WO2020256205A1

WO2020256205A1 - Electronic document management system and method for providing authenticity and integrity

Info

Publication number: WO2020256205A1
Application number: PCT/KR2019/007663
Authority: WO
Inventors: 김영관
Original assignee: 김영관
Priority date: 2019-06-20
Filing date: 2019-06-25
Publication date: 2020-12-24
Also published as: KR20200145133A; KR102280505B1

Abstract

An electronic document management system for providing authenticity and integrity comprises: a hash value calculation unit for calculating a hash value for a document consisting of a black and white image; a request data configuration unit for, on the basis of the hash value calculated by the hash value calculation unit, generating request data in a format required by a time stamp request standard protocol and a time stamp authority; a time stamp token reception unit for receiving a time stamp token issued by the time stamp authority according to the request data; a pattern insertion unit for inserting data included in the time stamp token into a pixel of the black and white image; and a data verification unit for verifying whether the extracted value of the data included in the inserted time stamp token equals the inserted value.

Description

Electronic document management system and method providing authenticity and integrity

The present invention relates to an electronic document management system and method that provides authenticity and integrity, and more particularly, to prove the existence and integrity of a document using an image in which a timestamp token issued by an authorized time stamp is inserted. It relates to an electronic document management system and method that provides authenticity and integrity that can be done.

General typed documents, printed documents, and hand-written documents are composed of letters, lines, and drawings on white paper, and these forms are scanned through an optical device and converted into image files for convenient use using IT technology. Alternatively, it is stored in the organization's document image storage system.

This conversion of paper documents into digital images is defined as an electronic document, and its format is black and white using CCITT Group 3 encoding and CCITT Group 4 encoding managed by the International Telegraph and Telephone Consultative Committee (CCITT), an international standardization group. A lossless data compression technique consisting of two colored pixel values is used. Also, the official names of this standard are used as CCITT T.4 and CCITT T.6, respectively.

In addition, the standardized technology to prove the existence of digital data is used under the official name of TimeStamp Protocol (TSP), and the standard specifications are disclosed in IETF RFC 3161. Time stamp is an international standard technology based on public key (PKI) for verifying the creation time and authenticity of electronic (Japanese) documents and electronic data. This proves that electronic information existed at a certain point in time and has not changed since. The service that performs such certification is the Time Stamp Authority (TSA), and a domestic certification authority currently provides the service in the private sector. The timing of the private TSA cannot be presented as legal evidence.

'Confirmation of official authentication time' is a method of certifying that the document has not been forged or altered after registering the time when the electronic document was first created. When transacting through electronic documents such as insurance subscriptions, it means that the'authenticity' and'safety' of the document will be further strengthened than before.

However, a document image storage system generally uses a bi-level image, and is composed of a series of 1-bit pixels (1 = black, 0 = white) representing black and white information. Unlike the image processing image format in which one pixel consists of 8-bits, the image format for processing scanned documents has a size between 4 kilobytes and 8 kilobytes using known steganography techniques because 1-bit is allocated to each pixel. There is a problem that is not suitable for concealing digital signature data and point-of-view tokens created with

Therefore, the technical problem of the present invention is conceived in this respect, and the object of the present invention is to prove the authenticity and integrity of the document by using an image in which a timestamp token issued by an authorized point of view confirmation center is inserted. It is to provide an electronic document management system that provides integrity.

In addition, another object of the present invention is to provide an electronic document management method that provides authenticity and integrity that can prove the existence and integrity of a document by using an image in which a timestamp token issued by an authorized point of view confirmation center is inserted. will be.

An electronic document management system that provides authenticity and integrity according to an embodiment for realizing the object of the present invention is a hash value calculation unit that calculates a hash value of a document composed of a black and white image, and the hash value calculation unit. Based on the hash value, a request data configuration unit that generates request data that meets the standards of the timestamp request protocol and the format required by the accredited point certification authority, and receives a timestamp token issued by the accredited point accreditation authority according to the request data. A timestamp token receiving unit, a pattern inserting unit for inserting data included in the timestamp token into the pixels of the black and white image, and data verification verifying whether the data included in the inserted typestamp token is extracted equal to the inserted value Includes wealth.

