Image Compression And Encryption Algorithm Based On 6-D Hyperchaotic System

The way of information communication in the 21 st century has undergone tremendous changes,and the Internet has become the main means of communication in people’s daily life and work.As an important part of Internet data transmission,digital images are frequently stolen due to the lack of security measures.Therefore,the demand for digital image encryption is gradually increasing,and with the increase of image resolution,encryption efficiency has become a problem that must be considered.In addition,with the soaring increase of multimedia data and the increasing tension of channel resources,alleviating the contradiction between the rapid increase in transmission data and the limited channel resources has become one of the inevitable problems,and image compression encryption technology can effectively solve these two problems.Due to the high sensitivity of chaotic systems to initial values and the randomness of chaotic sequences,many researchers have chosen to apply them to the field of digital image encryption.However,with the improvement of computer computing power,many image encryption algorithms based on low-dimensional chaotic systems have been proved to be bruteforce cracked by computers,so replacing low-dimensional chaotic systems with highdimensional chaotic systems is one of the current research hotspots in the field of image compression encryption.This paper proposes a digital image compression and encryption algorithm based on six-dimensional hyperchaos system for image preview scenes:(1)A new six-dimensional hyperchaotic system is designed to solve the problem that the low-dimensional chaotic system cannot provide the key space to meet the security requirements.(2)Based on the six-dimensional hyperchaotic system,a fast image encryption algorithm is proposed.In this algorithm,in order to reduce the computational complexity in the process of image encryption,only scrambling,full alignment and XOR operations are used to implement digital image encryption.The experimental results show that the algorithm can resist the common analysis methods and realize the digital image encryption in a short time,which improves the efficiency of image encryption.(3)Combining information hiding and data compression,a data compression algorithm which can effectively reduce the amount of data transmitted is proposed.In this algorithm,the original image is divided into information image and thumbnail image.The binary code flow of the information image after discrete cosine transform,threshold quantization and Huffman coding is embedded into the thumbnail by information hiding technology.Thumbnail image can be used as the carrier of information hiding,but also can realize the function of image preview.Experimental results show that the compression algorithm can transmit less data to represent the same image content,and the original image content can still be recovered well.(4)Combining the advantages of encryption algorithm and compression algorithm,an image compression and encryption algorithm is proposed.The original image is divided into information image and thumbnail image,and the code stream of the compressed information image is encrypted.Finally,the encrypted data is embedded into the thumbnail using the information hiding technology.The experimental simulation results show that the compression encryption algorithm can achieve certain data compression effect,reduce the amount of data transmission,and realize the security protection of embedded data.