Image encryption method based on hyperchaotic system and multi-level scrambling

Abstract

The invention discloses an image encryption method based on a hyperchaotic system and multi-level scrambling. The image encryption method comprises the following steps: firstly, acquiring a hyperchaotic sequence K through the hyperchaotic system; converting an original image into a two-dimensional matrix with the size of L= H x W, wherein H and W are dimensions of rows and columns of a matrix respectively; then converting original image pixel information into a one-dimensional vector sequence P, performing pixel-level, bit-level and DNA-level scrambling on the sequence P through an index sequence generated by the hyperchaotic sequence K, performing an exclusive OR operation on a pixel sequence through a mapping sequence, encrypting the original image to obtain an encrypted DNA sequence through binary bit conversion, DNA coding and DNA base operation, and converting the encrypted DNA sequence into a binary bit sequence B2; and finally, converting the sequence B2 into an encrypted image.According to the image encryption method based on the hyperchaotic system and the multi-level scrambling provided by the invention, the image is scrambled and encrypted at the pixel level, the bit level and the DNA level, the key sensitivity is high, the encryption effect of the image is effectively improved, attack operations such as statistical analysis and exhaustive analysis can be effectively resisted, and the safety is high.

Description

technical field [0001] The invention relates to the technical field of digital image encryption, in particular to an image encryption method based on a hyperchaotic system and multi-stage scrambling. Background technique [0002] With the development of information technology, as an important medium, images are widely disseminated through the Internet. How to prevent illegal dissemination of images has become one of the research hotspots in recent years, because images have the characteristics of large capacity, strong correlation and high redundancy. , Traditional encryption methods, such as Advanced Data Encryption Standard (ADES), International Data Encryption Algorithm (IDEA), etc., often cannot be directly applied to image encryption. [0003] Chaotic systems have some natural characteristics: pseudo-randomness, extreme sensitivity to initial values ​​and parameters, ergodicity and unpredictability, these characteristics provide favorable conditions for image encryption...

AI Technical Summary

Problems solved by technology

[0002] With the development of information technology, as an important medium, images are widely disseminated through the Internet. How to prevent illegal dissemination of images has become one of the research hotspots in recent years, because images have the characteristics of large capacity, strong correlation and high redundancy. , traditional encryption methods, such as Advanced Data Encryption Standard (ADES), International Data Encryption Algorithm (IDEA), etc., often cannot be directly applied to image encryption

[0003] Chaotic systems have some natural characteristics: pseudo-randomness, extreme sensitivity to initial values ​​and parameters, ergodicity and unpredictability, these characteristics provide favorable conditions for image encryption, and there are a large number of image encryption using chaotic systems Results; image encryption operations are generally divided into two types: diffusion and scrambling. The former mainly changes the content of pixels in the image, while the latter mainly changes the position of pixels in the image. There are some shortcomings in the existing results. For example, the chaotic system used Low dimension or few parameters, low anti-cracking ability; encryption operation is only performed at the pixel level, and the information of lower-level data is not fully utilized; diffusion operation and scrambling operation are performed independently, and the two are not organically combined, a single chaotic map The encryption algorithm formed cannot guarantee that the encrypted image has high security

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