In one embodiment of the present invention, the pattern insertion unit is a subset generation unit that generates a subset by dividing pixels of an image of a document composed of the black and white image into 3 pixels horizontally and 3 vertically, wherein the subset is the timestamp. When the insertion target determination unit that determines whether a token is to be inserted and the insertion target determination unit determines the subset as a target to which the timestamp token is to be inserted, a part of the data included in the timestamp token is determined as an insertion target. It may include an inserting unit that replaces and inserts a 1-bit value of data constituting the timestamp token into a central pixel of the subset.

In one embodiment of the present invention, the insertion target determination unit determines that three of the values of neighboring upper, lower, left, and right pixels are the same based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If so, it can be determined as an insertion target pixel.

In one embodiment of the present invention, the insertion unit fills a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as target pixels to be inserted with 0 or 1, and the hash value calculator includes a newly created black and white image. The hash value of is calculated, and based on the hash value of the document composed of the newly created black-and-white image calculated by the hash value calculation unit, the request data configuration unit meets the standards of the timestamp request protocol and the format required by the accredited time certification authority. Request data can be created.

In an embodiment of the present invention, the insertion target determination unit includes three values of the neighboring upper left, upper right, lower left and lower right pixels based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If it has a value, it can be determined as an insertion target pixel.

In one embodiment of the present invention, the insertion target determining unit is the insertion target pixel when three of four neighboring pixels have the same value based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. Can be determined by

In an embodiment of the present invention, the data verification unit includes a bit extracting unit for extracting bits of the inserted timestamp token, a restoration unit for combining the extracted bits to restore timestamp token data, and the restored timestamp. A certificate verification unit that converts token data into ASN.1 format and performs certificate verification, a hash value comparison unit that compares the hash value included in the timestamp token that has been verified by the certificate verification unit with the hash value of a black and white image to be verified, It may include a center verification unit for comparing the hash value included in the timestamp token with the issuance record of the authorized time point verification center, and a verification result display unit for displaying the verification result.

An electronic document management method for providing authenticity and integrity according to an embodiment for realizing the object of the present invention is the step of calculating a hash value of a document composed of a black and white image by a hash value calculation unit, and the hash value The step of generating request data that meets the format required by the timestamp request protocol standard rule and the accredited point certification authority based on the hash value calculated by the calculation unit, and the timestamp token receiving unit is issued by the accredited time stamp according to the request data. Receiving a timestamp token, inserting data included in the timestamp token into a pixel of the black and white image by a pattern insertion unit, and inserting data included in the inserted typestamp token by a data verification unit It includes the step of verifying whether the extracted properly.

In one embodiment of the present invention, the step of inserting the data included in the timestamp token by the pattern insertion unit into the pixels of the black-and-white image includes: And generating a subset by dividing it into 3 vertical pixels, determining whether the subset is a target into which the timestamp token is to be inserted, and the insertion unit determining whether the insertion target determining part is the subset of the timestamp token. In the case of determining that the timestamp token is to be inserted, a part of the data included in the timestamp token is replaced with a 1-bit value of the data constituting the timestamp token in the center pixel of the subset determined as the insertion target, and inserting the part. I can.

In one embodiment of the present invention, the step of determining, by the insertion target determination unit, whether the subset is a target to which the timestamp token is to be inserted, is neighboring based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If three of the values of one upper, lower, left, and right pixel have the same value, determining as an insertion target pixel.

In one embodiment of the present invention, the insertion unit fills a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as insertion target pixels with 0 or 1, and the hash value calculating unit is composed of a newly created black and white image. The step of calculating the hash value of the document and the request data configuration unit based on the hash value of the document composed of the newly created black and white image calculated by the hash value calculation unit, based on the timestamp request protocol standard protocol and the format required by the certification authority It may further include the step of generating the request data suitable for.

In one embodiment of the present invention, the step of determining, by the insertion target determination unit, whether the subset is a target to which the timestamp token is to be inserted, is neighboring based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If three of the values of one upper left, upper right, lower left, and lower right pixel have the same value, determining as an insertion target pixel.

In one embodiment of the present invention, the step of determining, by the insertion target determination unit, whether the subset is a target to which the timestamp token is to be inserted, is neighboring based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If three of the four pixels have the same value, determining as an insertion target pixel may be included.

