Image encryption method based on H fractal structure and dynamic self-reversible matrix

Abstract

The invention provides an image encryption method based on an H fractal structure and a dynamic self-reversible matrix. The method comprises the following steps: converting an original grayscale imageinto an image matrix I; using a SHA-256 algorithm to generating a Hash hashed value and performing operation to obtain an initial value of the chaotic system; substituting into a Lorenz hyper-chaotic system and carrying out iteration to obtain four sequences; carrying out global scrambling and recombination on the image matrix I by using the sequence; generating a self-reversible matrix by usingthe sequence and the prime number and encrypting the self-reversible matrix; performing global scrambling and recombination by using the sequence; encrypting by using an H fractal diffusion method; performing global scrambling and recombination by using the sequence; and carrying out ciphertext forward feedback operation to obtain a ciphertext image. According to the invention, the ciphertext image and the plaintext image are closely connected, so that the security of the encrypted image is enhanced. The method enriches digital image encryption means, is easy to realize, large in key space and high in sensitivity, can resist exhaustive attacks and statistical attacks, and has a certain recovery capability when data is lost.

Description

Technical field [0001] The invention relates to the technical field of image encryption, in particular to an image encryption method based on an H fractal structure and a dynamic self-invertible matrix. Background technique [0002] In modern society, the main forms of network information are text and images. Traditional encryption algorithms such as DES and RSA are widely used in text encryption. However, with the development of multimedia technology, the amount of information carried by images is increasing. The use of traditional encryption algorithms is not sufficient to encrypt information such as images. The timeliness and safety requirements. Therefore, how to quickly and effectively encrypt image information has become a hot topic of research. [0003] In image encryption algorithms, there are two main types of image encryption methods: scrambling and diffusion. Scrambling is achieved by changing the position of pixels. Changing the position of pixels can break the corr...

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Problems solved by technology

[0004] Aiming at the technical problems of poor security and complex calculation degree of existing image encryption methods, the present invention proposes an image encryption method based on H-fractal structure and dynamic self-reversible matrix, which combines the encryption method of scrambling and diffusion, and integrates the image encryption method based on graphics H-fractal diffusion algorithm and diffusion algorithm based on dynamic self-reversible matrix, the analysis results show that they have good security and can be applied in the field of image encryption

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