and efficient transmission system.Therefore,traditional text encryption methods,such as DES,AES,and RSA,are no longer suitable for image encryption.However,in order to protect the image data from being stolen during transmission and storage,and to protect the security of the information,some suitable encryption methods need to be developed for the characteristics of the image,so this research has very important research value.This paper focuses on the research of image encryption algorithms based on high-dimensional digital chaos.In order to further improve the transmission efficiency and reduce the storage of images,image compression is introduced on the basis of encryption to realize a new compression-encryption system of digital images.The main research content of this article lies in the following two aspects:1)An image in frequency-domain encryption algorithm based on high-dimensional digital chaos and dynamic DNA coding is proposed and studied.The innovation of this algorithm is that the DNA encoding algorithm of array images is introduced into the frequency domain,and the image is encrypted from two aspects of amplitude and phase.In addition,high-dimensional digital chaos is introduced to control each point of pixel with a chaotic sequence.DNA encoding method and DNA operation method improve the randomness of encoding and operation.After experimental verification,the algorithm has extremely high key sensitivity and huge key space,and the encryption effect can completely destroy the statistical characteristics of the plain-text image,so that the gray level histogram of the cipher-text image is averaged,and the information entropy is close to the theory maximum value,and the correlation between pixels is approximately 0.In terms of security,it can effectively resist typical attack types such as brute force attacks,statistical attacks,and differential attacks.And comparing the dynamic frequency-domain DNA algorithm with the airspace DNA algorithm and the fixed coding DNA algorithm,it is proved that the algorithm performs well in terms of encryption effect and security.2)An image block lossless compression-encryption algorithm based on high-dimensional digital chaos is proposed and studied.The algorithm fuses encryption and compression,uses the correlation between image pixels,uses block processing to perform lossless image compression,and uses a high-dimensional digital chaos control dynamic DNA coding algorithm to encrypt the compressed image to improve its security.After experimental verification,the algorithm can achieve an ideal compression ratio in terms of compression effect,and lossless compression and decompression of the image without loss of image information.In terms of security,the algorithm can have a huge key space to resist brute force attacks,and can destroy statisticalcharacteristics to resist statistical attacks.In short,this paper proposes and studies a new image encryption algorithm based on high-dimensional digital chaos on the basis of a variety of previous digital image encryption technologies,and fuses lossless image compression with image encryption to achieve lossless compressionencryption system.The detailed encryption effect and security analysis are also given,which proves that the algorithm in this paper can further improve the security and transmission efficiency of the image.