In one embodiment of the present invention, the step of verifying whether the data verification unit extracts the data included in the inserted typestamp token equal to the inserted value is the bit extraction unit extracts the bits of the inserted timestamp token. A step of performing a certificate verification by converting the restored timestamp token data into an ASN.1 format by a recovery unit combining the extracted bits and restoring the timestamp token data, a hash value comparison unit Comparing the hash value included in the timestamp token that has been verified by the certificate verification unit with the hash value of the black and white image to be verified, and the center verification unit compares the hash value included in the timestamp token with the issuance record of the certified time stamp token And displaying the verification result by the display unit.

According to embodiments of the present invention, a means for clearly proving that a black and white image with a timestamp token issued by an authorized viewpoint check center has not been changed since the initial image viewpoint check processing through a verification process is mounted in the black and white image itself. And, the time of image verification can be used equally with the original through proof of existence that proves through a third-party accredited agency.

1 is a block diagram illustrating an electronic document management system providing authenticity and integrity according to an embodiment of the present invention.

2 is a block diagram showing a pattern inserting unit of an electronic document management system providing authenticity and integrity according to an embodiment of the present invention.

3 is a block diagram illustrating a data verification unit of an electronic document management system providing authenticity and integrity according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating a method of determining an insertion target pixel by an insertion target determination unit of an electronic document management system providing authenticity and integrity according to an embodiment of the present invention.

5 is a diagram illustrating a method of determining an insertion target pixel by an insertion target determination unit of an electronic document management system providing authenticity and integrity according to an embodiment of the present invention.

6 is a diagram illustrating a method of determining an insertion target pixel by an insertion target determination unit of an electronic document management system providing authenticity and integrity according to an embodiment of the present invention.

7 is a flowchart illustrating an electronic document management method providing authenticity and integrity according to an embodiment of the present invention.

8 is a flowchart illustrating a data insertion step in an electronic document management method that provides authenticity and integrity according to an embodiment of the present invention.

9 is a flowchart illustrating a reversible processing step of an electronic document management method that provides authenticity and integrity according to an embodiment of the present invention.

10 is a flowchart illustrating a data verification step in an electronic document management method that provides authenticity and integrity according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

1 is a block diagram illustrating an electronic document management system providing authenticity and integrity according to an embodiment of the present invention. 2 is a block diagram showing a pattern inserting unit of an electronic document management system providing authenticity and integrity according to an embodiment of the present invention. 3 is a block diagram illustrating a data verification unit of an electronic document management system providing authenticity and integrity according to an embodiment of the present invention.

1 to 3, the electronic document management system 10 providing authenticity and integrity according to an embodiment of the present invention includes a hash value calculation unit 100, a request data configuration unit 200, and a timestamp token. It includes a receiving unit 300, a pattern insertion unit 400, and a data verification unit 500.

The hash value calculating unit 100 may calculate a hash value of a document composed of a black and white image. The hash value calculator 100 may calculate a unique hash value for only a pixel area excluding a meta data area in a document composed of a monochrome image. In addition, the hash value calculation unit 100 may calculate a hash value for the entire area including the metadata area in a document composed of a black and white image. After creation, the imaged electronic document is distributed in the process of adding/changing/deleting information in the metadata area. Therefore, in order to have the integrity and authenticity of the image itself regardless of the change of the metadata area, it is necessary to calculate and process the hash value considering only the pixel data excluding the image metadata. However, in the case of objects that need to pursue integrity and authenticity including metadata, the hash value including metadata is calculated and processed, and in this case, the integrity is considered to be damaged if an external addition/change/deletion of metadata occurs. I can judge.

The request data construction unit 200 may generate request data suitable for a format required by a timestamp request protocol standard rule and an authorized time certification authority based on the hash value calculated by the hash value calculation unit 100. After the request data construction unit 200 generates the request data, the request data may be transmitted to the authorized time certification authority to request the timestamp token transmission.

When the timestamp token receiver 300 transmits the timestamp token according to the timestamp token transmission request, the timestamp token may be received.

The pattern insertion unit 400 may insert data included in the timestamp token into a pixel of the monochrome image. The pattern insertion unit 400 may include a subset generation unit 410, an insertion target determination unit 420, and an insertion unit 430.

The subset generator 410 may generate a subset by dividing pixels of an image of a document composed of the monochrome image into 3 pixels horizontally and 3 vertical pixels.

