CN115396676B - Encryption domain satellite image information hiding method - Google Patents
Encryption domain satellite image information hiding method Download PDFInfo
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- CN115396676B CN115396676B CN202210899424.0A CN202210899424A CN115396676B CN 115396676 B CN115396676 B CN 115396676B CN 202210899424 A CN202210899424 A CN 202210899424A CN 115396676 B CN115396676 B CN 115396676B
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- 238000000034 method Methods 0.000 title claims abstract description 44
- 238000012545 processing Methods 0.000 claims description 12
- 238000000605 extraction Methods 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 abstract description 9
- 238000004891 communication Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/46—Embedding additional information in the video signal during the compression process
- H04N19/467—Embedding additional information in the video signal during the compression process characterised by the embedded information being invisible, e.g. watermarking
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
- H04N19/124—Quantisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/65—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using error resilience
- H04N19/69—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using error resilience involving reversible variable length codes [RVLC]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/20—Adaptations for transmission via a GHz frequency band, e.g. via satellite
Abstract
The invention provides an encryption domain satellite image information hiding method, which can embed more secret information in image encryption data, does not influence normal decryption operation, and the encrypted image after the secret information is embedded still has random characteristics and cannot be visually distinguished. The concealment capacity can be adjusted according to the threshold, between 12.5% and 50%. The invention combines information hiding and data encrypting, breaks through the problem that the traditional encryption domain method is difficult to hide large-capacity information, and is suitable for the encryption transmission system of various image data of satellites and the ground.
Description
Technical Field
The invention relates to an encryption domain satellite image information hiding method, and belongs to the field of communication (such as data communication technology and the like).
Background
The data is divided into original data, compressed domain data and encrypted domain data, so that information hiding is also divided into information hiding of satellite original data, satellite compressed domain information hiding and satellite encrypted domain information hiding.
With the development of information security, satellite data encryption is more and more important, and more information can be transmitted by fully utilizing encrypted data by hiding the information in a satellite encryption domain, so that decryption and carrier recovery are not affected.
The main technical content is as follows: based on image data encryption and information hiding coding, the aim of hiding the satellite image information in an encryption domain is fulfilled. The current encryption domain information hiding method is mainly divided into information hiding before encryption, information hiding in encryption and information hiding after encryption. Most encryption methods for information hiding of the encryption domain in the literature are known, or a special encryption operation is performed, so to speak, what is supposed to be known about a specific encryption method when information hiding is performed. If only the encrypted data is known when information hiding is performed, the specific method is not known, the image cannot be encoded in advance, at this time, only the characteristics of the encrypted data can be utilized when information hiding is performed, the characteristics of the original image cannot be utilized, and the difficulty is greater when the hiding capacity is increased.
Disclosure of Invention
The invention solves the technical problems that: the method overcomes the defects of the prior art, utilizes the encrypted data characteristics and the information codes to hide the information, does not need to know an encryption method in advance, can adjust the hidden capacity according to a threshold, and can normally decrypt the image after the receiving end is unhidden. Typical hiding capacity can be between 12.5% and 50%, PSNR is between 30dB and 50dB, and the method is suitable for various image encryption transmission systems.
The technical scheme of the invention is as follows: an encryption domain satellite image information hiding method comprises the following steps:
1) Formatting the encrypted domain satellite image to obtain an 8-bit quantized image A;
2) Bit extraction is carried out on any pixel value a of the image A to obtain a high decimal number F1 and a low decimal number F2;
3) Calculating the difference between F1 and F2, and if the absolute value of the difference is smaller than or equal to a threshold T, marking S=0; if the absolute value of the difference is greater than the threshold T, the sign s=1;
4) After the lowest bit of the pixel value a of the image A is changed into S, generating a pixel value a' of the image C;
5) Embedding the data B into a pixel value a' of the image C to obtain a pixel value of the image D;
6) Step 2) -5) is carried out on each pixel value of the image A to obtain an image D, and the image D is stored and transmitted;
7) The receiving end carries out inverse processing on the image D to obtain restored data B;
8) The image D is subjected to an inverse process to obtain a restored encrypted image a.
