Image encryption method based on chaotic mapping and bit-level replacement

Abstract

The invention provides an image encryption method based on chaotic mapping and bit-level replacement. The method comprises the following steps: converting a grayscale image into an image matrix; iterating 2D-LSCM mapping to generate a chaotic sequence and mapping the chaotic sequence into a matrix, and returning a position index to perform pixel position exchange on the image matrix after descending sorting of each row; sequentially exchanging the lowest three bits in every two pixel bits to obtain an information fusion sequence of the image; performing iteration on the Logistic mapping to generate a chaotic sequence, and performing operation on the information fusion sequence and the chaotic sequence to obtain a pixel replacement column of the image; and performing pixel diffusion on thepixel replacement sequence of the image by using a chaotic sequence and a ciphertext diffusion technology to obtain an encrypted image. The chaotic mapping and scrambled images are used for replacement operation, the differential attack resistance is enhanced through bit information fusion operation and an image pixel-based diffusion method, the secret key space is large enough, violent attack canbe better resisted, and good safety is achieved.

Description

Technical field [0001] The present invention relates to the field of digital image encryption, in particular it relates to an image encryption method based on chaotic map and replaced with bit-level. Background technique [0002] As we all know, an effective encryption policy to better protect the image information. With the continuous development of society, especially when we are about to enter the era of 5G, digital image in people's daily lives is widely used to study the digital image to improve the security of an important topic of current computer science research. Traditional encryption algorithms can not meet the demand for rapid development of image encryption, image information because the class has a large amount of data, and high correlation between the data. This data has the characteristics of traditional cryptography encryption can cause inefficient. [0003] Chaos applications in image encryption algorithm a good choice, specifically, strong sensitivity, ergodic,...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the technical problems of the existing image encryption method with small key space, insufficient anti-attack ability, and long time-consuming, in order to ensure the security of image information, the present invention proposes an image encryption method based on chaotic mapping and bit-level permutation, using two-dimensional Chaos map and bit scrambling are used to encrypt images, which increases the key space, improves the security of ciphers, and reduces computational complexity, and the pixel scrambling method has a good effect on image pixel scrambling

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