KR20140077731A - Original data comparing apparatus and method, and original data restoring apparatus and method - Google Patents

Abstract

The present invention relates to an apparatus and method for original data comparison, and apparatus and method for original data recovery. The apparatus which compares the original digital data and modified data including security information which is generated by modifying the security information of the original data and is inserted to the modified data includes: a security area detection unit which detects a security area related to the security information of the data; an additional information detection unit which detects the additionally inserted information in response to the security information in the modified data; a distributed source decoding unit which decodes distributed sources based on the detected additional information and the detected security area; and a matching determination unit which compares the result of the distributed source decoding and the security area information and determines whether the result of the distributed source decoding and the security area information match.

Description

Technical Field [0001] The present invention relates to an original comparison apparatus and method, and an original restoration apparatus and method. BACKGROUND OF THE INVENTION 1. Field of the Invention < RTI ID =

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original comparison method and apparatus, and an original restoration apparatus and method, and it is necessary to show that security information is true while preventing important security information such as stamps, signatures, And more particularly, to a method and an apparatus for easily proving it when necessary.

The image forming apparatus forms an image to be printed on a document. The image forming apparatus may be implemented by a printer, a copying machine, a fax machine, a multifunction peripheral having two or more functions, or a device having an output function to be displayed on the screen.

2. Description of the Related Art In recent years, there has been a growing demand for office automation devices such as a multifunction peripheral that performs various functions such as a scanner and a fax, as well as a printing function of displaying an image on a screen or outputting a document (hereinafter, , A function of a multifunction apparatus, and a function of displaying on the screen together are referred to as a printing function). The image forming apparatus is gradually developed with high performance in order to expand its inherent functions.

In addition, although it is possible to consider a method of handling security information invisible to anyone because it is reluctant to disclose security information, this method is not limited to the use of documents requiring authentication such as certificates or papers .

Accordingly, the image forming apparatus can have a security printing function that restricts the security contents from being viewed or output, for printing, copying, etc., to the security document whose outflow is restricted.

In the conventional security printing function, when the image forming apparatus recognizes that the document is a secure document, it does not perform the printing itself, or does not process the input information at the time of scanning for copying. In addition, security information is processed by a method of inserting a barcode including security information, a method of reducing a readability of a document by superimposing a predetermined pattern on the entire document, or the like.

This processing method is inconvenient because it does not provide all the information in the document as well as the security related part.

In order to compensate for this, there may be a method of generating additional information by modifying only the security related part and inserting additional information to generate an original document as a public document. However, it is not possible to know whether a public document that only modifies the security-related part actually matches the original document. Therefore, authentication can not be easily performed when authentication is required. If there is no original data, If there is only an analog original document, there is a problem that restoration of the original document is difficult.

It is an object of the present invention to overcome the above-mentioned problems, and it is an object of the present invention to provide a security information management system and a security information management system, which can prevent important security information such as stamps, signatures, fingerprint information, And to provide an original comparing apparatus and method, and an original restoring apparatus and method, which can easily prove if there is a need to prove, and can restore actual original data when the original similar data is retained.

In order to accomplish the above object, the apparatus for comparing the digital original data and the modified data-modified data of the present invention with the security information of the original data means the inserted data, A supplementary information detecting unit for detecting additional information embedded in the deformation data corresponding to the security information, a distributed source decoding unit for performing distributed source decoding based on the detected secure area and the detected supplementary information, And a matching determining unit for comparing the decoding result of the distributed source with the information of the security area to determine whether or not they coincide with each other.

The original comparison apparatus includes a first hash generation unit for generating a first hash value using a hash function based on the security area of the original data and a second hash value generation unit for generating a second hash value using a hash function based on the distributed source decryption result, And a second hash generator for generating a hash value, wherein the first and second hash generators can use the same hash function.

The matching determining unit may compare the first hash value with the second hash value to determine whether the first hash value matches the first hash value.

The additional information detection unit may be spaced apart and disposed at a remote place.

Wherein when the digital original data is transmitted to the remote location as a result of the determination by the matching determining unit, the digital original data is inserted into the secure area of the digital original data by inserting a degree of recoverable error at the remote location, May restore the digital original data based on the detected additional information and the received security area information.