The method for acquiring the high decimal number F1 and the low decimal number F2 is weighted summation.
The specific method for obtaining the high decimal number F1 and the low decimal number F2 is as follows:
F1＝8*A8+4*A7+2*A6+A5
F2＝8*A4+4*A3+2*A2+A1
wherein the image a pixel values are represented from high order to low order as: a8, A7, A6, A5, A4, A3, A2, A1.
The threshold t=0 to 15.
The receiving end carries out inverse processing on the image D to obtain restored data B, which comprises the following steps:
each pixel bit of the image D is D8, D7, D6, D5, D4, D3, D2, D1;
if d1=0, then take D4, D3, D2 for each pixel of the image D; obtaining B3, B2 and B1; if d1=1, then take D3, D2 for each pixel of the image D; obtaining B2 and B1;
the above-described processing is performed for each pixel value of the image D, and all bits of the data B are sequentially restored.
The inverse processing of the image D results in a restored encrypted image a, comprising:
if d1=0, setting D4, D3, D2, D1 of each pixel of the image D to D8, D7, D6, D5, to obtain a pixel value of the restored encrypted image a; if d1=1, then keeping D4, D3, D2, D1 of each pixel of the image D unchanged, obtaining a pixel value of the restored encrypted image a;
the above-described processing is performed for each pixel value of the image D, resulting in a restored encrypted image a.
Said embedding data B into pixel values a' of image C to obtain a pixel value of image D, comprising:
if s=0, selecting three bits of data B, and directly replacing bits C4, C3, C2 of pixel value a' of image C with B3, B2, B1 to obtain a pixel value of image D, where d1=c1=s;
if s=1, two bits of data B are selected, and B2, B1 is used to directly replace bits C3, C2 of pixel value a' of image C, to obtain a pixel value of image D, and d1=c1=s.
Said embedding data B into pixel values a' of image C to obtain a pixel value of image D, comprising:
if s=0, selecting three bits of data B, and directly replacing bits C4, C3, C2 of pixel value a' of image C with B3, B2, B1 to obtain a pixel value of image D, where d1=c1=s is unchanged;
if s=1, two bits of data B are selected, and B1 is directly substituted for bit C2 of pixel value a' of image C, resulting in one pixel value of image D, and d1=c1=s is unchanged.
Said embedding data B into pixel values a' of image C to obtain a pixel value of image D, comprising: the lower bits corresponding to the pixel value a' of the image C are directly replaced with the data B.
Compared with the prior art, the invention has the beneficial effects that:
(1) The invention breaks the conventional thinking and combines the characteristics of the image based on the encryption domain with information hiding; the contradiction that the traditional method can not give consideration to the hiding effect and the hiding capacity is overcome;
(2) The invention extracts the characteristics in the encrypted data, realizes new information hiding based on the threshold and the data mark, increases the hiding capacity and improves the image quality of hiding and recovering;
(3) The encryption domain information hiding method provided by the invention can be used for information hiding of satellite encryption domains and can also be used for encryption systems based on a sequence encryption algorithm in ground and other occasions.
(4) The hiding method provided by the invention has the advantages that the typical information hiding embedding capacity can be selected and adjusted according to the threshold T, and the difficulty that information hiding of different capacities of multiple types can be applicable by one method is solved; the method can also be simplified to a conventional least significant bit substitution method, and the hiding capacity of 12.5% can be directly achieved.
(5) The invention has high quality of recovered image, PSNR can be better than 30dB compared with the original image, and typical value can reach 35-50dB or even higher. The threshold T can be adjusted to achieve near-lossless or lossless carrier at a hiding capacity of about 12.5%, so that the method is not limited to image data, is not limited to encrypted data, and can be regarded as a special case of encryption (data and 0 are subjected to encryption operation).
Drawings
FIG. 1 is a flow chart of the method of the present invention.
