JP2020027267A - Device for checking electronic signature, method and program therefor - Google Patents

Abstract

To provide a device for checking an electronic signature for a paper document.SOLUTION: An apparatus acquires signature target data and a signature (S 501). Next, the apparatus determines whether the signature is provided by a public key's holder by a public key and verifies the signature (S 502). Verification of the signature may be performed in a verification device accessible from the apparatus, and verification results may be returned to the apparatus. If verification of the signature is successful, the apparatus overlays a predetermined seal on a document image and displays it on a display screen of the apparatus (S 503).EFFECT: A user of the apparatus can visually check that an electronic signature has been given by those having authorization authority.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an apparatus, a method, and a program for verifying an electronic signature, and more particularly, to an apparatus, a method, and a program for mainly verifying an electronic signature on a paper document.

  There is an endless number of daily activities in which some kind of document is created, such as a request for approval for internal approval, and a person who has the approval authority gives approval to it.

  However, there are still many paper media as documents, and it is desired to increase efficiency by digitization. The present invention has been made to solve such a problem, and the purpose of the present invention is to use an electronic signature. To make it easier.

  In order to achieve the above object, a first aspect of the present invention is a method for performing an electronic signature on a paper document, the method comprising: A signature using a secret key; and transmitting the signature target data and the signature.

  According to a second aspect of the present invention, in the first aspect, the signature target data includes a signature date or date and time.

  According to a third aspect of the present invention, in the first or second aspect, the signature target data includes an input relating to approval or rejection by a signer.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the signature target data includes a signer ID.

  Further, according to a fifth aspect of the present invention, in the first aspect, the transmission is performed by using, as the signature target data, an image obtained by filling an area in the document image with a predetermined color as the signature target data. The transmission of an image in which a dimensional code is arranged in the area is characterized.

  According to a sixth aspect of the present invention, in the fifth aspect, the predetermined color is 0xFFFFFF or 0xFBFBFB.

  According to a seventh aspect of the present invention, in the fifth or sixth aspect, the two-dimensional code represents a signer ID in addition to the signature.

  According to an eighth aspect of the present invention, in any one of the fifth to seventh aspects, the data to be signed includes a date or date and time of a signature arranged at any position in the document image. It is characterized by.

  In a ninth aspect of the present invention, in any one of the fifth to seventh aspects, the data to be signed is an input related to approval or rejection by a signer located at any position in the document image. It is characterized by including.

  According to a tenth aspect of the present invention, there is provided a program for causing a computer to execute a method for performing an electronic signature on a paper document, the method comprising: a signature including a document image obtained by digitizing the document. The method includes the steps of: signing target data with a secret key; and transmitting the signature target data and the signature.

  An eleventh aspect of the present invention is an apparatus for performing an electronic signature on a paper document, wherein the signature is applied to signature target data including a document image obtained by digitizing the document with a secret key, and The signature target data and the signature are transmitted.

  According to a twelfth aspect of the present invention, there is provided a method for confirming an electronic signature on a paper document, the signature target data including a document image obtained by digitizing the document, and a signature using a secret key for the signature target data. , Verifying the signature with a public key, and, if the verification is successful, overlaying and displaying a visual element on the document image.

  In a thirteenth aspect of the present invention, in the twelfth aspect, the visual element is associated with an owner of the public key.

  According to a fourteenth aspect of the present invention, in the thirteenth aspect, the visual element is an imprint associated with the owner of the public key.

  According to a fifteenth aspect of the present invention, in the twelfth aspect, the data to be signed includes an input related to approval or rejection by a signer, and the visual element is different depending on the input. I do.

  In a sixteenth aspect according to the twelfth aspect, in the twelfth aspect, the signature target data includes a comment input by a signer, and when the verification is successful, the signature target data is overlaid on the document image and the comment is displayed. Or a step of enabling display.

  According to a seventeenth aspect of the present invention, in any one of the twelfth to sixteenth aspects, the signature target data includes a signer ID.

  According to an eighteenth aspect of the present invention, in the twelfth aspect, the reception is performed in such a manner that an image in which any area in the document image is filled with a predetermined color is used as the signature target data to represent the signature. It is characterized by receiving an image in which a dimensional code is arranged in the area.