The amount of error to be inserted may vary depending on the type of channel code encoding and decoding technique performed for distributed source decoding.

It is possible to insert the error into the security area of the digital original data through at least any one of the various blurring and geometric conversion techniques utilizing Gaussian noise and various error generation techniques.

If it is determined that the comparison result does not match, the matching determining unit may calculate the similarity by using a conventional motion compensation technique, a motion compensation technique considering a geometric feature, and an image processing technique considering a statistical value, color and brightness of the security area have.

The original comparison apparatus may further include a digital conversion unit for converting the analog modified document into digital modified data.

Instead of the digital original data, digital original similar data having a degree of similarity higher than the threshold value with the digital original data can be input.

According to an aspect of the present invention, there is provided an apparatus for restoring digital original data based on digital original data and modified data-modified data of the present invention, A supplementary information detecting unit for detecting additional information embedded in correspondence with the security information in the modified data, a supplementary information detecting unit for detecting a security area associated with the security information of the similar data, A distributed source decoding unit for performing source decoding and a data restoring unit for recovering digital original data based on the distributed source decoding result.

The data decompression unit may restore the original data by inserting the resultant data obtained by performing distributed source decoding on the transformed data based on the original similarity data and the additional information in the form of additional data.

The original similarity data may be data having an error less than a certain reference value with the original data.

The original restoration apparatus may further include a first digital conversion unit for converting the analog original document into digital original data, and a second digital conversion unit for converting the analog modified document into digital modified data.

And the additional information detecting unit may be disposed apart from each other.

According to an aspect of the present invention, there is provided a method for comparing digital original data and modified data-modified data of the present invention, Detecting additional information inserted in correspondence with the security information in the modified data, performing distributed source decoding based on the detected secure area and the detected additional information, And deciding whether or not the distributed source decryption result is identical to the decrypted decryption result by comparing the distributed source decryption result and the secure area information.

The original comparison method includes a first hash generation step of generating a first hash value using a hash function based on a security area of the original data and a second hash value generation step of generating a first hash value using a hash function based on the distributed source decryption result, And a second hash generation step of generating a hash value, wherein the same hash function can be used in the first and second hash generation steps.

If it is determined that the comparison result does not match, the similarity determination step calculates the similarity using a general motion compensation technique, a motion compensation technique considering a geometric feature, and an image processing technique considering a statistical value, color and brightness of the secure area Step < / RTI >

According to another aspect of the present invention, there is provided a method for restoring digital original data based on digital original data and modified data-modified data of the present invention, A security area detecting step of detecting a security area associated with security information of the similar data; an additional information detecting step of detecting additional information embedded in the modified data corresponding to the security information; And a data restoring step of restoring digital original data based on the distributed source decoding result.

And restoring the original data by inserting resultant data obtained by performing distributed source decoding on the modified data based on the original similarity data and the additional information in the form of additional data.

According to the original comparison apparatus and method and the original document restoration apparatus and method of the present invention, in a publicly distributed document including specific security information, information that needs to restrict public exposure as much as possible, such as a signature or a signature, It is possible to authenticate the authentication when it is required to be authenticated in the future, and when the original data is not available, the original data can be restored with only data similar to the original.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram illustrating an image document, security information, and security areas that need to limit public exposure,
2 is a diagram for explaining generation of a distribution document by applying security information processing for inserting additional information associated with security information,
FIGS. 3A and 3B are diagrams for explaining distributed source decryption used in the original comparison apparatus and the original copy recovery apparatus according to an embodiment of the present invention;
4 is a block diagram schematically showing a security information processing apparatus for inserting additional information associated with security information,
5 is a block diagram schematically showing a configuration of an original comparison apparatus according to an embodiment of the present invention.
6 is a block diagram illustrating a configuration of an original comparison apparatus including a digital conversion unit and a hash generation unit according to another embodiment of the present invention.
FIG. 7 is a flowchart illustrating a process of calculating a degree of similarity of an original comparing apparatus according to an exemplary embodiment of the present invention. FIG.
8 is a block diagram showing a configuration of an original comparison apparatus including a separated additional information detection unit according to another embodiment of the present invention;
FIG. 9 is a flowchart illustrating a process in which an original comparison apparatus transmits digital original data to a remote location according to another embodiment of the present invention;
10 is a block diagram schematically showing the configuration of an original restoration apparatus according to an embodiment of the present invention.
11 is a block diagram illustrating a configuration of an original restoration apparatus including a digital conversion unit according to another embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

