KR101028163B1 - Method of issuing and verifying time stamp of electronic document using embedded technology - Google Patents

Abstract

PURPOSE: A time stamp issuing/inspecting method of an electronic document by using an embedded technique including visual information is provided to easily verify conservation without modulation of the electronic document. CONSTITUTION: A time stamp plugin senses a time stamp issuance request about an electronic document(S210). A time stamp token is generated by including a hash value of the electronic document by commnicating with a time stamp server(S220). The time stamp is merged by using the time stamp plugin(S230). The time stamp includes visual information in a setting region which the document form of the electronic document offers.

Description

Issuing and verifying time stamp of electronic document using embedded technology}

The present invention relates to a time stamp for verifying the timing and authenticity of an electronic document. In particular, the present invention relates to a time stamp for adding a time stamp token and human information to an area provided by a document format of an electronic document while maintaining the document format of the electronic document. It relates to a stamp issuance method and electronic document verification method.

Forgery of documents has been a problem for many years. In particular, the forgery / falsification of official documents has emerged as a social issue that produces many well-intentioned victims due to the nature of its contents. Every year, a growing number of public officials are deposed or forfeited due to forgery / falsification of documents and forge private documents such as report cards or contracts.

On the other hand, with the widespread use of computers, electronic documents are becoming more common. However, the electronic document is very easy to forgery / forgery, unlike the paper document, there is a problem that is difficult to identify when the forgery / forgery. Furthermore, since the forgery / modulated document can be widely spread in a short time due to the characteristics of the electronic document, verifying the authenticity of the electronic document is a very important problem.

Electronic signatures were introduced to ensure the authenticity of electronic documents. An electronic signature is an electronic form of data attached or logically attached to an electronic document that is used to verify the identity of the signer and indicate the person's approval of the content of the electronic document. It is a computer-generated information instead of a pen as a manual signature or electronic substitute for a stamp.

Digital signatures are an effective tool that can reduce the risk of information leakage that can occur in internet shopping or cyber financial transactions. The use of electronic signatures can greatly help prevent theft or alteration of personal information.

However, the electronic signature has the disadvantage that it is impossible to check the timing of authenticity since the individual can change the time and re-sign. In other words, since the signature point is not clear, the integrity of the electronic document cannot be fully verified at a specific point in time.

A time stamp is an electronic technique that verifies the timing of an electronic document and proves that it has not been modified since. This is an element technology of Public Key Infrastructure (PKI), which adds visual information to digital signatures, enabling users to more effectively verify the integrity of electronic documents.

Specifications for time stamp technology have been introduced, for example, by RFC3161. However, in practice, it is not easy to add a time stamp to an electronic document in conformity with a standard such as RFC3161. That is, in the related art, when adding time stamp information added to an original electronic document, the extension of the electronic document is changed or the time stamp information is managed as a separate file. In particular, when the extension of the electronic document is changed, a lot of inconveniences occur in that a separate viewer program must be used to read the electronic document to which the time stamp is added.

Therefore, there is an urgent need for a new timestamp issuing method and an electronic document verification method that can more easily apply a timestamp to an electronic document and easily verify the authenticity of the electronic document using the timestamp.

An object of the present invention for solving the above problems is to easily verify that an electronic document existed without forgery / falsification at a specific point in time using a timestamp issued by adding a visual information from a third trusted institution. The purpose is to make it possible.

In addition, the present invention allows to manage the time stamp information integrated into a single file without compromising the file format of the electronic document to maintain compatibility with the existing electronic document, adding the time stamp information without a separate viewer program The purpose is to make it possible.

In addition, an object of the present invention is to apply a hierarchical structure to time stamp printing, to optimize the amount of data for time stamp printing, and to effectively display the time stamp printing.

In addition, the present invention includes the image data corresponding to the time stamp imprint in the dynamic link library, and by using a hash value corresponding to the dynamic link library to determine whether or not to change it caused by time stamp imprint damage by a third party It aims to solve possible problems.

Time stamp issuing method according to the present invention for achieving the above object, the time stamp plug-in installed in the form of a plug-in (electronic plug-in) in the electronic document program, detecting a time stamp issuance request for the electronic document; Generating, by the timestamp plug-in, a timestamp token including time information and a hash value of the electronic document by communicating with a timestamp server based on the issuance request; And incorporating the timestamp plug-in by including the timestamp token information in a predetermined area provided by the document format of the electronic document by using the timestamp plug-in.