  According to a nineteenth aspect of the present invention, in the eighteenth aspect, the two-dimensional code represents a signer ID in addition to the signature.

  According to a twentieth aspect of the present invention, in the seventeenth or nineteenth aspect, the signer ID is the public key.

  In a twenty-first aspect of the present invention, in the twentieth aspect, based on the public key, the validity of the received public key is confirmed by referring to a correspondence between the public key and a potential signer. The method further comprises the step of:

  In a twenty-second aspect of the present invention, in the seventeenth or nineteenth aspect, the signer ID is not the public key, and the public key is a signer based on the signer ID. It is obtained by referring to the association between the user and the public key.

  A twenty-third aspect of the present invention, in the twentieth or twenty-second aspect, further comprises a step of transmitting a request for identification of the holder of the acquired public key.

  In a twenty-fourth aspect of the present invention, in any one of the twelfth to twenty-third aspects, the signature target data includes a date or date and time, the verification is successful, and the date or date and time is a verification rule. If the condition is satisfied, the method further comprises overlaying and displaying a positive visual element on the document image.

  A twenty-fifth aspect of the present invention is a method for verifying an electronic signature, comprising: receiving a signature target data including a video and a signature using a secret key for the signature pair data; And, if the verification is successful, overlaying and displaying a visual element on the video.

  A twenty-sixth aspect of the present invention is a program for causing a computer to execute a method for confirming an electronic signature on a paper document, wherein the method includes a document image obtained by digitizing the document. Receiving a signature with the private key for the signature target data and the signature pair data, verifying the signature with a public key, and, if the verification is successful, overlaying and displaying a visual element on the document image And a step.

  According to a twenty-seventh aspect of the present invention, there is provided an apparatus for confirming an electronic signature on a paper document, the signature target data including a document image obtained by digitizing the document, and a signature using a secret key for the signature pair data. The signature is verified with a public key, and if the verification is successful, a visual element is overlaid on the document image and displayed on the display screen of the device.

  According to an aspect of the present invention, in a method for verifying an electronic signature, a visual element is overlaid on a document image when the signature received together with the data to be signed including the document image is successfully verified by a public key. By displaying the electronic signature, the use of the electronic signature can be facilitated.

FIG. 1 is a diagram illustrating an electronic signature device according to an embodiment of the present invention. FIG. 2 is a diagram schematically illustrating signature target data according to an embodiment of the present invention. FIG. 2 is a diagram showing a flow of an electronic signature method according to an embodiment of the present invention. FIG. 4 is a diagram illustrating an example in which a two-dimensional code is used for a signature according to an embodiment of the present invention. FIG. 2 is a diagram showing a flow of a method for confirming an electronic signature according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)

  FIG. 1 shows an electronic signature device according to the first embodiment of the present invention. The electronic signature device 100 has an imaging unit 101 such as an imaging device, and digitizes a document 110 to be approved by an approver who uses the device 100 as an image 201. For example, the image can be in a general JPEG format or the like. Then, an electronic signature is performed as the signature target data 200 (see FIG. 2) including a date 202 such as an approval date and an input 203 at the time of signature as necessary. The date 202 may be a date and time, but will be described below as a date for simplicity.

  The electronic signature device 100 includes, in addition to the imaging unit 101, a communication unit 102 such as a communication interface, a processing unit 103 such as a processor and a CPU, and a storage unit 104 including a storage device or storage medium such as a memory and a hard disk. The computer is a computer, and can execute each process described in this specification by executing a predetermined program. The program may include one or more programs, and may be recorded on a computer-readable storage medium to be a non-transitory program product. The electronic signature device 100 can be a mobile terminal capable of imaging, such as a smartphone and a tablet.

  The device 120 can directly or indirectly communicate with the electronic signature device 100 via a computer network to receive a signed document image. Although not shown, the device 120 may have a similar hardware configuration. Alternatively, the imaging unit may not be provided.

