A Color Image Encryption Algorithm Based On Spatiotemporal Chaotic Systems

With the rapid development of the information technology era, in order to meet the needs of thegrowing exchange of information, the digital image as an important means of communication, facilitatesand enriches people’s lives. With the widespread use of digital images, digital image information securityhas become increasingly important and urgent. Especially in the modern society that the Internet becomesthe main communication platform, certain sensitive information once it has been stolen and spread outlawswill have immeasurable influences in personal, corporate, financial risk prevention, social stability andnational secrets, and many other aspects. Digital image security has become the common focus of bothacademia and enterprises.Chaotic systems have some special characteristics, such as the extreme sensitivity to initialconditions, the internal randomness, and the orbital unpredictability. These characteristics have coincidedwith requirements of cryptography, and are closely linked with the image encryption technologies.Therefore, it is one of the hot promising projects to apply chaos to digital image security. This paperfocuses on the digital color image encryption based on spatiotemporal chaotic system, launches an in-depthresearch. The paper can be divided into two areas.(1) We propose a color image encryption algorithm based on CML-NCA spatiotemporal chaoswhich consists of CML and NCA chaotic map. The algorithm uses the spatiotemporal chaos system whichhave the complex structure, large key space and more excellent chaotic sequences and other characteristics,combines with the SHA-384function to generate unique keys which depend on the original image, anduses the rows scrambling and columns scrambling and double diffusion to enhance security and encryptioneffect in encryption and decryption process.(2) We propose a color image encryption algorithm based on CML-Logistic spatiotemporal chaos,quantum chaos system and neural network. The original scrambling-diffusion structure has been improved.We use chaotic sequences generated by spatiotemporal chaos to original image for the rows scrambling andcolumns scrambling. It not only changes the position of the pixel, but also improves the speed of confusionand the confusion effect. After that, we use quantum chaotic systems and the neural network to image for diffusion processing, and get the encryption image. Finally, we make anti-noise and anti-shear test.