CN104463767A - Visible encryption and decryption method with image disguising function and tampering identification function - Google Patents
Visible encryption and decryption method with image disguising function and tampering identification function Download PDFInfo
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Abstract
The invention discloses a visible encryption and decryption method with the image disguising function and the tampering identification function. In the visible encryption process, an encryption rule table T designed in the method is used, and two meaningful separated-storage images are built from an input secret image, two input disguising images and an input watermark image; in other words, the separated-storage images have the characteristics of the disguising images, and therefore an attacker can be confused; meanwhile, the watermark image is embedded into the two separated-storage images to be capable of being used for identifying false separated-storage images made by the attacker, and illegal tampering to the separated-storage images is accordingly identified; in the visible decryption process, the secret image can be recovered by stacking the two separated-storage images; as for extracting of watermark information, the watermark image can be extracted from the two separated-storage images according to the encryption rule table T of the method. By means of the visible encryption and decryption method, the contrast ratio of the separated-storage images and the contrast ratio of the recovered secret image are not changed, and the watermark image can be completely recovered.
Description
Technical field
The present invention relates to a kind of information concealing method, be specifically related to a kind of camouflage test and distort the visual encryption method of authentication function and a kind of visual decryption method that there is camouflage test and distort authentication function of having.
Background technology
In recent years, network service and portable communication are developed rapidly and popularize, and also bring serious problem of data safety simultaneously, and data encryption technology is the important means solving this problem.But conventional encryption technique relies on complicated cryptographic algorithm, its huge operand limits its application on portable equipment.And user also needs to preserve secret key, in order to avoid lose or intercepted and captured by other people, like this, seriously constrain portability and the reliability of data encryption.
In recent years, visual password, as Secret Sharing Scheme, Theory and applications had had large development.Use visual cryptography technology, a width picture can be divided into two parts or many parts to transmit and store, every part is called that point is deposited an image.From point depositing the information that image cannot obtain original image, receiving end collect two parts or many parts points deposit image after, by its simple superposition, just can recover original private image information.In general visual cryptography, point deposit the meaningless image that image is black-white point stochastic distribution, easily cause the suspection of active attack person, thus cause it to point depositing distorting or destroying of picture.
Two width of the schemes generation of the visual password with camouflage test divide that to deposit image be significant image, have so just disperseed the notice of assailant.But, after image is deposited in assailant's intercepting and capturing point, can Tampering attack be implemented, namely deposit image 1 and false Secret Image according to intercepted and captured dividing, generate and deposit image 2 dividing of a width falseness.Deposit image 2 and real point for false point to deposit image 1 and superpose, recovery be false Secret Image, and general user cannot distinguish false Secret Image and real Secret Image.
Summary of the invention
For the above-mentioned technical matters existed in prior art; the present invention proposes a kind of visual encryption method that there is camouflage test and distort authentication function; the method can in the visual cryptography process with camouflage test; embed concealed watermark information simultaneously; this Information Availability detects assailant to point depositing distorting of image, thus serves and distort protective effect.
To achieve these goals, the present invention adopts following technical scheme:
There is camouflage test and the visual encryption method distorting authentication function, comprise the steps:
A1 inputs a width Secret Image, two width camouflage test and a width watermarking images, and by each width image binaryzation;
A2 uses key K w that watermarking images is used random number scramble, generates the scramble watermarking images of same size;
A3, according to following requirement, builds visual cryptography rule and watermark embedment rule, is called encryption rule table T:
1) if Secret Image bit is 0, then, after the 2x2 block of pixels superposition needing guarantee two width to divide to deposit image corresponding, one 0 is had at least; If camouflage test respective pixel is 0, then corresponding point deposit four pixels corresponding on image must have two 0, two 1; If the pixel that camouflage test is corresponding is 1, then divide four pixels of depositing image corresponding must have three 1, one 0;
If the image pixel combination of point depositing meeting above-mentioned condition has N couple, often pair is made up of two 2x2 block of pixels, the pixel of point to deposit image respectively constructed by correspondence; Be two groups by N to block of pixels random division, be called G1 and G0;
If watermark bit is 1, then select a pair block of pixels in first group of G1; If watermark bit is 0, then select a pair block of pixels in second group of G0 at random;
Selected block of pixels is filled out and point deposits on image correspondence position;
2) if Secret Image bit is 1, then, after four the bits superpositions needing guarantee two width to divide to deposit image corresponding, be all 1; If camouflage test respective pixel is 0, then corresponding point deposit four pixels corresponding on image must have two 0, two 1; If the pixel that camouflage test is corresponding is 1, then divide four pixels of depositing image corresponding must have three 1, one 0;
If the image pixel combination of point depositing meeting above-mentioned condition has N couple, often pair is made up of two 2x2 block of pixels, the pixel of point to deposit image respectively constructed by correspondence; Be two groups by N to block of pixels random division, be called G1 and G0;
If watermark bit is 1, then select a pair block of pixels in first group of G1; If watermark bit is 0, then select a pair block of pixels in second group of G0 at random;
Selected block of pixels is filled out and point deposits on image correspondence position;
Wherein, occur in bit, pixel 1,0 represents black pixel and white pixel respectively;
A4 utilizes above-mentioned encryption rule table T, builds two width divide and deposit image from a width Secret Image of input, two width camouflage test and a width watermarking images, and the structure rule of point to deposit image is:
Divide the pixel of depositing image from top to bottom, by left-to-right two width that build one by one, four pixels that each Secret Image pixel correspondence point is deposited on image, namely divide and deposit 4 times that image size is Secret Image.