In this specification, a document includes a digital document and an analog document. A digital document means a document that can be displayed in electronic form through a scan or the like, and an analog document means a document that is not a digital form, such as a document printed on paper. Analog documents can be converted to digital through scanning. In addition, the distribution document is a public document that can be publicly promulgated, and the distribution document may have the form of an analog or digital document. The data implies that the data has a digital form. The modified data may be modified data of the original data, and may include data including additional information that modified the security information.

FIG. 1 is a diagram showing a security document and security information 20 with a video document 10 in need of limiting public exposure. As shown in FIG. 1, the image document 10 includes a security area 20 (which may mean an area including security information) including security information (a seal described as private in FIG. 1) . ≪ / RTI > In some cases, the security information may include security information such as a seal, a signature, fingerprint information, and the like, and may include personal information such as a car number and a resident registration number.

2 is a diagram for explaining generation of a distribution document 200 by applying security information processing for inserting additional information associated with security information.

2, the security area 110 of the analog original document 100 may be modified and inserted as the parity information 210 of the distribution document 200 by security information processing. That is, the additional information (parity information 210) can be generated using the digital information of the security area 110 related to the security information (any) included in the original document 100. When the original document 100 is modified by inserting only the part of the secure area 110 into the parity information 210 and inserted, the document 200 becomes a distributed document. Parity information 210 is inserted in the distribution document 200 in which the original document 100 is processed as a result of security information processing. Therefore, the security information on the analog original document 100 can not be directly discriminated from the distribution document 200 alone, and an appropriate attempt must be made to find out.

Even if you have an analog original document, if there is no digital original data, 100% restoration of digital original data may be difficult because even minute differences occur when scanning an analog original document. In this case, digital original data is required for comparison with a distribution document in order to confirm whether a document such as a specific person's article is correct. In the case where there is only a loss or analog document as described above, inconvenience that comparison with the original is impossible can not be performed.

According to an embodiment of the present invention, if similar information is present even when the original original information is lost due to an accident or a problem (however, it may not be possible if the difference exceeds a predetermined threshold value) Restoration of the document may be possible. Then, a comparison with the distribution document can be performed based on the restored original document.

FIGS. 3A and 3B are diagrams for explaining dispersion sod decoding used in the original comparison apparatus and the original copy restoration apparatus according to an embodiment of the present invention.

The original comparison apparatus and method, and the original restoration apparatus and method according to the present invention basically use Distributed Source Coding (DSC) and distributed source decoding based on the Slepian-Wolf theory. More specifically, channel coding is used to generate parity information required for distributed source coding. The Slepian-Wolf theory mathematically proves that even if the sources with correlation are independently encoded, the coding gain can be obtained to the same degree as that obtained by predictive coding of the respective sources if the decoding is linked to each other.

For example, the Slepian-Wolf theory is shown in FIG. 3A. In FIG. 3A, A is input to the encoder and the encoded information is decoded by the decoder 60, and information B is output. B can be expressed as A + e, where e means an encoding error. If e = 0, there is no error in B and B = A, which is commonly referred to as lossless coding. However, in general, allowing a certain amount of loss contributes to a higher compression ratio. Therefore, the e value may be larger than 0, and this case is referred to as lossy coding.

As shown in FIG. 3B, suppose that the decoder 60 can use not only encoding information sent from the encoder 50 but also information Y, which is similar to A, in an arbitrary manner. Then, it can be thought that it would be more advantageous to decode common sense. The advantage of decryption is that the encoder 50 can restore the information with the same accuracy even if the encoder 50 transmits less information to the decoder 60 (R2 <R1) (R2> R1), it is possible to improve the accuracy (e> δ) more than before.

3A and 3B, the information B reconstructed in FIG. 3A includes an error of e as compared to A. In FIG. 3B, the auxiliary information Y = A + Δ includes information about an error of Δ with respect to A it means.