  FIG. 3 shows a flow of the electronic signature method according to the first embodiment of the present invention. First, the digital signature device 100 captures the document 110 to be signed and digitizes it as an image 201 (S301). The document image 201 is signed with the date 202, the comment 203, and the like, as necessary, as signature target data 200 using the digital signature device 100 or a storage medium accessible from the digital signature device 100 or a secret key stored in a storage device. (S302). Then, the digital signature device 100 adds a signature to the signature target data 200 and transmits the data to the device 120 (S303). Until the signature and further the transmission, the document may be automatically captured or triggered by storing the captured image. The signature target data 200 and the signature added thereto may be collectively referred to as “verification target data”.

  In order to verify the signature in the device 120 that has received the signed data 200 to be signed, a public key corresponding to the secret key used for the signature is required, and an approver ID for identifying the approver is used. Can be transmitted as a part of the signature target data 200, or can be transmitted in addition to or before and after the signature target data 200 in addition to the signature target data 200. Here, in one example, the public key itself is used as the approver ID. The signature for the signature target data 200 includes a signature for the hash value of the signature target data 200.

  For example, when the document 110 is a request for approval, the signature target data 200 with the signature may be transmitted to the device 120 used by the drafter. Instead of sending it directly to the originator, etc., store the data to be signed and the signature for it in a database or blockchain accessible from a certain range of devices or devices that meet certain conditions, such as in-house, The device 120 may access the database or blockchain to obtain these data. It is conceivable that access to the database or the blockchain is not limited to the inside of the company.

  As an example, the addition of a signature to the signature target data 200 can be performed by arranging a two-dimensional code such as a QR code (registered trademark) representing the signature at any position in or near the image 201. Although the arrangement position of the two-dimensional code can be predetermined such as upper right, upper left, lower left, lower right, etc., a screen for determining the arrangement position of the two-dimensional code after the image of the document 110 is displayed on the electronic signature device. It can also be displayed on the display screen 100 and specified by the approver. Regarding the date 202, the input 203, and the like, any position in or near the image 201 can be similarly determined and arranged. More specifically, the pixels in the upper right, upper left, lower left, or lower right region inside the image 201 are cleared in white or black, and the date 202, the input 203, and the like are displayed in black or white in this region. It is also conceivable to display a two-dimensional code representing the signature. The date 202 and the like may be displayed in a first white or black area, and the two-dimensional code may be displayed in a second white or black area other than the first area. As the color of the area to be cleared, 0xFBFBFB or the like may be used instead of using 0xFFFFFF.

  When there is no element other than the image 201 such as the date 202 and the input 203, the image in which the two-dimensional code is arranged is newly generated as an image in a general JPEG format or the like, so that the data to be verified is generally generated. The image can be easily handled as compared with the case of employing the unique data structure shown in FIG. When the date 202 exists, an image in which the date 202 is arranged in addition to the two-dimensional code may be newly generated as an image, and the same applies when the input 203 exists. In this case, the signature target data 200 of the signature represented by the two-dimensional code is an image in which the date 202 is arranged on the image 201. If the input 203 exists and is also arranged on the image 201, the image in which the date 202 and the input 203 are arranged on the image 201 becomes the signature target data 200.

  For the approver ID, the approver ID and signature can be represented by a two-dimensional code, the file name of the image can be used as the approver ID, and depending on the type of the public key cryptosystem, from the signature to the public The key can be calculated back as the approver ID. An example is ECDSA.

  FIG. 4 shows an example in which a two-dimensional code is used for the signature. The signature target data 400 is an image obtained by replacing the lower right area 401 in the image of the document 110 with a predetermined color such as 0xFBFBFB as a two-dimensional code display area. The region 401 does not necessarily have a boundary line, and thus is indicated by a broken line. Although the shape of the region 401 is rectangular, the shape may be a circle, an ellipse, or the like. The signature target data 400 includes the date 402 of the signature. More specifically, the signature target data 400 is an image in which the date 402 is arranged on the image of the document 110, and includes the date 402 and is to be signed by the private key. By arranging the two-dimensional code 403 representing the signature for the signature target data 400 in the area 401 and newly generating an image, the data transmitted from the electronic signature processing 100 can be an image in a general format. The date 402 can be located in the area 401, and the input for approval or rejection by the signer can be located in or outside the area 401.