In addition, the invention allows for a kind of visual decryption method having camouflage test and distort authentication function, it adopts following technical scheme:
Have camouflage test and a visual decryption method of distorting authentication function, adopt the above-mentioned visual encryption method having camouflage test and distort authentication function, it comprises the steps:
B1 receiving end receives two width and divides and deposit image, will divide to deposit imaging importing and recover Secret Image information;
B2 obtains above-mentioned encryption rule table T, is divided by two width to deposit image and collect, and generates scrambling sequence according to key K w;
B3 divides the block of pixels of depositing image from top to bottom, by left-to-right two width that process one by one, deposits image at every turn and takes out a 2x2 block, namely obtain a pair 2x2 image block, be called image block pair, therefrom extract 1 bit watermark Pixel Information from each point;
B4 inquires about above-mentioned encryption rule table T; If image block is to being arranged in first group of G1, then the watermark bit decoded is 1; If image block is to being arranged in first group of G0, then the watermark bit decoded is 0;
Watermarking images that step b4 solves by b5 uses the scrambling sequence in step b1 to be inverted unrest, recovers watermarking images information, thus completes watermark decode.
The inventive method build visual cryptography divide deposit image time, can meet below three restrictions simultaneously:
(1) two width divides deposits Restore Secret image after imaging importing;
(2) feature of depositing image embodiment camouflage test is divided;
(3) point to deposit containing watermark information in image, thus receiving end can divide to deposit image from two width and extracts watermark information.
Tool of the present invention has the following advantages:
In the inventive method; simultaneously watermark information is embedded in point depositing in image in the visual cryptography process of band camouflage test; the image of point depositing generated is significant image and containing watermark information; so just disperse the notice of assailant; protect the copyright ownership of Secret Image further, carry out after avoiding assailant to obtain point depositing image distorting and then deliberate to change Secret Image information.When needs carry out dispute over copyright certification to Secret Image, watermarking images can be proposed to belonging to the copyright proving Secret Image from point to deposit image.Also can realize dividing the detection of depositing distorted image by extracting watermark.Visual cryptography combines with digital watermarking by the inventive method; namely visual cryptographic algorithm can protect the feature of copyright to combine by the feature of uncomplicated calculating Restore Secret information and digital watermarking effectively; both visual cryptography can be carried out to Secret Image by the inventive method; the copyright of image can be protected again further; therefore, the inventive method has certain theory significance and using value.The inventive method does not change a point contrast of depositing image and the rear Secret Image of recovery, and can recover watermarking images completely.
Accompanying drawing explanation
Fig. 1 has camouflage test and distorts the visual cryptography of authentication function and the FB(flow block) of decryption method in the present invention;
Fig. 2 is digital watermark embedding block diagram in Fig. 1 visual cryptography process;
Fig. 3 is the schematic diagram of encryption rule table T.