As shown in FIG. 3B, if the decoder 60 restores the encoded information R2 and the Y information received from the encoder 50 at the same time, the result of C = A + Since?>?, The final restoration result C is close to A rather than Y information.

C = A + [delta] more than B = A + e, even though the encoder 50 shown in FIGS. 3A and 3B transmits the same information to the decoder 60 (R1 = R2) .

The Slepian-Wolf Theorem prove mathematically precisely this concept, which can be used to develop an encoder 50 that is very fast and computationally smaller than the conventional image coding method, You can also build a system. The present invention applies the concept of the Slepian-Wolf theorem, and it can be said that the application of the distributed source coding and decoding technique is particularly applied

4 is a block diagram schematically illustrating a security information processing apparatus for inserting additional information associated with security information. 4, the security information processing apparatus 400 may include a secure region setting unit 410, a distributed source encoding unit 420, and an additional information inserting unit 430. [

Referring to FIG. 4, the security area setting unit 410 detects an area to be processed as a security area in the input original. The security area means an area containing information requiring security such as painting, signature, fingerprint information, etc. from the original. The entire area of the original may be a security area, or only a part thereof may be detected as a security area.

The distributed source encoding unit 420 encodes the digital information corresponding to the secure region using a distributed source encoding technique. Two methods for distributed source coding can be considered as follows. In one embodiment, the distributed source coding unit 420 performs distributed source coding on the original digital information corresponding to the security area, i.e., the digital image itself corresponding to the security area. Alternatively, as another embodiment, the distributed source encoding unit 420 may extract the elements characteristic of the digital information corresponding to the secure region, that is, the feature values, and perform distributed source encoding on the feature values . Here, the feature value may be statistical information such as mean or variance information of brightness of the image, or may be arbitrary information generated by performing linear transformation on digital information corresponding to the security area It is possible.

The additional information inserting unit 430 inserts the parity information generated by the distributed source coding unit 420 into the input original data according to the selection. As an example, if the result of the processing on the original data is outputted in the form of digital information, the additional information inserting unit 430 may insert the parity information into the digital information file in the form of metadata. As another example, if the result of the processing on the original data 100 is output in the form of being printed on paper or the like, the additional information inserting section 430 may output the parity information to the printed matter by a predetermined method, .

Meanwhile, the additional information inserting unit 430 inserts the parity information into the original data as described above, and performs an image process to prevent any unauthenticated user of the security area from correctly viewing the corresponding information can do.

Since the video loss process is performed so that the security area is not accurately visualized, it is not easy to compare the original document with the distribution document in which the video loss process is performed, and a method for accurate comparison in various situations is required.

As a result, the security information on the original can not be directly discriminated from the distributed document generated through the above-described security processing, and it is very difficult to obtain the original information even if various attempts are made to detect it.

5 is a block diagram schematically illustrating the configuration of the original comparison apparatus 500 according to an embodiment of the present invention. The original comparison apparatus 500 is a device for detecting and restoring security information. If there is an analog or digital distribution document 504, it is checked whether or not each of the analog or digital distribution documents 504 coincides with the digital original 502. At this time, all comparisons are performed only for the security area. 5, the original comparison apparatus 500 according to an embodiment of the present invention includes a security area detection unit 510, a side information detection unit 520, a distributed source coding unit 530, 540).

Referring to FIG. 5, the secure area detection unit 510 detects a security area of the input digital source. As described above, the security area means an area related to the security information, and the security information means information requiring security such as stamp, signature, fingerprint information, and the like.

The additional information detection unit 520 detects additional information of an analog or digital distribution document 504 (the distribution document may be a document in which the security area is modified) requiring verification with the original. The additional information may be parity information that can be matched with the security area of the original data.

The distributed source decryption unit 530 decrypts the supplementary information acquired through the supplementary information detection unit 520 based on the secure area acquired through the secure area detection unit 510 and the distribution document 504 based on the digital source 502 To perform distributed source decoding. Since the security area of the digital source 502 is used as well as the additional information based on the distribution document 504 as a source input to the distributed source decoding unit 530, accurate decoding of the security area through distributed source decoding Lt; / RTI &gt; At this time, even if the digital original 502 does not exist, if there is data analogous to the original or the original, it is possible to invert the information of the security area.