In this case, generating the timestamp token may include transmitting a timestamp issue request message including a hash value of the electronic document to the timestamp server; And receiving, by the timestamp plug-in, the timestamp token from the timestamp server.

In this case, the step of integrating the timestamp printout may re-save the electronic document while maintaining the document format of the electronic document by adding the timestamp printout to a predetermined area provided by the document format of the electronic document.

In this case, the predetermined area provided by the document format of the electronic document may be a specific layer of the electronic document.

In this case, the electronic document may be any one of a Microsoft Office document, a Hangul Hangul document, and an Adobe Acrobat document.

In this case, the timestamp printout may include a first layer for displaying a background image; A second layer for displaying the visual information; And third and fourth layers for indicating whether the electronic document is forged / modulated, respectively.

At this time, the image data corresponding to the time stamp printing may be integrated and stored in the dynamic link library (DLL) for the time stamp plug-in at compile time. At this time, the timestamp plug-in may register a hash value for the dynamic link library to determine a modification to the dynamic link library.

At this time, the timestamp token may be in conformity with the RFC3161 standard, which is a timestamp standard using an international digital signature.

In addition, the electronic document verification method according to the present invention, the time stamp plug-in installed in the form of a plug-in to the electronic document program, detecting the electronic document verification request for the electronic document incorporating the time stamp printing; The timestamp plug-in calculates a current hash value of the electronic document based on the verification request, and compares the current hash value with a hash value included in a timestamp token of the electronic document stored by the timestamp plug-in. Determining whether forgery / modulation; And when the electronic document is judged to be forged / falsified, forgery / modulation in a predetermined layer of a timestamp print that is integrated in a predetermined area provided by a document format of the electronic document and includes externally issued visual information. And displaying the mark.

At this time, the electronic document verification method, if it is determined that the change in the hash value of the dynamic link library for the timestamp plug-in including the image data corresponding to the timestamp imprinting so that the dynamic link library is not executed. Can be.

According to the present invention, it is possible to easily verify that an electronic document existed without forgery / falsification at a specific time point by using a timestamp issued by adding a visual information from a third trusted organization.

In addition, the present invention enables to manage the time stamp information in a single file without compromising the file format of the electronic document, adds the time stamp information while maintaining compatibility with the existing electronic document, so that a separate viewer program Not required.

In addition, the present invention can apply the hierarchical structure to the time stamp printing to optimize the amount of data for the time stamp printing, and can effectively display the printing in the electronic document.

In addition, the present invention can be generated by including the image data corresponding to the time stamp imprint in the dynamic link library, and by using a hash value corresponding to the dynamic link library to determine whether to change it by the third party damaged the time stamp imprint. You can solve the problem.

The present invention will now be described in detail with reference to the accompanying drawings. Here, the repeated description, well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention, and detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity.

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

1 is a view showing a time stamp issuance / verification system according to the present invention.

Referring to FIG. 1, the time stamp issuing / verifying system includes a client terminal 110 and a time stamp server 120.

The client terminal 110 may be a user computer, a notebook, a tablet, a handheld PC, a personal digital assistant (PDA), a mobile phone, or the like, and an electronic document program for opening or editing an electronic document is installed.

The time stamp server 120 generates a time stamp token including time information when the time stamp issuance request is provided to the client terminal 110.

The time stamp server 120 is a comprehensive concept including all configurations for receiving a time stamp issue request message from the client terminal 110 and generating a reliable time stamp token including accurate time information. The time stamp server 120 corresponds to a trusted third party as a subject providing visual information that can prove the existence of data at a specific point in time. For example, the time stamp server 120 may be a concept including a time stamping authority (TSA), a time authority (TA), a certificate authority (CA), and the like.

That is, although the time stamp server 120 is illustrated as one hardware device in FIG. 1, the time stamp server 120 may be a set of a plurality of server devices connected through a network.

In addition to the electronic document program, the client terminal 110 is provided with a timestamp plug-in for performing a timestamp issuance and verification function for the electronic document.

At this time, the installation of the timestamp plug-in may be performed by downloading online or by a distributed recording medium or the like.

The timestamp plug-in may be provided in the form of a dynamic link library (DLL). As such, it is provided in the form of a dynamic link library and can be plugged in to an electronic document program, thereby easily extending the time stamp function of the existing electronic document program.