Fig. 2 shows a partial simulation result, and the information uses random numbers. The upper left corner is the original image, the upper right corner is the encrypted image, the lower left corner is the encrypted information hidden image, and the lower right corner is the decrypted image.
Detailed Description
In order to verify the performance of the algorithm provided herein, an 8-bit gray scale image with the size of 512×512 is adopted as an image in a simulation experiment, and the method is used for information hiding transmission and recovery after encryption.
The invention discloses a method for hiding encrypted domain satellite image information, which comprises the following steps:
1) Formatting the encrypted domain satellite image to obtain an 8-bit quantized image A;
2) Carrying out bit extraction on the pixel value of the image A to obtain a high decimal number F1 and a low decimal number F2;
the method for acquiring the high decimal number F1 and the low decimal number F2 is weighted summation;
F1＝8*A8+4*A7+2*A6+A5
F2＝8*A4+4*A3+2*A2+A1
wherein the image a pixel values are represented from high order to low order as: a8 A7 A6 A5 A4 A3 A2 A1;
3) Calculating the difference between F1 and F2, and if the absolute value of the difference is smaller than or equal to a threshold T, marking S=0; if the absolute value of the difference is greater than the threshold T, the sign s=1, where t=0 to 15;
4) The lowest bit of the pixel value of the image A is changed into S, so that the pixel value of the image C is obtained, and the bits from the upper bit to the lower bit are C8, C7, C6, C5, C4, C3, C2, C1=A8, A7, A6, A5, A4, A3, A2 and S;
5) Embedding data B into pixels of an image C, wherein bits of the data B are B6, B5, B4, B3, B2 and B1 from high order to low order, and obtaining pixel values of the image D; the embedding of data B into pixels of image C is as follows: (two other steps for embedding data B into pixels of image C are similar)
If s=0, then bits C4, C3, C2 of the image C pixel values are directly replaced with B3, B2, B1; bits D4, D3, d2=b3, B2, B1, bits d1=c1=s unchanged;
if s=1, then bits C3, C2, D3, d2=b2, B1 of the pixel value of image C are directly replaced with B2, B1, bit d1=c1=s unchanged;
6) Storing and transmitting the image D;
7) The receiving end carries out inverse processing on the image D to obtain restored data B, and the method concretely comprises the following steps:
if d1=0, then the bits D4, D3, D2 of the image D are taken; obtaining bits B3, B2, B1;
if d1=1, then the bits D3, D2 of the image D are fetched; obtaining bits B2, B1;
8) The image D is subjected to inverse processing to obtain a restored image A, which is specifically as follows:
if d1=0, bits D4, D3, D2, D1 of the image D are set as bits D8, D7, D6, D5, resulting in a restored encrypted image a;
if d1=1, the bits D4, D3, D2, D1 of the image D are kept unchanged, resulting in a restored image a.
The invention provides an encryption domain satellite image information hiding method, which can embed more secret information data in image encryption data, wherein the encrypted image after being embedded with the secret data still has random characteristics, and the difference is not seen by vision.
By using the method provided by the invention, the information hiding of any sequence of encrypted images and other sequences of encrypted data can be realized. The concealment capacity is adjustable according to a threshold, typically between 12.5% and 50%.
The PSNR of the image after information hiding and the original encrypted image can reach 32-51dB. If S is compressed, the information hidden image and the original encrypted image PSNR may be 51dB to infinity.
The invention provides a method for hiding the image data information of an encrypted domain satellite, which solves the difficult problem of high-efficiency and high-quality hidden transmission of images, other images or data information through innovation, meets the actual requirement of users for carrying out multi-type information safe transmission, and also solves the key technology of encrypting and transmitting secret information in a satellite data transmission system. The method increases the capacity of satellite data transmission, expands the use of satellite information hiding, and has the realizability of software and hardware. Has practical value in satellite, satellite-ground data transmission and ground information transmission systems,
the invention is not described in detail in the field of technical personnel common knowledge.