The coincidence determining unit 540 compares the decryption result generated through the distributed source decryption unit 530 and the security area part of the actual digital source 502 to determine whether they match or not. As a result of the determination, it is possible to output "coincidence" if they are exactly the same, and "inconsistency" if they are different.

According to the embodiment of the present invention, the coincidence determining unit 540 can determine the similarity or non-similarity degree by measuring the similarity even in the case of "inconsistency"

6 is a block diagram illustrating a configuration of an original comparison apparatus 600 including a digital conversion unit 622 and hash generation units 640 and 642 according to another embodiment of the present invention. 6, the original comparison apparatus 600 includes a secure area detection unit 610, a digital conversion unit 622, an additional information detection unit 620, a distributed source decoding unit 630, a hash generation unit 640, 642) and a coincidence determining unit 650. [ Here, the secure area detection unit 610, the additional information detection unit 620, and the distributed source decoding unit 630 perform the same functions as those of the same components in FIG.

Referring to FIG. 6, in the case of the digital distribution document 606, since it is in the form of a digital file, the digital distribution document 606 can be directly input to the additional information detection unit 620. However, in the case of the analog distribution document 604, conversion to digital is required. For this, a digital converter 622 exists. The digital conversion unit 622 converts the analog distribution document 604 into digital information through a method such as scanning. The digital conversion unit 622 may be a scanner, a multifunction peripheral, or the like.

In relation to the hash generators 640 and 642, the hash generator 640 generates hash information for the secure area of the digital original 602 using a hash function. The hash generation unit 642 generates a hash for the decoded result through the distributed source decoding unit 630. [ Since the hash generation unit 640 and the hash generation unit 642 use the same hash function, the same output is always generated when the same data is input. Here, since it is very difficult to find the inverse function, it is very difficult to estimate the previous value with the output hash value.

The coincidence determining unit 640 compares the two hash values generated through the hash generating units 640 and 642 and outputs "coincidence" if the two values are exactly the same, and " .

As described above, the coincidence determining unit 640 compares the result with the security area of the digital original through distributed source decryption, and has two output values of coincidence or inconsistency. If the coincidence determining unit 640 and the coincidence determining unit 640 match, . However, if inconsistencies are reported, the following three causes are possible and additional considerations are needed.

1) First, when the digital original differs from the distribution document: In this case, the decoding result of the distributed source decoding unit 630 and the security area information on the digital source are completely different from each other.

2) In the case where the digital original and the distribution document are originally the same but can not be restored due to an error occurring in the middle: In this case, the decoding result of the distributed source decoding unit 630 and the security area information on the digital original are different Print the result.

3) If the digital original and the distribution document were the same and the error is below the threshold and can be restored, but the digital source has failed or has no digital origin, and other information similar to the analog or digital origin is used: , The decoding result of the distributed source decoding unit 630 and the security area information on the digital source are not perfectly the same, but the similar result is visually observed.

In order to quickly compare the correspondence between the digital original and the distribution document as in the case of 1) or 2), the hash generators 640 and 642 (also referred to as " 6) are useful. However, even if there is no hash generation part, it is possible to calculate the mutual difference value or calculate the similarity degree to check whether or not there is a match.

The reason why the above-described situation 3) occurs is that the distributed source decoding unit 630 This is because security information processing outputs the security area for the digital original used in creating the additional information. That is, if the information input to the secure area detection unit 610 is not 100% identical to the digital original, it is determined that the information is inconsistent. Of course, in this case, it can be judged that there is almost no match with the eye. To solve this problem, it is possible to measure the arithmetic similarity only when it is judged that there is a discrepancy.

FIG. 7 is a flowchart illustrating a process of calculating the similarity of the original comparison apparatuses 540 and 650 (see FIGS. 5 and 6) according to an embodiment of the present invention. In FIG. 7, although similarity is measured and the similarity with the original is determined based on the threshold value, the similarity value itself may be presented to the user to request the determination of whether or not the match is present.