In this case, the image data corresponding to the timestamp print may be integrated and stored in the dynamic link library for the timestamp plug-in. In other words, in order to prevent forgery / falsification of time stamp imprint, image data corresponding to time stamp imprint is integrated into the dynamic link library, and the hash value for the dynamic link library is stored and a change to this value occurs. In this case, the dynamic link library itself can be prevented from running, thereby preventing the forgery / falsification problem of time stamp printing.

2 is a flowchart illustrating a method of issuing a time stamp according to an embodiment of the present invention.

Referring to FIG. 2, according to the method for issuing a time stamp according to an embodiment of the present invention, a timestamp plug-in installed in the form of a plug-in in an electronic document program may be included in the electronic document corresponding to the electronic document program. A time stamp issuance request is detected (S210).

At this time, the time stamp issuing request may be generated by the user's click on the "issuance" menu of the electronic document program generated by installing the time stamp plug-in.

That is, when the timestamp plug-in is installed, a menu bar or a toolbar may be added to the corresponding electronic document program, and the menu bar or the toolbar may be "issued", "confirmed", "verification", "delete", "issuance information", " Menus such as "Preferences", "Version", and "Help".

The user can execute a desired timestamp related function by selecting a desired function from an added menu bar or toolbar.

For example, the electronic document may be any one of an Adobe Acrobat document, a Hangul document, and a Microsoft Office document.

Further, according to an embodiment of the present invention, based on the issuance request, the timestamp plug-in communicates with a timestamp server to generate a timestamp token including time information and a hash value of the electronic document ( S220).

At this time, the timestamp token may satisfy RFC3161 standard.

That is, the timestamp token includes reliable time information for which the corresponding timestamp was issued, and a hash value of the electronic document requesting the timestamp. At this time, the hash value may be recorded together with a hash algorithm identifier, a hash algorithm name, and a hash length.

In addition, the timestamp token may include version information of the timestamp, policy identifier information, serial number, creation date, timestamp server name, and certificate information.

In particular, the certificate information may include a time stamp station (TSA) certificate and a time attribute certificate.

In addition, according to an embodiment of the present invention, the timestamp plug-in integrates the timestamp imprint including the time information into a predetermined area provided by the document format of the electronic document using the timestamp token (S230). ).

At this time, the integration of the timestamp printout may be performed by adding the timestamp printout to a predetermined area provided by the document format of the electronic document and restoring the electronic document while maintaining the document format of the electronic document.

In other words, the timestamp plug-in allows time stamp printing to be added to a specific expandable area or layer of the electronic document, thereby efficiently integrating the time stamp printing into the electronic document while maintaining the document format of the existing electronic document.

The predetermined area provided by the document format of the electronic document may vary depending on the type of electronic document or the manufacturer of the electronic document software.

For example, if the document format of the electronic document defines a specific layer of the electronic document as an extensible layer, the timestamp plug-in allows the timestamp imprint to be added to this extensible layer.

In this case, the timestamp imprint may have a multiple layer structure. For example, the timestamp printout may include a first layer for displaying a background image, a second layer for displaying visual information, and third and fourth layers for indicating whether the electronic document is forged or forged, respectively. have.

At this time, the image data corresponding to the timestamp print may be integrated and stored in a dynamic link library (DLL) for the timestamp plug-in at compile time. At this time, the timestamp plug-in may register a hash value for the dynamic link library to determine the modification to the dynamic link library.

FIG. 3 is an operation flowchart illustrating an example of generating a timestamp token shown in FIG. 2.

Referring to FIG. 3, the timestamp token generation step first transmits a timestamp issue request message including a hash value of the electronic document to the timestamp server (S310).

At this time, the time stamp issuance request message may include the hash algorithm information used as well as the hash value.

In addition, in the timestamp token generation step, the timestamp plug-in receives the timestamp token from the timestamp server (S320).

At this time, the timestamp server is a comprehensive concept including all configurations for receiving a timestamp issue request message and generating a reliable timestamp token including accurate time information. For example, the time stamp server may be a concept including a time stamping authority (TSA), a time authority (TA), a certificate authority (CA), and the like.

4 is a flowchart illustrating an electronic document verification method according to an embodiment of the present invention.

Referring to FIG. 4, an electronic document verification method according to an embodiment of the present invention includes a timestamp plug-in installed in a plug-in form in an electronic document program, and an electronic document for an electronic document in which a timestamp print is integrated. A verification request is detected (S410).

