Research On Image Encryption Algorithm Based On Chaotic System And Compressive Sensing

Information is an important strategic resource for national development.At present,the struggle between countries for information acquisition and control is becoming more and more fierce.Information security is related to national security and social stability.In such an information age,the ability to ensure information security is important for comprehensive national strength.reflect.For individuals,the rapid development of technology and multimedia has made it easier to obtain information.At the same time,information security issues such as information leakage often occur.As digital images are an important carrier of information exchange and transmission,the security of image data may be related to the interests of individuals and even the country.Therefore,designing a safe and efficient image encryption algorithm has great theoretical value and practical significance.The chaotic system has the characteristics of being sensitive to initial values and ergodic;compressive sensing can realize image compression and encryption at the same time,reducing the amount of data in the transmission process;two-dimensional linear canonical transformation is more flexible,with six free parameters,which can increase the image encryption system key space and security;The data storage and parallel computing capabilities of DNA sequence are very suitable for encryption systems.This paper makes full use of the characteristics of these technologies and proposes three safe and efficient image encryption algorithms.The main structures and innovations of the algorithms are as follows:The first part proposes an image encryption algorithm based on compressive sensing,hyperchaotic system and two-dimensional linear canonical transformation.First,the plaintext image is compressed and encrypted through compressive sensing;second,the obtained compressed image is scrambled using Lorenz’s hyperchaotic system;then it undergoes a two-dimensional linear canonical transformation of chaotic double random phases;finally,the ciphertext image is obtained by add-modular operation.All the keys of image encryption are related to the plaintext image,so the proposed algorithm can resist the chosen plaintext attack very well.The simulation results show that the proposed encryption system accords with the characteristics of cryptographic system,has a good encryption effect,and can resist common attacks.The second part proposes a fast encryption algorithm based on parallel compressive sensing,compound chaos and DNA sequence.First,in order to reduce the amount of information transmission and improve the computational efficiency,parallel compressive sensing is applied to the encryption scheme,and the Logistic-Tent chaotic system is used to generate the parallel compressive sensing measurement matrices.The encrypted and compressed image is diffused and encrypted column by column using the DNA sequence generated by the Logistic-Sine chaotic system.Finally,the Tent-Sine chaotic system is used to scramble the image.The initial value of the compound chaotic system and the rules of DNA encoding and decryption are related to the plaintext image.Therefore,the proposed encryption algorithm is highly sensitive to the plaintext image and can resist common attacks.The simulation results and security analysis show that the cryptographic system has high safety.In the third part,a new secure image encryption algorithm based on hyperchaotic system and bit level permutation is proposed.Firstly,the plaintext image is diffused by two-dimensional forward XOR operation,and the random matrix is generated by Chen hyperchaotic system;then the image is scrambled twice at bit level,and finally the ciphertext image is obtained by two-dimensional backward XOR diffusion.Compared with low dimensional chaotic system,Chen hyperchaotic system can obtain better random chaotic sequences,and increase the key space of encryption algorithm.The use of SHA-256 function enhances the sensitivity of encryption algorithm to plaintext image,so that the encryption algorithm can resist the chosen plaintext attack well.Bit plane permutation can not only change the position of the pixel,but also change the value of the pixel,and increase the efficiency.To improve the security of encryption algorithm,we propose a new bit plane permutation algorithm.Simulation results show that the cryptosystem has satisfactory encryption effect and can resist common attacks.