Referring to FIG. 7, the coincidence determining unit performs a strict original comparison (S710). It is determined whether there is a match with the original through comparison of the original (S720). If the original is strictly matched, it is determined that the original is exactly matched (S754), and "match" If they are not strictly matched, the degree of similarity is measured (S730).

At this time, various calculation methods including Mean Squared Error (MSE), Mean Absolute Error (MAE), and Root Mean Squared Error (RMSE) can be used for the measurement of the arithmetic similarity. In particular, even when the security domain is geometrically deformed such as rotation, distortion, and position movement, it is possible to measure the similarity in consideration of motion compensation considering geometric features and conventional motion compensation techniques. In addition, similarity measurement can be attempted by applying various image processing techniques considering statistical values such as histogram of security area and color and brightness. All of the above schemes may be considered, and the degree of similarity may be measured by selectively applying at least one of the above schemes.

Based on the measured degree of similarity, it is compared with a threshold value or more (S740). It is determined that the distribution document is similar to the digital original. If the distribution document is equal to or smaller than the threshold value, it is determined that the distribution document is inconsistent with the original (S750), and the distribution document is different from the digital original It can be judged.

8 is a block diagram illustrating a configuration of an original comparison apparatus including a separated additional information detection unit 820 according to another embodiment of the present invention. 8, the original comparison apparatus 800 according to another embodiment of the present invention may include the original comparison apparatus part 1 800-1 and the original comparison apparatus part 2 800-2 . The original comparison apparatus 800-1 may include a security area detection unit 810, a distributed source decoding unit 830, a hash generation unit 840 and 842 and a consistency determination unit 850, 800-2 may include a digital conversion unit 822 and an additional information detection unit 820. [ Here, the secure area detection unit 810, the distributed source decryption unit 830, and the hash generation units 840 and 842 perform the same functions as the same components of FIG.

Referring to FIG. 8, security area detection and additional information detection can be remotely performed. Considering that the original comparison apparatus is divided into part 1 (800-1) and part 2 (800-2), a verification request having distribution documents 804 and 806 performs comparison with the digital original 802 at a remote site The remote comparison device part 2 (800-2) located at the remote location can determine whether the distribution document of the remote comparison device 800-2 matches the original document. That is, when the verification requestor wishes to perform verification with the analog distribution document 804, the analog distribution document 804 is converted into digital information via the digital conversion section 822. [ After detecting the additional information included in the distribution document through the additional information detecting unit 820 of the remote comparison apparatus 800-2, the additional information is transmitted to the part 1 800-1 in which the digital original 802 exists The part 1 800-1 can confirm whether or not there is a match using the digital original 802 secured in advance.

According to an embodiment of the present invention, since additional information uses parity information generated in distributed source coding, decoding of original information is almost impossible with only such additional information, so that it is naturally strong against security. That is, in this case, when the additional information is transmitted using e-mail, instant messenger, or the like, it is very difficult to decipher the original information even if someone intercepts the information or sees it secretly.

However, in the case where it is determined that the original information is communicated to the remote site, it is necessary to transmit the original information to the remote site. For example, if the original information should be transmitted using the mobile messenger or e-mail, When information is transmitted via messenger or e-mail, most of the information is stored in the e-mail server or the instant messenger server, so that there is a risk that the original information is exposed in the future.

In order to reduce the above problem, according to an embodiment of the present invention, only when the original information is determined to be exactly the same or equal to or greater than the threshold value, It provides a way to restore original source information, even if it does not contain the error itself to send the original. This method is characterized by using a core principle of a distributed source encoding and decoding method as a method different from a conventionally used encryption method. A specific method will be described with reference to FIG.

9 is a flowchart illustrating a process in which the original comparison apparatus transmits digital original data to a remote location according to another embodiment of the present invention.

First, referring to FIG. 8, a device (original comparison device part 1 (800-1)) having an original is used to confirm whether or not the original is matched from a remote device (original comparison device part 2 It has already received additional information of the remote device. It is supposed that if it is confirmed that it is very similar to the original or exactly matches with the original and that it is necessary to request not only the existence of the original at the remote site but also the information of the original itself.