Embodiment
Below in conjunction with accompanying drawing and embodiment, the present invention is described in further detail:
As depicted in figs. 1 and 2, a kind of visual encryption method having camouflage test and distort authentication function, comprises the steps:
A1 inputs a width Secret Image, two width camouflage test and a width watermarking images, utilizes error-diffusion method to carry out binary conversion treatment to each width image, each width Computer image genration binary image of input;
A2 uses key K w that watermarking images is used random number scramble, generates the scramble watermarking images of same size;
A3, according to following requirement, builds visual cryptography rule and watermark embedment rule, is called encryption rule table T, as shown in Figure 3:
1) if Secret Image bit is 0, then, after the 2x2 block of pixels superposition needing guarantee two width to divide to deposit image corresponding, one 0 is had at least; If camouflage test respective pixel is 0, then corresponding point deposit four pixels corresponding on image must have two 0, two 1; If the pixel that camouflage test is corresponding is 1, then divide four pixels of depositing image corresponding must have three 1, one 0;
If the image pixel combination of point depositing meeting above-mentioned condition has N couple, often pair is made up of two 2x2 block of pixels, the pixel of point to deposit image respectively constructed by correspondence; Be two groups by N to block of pixels random division, be called G1 and G0;
If watermark bit is 1, then select a pair block of pixels in first group of G1; If watermark bit is 0, then select a pair block of pixels in second group of G0 at random;
Selected block of pixels is filled out and point deposits on image correspondence position;
2) if Secret Image bit is 1, then, after four the bits superpositions needing guarantee two width to divide to deposit image corresponding, be all 1; If camouflage test respective pixel is 0, then corresponding point deposit four pixels corresponding on image must have two 0, two 1; If the pixel that camouflage test is corresponding is 1, then divide four pixels of depositing image corresponding must have three 1, one 0;
If the image pixel combination of point depositing meeting above-mentioned condition has N couple, often pair is made up of two 2x2 block of pixels, the pixel of point to deposit image respectively constructed by correspondence; Be two groups by N to block of pixels random division, be called G1 and G0;
If watermark bit is 1, then select a pair block of pixels in first group of G1; If watermark bit is 0, then select a pair block of pixels in second group of G0 at random;
Selected block of pixels is filled out and point deposits on image correspondence position;
Wherein, occur in bit, pixel 1,0 represents black pixel and white pixel respectively;
As can be seen from Figure 3, after the pixel of Secret Image, two width camouflage test is determined, a point block of pixels of depositing image corresponding has multiple choices, selects any allocation plan actually, and the pixel value corresponding by watermark determines.
Such as, when the pixel of Secret Image is white, the pixel that first camouflage test is corresponding is white, the pixel that second camouflage test is corresponding is also white, as seen from Figure 3, deposit image configurations scheme and have 4 kinds of selections for corresponding point, select any scheme on earth, the present invention selects according to the value of embed watermark, if watermarking images respective pixel is 1, we then can Stochastic choice first and second kind of allocative decision wherein a kind of, if watermark pixel is 0, we then can Stochastic choice third and fourth kind of allocative decision wherein a kind of.Therefore, while visual cryptography is carried out to Secret Image, embedded in watermark information, and in this process, make use of and produce random number to select different allocative decisions by the secret key K of embedding, improve the security of algorithm.
A4 utilizes above-mentioned encryption rule table T, builds two width divide and deposit image from a width Secret Image of input, two width camouflage test and a width watermarking images, and the structure rule of point to deposit image is:
Divide the pixel of depositing image from top to bottom, by left-to-right two width that build one by one, four pixels that each Secret Image pixel correspondence point is deposited on image, namely divide and deposit 4 times that image size is Secret Image;
Use two width camouflage test, the feature that two width can be made to divide deposit image and present camouflage test, thus can confuse assailant, assailant can not be caused to note;
Can generate significant point of two width visual cryptography by said process and deposit image, each width divides to be deposited image and not to reveal watermark information and Secret Image information; The present invention is embedded in meaningful point of watermark of depositing in image and can be used for identifying that the falseness that assailant makes is divided and deposited image, thus identifies for point depositing illegally distorting of image;
A5 is open by above-mentioned encryption rule table T, and informs receiving end.
In addition, the present invention also proposes a kind of visual decryption method for above-mentioned visual encryption method, and it comprises the steps:
B1 receiving end receives two width and divides and deposit image, will divide to deposit imaging importing and recover Secret Image information;
B2 obtains above-mentioned encryption rule table T, is divided by two width to deposit image and collect, and generates scrambling sequence according to key K w;
B3 divides the block of pixels of depositing image from top to bottom, by left-to-right two width that process one by one, deposits image at every turn and takes out a 2x2 block, namely obtain a pair 2x2 image block, be called image block pair, therefrom extract 1 bit watermark Pixel Information from each point;
B4 inquires about above-mentioned encryption rule table T; If image block is to being arranged in first group of G1, then the watermark bit decoded is 1; If image block is to being arranged in first group of G0, then the watermark bit decoded is 0;
Due in telescopiny, the random number produced according to embed watermark secret key K, in the scheme of point to deposit random selecting in block of image pixels allocation plan corresponding to Secret Image, two width camouflage test and watermarking images various combination, therefore still needs the secret key K of embed watermark in watermark extraction process; Divide the various combination situation of depositing image pixel value successively according to two width, as shown in Figure 3, check that corresponding dividing is deposited in image configurations scheme to corresponding watermark assignment;
Whether watermarking images that step b4 solves by b5 uses the scrambling sequence in step b1 to be inverted unrest, recovers watermarking images information, thus completes watermark decode, judge point to deposit image receive and distort according to the watermarking images information extracted.