At this time, the electronic document verification request may be generated by the user clicking on the "verification" menu of the electronic document program generated by the time stamp plug-in is installed.

For example, the electronic document may be any one of an Adobe Acrobat document, a Hangul document, and a Microsoft Office document.

According to an embodiment, the electronic document program in which the time stamp plug-in is installed may generate a time stamp verification request every time the electronic document to which the time stamp is added is opened.

In addition, according to the timestamp verification method according to an embodiment of the present invention, the timestamp plug-in calculates a current hash value of the electronic document based on the verification request, by the current hash value and the timestamp plug-in. The hash value included in the timestamp token of the stored electronic document is compared to determine whether the data is forged or forged (S420).

In this case, when the current hash value of the electronic document and the hash value included in the time stamp token corresponding to the electronic document are different, it may be determined that the forgery / modulation occurred because the electronic document has changed.

In this case, when the current hash value of the electronic document and the hash value included in the timestamp token corresponding to the electronic document are the same, it may be determined that the forgery / modulation did not occur because no change occurred in the electronic document.

In addition, in the electronic document verification method according to an embodiment of the present invention, when it is determined that the electronic document is forged / modulated, the electronic document is integrated into a predetermined area provided by the document format of the electronic document and visually issued from the outside. The forgery / modulation marker is displayed on the predetermined layer of the included timestamp print (S430).

At this time, the time information may be generated by the timestamp server based on the detection of the timestamp issue request of the timestamp plug-in. Further, the time information may be reliable, authorized by a time authority, or the like, and may be provided with a corresponding time attribute certificate or time stamp station certificate.

In this case, the predetermined area provided by the document format of the electronic document may be a specific expandable layer of the electronic document.

In this case, the specific layer may vary depending on the type of the electronic document.

In this case, the time stamp imprint may have a multi-layer structure. In this case, the multi-layer may include a first layer for displaying a background image, a second layer for displaying visual information, and third and fourth layers for indicating whether the electronic document is forged / modulated, respectively. In this case, the forgery / modulation mark may be displayed on the third layer or the fourth layer.

As such, by implementing the time stamp imprint through multiple layers, unnecessary duplication of data can be prevented and only changed information can be efficiently displayed.

In this case, image data corresponding to the timestamp print may be integrated and stored in a dynamic link library (DLL) for the timestamp plug-in. At this time, the timestamp plug-in may register a hash value for the dynamic link library to determine the modification to the dynamic link library. The electronic document verification method illustrated in FIG. 4 may prevent the dynamic link library itself from being executed when a change is made to the registered hash value.

The timestamping method described with reference to FIGS. 2 to 3 and the electronic document verification method described with reference to FIG. 4 may not be separate methods. Therefore, after the time stamp is issued according to the time stamp issuing method described with reference to FIGS. 2 to 3, the electronic document verification according to the electronic document verification method described with reference to FIG. 4 may be performed.

5 and 6 are examples of timestamps printed according to an embodiment of the present invention, respectively.

Referring to FIG. 5, the timestamp stamp may include visual information 510 and may include a circular logo image around the visual information 510.

In this case, the visual information 510 and the circular logo image may belong to different layers.

Referring to FIG. 6, the time stamp imprint may include visual information 610 and may include a band-shaped logo image around the visual information 610.

In this case, the visual information 610 and the band-shaped logo image may belong to different layers.

Of course, there may be various forms of time stamps other than the examples shown in FIGS. 5 and 6.

7 is a diagram illustrating a multi-layer structure of a timestamp imprint according to an embodiment of the present invention.

Referring to FIG. 7, the timestamp print layer includes a layer 710 for displaying a background image, a layer 720 for displaying visual information, and a layer 730 for displaying a mark indicating that forgery / modulation has not occurred. ) And a layer 740 for displaying an indication that forgery / modulation has occurred.

The layer 710 for displaying a background image and the layer 720 for displaying visual information may always be displayed. In this case, the time information may be provided from the time stamp token.

The layer 730 for displaying the mark indicating that the forgery / modulation has not occurred is not displayed when the layer 740 for displaying the mark indicating the forgery / modulation has occurred.

The layer 740 for displaying a mark indicating that forgery / modulation has occurred is not displayed when the layer 730 for displaying a mark indicating that forgery / modulation has not occurred is displayed.

By using the multilayered structure as described above, it is easy to correct the change in a specific part of the image, efficiently display the forgery / modulation markers, etc., and prevent unnecessary duplication of image data.