Referring to Fig. 9, the device (original comparison device part 1 800-1 (see Fig. 8)) having the original is received from the remote device (original comparison device part 2 800-2 (S910) whether it is very similar or exactly matches the original in response to the request of the user. If it is confirmed that the original is very similar or exactly matches, the device having the original inserts an error to the security area of the original document so that it can be restored by the distributed source decoding method at the remote site (S920) The security zone information can be transmitted to the remote site (S930). In this case, the amount of errors to be inserted may vary depending on the channel code encoding and decoding techniques used for distributed source decoding. Error insertion can be performed using various image processing techniques such as Gaussian noise, various blurring, and various geometric transformations. The remote site can restore the original information using the additional information it owns and the transmitted security area information (S940). In this case, the remote site needs a configuration for decoding the distributed source.

10 is a block diagram schematically showing the configuration of an original restoration apparatus 1000 according to an embodiment of the present invention. The original restoration apparatus 1000 according to an embodiment of the present invention may include a secure area detection unit 1010, a side information detection unit 1020, a distributed source decoding unit 1030, and a data restoration unit 1040.

Referring to FIG. 10, when a digital original does not exist, the original document data 1052 or the similar data (not shown) is generated using the distribution document 1006 based on the analog original document 1004 or the analog original document 1004, 1054 &lt; / RTI &gt;

The security area detecting unit 1010 detects a security area of the digital original similarity data 1002 and the additional information detecting unit 1020 detects embedded additional information corresponding to the security information of the changed data based on the distribution document. The distributed source decryption unit 1030 performs distributed source decryption based on the detected security area and the additional information to decrypt the information about the secure area. The data restoration unit 1040 can restore the digital original data based on the decoding result of the distributed source decoding unit 1030.

According to an embodiment of the present invention, the data decompression unit 1040 decompresses distributed data based on the digital original similar data 1002 and the additional information to the modified data based on the distribution document, So that the original data can be restored. That is, since the additional information may be parity information, which is information based on matching with the original, if it is difficult to restore the original information by using only the parity information but has information estimated as original information, You can try to restore the original information. However, here, the original similarity data 1002 should be data substantially similar to the original, and may be data having a small error based on a certain reference value. Otherwise, restoration of the original may be difficult.

11 is a block diagram illustrating a configuration of an original restoration apparatus including a digital conversion unit according to another embodiment of the present invention. Here, the secure area detection unit 1110, the additional information detection unit 1120, the distributed source decoding unit 1130, and the data restoration unit 1140 perform the same functions as those in FIG.

Referring to FIG. 11, since the digital original similarity data 1102 is in the form of a digital file, the digital original similarity data 1102 can be directly input to the secure area detection unit 1110. However, the analog original document 1104 needs to be converted to digital, and for this purpose, the digital conversion unit 1115 exists. The digital conversion unit 1115 converts the analog original document 1104 into digital information through a method such as scanning. Likewise, in the case of the digital distribution document 1108, since it is in the form of a digital file, it can be directly input to the additional information detection unit 1120. However, in the case of the analog distribution document 1106, conversion to digital is required, and therefore, the digital conversion section 1125 is required. The digital converters 1115 and 1125 may be a scanner, a multifunction machine, or the like.

Also, although not shown in the figure, the digital conversion unit associated with the additional information detection unit and the additional information detection unit of the original restoration device may exist in a remote place as in the original comparison device 800 (see FIG. 8).

The original comparison method and the original restoration method according to the present invention can be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording media storing data that can be decoded by a computer system. For example, there may be a ROM (Read Only Memory), a RAM (Random Access Memory), a magnetic tape, a magnetic disk, a flash memory, an optical data storage device and the like. The computer-readable recording medium may also be distributed and executed in a computer system connected to a computer network and stored and executed as a code that can be read in a distributed manner.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions as defined by the following claims It will be understood that various modifications and changes may be made thereto without departing from the spirit and scope of the invention.