The insertion target determination unit 420 may determine whether the subset is a target to which the timestamp token is to be inserted. A method by which the insertion target determination unit 420 determines whether the subset is a target to which the timestamp token is to be inserted will be described in detail with reference to FIGS. 4 to 6.

When the insertion target determination unit determines that the subset is a target to which the timestamp token is to be inserted, the insertion unit 430 inserts part of the data included in the timestamp token into a center pixel of the subset determined to be an insertion target. The 1-bit value of data constituting the timestamp token can be replaced and inserted.

The data verification unit 500 may verify whether the data included in the inserted typestamp token is extracted equal to the inserted value. The data verification unit 500 includes a bit extracting unit 510, a restoration unit 520, a certificate verification unit 530, a hash value comparison unit 540, a center verification unit 550, and a verification result display unit 560. Can include.

The bit extraction unit 510 may extract bits of the inserted timestamp token. The method of extracting bits of the inserted timestamp token by the bit extracting unit 510 is the same as the method of determining whether the subset is a target to which the timestamp token is to be inserted. Thus, the bit can be extracted from the pixel into which the timestamp token is inserted.

The restoration unit 520 may restore the timestamp token data by combining the extracted bits.

The certificate verification unit 530 may perform certificate verification by converting the restored timestamp token data into ASN.1 format. When converted to ASN.1 format, the digital signature data used for time point verification, the public key of the certificate, and certificate validation information can be included. Therefore, you can use this information to perform verification using the certificate verification standard API.

The hash value comparison unit 540 may compare a hash value included in a timestamp token for which verification by the certificate verification unit is completed with a hash value of a black and white image to be verified.

The center verification unit 550 may compare the hash value included in the timestamp token with the issuance record of the authorized time point verification center. Thereafter, a verification result is created, and the created verification result may be displayed on the verification result display unit 560.

Referring to FIG. 4, the insertion target determination unit of the electronic document management system that provides authenticity and integrity according to an embodiment of the present invention is based on a neighboring image based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If three of the values of the, lower, left and right pixels have the same value, it may be determined as an insertion target pixel.

Referring to FIG. 5, the insertion target determination unit of the electronic document management system providing authenticity and integrity according to an embodiment of the present invention is adjacent to the upper left corner based on the center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If three of the values of the upper right, lower left, and lower right pixels have the same value, it may be determined as an insertion target pixel.

Referring to FIG. 6, the insertion target determination unit of the electronic document management system providing authenticity and integrity according to an embodiment of the present invention is based on the center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. If three of the four pixels of are the same, it may be determined as an insertion target pixel.

7 is a flowchart illustrating an electronic document management method providing authenticity and integrity according to an embodiment of the present invention. 8 is a flowchart illustrating a data insertion step in an electronic document management method that provides authenticity and integrity according to an embodiment of the present invention. 9 is a flowchart illustrating a reversible processing step of an electronic document management method that provides authenticity and integrity according to an embodiment of the present invention. 10 is a flowchart illustrating a data verification step in an electronic document management method that provides authenticity and integrity according to an embodiment of the present invention.

7 to 10, in the electronic document management method providing authenticity and integrity according to an embodiment of the present invention, a hash value calculation unit calculates a hash value of a document composed of a black and white image (S100), request data The step of generating the request data in accordance with the format required by the timestamp request protocol standard rule and the authorized time certification authority based on the hash value calculated by the hash value calculation unit by the configuration unit (S200), the timestamp token receiving unit the request data Receiving a timestamp token issued by an authorized time stamp authentication authority according to (S300), inserting the data included in the timestamp token by a pattern insertion unit into the pixels of the black and white image (S400), and the insertion of the data verification unit And verifying whether the data included in the typestamp token is extracted equal to the inserted value (S500).

The step of inserting the data included in the timestamp token by the pattern insertion unit into the pixels of the black and white image (S400) is the step of creating a subset (S410), and determining whether the subset is a target to which the timestamp token is to be inserted Step (S420), inserting data (S430), performing reversible processing (S440), calculating a hash value for the reversibly processed black and white image (S450), and request data for the reversibly processed black and white image It may include generating (S460). Subsequently, steps S300 to S500 may be applied to the reversibly processed monochrome image. In addition, steps S420 to S430 may be performed in parallel for a plurality of pixels. Accordingly, the processing speed can be improved. The reversible processing means inserting data into a subset that is determined to be insertable, and then processing the original pixel values to be restored later in the verification process. For the reversible processing method, the address of the subset determined that the original pixel value can be restored even if the point-of-view token data is inserted is recorded in a separate memory area, and the subset address map is used in the data header to utilize this in the verification process. Can be placed in

The electronic document management method for providing authenticity and integrity according to the present embodiment is substantially the same as the electronic document management system for providing authenticity and integrity of FIGS. 1 to 6. Therefore, repeated description will be omitted.