Certainly; more than illustrate and be only preferred embodiment of the present invention; the present invention is not limited to enumerate above-described embodiment; should be noted that; any those of ordinary skill in the art are under the instruction of this instructions; made all equivalently to substitute, obvious form of distortion, within the essential scope all dropping on this instructions, protection of the present invention ought to be subject to.
Claims (2)
1. there is camouflage test and the visual encryption method distorting authentication function, it is characterized in that, comprise the steps:
A1 inputs a width Secret Image, two width camouflage test and a width watermarking images, and by each width image binaryzation;
A2 uses key K w that watermarking images is used random number scramble, generates the scramble watermarking images of same size;
A3, according to following requirement, builds visual cryptography rule and watermark embedment rule, is called encryption rule table T:
1) if Secret Image bit is 0, then, after the 2x2 block of pixels superposition needing guarantee two width to divide to deposit image corresponding, one 0 is had at least; If camouflage test respective pixel is 0, then corresponding point deposit four pixels corresponding on image must have two 0, two 1; If the pixel that camouflage test is corresponding is 1, then divide four pixels of depositing image corresponding must have three 1, one 0;
If the image pixel combination of point depositing meeting above-mentioned condition has N couple, often pair is made up of two 2x2 block of pixels, the pixel of point to deposit image respectively constructed by correspondence; Be two groups by N to block of pixels random division, be called G1 and G0;
If watermark bit is 1, then select a pair block of pixels in first group of G1; If watermark bit is 0, then select a pair block of pixels in second group of G0 at random;
Selected block of pixels is filled out and point deposits on image correspondence position;
2) if Secret Image bit is 1, then, after four the bits superpositions needing guarantee two width to divide to deposit image corresponding, be all 1; If camouflage test respective pixel is 0, then corresponding point deposit four pixels corresponding on image must have two 0, two 1; If the pixel that camouflage test is corresponding is 1, then divide four pixels of depositing image corresponding must have three 1, one 0;
If the image pixel combination of point depositing meeting above-mentioned condition has N couple, often pair is made up of two 2x2 block of pixels, the pixel of point to deposit image respectively constructed by correspondence; Be two groups by N to block of pixels random division, be called G1 and G0;
If watermark bit is 1, then select a pair block of pixels in first group of G1; If watermark bit is 0, then select a pair block of pixels in second group of G0 at random;
Selected block of pixels is filled out and point deposits on image correspondence position;
Wherein, occur in bit, pixel 1,0 represents black pixel and white pixel respectively;
A4 utilizes above-mentioned encryption rule table T, builds two width divide and deposit image from a width Secret Image of input, two width camouflage test and a width watermarking images, and the structure rule of point to deposit image is:
Divide the pixel of depositing image from top to bottom, by left-to-right two width that build one by one, four pixels that each Secret Image pixel correspondence point is deposited on image, namely divide and deposit 4 times that image size is Secret Image.
2. there is camouflage test and a visual decryption method of distorting authentication function, adopt a kind of visual encryption method that there is camouflage test and distort authentication function as claimed in claim 1, it is characterized in that, comprise the steps:
B1 receiving end receives two width and divides and deposit image, will divide to deposit imaging importing and recover Secret Image information;
B2 obtains above-mentioned encryption rule table T, is divided by two width to deposit image and collect, and generates scrambling sequence according to key K w;
B3 divides the block of pixels of depositing image from top to bottom, by left-to-right two width that process one by one, deposits image at every turn and takes out a 2x2 block, namely obtain a pair 2x2 image block, be called image block pair, therefrom extract 1 bit watermark Pixel Information from each point;
B4 inquires about above-mentioned encryption rule table T; If image block is to being arranged in first group of G1, then the watermark bit decoded is 1; If image block is to being arranged in first group of G0, then the watermark bit decoded is 0;
Watermarking images that step b4 solves by b5 uses the scrambling sequence in step b1 to be inverted unrest, recovers watermarking images information, thus completes watermark decode.
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| CN109214971A (en) * | 2018-08-08 | 2019-01-15 | 山东科技大学 | A kind of gray level image visual encryption method |
| CN110430337A (en) * | 2019-08-02 | 2019-11-08 | 陕西师范大学 | Method, equipment and the storage medium that image camouflage and image restore |
| CN110460737A (en) * | 2019-07-09 | 2019-11-15 | 华北电力大学（保定） | A kind of images share and restoring method |
| WO2021104345A1 (en) * | 2019-11-29 | 2021-06-03 | 童勤业 | Anti-counterfeiting and encryption method based on local random image transformation technique |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109214971A (en) * | 2018-08-08 | 2019-01-15 | 山东科技大学 | A kind of gray level image visual encryption method |
| CN109214971B (en) * | 2018-08-08 | 2019-05-28 | 山东科技大学 | A kind of gray level image visual encryption method |
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