Claims (20)

The digital original data and the transformed data - the transformed data means the inserted data in which the security information of the original data is transformed,
A security area detector for detecting a security area associated with security information of the original data;
An additional information detection unit for detecting additional information embedded in the deformation data corresponding to the security information;
A distributed source decryption unit for performing distributed source decryption based on the detected security zone and the detected additional information; And
And a coherency determining unit for comparing the decoded result of the decentralized source and the secure area information to determine whether they coincide with each other.
The method according to claim 1,
A first hash generation unit for generating a first hash value using a hash function based on a security area of the original data; And
And a second hash generator for generating a second hash value using the hash function based on the result of the distributed source decoding,
Wherein the first and second hash generators use the same hash function.
3. The apparatus of claim 2, wherein the matching determining unit
And compares the first hash value with the second hash value and determines whether the first hash value matches the second hash value.
The method according to claim 1,
Wherein the additional information detecting unit is spaced apart from the other information detecting unit.
5. The method of claim 4,
When the digital original data is transmitted to the remote site, if the digital original data is determined to be a match as a result of the determination by the matching determining unit, the error is inserted into the secure area of the digital original data,
Wherein the remote restoration device restores the digital original data based on the detected additional information and the received security area information.
6. The method of claim 5,
Wherein the amount of error to be inserted varies depending on a type of a channel code encoding and decoding technique performed for distributed source decoding.
6. The method of claim 5,
Wherein the error is inserted into the secure area of the digital original data through at least one of performing various blurring and using a geometric conversion technique by utilizing Gaussian noise and various error generating techniques.
2. The apparatus of claim 1, wherein the matching determining unit
Wherein the similarity is calculated by using a conventional motion compensation technique, a motion compensation technique considering a geometric feature, and an image processing technique considering statistical value, color and brightness of the security area, Device.
The method according to claim 1,
Further comprising: a digital conversion unit for converting the analog modified document into digital deformation data.
The method according to claim 1,
Wherein the digital original similar data having a degree of similarity equal to or higher than a threshold value to the digital original data is used instead of the digital original data.
1. An apparatus for restoring digital original data based on digital original similar data and transformed data - transformed data means data inserted by transforming security information of digital original data,
A security zone detecting unit detecting a security zone associated with the security information of the original similarity data;
An additional information detection unit for detecting additional information embedded in the deformation data corresponding to the security information;
A distributed source decryption unit for performing distributed source decryption based on the detected security zone and the additional information; And
And a data restoring unit for restoring the digital original data based on the result of the distributed source decoding.
12. The apparatus of claim 11, wherein the data restoration unit
And restoring the original data by inserting resultant data obtained by performing distributed source decoding on the transformed data based on the original similarity data and the additional information in the form of additional data.
12. The method of claim 11,
Wherein the original similarity data is data having an error less than a predetermined reference value with respect to the original data.
12. The method of claim 11,
A first digital converter for converting the analog original document into digital original data; And
Further comprising: a second digital conversion unit for converting the analog modified document into digital deformation data.
12. The method of claim 11,
Wherein the additional information detection unit is spaced apart from the other information detection unit.
A method for comparing digital original data and transformed data - transformed data, wherein the security information of original data is modified and inserted data,
A security area detecting step of detecting a security area associated with the security information of the original data;
An additional information detecting step of detecting additional information embedded in the deformation data corresponding to the security information;
A distributed source decoding step of performing distributed source decoding based on the detected security area and the detected additional information; And
And comparing the decryption result of the distributed source with the security area information to determine whether or not they match.
17. The method of claim 16,
A first hash generation step of generating a first hash value using a hash function based on the security area of the original data; And
And a second hash generation step of generating a second hash value using the hash function based on the distributed source decoding result,
Wherein the same hash function is used in the first and second hash generation steps.
17. The method of claim 16,
And calculating a degree of similarity by using a conventional motion compensation technique, a motion compensation technique considering a geometric feature, and an image processing technique considering a statistical value, color, and brightness of the security area, when it is determined that the comparison result does not match .
A method for restoring digital original data based on digital original similar data and transformed data - transformed data means data inserted by transforming security information of digital original data,
A security area detecting step of detecting a security area associated with the security information of the original similarity data;
An additional information detecting step of detecting additional information embedded in the deformation data corresponding to the security information;
A distributed source decoding step of performing distributed source decoding based on the detected security area and the additional information; And
And restoring the digital original data based on the distributed source decoding result.
20. The method of claim 19,
And restoring the original data by inserting resultant data obtained by performing distributed source decoding on the transformed data based on the original similarity data and the additional information in the form of additional data.

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