Rapid chaotic image encryption method capable of simultaneously scrambling and diffusing rows and columns

Abstract

The invention discloses a rapid chaotic image encryption method capable of simultaneously scrambling and diffusing rows and columns, and aims to provide a novel image encryption method capable of simultaneously scrambling and diffusing rows and columns based on hyperchaos and dynamically related to plaintext pixels, which comprises the following steps of: time-delayed nonlinear combined hyperchaosmapping , image encryption and image decryption. According to the method, a time-delayed nonlinear combined hyperchaos mapping NMHMD is designed on the basis of nonlinear combined mapping provided byZhou Y, and the mapping has the characteristics of wider hyperchaotic interval, no periodic window, more complex dynamic characteristics and better randomness of generated state sequence classes; first-selected plaintext attacks can be effectively resisted; the whole method only needs one round of scrambling and diffusion operation, and the calculation complexity of the method is reduced.

Description

technical field [0001] The invention relates to the technical field of digital image encryption. Background technique [0002] With the rapid development of modern communication technology and computer technology, real-time communication of multimedia information based on open channels and digital images as carriers is becoming more and more common. Chaotic systems have pseudo-randomness, sensitivity to initial values ​​and initial parameters, unpredictable trajectory, interval ergodicity, and boundedness. These characteristics have a natural connection with cryptography, which makes chaotic systems widely used in the field of encryption. . Compared with text data, digital image data has the characteristics of large data volume, strong correlation between data and large data redundancy, which makes traditional encryption systems based on text information encryption such as DES, AES, RSA and other methods no longer Be applicable. J. Fridrich applied the chaotic system to d...

AI Technical Summary

Problems solved by technology

[0004] From the above explanations, it can be concluded that although block-level chaotic image encryption has relatively fast encryption and decryption speeds, there are still several obvious problems as follows: (1) The dynamic characteristics of the chaotic system used are not complex enough. In the chaotic state, the chaotic interval is relatively narrow; in the hyperchaotic system, whether it is a discrete chaotic system or a continuous chaotic system, there is a narrow hyperchaotic interval, and there is a periodic window in the interval, which leads to the key space being too small and chaotic. The randomness of the sequence is not strong enough; (2) In the design of the encryption method, because the key stream scrambling operation is not associated with the plaintext, it cannot effectively resist the chosen plaintext attack; (3) in the scrambling operation In the phase of diffusion and diffusion, different mixed state sequences are usually used, so that the utilization rate is not high, and the computational complexity and storage space of the method are increased.

Images