Research And Design Of Digital Image Encryption Algorithm Based On Chaos

With the rapid development of technologies such as the Internet and multimedia,the transmission of information,especially images,has become more and more common.Therefore,information security has become particularly important.However,the amount of data in digital images is huge,and the amount of data redundancy is high.The neighboring pixels are related.Strong,so the traditional encryption technology,such as AES,DES these data encryption technology is not suitable for image encryption,chaos theory as an important branch of nonlinear science,has its own unique characteristics:the extreme sensitivity of the initial conditions;pseudo Randomness;ergodicity,etc.,which have many similarities with the traditional cryptography,so people began to use chaos theory to study image encryption technology,put forward a large number of encryption algorithms.This paper briefly introduces the research background and significance of chaotic cryptography,analyzes the development history of chaotic digital image encryption,and summarizes the advantages and disadvantages of several common chaotic digital image encryption schemes.Based on the above work,it proposes two The chaotic digital image encryption scheme,the main work is as follows:(1)A hyperchaotic image encryption algorithm based on rotation of bit-plane matrix is proposed.Firstly,MD5 hash algorithm is combined with hyperchaotic Lorenz system to generate sequences closely related to images.Then these pseudo-random sequences are used to perform the following encryption steps:The pixel position of the plaintext image is scrambled firstly;the second step is to decompose a pixel plane into bit planes,and the chaotic sequence is used to control the position,size,and rotation angle of each rotation matrix in the space,and the rotation is performed bit by bit;Steps merge bit planes and perform spreading operations.The entire process algorithm depends on the plaintext,so it can effectively resist differential attacks.Experimental results and theoretical analysis show that the algorithm not only effectively avoids the low-dimensional chaotic low security defect,but also has strong key sensitivity,large key space,and high security.(2)A new bit scrambling image encryption scheme based on hyper-chaotic chen system is proposed.The algorithm's innovation is to perform two different bits scrambling between the original pixel scrambling and diffusion.In a round of spatial bit plane,8 bits are used to shift the XOR under chaos control,and the other pixel isThe unit performs the same operation under different chaos control.The entire encryption process depends on the plaintext and exploits the superior characteristics of the hyperchaotic system.The experimental simulation results show that the algorithm has a strong ability to resist statistical characteristics analysis and select the plaintext attack.It has the advantages of large key space,strong key sensitivity,and good encryption effect.