8 is a diagram illustrating an example of an electronic document program screen in which a time stamp plug-in is installed according to an embodiment of the present invention.

Referring to Fig. 8, "issuance" 811, "confirmation" 812, "verification" 813, "delete" 814, "issuance information" 815, "environmental setting" on the electronic document program screen It can be seen that there is a toolbar 810 including "816," version "817, and" help "818.

The user can easily use a timestamp related function such as issuing or verifying a timestamp by using the toolbar 810 generated by installing the timestamp plug-in.

9 is a diagram illustrating an example of an electronic document program screen when a time stamp issuance is requested through a time stamp plug-in.

Referring to FIG. 9, when the user clicks "issuance" of the toolbar generated through the time stamp plug-in, the temporary time stamp print 910 is displayed.

The user may position the temporary timestamp stamp 910 at a desired position by dragging the mouse.

FIG. 10 is a diagram illustrating an example of an electronic document program screen when a timestamp confirmation is requested through a timestamp plug-in.

Referring to FIG. 10, when the user places a temporary timestamp inprint by dragging the mouse to a desired position, and clicks "Confirm" of the toolbar created through the timestamp plugin, the "Save As" window is displayed. Can be.

That is, when "confirm" of the toolbar generated by the timestamp plug-in is selected by the user, the electronic document to which the timestamp imprint is added is newly stored.

At this time, the document format of the newly stored electronic document is the same as the document format of the existing electronic document. Therefore, the extension of the newly stored electronic document and the extension of the existing electronic document may be the same.

11 is a diagram illustrating an example of an electronic document program screen for requesting time stamp verification through a timestamp plug-in.

Referring to FIG. 11, when the electronic document to which the time stamp is added is opened, the toolbar 110 generated by the time stamp plug-in is displayed, and the commercial user clicks the “verification” 120 on the toolbar 110 to display the electronic document. You can verify whether a document has been forged / modulated after the timestamp issue.

If the electronic document is not forged / falsified, the time stamp imprint 130 may include a forgery / modulation mark 140 indicating that the electronic document was not forged.

12 is a diagram illustrating an example of an electronic document program screen when forgery / modulation does not occur in an electronic document.

Referring to FIG. 12, the user can easily forge / modify the electronic document after the time stamp is issued through the forgery / modulation mark 140 provided by the timestamp plug-in or the timestamp verification result window 120. Can be verified.

FIG. 13 is a diagram illustrating an example of an electronic document program screen when forgery / modulation occurs in an electronic document.

Referring to FIG. 13, the user can easily forge / modify the electronic document after the time stamp is issued through the forgery / modulation mark 140 provided by the timestamp plug-in or the timestamp verification result window 120. Can be verified.

14 is a diagram illustrating an example of an electronic document program screen displaying timestamp token information through a timestamp plug-in.

Referring to FIG. 14, it can be seen that the timestamp token information includes a version, a policy identifier, a serial number, a creation date, a timestamp server name, and hash information.

In this case, the hash information may include a hash algorithm identifier, a hash algorithm name, a hash value, and a hash length.

15 is a diagram illustrating an example of an electronic document program screen displaying a time attribute certificate through a time stamp plug-in.

Referring to FIG. 15, it can be seen that the time attribute certificate includes a certificate issuer, issuer, signature information, time audit information, time audit policy information, and the like, together with the version, serial number, and validity period of the certificate.

The visual attribute certificate can confirm the result of visual audit by the time certification authority (TA).

The visual attribute certificate shown in FIG. 15 may be displayed by clicking the "Visual Attribute Certificate" button shown in FIG.

FIG. 16 is a diagram illustrating an example of an electronic document program screen displaying a time stamp station certificate (TSA certificate) through a time stamp plug-in.

Referring to FIG. 16, it can be seen that the time stamp station certificate includes information on issuance subject, issuer, validity period, and the like.

The time stamp station certificate shown in FIG. 16 can be displayed by clicking the "TSA certificate" button shown in FIG.

The method for issuing a time stamp and the method for verifying an electronic document according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

As described above, the time stamp issuing method and the electronic document verification method according to the present invention are not limited to the configuration and method of the embodiments described as described above, but the embodiments may be modified in various ways. All or some of the embodiments may be optionally combined.

1 is a view showing a time stamp issuance / verification system according to the present invention.

2 is a flowchart illustrating a method of issuing a time stamp according to an embodiment of the present invention.

