Chaotic image encryption method based on bit replacement and dynamic DNA coding

Abstract

The invention provides a chaotic image encryption method based on bit replacement and dynamic DNA coding. The objective of the invention is to solve the problem that security of chaotic encryption is affected by degradation of chaotic dynamics characteristics of an image encryption method based on a chaotic system in the prior art. The chaotic image encryption method comprises steps of firstly using the Keccak algorithm to calculate a hash value of a DNA sequence; based on the hash value, generating an initial state value of the chaotic mapping; by use of a hyperchaotic Chen system, generating a chaotic mapping index to carry out pixel position overall scrambling on an image; combining the Butterfly network to carry out bit position scrambling on each pixel, thereby achieving position grade scrambling; carrying out dynamic DNA coding on the image and combining the given DNA sequence to carry out XOR operation, thereby achieving replacing of the pixels; and finally, through the ciphertext feedback, further enhancing the chaotic and diffusion features. According to the invention, the chaotic image encryption method has big key space and is highly sensitive to a key, and capable of effectively resisting attacking operation of statistical analysis and exhaustion analysis.

Description

technical field [0001] The invention relates to the technical field of digital image encryption, in particular to a chaotic image encryption method based on bit replacement and dynamic DNA encoding. Background technique [0002] With the rapid development of multimedia technology and network technology, digital image processing has been widely used in all aspects of human social life, such as: remote sensing, industrial inspection, medicine, meteorology, communication, investigation and intelligent robots. Therefore, image information is getting more and more attention. It is even more important to protect the security of image data, especially in special fields such as military, commercial and medical treatment. Image encryption technology has become an effective method to protect transmitted digital images. Image data has the characteristics of large data volume, strong correlation, and high redundancy. The existing classical encryption methods cannot meet the needs of i...

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Problems solved by technology

[0006] Aiming at the degradation of chaotic dynamics characteristics of existing image encryption methods based on chaotic systems, which affects the security of chaotic encryption, the present invention relies on the sensitivity and pseudo-randomness of chaotic maps to initial conditions, and combines the inherent spatial structure of DNA molecules. Based on the advantages of type and unique information processing ability, a chaotic image encryption method based on bit permutation and dynamic DNA coding is proposed

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