Image encryption method and device, electronic equipment and readable storage medium

Abstract

The invention provides an image encryption method and device, electronic equipment and a readable storage medium. The method comprises following steps of acquiring a first pseudo-random sequence and asecond pseudo-random sequence with preset lengths by connecting a hybrid chaotic system in parallel in a precision limited mode; processing the first pseudo-random sequence with the preset length toobtain a first permutation matrix and a first diffusion matrix; according to the first permutation matrix, replacing the to-be-encrypted image by a square formed by four adjacent pixel points as a unit to obtain a first image after replacement; and performing row diffusion and column diffusion on the replaced first image according to a first diffusion matrix to obtain an intermediate result image,and performing a second round of replacement and diffusion on the intermediate result image through the same method to obtain an encrypted image. With the method, the secret key space is increased, the operation speed is increased, higher safety is achieved, and the calculated amount during replacement and diffusion can be reduced.

Description

technical field [0001] The invention relates to the technical field of image encryption, in particular to an image encryption method, device, electronic equipment and readable storage medium. Background technique [0002] With the rapid development of multimedia services, more and more videos and pictures are generated on the network. Compared with text, pictures and videos contain richer information and are more prone to privacy leakage. Therefore, there have been more and more researches on image encryption in recent years. There is a strong correlation between adjacent pixels of an image, so traditional encryption algorithms such as RSA, DES, and AES are not suitable for image encryption. In recent years, more and more image encryption algorithms based on chaos theory have been proposed. Chaotic systems have many properties suitable for image encryption, such as initial value sensitivity, unpredictability and ergodicity. [0003] Permutation-Diffusion Network (PDN) is...

AI Technical Summary

Problems solved by technology

The precision of the chaotic function in practical application is not infinite, and the limited precision will bring two important problems: 1. The quality of the pseudo-random sequence generated by the chaotic system is reduced; 2. Limiting the key space of the chaotic system

Although both problems can be solved when the accuracy is high enough, it is often at the expense of speed

And in the related image encryption technology, when the image is large, the calculation amount of displacement and diffusion is large

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