Digital image hiding method based on chaotic random phase and coherence stack principle

Abstract

The invention provides a digital image hiding method based on the chaotic random phase and the coherence stack principle. The digital image hiding method comprises two major steps which are respectively the step of hiding the image, and the step of recovering the image, wherein the step of hiding the image is carried out as follows: respectively adopting two gray images which are the same size as the image to be hidden and the hiding result image; generating a sequence through key parameters by virtue of chaotic functions; converting the sequence into a phase matrix; calculating a matrix through the phase matrix and the image to be hidden; and then calculating to obtain the phase matrix serving as the key by virtue of the obtained matrix and the hiding result image; and the step of recovering the image is carried out as follows: completely recovering the original image by virtue of a key set and the hiding result, wherein the recovery process is the inverse process of the hiding process. The digital image hiding method based on the chaotic random phase and the coherence stack principle is applied to quick encrypting and decrypting of the images, and has the characteristics of being simple and direct in calculating and high in safety; and by adopting the method, a large number of images which are the same size can be encrypted into the same image, relative different plaintexts can be recovered based on different key sets, the obtained encrypting result can be any known image which is as large as the original image, and thus higher fraudulence is ensured.

Description

Technical field

[0001] The invention relates to the technical field of information security, in particular to an image encryption and hiding method.

Background technique

[0002] With the rapid development of Internet technology and the increasing demand for the transmission of a large amount of image information, digital image security processing technology has become more important. Exploring and developing image encryption and hiding technology has high academic and application value. Image processing technology based on optical principles is a new research hotspot in the field of image security processing. At present, it is widely used to use double random phase encoding technology, combined with optical Fourier transform, optical fractional Fourier transform or Fresnel transform image encoding method. The encryption result is uniform random noise which is nearly statistically irrelevant. In addition, the plaintext can also be encrypted into another known image by i...

Examples

Embodiment Construction

[0023] The specific implementation of method of the present invention is as follows:

[0024] 1. Image hiding process (such as figure 1 shown) in the following steps:

[0025] (1) Two grayscale images with known pixel sizes of M*N, where M and N are two integers, * means multiplication, and the normalized grayscale value matrix is ​​X 1 、X 2 , by X 1 Transform to X 2 The key group of is set to (a, b 1 , R), where R is generated during the hiding process;

[0026] (2) by key parameters (a, b 1 ) According to the chaotic function b n+1 =a·b n ·(1-b n ) to obtain a non-convergent sequence b, in order to ensure the high degree of chaos of the function, the parameter range is set to 3.9≤a≤4, b n ∈[0,1] and n∈[1,M*N], convert the sequence b into a phase sequence c, whose value satisfies c n =exp(ib n ), the sequence c can construct a chaotic random phase matrix C whose size is M*N according to the column formula;

[0027] (3) by X 1 (x,y) is calculated to get a new mat...

Technical field

[0001] The invention relates to the technical field of information security, in particular to an image encryption and hiding method.

Background technique

[0002] With the rapid development of Internet technology and the increasing demand for the transmission of a large amount of image information, digital image security processing technology has become more important. Exploring and developing image encryption and hiding technology has high academic and application value. Image processing technology based on optical principles is a new research hotspot in the field of image security processing. At present, it is widely used to use double random phase encoding technology, combined with optical Fourier transform, optical fractional Fourier transform or Fresnel transform image encoding method. The encryption result is uniform random noise which is nearly statistically irrelevant. In addition, the plaintext can also be encrypted into another known image by i...

Examples

Embodiment Construction

[0023] The specific implementation of method of the present invention is as follows:

[0024] 1. Image hiding process (such as figure 1 shown) in the following steps:

[0025] (1) Two grayscale images with known pixel sizes of M*N, where M and N are two integers, * means multiplication, and the normalized grayscale value matrix is ​​X 1 、X 2 , by X 1 Transform to X 2 The key group of is set to (a, b 1 , R), where R is generated during the hiding process;

[0026] (2) by key parameters (a, b 1 ) According to the chaotic function b n+1 =a·b n ·(1-b n ) to obtain a non-convergent sequence b, in order to ensure the high degree of chaos of the function, the parameter range is set to 3.9≤a≤4, b n ∈[0,1] and n∈[1,M*N], convert the sequence b into a phase sequence c, whose value satisfies c n =exp(ib n ), the sequence c can construct a chaotic random phase matrix C whose size is M*N according to the column formula;

[0027] (3) by X 1 (x,y) is calculated to get a new mat...

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