The Research And Design Of Hyper-chaotic Image Encryption System Based On Intelligent Optimization Algorithms

With the advent of the age of interconnection of all things,the network transmission technology has been developed rapidly.Using the network for information transmission has become the choice of most people.However,while using the network conveniently,the information security problem has also attracted attention.As an important carrier of information.The digital image plays a significant role in the process of network transmission.Compared with the traditional information,the digital image has some different characteristics,such as a large amount of data,high redundancy and strong correlation between adjacent pixels.Traditional encryption algorithms are unable to guarantee the security of image information.I n nonlinear dynamics,chaotic systems have uni que cryptographic characteristics,such as pseudo-randomness,ergodicity of each state and highly sensitive to initial conditions,etc.Therefore,in the field of image encryption,chaos system has been widely used.In addition,intelligent optimization al gorithm can better optimize some characteristics of image to improve the reliability and stability of encryption results.Firstly,this thesis briefly introduces the research background and significance of image encryption based on chaos theory,expounds t he research status of chaotic image encryption at home and abroad in recent year s,and then introduces the chaos theory,cryptography knowledge and intelligent optimization algorithms related to the subject.On this basis,the hyperchaotic image encryption system based on intelligent optimization algorithm is studied and designed in this thesis.The specific work is as follows:(1)A hyperchaotic image encryption system,based on quantum genetic algorithm and compressed sensing technology,is proposed.Firstly,compared with the lowdimensional chaotic system,the encryption system ado pts the complex highdimensional hyperchaotic system,which increases the key space and reduces the risk of being cracked due to exhaustive attack.Secondly,we utilize quantum genetic algorithm to replace the traditional genetic algorithm to enhance the o ptimization effect and improve encryption performance.Then use compressed sensing technology to reduce data storage and speed up the encryption and decryption process.Finally,in order to ensure that the encryption system is highly sensitive to the plain text image,in the process of generating initial value of hyperchaotic system,SHA-512 hash function value of plaintext image is used as a part of key.In addition,the results of experimental simulation and security analysis reveal that for common attack methods,the proposed encryption system can achieve effective defense,so it has better encryption effect and superior security performance.(2)A hyperchaotic image encryption system based on particle swarm optimization algorithm and cellular automata is proposed.To improve the ability to resist pl aintext attacks,the initial conditions of the hyperchaotic system are generated by the hash function value which is closely related to the plaintext image to be encrypted.In addition,the fitness of particle s warm optimization algorithm is the correlatio n coefficient between adjacent pixels of the image.On the basis of hyperchaotic system,cellular automata technology is adopted,which can enhance the randomness of population distribution,increase the complex ity and diversity of the population,and finally enhance the security of the encryption system.Through experimental simulations and security analysis,the effectiveness and reliability of the image encryption system are verified.