  When there are a plurality of signers, a plurality of similar areas may be provided, and an image including a two-dimensional code of a signature by another signer may be used as signature target data of a signature by the next signer.

  FIG. 5 shows a flow of a method for checking a digital signature according to the first embodiment of the present invention. First, the device 120 acquires data to be verified, that is, data to be signed and a signature (S501). Next, the device 120 determines whether the signature is given by the holder of the public key using the public key, and verifies the signature (S502). The signature may be verified by a verification device (not shown) accessible from the device 120, and the verification result may be returned to the device 120.

  As an example, when a new image in which a two-dimensional code representing a signature is arranged in or near the image 201 is data to be verified, an image in which the two-dimensional code is replaced by the color of the area where the two-dimensional code is arranged Verification can be performed by determining whether or not the signature is for the hash value of.

  If the signature has been successfully verified, the device 120 overlays a predetermined imprint on the document image 201 and displays it on the display screen of the device 120 (S503). In this way, the user of the device 120 can visually confirm that the electronic signature has been attached by an authorized person. Not only the seal but also a visual element stored in association with the approver or the approver ID may be displayed.

  When the received signature target data 200 is an image in which the two-dimensional code representing the signature is arranged, the overlay of the visual element is preferably displayed at the arrangement position of the two-dimensional code. By doing so, the user of the device 120 can more intuitively confirm that the signature verification has succeeded. In this case, the visual element may be opaquely displayed to enhance visibility.

  Regarding the overlay of the visual element, even when the signature is not used by the two-dimensional code, the position of the overlay on the image 201 can be specified by the approver at the time of the signature, and the overlay may be displayed at the specified position. Further, the size may be specified.

  In one embodiment, when the signature target data 200 includes the date 202, even if the signature is successfully verified by a valid signer, the signature is invalidated if a certain condition is satisfied. Sometimes. In this case, no overlay of the seal is performed. As an example, it is conceivable that the signature target data 200 includes as input 203 the expiration date or the validity period of the signature. Further, it is conceivable that the device 120 stores the verification rule of the date 202 including the expiration date or the validity period of the signature, and executes the verification of the date 202 simultaneously with or before and after the verification of the signature.

  The device 120 is capable of executing a program for verifying a signature and displaying an imprint, and can be preferably installed in the device 120 as an application. The device 120 has access to the public key corresponding to the private key used for the signature for verifying the signature, and stores a list of the public keys of those who can be signers from the device 120 or the device 120. It can be stored in a medium or a storage device.

  For example, when the document 110 is a draft approval document, the public key of a person who can be a setter in the company is formally distributed to a person who can be a drafter and stored in the device 120 of each drafter, so that the document can be smoothly processed. Confirmation of the electronic signature can be performed. At this time, by associating the public key with the authorizer, the drafter can confirm that the electronic signature has been issued by the holder of the public key, and that the holder has a valid It can be confirmed that it is positioned as. The association between the public key and the approver or the approver ID may be stored in a database or a block chain accessible by a device within a certain range or a device that satisfies certain conditions, such as in a company. Alternatively, it is conceivable that access to the blockchain is not limited to the inside of the company.

  When the device 120 receives the public key from the electronic signature device 100 as the approver ID, the device 120 may use one or more public keys stored in the device 120 or a storage medium or a storage device accessible from the device 120 or a blockchain. The validity of the approver can be confirmed by determining whether the public key or its hash value matches the key or its hash value.

  When the device 120 receives data other than the public key as the approver ID from the electronic signature device 100, the approver ID and the public key stored in the device 120 or a storage medium or a storage device accessible from the device 120 or a blockchain. By obtaining the public key associated with the approver or the approver ID with reference to the association with, and verifying the signature, the validity of the approver can be confirmed. Alternatively, the device 120 sends the request for identification of the holder of the public key obtained directly or indirectly to the device 120 or a server or a block chain network accessible from the device 120 or a node constituting the block chain network. It is also conceivable to transmit the ID and perform identity verification by inquiring of an external identity verification service.

  In the above description, the electronic signature device 100 captures a paper document and generates an electronic document image. However, the electronic signature device 100 receives a document image generated by another device, It is also possible to make a signature. Further, the spirit of the present invention can be applied to a case where an electronic document is generated or received by the electronic signature device 100 and signed. The spirit of the present invention can be applied to a case where a video other than a document image such as a moving image is signed as data to be signed.

