Image two-grade encrypting method based on double-chaos system

Abstract

The invention discloses an image two-grade encrypting method based on a double-chaos system, relating to the field of image encrypting systems. The adopted method comprises the steps of creating an auxiliary key by a plaintext image firstly; creating a two-dimension chaos scrambling matrix by the auxiliary key combined with the double-chaos system of the Chebyshev mapping and Logistic mapping to dually scramble the position and grey level of the pixels of plaintext image so as to realize the encryption of images. According to the image two-grade encrypting method, the auxiliary key based on the plaintext image is introduced to expand key space and correlate the key with the plaintext, so that the ability of the image encryption system for resisting attack of the known plaintext is enhanced; and meanwhile, the complicated characteristics of dynamics of the double-chaos system is utilized to dually scramble the position and grey level of the plaintext image, with good encryption effect and high security.

Description

technical field [0001] The invention relates to the fields of image processing and information security, in particular to an image secondary encryption method based on a double chaotic system. Background technique [0002] With the rapid development of multimedia communication technology, the demand for the transmission of a large amount of image information is also increasing, and image security and confidentiality technology has become more and more important. Image information itself has the characteristics of large amount of data and high data correlation. Traditional encryption methods for text information, such as Data Encryption Standard (DES), International Data Encryption Algorithm, RSA Asymmetric Encryption Algorithm, etc., are not completely suitable for image encryption. . Due to the characteristics of initial value sensitivity, aperiodicity, nonlinearity and unpredictability of chaotic systems, image encryption methods based on chaos have advantages in security...

AI Technical Summary

Problems solved by technology

The former achieves image encryption by changing the gray value of the original image pixels, and the latter scrambles the arrangement of the original image pixel positions, making it difficult for attackers to identify the original image, thereby achieving the purpose of image encryption, but the traditional two types of encryption The encryption key of the method has nothing to do with the plaintext image, and it is difficult to resist the known plaintext attack

[0004] In addition, currently commonly used chaos-based image encryption methods use a single discrete chaotic iterative system

Although the use of a single discrete chaotic iterative system in image encryption has the advantage of fast speed, it has disadvantages such as small key space and weak security functions, and the effect of one-time encryption is not ideal, and it is often still possible to distinguish the outline

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