Claims (9)
1. An encryption domain satellite image information hiding method is characterized by comprising the following steps:
1) Formatting the encrypted domain satellite image to obtain an 8-bit quantized image A;
2) Bit extraction is carried out on any pixel value a of the image A to obtain a high decimal number F1 and a low decimal number F2;
3) Calculating the difference between F1 and F2, and if the absolute value of the difference is smaller than or equal to a threshold T, marking S=0; if the absolute value of the difference is greater than the threshold T, the sign s=1;
4) After the lowest bit of the pixel value a of the image A is changed into S, generating a pixel value a' of the image C;
5) Embedding the data B into a pixel value a' of the image C to obtain a pixel value of the image D;
6) Step 2) -5) is carried out on each pixel value of the image A to obtain an image D, and the image D is stored and transmitted;
7) The receiving end carries out inverse processing on the image D to obtain restored data B;
8) The image D is subjected to an inverse process to obtain a restored encrypted image a.
2. The method for hiding encrypted domain satellite image information according to claim 1, wherein: the method for acquiring the high decimal number F1 and the low decimal number F2 is weighted summation.
3. The method for hiding encrypted domain satellite image information according to claim 2, wherein: the specific method for obtaining the high decimal number F1 and the low decimal number F2 is as follows:
F1＝8*A8+4*A7+2*A6+A5
F2＝8*A4+4*A3+2*A2+A1
wherein the image a pixel values are represented from high order to low order as: a8, A7, A6, A5, A4, A3, A2, A1.
4. The method for hiding encrypted domain satellite image information according to claim 1, wherein: the threshold t=0 to 15.
5. The method for hiding encrypted domain satellite image information according to claim 1, wherein: the receiving end carries out inverse processing on the image D to obtain restored data B, which comprises the following steps:
if d1=0, then three bits D4, D3, D2 for each pixel of the image D are taken; obtaining bits B3, B2, B1; if d1=1, then two bits D3, D2 for each pixel of the image D are taken; obtaining bits B2, B1;
the above-described processing is performed for each pixel value of the image D, and all bits of the data B are sequentially restored.
6. The method for hiding encrypted domain satellite image information according to claim 5, wherein: the inverse processing of the image D results in a restored encrypted image a, comprising:
if d1=0, setting the four bits D4, D3, D2, D1 of each pixel of the image D to the bits D8, D7, D6, D5, to obtain a pixel value of the restored encrypted image a; if d1=1, the four bits D4, D3, D2, D1 of each pixel of the image D are kept unchanged, obtaining a pixel value of the restored encrypted image a;
the above-described processing is performed for each pixel value of the image D, resulting in a restored encrypted image a.
7. The method for hiding encrypted domain satellite image information according to claim 1, wherein: said embedding data B into pixel values a' of image C to obtain a pixel value of image D, comprising:
if s=0, selecting three bits of data B, and directly replacing bits C4, C3, C2 of pixel value a' of image C with bits B3, B2, B1 to obtain a pixel value of image D, where d1=c1=s;
if s=1, two bits of data B are selected, and bits B2, B1 are used to directly replace bits C3, C2 of pixel value a' of image C, to obtain a pixel value of image D, and d1=c1=s.
8. The method for hiding encrypted domain satellite image information according to claim 1, wherein: said embedding data B into pixel values a' of image C to obtain a pixel value of image D, comprising:
if s=0, selecting three bits of data B, and directly replacing bits C4, C3, C2 of pixel value a' of image C with bits B3, B2, B1 to obtain a pixel value of image D, where d1=c1=s is unchanged;
if s=1, two bits of data B are selected, bit B1 is used to directly replace bit C2 of pixel value a' of image C, resulting in a pixel value of image D, and d1=c1=s is unchanged.
9. The method for hiding encrypted domain satellite image information according to claim 1, wherein: said embedding data B into pixel values a' of image C to obtain a pixel value of image D, comprising: the lower bits corresponding to the pixel value a' of the image C are directly replaced with the data B.
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