Although the above has been described with reference to embodiments, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the following claims. You will understand that there is.

Claims

A hash value calculator for calculating a hash value of a document composed of a black and white image;

A request data constructing unit for generating request data suitable for a format required by a timestamp request protocol standard rule and a certified time certification authority based on the hash value calculated by the hash value calculating unit;

A timestamp token receiving unit for receiving a timestamp token issued by an authorized time certification authority according to the requested data;

A pattern inserting unit for inserting data included in the timestamp token into pixels of the black and white image; And

An electronic document management system that provides authenticity and integrity including a data verification unit that verifies whether data included in the inserted typestamp token is extracted equal to the inserted value.
The method of claim 1, wherein the pattern insertion unit

A subset generator for generating a subset by dividing pixels of an image of the document composed of the black and white image into 3 pixels horizontally and 3 vertically pixels;

An insertion target determination unit determining whether the subset is a target to which the timestamp token is to be inserted; And

When the insertion target determining unit determines the subset as a target to which the timestamp token is to be inserted, part of the data included in the timestamp token is configured to form the timestamp token in a center pixel of the subset determined as an insertion target. An electronic document management system that provides authenticity and integrity, comprising an inserting unit that replaces and inserts a 1-bit value of data.
The method of claim 2, wherein the insertion target determination unit,

Intrinsicity characterized in that when three of the values of neighboring upper, lower, left, and right pixels have the same value based on the center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel, it is determined as the insertion target pixel. Electronic document management system that provides integrity.
The method of claim 3, wherein the insertion unit fills a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as the insertion target pixels with 0 or 1,

The hash value calculator calculates a hash value of a document composed of a newly created black and white image,

The request data construction unit generates request data that meets a format required by a timestamp request protocol standard rule and an accredited point certification authority based on a hash value of a document composed of a newly created black and white image calculated by the hash value calculation unit. An electronic document management system that provides authenticity and integrity.
The method of claim 2, wherein the insertion target determination unit,

When three of the neighboring upper left, upper right, lower left, and lower right pixels have the same value based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel, it is determined as an insertion target pixel. Electronic document management system that provides authenticity and integrity.
The method of claim 5, wherein the insertion unit fills a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as the insertion target pixel with 0 or 1,

The hash value calculator calculates a hash value of a document composed of a newly created black and white image,

The request data construction unit generates request data that meets a format required by a timestamp request protocol standard rule and an accredited point certification authority based on a hash value of a document composed of a newly created black and white image calculated by the hash value calculation unit. An electronic document management system that provides authenticity and integrity.
The method of claim 2, wherein the insertion target determination unit,

Electronic providing authenticity and integrity, characterized in that when three of four neighboring pixels have the same value based on a center pixel value of 3 pixels horizontally and 3 vertically of the judgment target pixel, it is determined as the insertion target pixel. Document management system.
The method of claim 7, wherein the insertion unit fills a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as the insertion target pixel with 0 or 1,

The hash value calculator calculates a hash value of a document composed of a newly created black and white image,

The request data construction unit generates request data that meets a format required by a timestamp request protocol standard rule and an accredited point certification authority based on a hash value of a document composed of a newly created black and white image calculated by the hash value calculation unit. An electronic document management system that provides authenticity and integrity.
The method of claim 1, wherein the data verification unit,

A bit extraction unit for extracting bits of the inserted timestamp token;

A recovery unit that combines the extracted bits and restores timestamp token data;

A certificate verification unit for converting the restored timestamp token data into ASN.1 format to perform certificate verification;

A hash value comparison unit comparing a hash value included in a timestamp token for which verification is completed by the certificate verification unit with a hash value of a black and white image to be verified;

A center verification unit comparing a hash value included in the timestamp token with an issuance record of an authorized time point verification center; And

An electronic document management system that provides authenticity and integrity, comprising a verification result display unit that displays the verification result.
Calculating a hash value of a document composed of a black and white image by a hash value calculator;