FIG. 3 is an operation flowchart illustrating an example of generating a timestamp token shown in FIG. 2.

4 is a flowchart illustrating an electronic document verification method according to an embodiment of the present invention.

5 and 6 are examples of timestamps printed according to an embodiment of the present invention, respectively.

7 is a diagram illustrating a multi-layer structure of a timestamp imprint according to an embodiment of the present invention.

8 is a diagram illustrating an example of an electronic document program screen in which a time stamp plug-in is installed according to an embodiment of the present invention.

9 is a diagram illustrating an example of an electronic document program screen when a time stamp issuance is requested through a time stamp plug-in.

FIG. 10 is a diagram illustrating an example of an electronic document program screen when a timestamp confirmation is requested through a timestamp plug-in.

11 is a diagram illustrating an example of an electronic document program screen for requesting time stamp verification through a timestamp plug-in.

12 is a diagram illustrating an example of an electronic document program screen when forgery / modulation does not occur in an electronic document.

FIG. 13 is a diagram illustrating an example of an electronic document program screen when forgery / modulation occurs in an electronic document.

14 is a diagram illustrating an example of an electronic document program screen displaying timestamp token information through a timestamp plug-in.

15 is a diagram illustrating an example of an electronic document program screen displaying a time attribute certificate through a time stamp plug-in.

FIG. 16 is a diagram illustrating an example of an electronic document program screen displaying a time stamp station certificate (TSA certificate) through a time stamp plug-in.

Claims (16)

Detecting, by the timestamp plug-in installed in the client terminal in the form of a plug-in to the electronic document program, a request for issuing a time stamp for the electronic document corresponding to the electronic document program; Generating, by the timestamp plug-in, a timestamp token including time information and a hash value of the electronic document by communicating with a timestamp server based on the issue request; And The timestamp plug-in using the timestamp token to integrate a timestamp print including the time information into a predetermined area provided by a document format of the electronic document; Integrating the timestamps Re-save the electronic document while maintaining the document format of the electronic document by adding the timestamp imprint to a preset area provided by the document format of the electronic document, The preset area provided by the document format of the electronic document is Is a specific layer of the electronic document, The timestamp imprint A first layer for displaying a background image; A second layer for displaying the visual information; And Time stamp issuing method, characterized in that each of the multi-layer structure comprising a third and fourth layers for indicating whether the electronic document forgery / forgery. The method according to claim 1, Generating the timestamp token Transmitting a timestamp issue request message including a hash value of the electronic document to the timestamp server; And The timestamp plug-in receiving the timestamp token from the timestamp server Method for issuing a time stamp, characterized in that it comprises a. delete delete delete delete The method according to claim 1, The original ID mark image data corresponding to the timestamp stamp is Method of issuing a time stamp, characterized in that the integrated is stored in the dynamic link library (DLL) for the time stamp plug-in at compile time. The method of claim 7, The timestamp plug-in And registering a hash value for the dynamic link library to determine a modification to the dynamic link library. The method according to claim 1, The timestamp token is Method of issuing a time stamp, characterized by conforming to the RFC3161 standard. Detecting, by the timestamp plug-in installed in a form of a plug-in in the electronic document program, an electronic document verification request for the electronic document in which the timestamp print is integrated; The timestamp plug-in calculates a current hash value of the electronic document based on the verification request, and compares the current hash value with a hash value included in a timestamp token of the electronic document stored by the timestamp plug-in. Determining whether forgery / modulation; And If it is determined that the electronic document is forged / falsified, a forgery / falsification mark on a predetermined layer of a timestamp print that is integrated into a predetermined area provided by the document format of the electronic document and includes externally issued visual information. Steps to display Including, The timestamp imprint A first layer for displaying a background image; A second layer for displaying the visual information; And A multi-layered structure each including third and fourth layers for indicating whether the electronic document is forged / modulated, and the forged / falsified marker is displayed on the third layer or the fourth layer Document verification method. The method according to claim 10, The visual information The electronic document verification method, characterized in that generated in the time stamp server based on the time stamp issuance request detection of the time stamp plug-in. The method according to claim 10, The preset area provided by the document format of the electronic document is Electronic document verification method, characterized in that the specific layer of the electronic document. delete delete The method according to claim 10, The electronic document verification method And if it is determined that a change is made in the hash value of the dynamic link library for the timestamp plug-in including the image data corresponding to the timestamp imprint, the dynamic link library is not executed. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 1, 2, 7-12 and 15.

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