  In the above description, the signature is given by the approver. However, as described in the second embodiment, the signature can be given not only in the case of approval but also in the case of rejection. It should be noted that the approver can be read as the signer, and the approver ID can be read as the signer ID.

  In addition, unless there is a description such as “only based on xx”, “only according to xx”, or “only xx”, in this specification, additional information is used. Note that it is envisaged that this may also be considered. Also, as an example, it should be noted that the description "b in the case of a" does not necessarily mean "b always in the case of a".

  Also, just in case, any method, program, terminal, device, server or system (hereinafter referred to as “method or the like”) may perform an operation different from the operation described in this specification. The aspect is directed to the same operation as any of the operations described in the present specification, and the existence of an operation different from the operation described in the present specification means that the method and the like are described in each of the present invention. It is noted that the embodiment is not out of the scope of the embodiment.

(Second embodiment)
In the first embodiment, when the verification of the signature or the like is successful, the visual element associated with the approver such as the seal is overlaid on the document image 201. However, in the second embodiment, the signature target data is It includes an input 203 by the approver, and after verifying the signature, performs a process according to the content of the input.

  Specifically, when the document is a draft of approval, input of approval or rejection can be made by selecting an option or filling in an input field, and a visual element corresponding to approval or rejection can be displayed. In the case of approval, the imprint of the signer may be displayed as a visual element, and in the case of rejection, the characters "rejected" may be displayed as a visual element. More generally, it is conceivable to display a positive visual element in the case of approval and a negative visual element in the case of rejection.

  When the input is a comment, the comment can be displayed or displayable by overlaying the comment on the document image 201 in addition to or instead of the visual element. As an example, it is conceivable that an element associated with the comment is displayed, and the comment can be displayed by tapping the element to display details of the comment.

REFERENCE SIGNS LIST 100 electronic signature device 101 imaging unit 102 communication unit 103 processing unit 104 storage unit 110 document 120 device 200 signature target data 201 image 202 date 203 input

Claims (10)

A method for verifying an electronic signature on a paper document,
Receiving signature target data including a document image obtained by digitizing the document and a signature of the signature target data with a secret key;
Verifying the signature with a public key;
Overlaying and displaying a visual element on the document image if the verification is successful,
The receiving is an image in which a two-dimensional code representing the signature is arranged in the area, with an image obtained by filling any area in the document image with a predetermined color as the signature target data. And how.   The method of claim 1, wherein the visual element is associated with an owner of the public key.   The method of claim 2, wherein the visual element is an imprint associated with an owner of the public key. The data to be signed includes an input regarding approval or rejection by the signer,
The method of claim 1, wherein the visual element is different depending on the input. The signature target data includes a comment input by the signer,
The method of claim 1, comprising, if the verification is successful, overlaying the document image to display or enable the comment.   The method according to claim 1, wherein the signature target data includes a signer ID.   The method of claim 1, wherein the two-dimensional code represents a signer ID in addition to the signature. The signature target data includes a date or date and time,
8. The method of claim 1, further comprising overlaying and displaying a positive visual element on the document image if the verification is successful and the date or date and time satisfies a verification rule. The method according to any of the above. A program for causing a computer to execute a method for verifying an electronic signature on a paper document, the method comprising:
Receiving a signature with a secret key for the signature target data including the document image obtained by digitizing the document and the signature pair data,
Verifying the signature with a public key;
Overlaying and displaying a visual element on the document image if the verification is successful,
The receiving is an image in which a two-dimensional code representing the signature is arranged in the area, with an image obtained by filling any area in the document image with a predetermined color as the signature target data. And the program. A device for confirming an electronic signature on a paper document,
Receiving a signature with a private key for the signature target data and the signature pair data including a document image obtained by digitizing the document,
Verifying the signature with a public key,
If the verification is successful, overlay a visual element on the document image and display it on the display screen of the device,
The receiving is an image in which a two-dimensional code representing the signature is arranged in the area, with an image obtained by filling any area in the document image with a predetermined color as the signature target data. And equipment.

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