Generating, by the request data construction unit, the request data suitable for a format required by a timestamp request protocol standard rule and an authorized time certification authority based on the hash value calculated by the hash value calculation unit;

Receiving, by a timestamp token receiver, a timestamp token issued by an authorized time point certification authority according to the requested data;

Inserting, by a pattern inserting unit, data included in the timestamp token into the pixels of the monochrome image; And

An electronic document management method for providing authenticity and integrity, comprising the step of verifying whether data included in the inserted typestamp token is extracted equal to the inserted value by a data verification unit.
The method of claim 10, wherein the step of inserting the data included in the timestamp token by the pattern insertion unit into the pixels of the black and white image,

Generating a subset by dividing, by a subset generator, pixels of an image of the document composed of the black and white image into 3 pixels horizontally and 3 pixels vertically;

Determining, by an insertion target determination unit, whether the subset is a target into which the timestamp token is to be inserted; And

When the insertion unit determines that the insertion target determination unit determines the subset as the target to which the timestamp token is to be inserted, a part of the data included in the timestamp token is added to the center pixel of the subset determined as an insertion target. An electronic document management method that provides authenticity and integrity, comprising the step of replacing and inserting a 1-bit value of constituting data.
The method of claim 11, wherein the step of determining whether the subset is a target into which the timestamp token is to be inserted,

And determining an insertion target pixel when three of the values of the neighboring upper, lower, left, and right pixels have the same value based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. An electronic document management method that provides authenticity and integrity by means of.
The method of claim 12,

Filling a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as target pixels by the insertion unit with 0 or 1;

Calculating a hash value of a document composed of a newly created black and white image by the hash value calculator; And

The request data construction unit generates request data suitable for a format required by a timestamp request protocol standard rule and an authorized time certification authority based on the hash value of a document composed of a newly created black and white image calculated by the hash value calculation unit. Electronic document management method for providing authenticity and integrity, characterized in that it further comprises.
The method of claim 11, wherein the step of determining whether the subset is a target into which the timestamp token is to be inserted,

Comprising the step of determining an insertion target pixel when three of the values of the neighboring upper left, upper right, lower left and lower right pixels have the same value based on the center pixel values of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. Electronic document management method that provides authenticity and integrity, characterized in that.
The method of claim 14,

Filling a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as target pixels by the insertion unit with 0 or 1;

Calculating a hash value of a document composed of a newly created black and white image by the hash value calculator; And

The request data construction unit generates request data suitable for a format required by a timestamp request protocol standard rule and an authorized time certification authority based on the hash value of a document composed of a newly created black and white image calculated by the hash value calculation unit. Electronic document management method for providing authenticity and integrity, characterized in that it further comprises.
The method of claim 11, wherein the step of determining whether the subset is a target into which the timestamp token is to be inserted,

Integrity and integrity, comprising the step of determining an insertion target pixel when three of four adjacent random pixels have the same value based on a center pixel value of 3 horizontal pixels and 3 vertical pixels of the determination target pixel. Electronic document management method to provide.
The method of claim 16,

Filling a center pixel value of 3 horizontal pixels and 3 vertical pixels of all pixels determined as target pixels by the insertion unit with 0 or 1;

Calculating a hash value of a document composed of a newly created black and white image by the hash value calculator; And

The request data construction unit generates request data suitable for a format required by a timestamp request protocol standard rule and an authorized time certification authority based on the hash value of a document composed of a newly created black and white image calculated by the hash value calculation unit. Electronic document management method for providing authenticity and integrity, characterized in that it further comprises.
The method of claim 10, wherein the step of verifying whether data included in the inserted typestamp token is extracted equal to the inserted value by the data verification unit,

Extracting bits of the inserted timestamp token by a bit extractor;

Restoring the extracted bits into timestamp token data by combining the extracted bits;

Performing a certificate verification by converting the restored timestamp token data into an ASN.1 format by a certificate verification unit;

Comparing, by a hash value comparison unit, a hash value included in a timestamp token for which verification is completed by the certificate verification unit with a hash value of a black and white image to be verified;

Comparing, by a center verification unit, a hash value included in the timestamp token with an issuance record of an authorized time point verification center; And

Electronic document management method for providing authenticity and integrity, comprising the step of displaying the verification result by the display unit.