WO2017130711A1

WO2017130711A1 - Electronic signature management system

Info

Publication number: WO2017130711A1
Application number: PCT/JP2017/000775
Authority: WO
Inventors: 輝夫相原
Original assignee: 株式会社ファインデックス
Priority date: 2016-01-29
Filing date: 2017-01-12
Publication date: 2017-08-03
Also published as: JP6660193B2; JP2017134698A

Abstract

[Problem] To provide an electronic signature management system capable of preventing the creation of a forged signed document. [Solution] An electronic signature management system 1 is provided with: a degraded signature handwriting image generation unit 21 that generates a degraded signature handwriting image in which an original signature handwriting image is irreversibly degraded; a pixel color code generation unit 22 that encodes, with a first code key, simple signature information relating to an electronic signature that includes the degraded signature handwriting image without including the original signature handwriting image, and also references a pixel color conversion table to convert the information to a pixel color and generate a pixel color code; a signed document image generation unit 23 that generates a signed document image in which the degraded signature handwriting image and the pixel color code are overlaid at a prescribed position on the signature document; and a simple certification unit 31 that decodes the pixel color code of the signed document image and restores the simple signature information.

Description

Electronic signature management system

The present invention relates to an electronic signature management system for managing an electronic signature input by handwriting with a pen input device or the like.

2. Description of the Related Art Conventionally, electronic signature systems that perform personal authentication using an electronic signature input by handwriting with a pen input device have been provided. In such an electronic signature authentication system, handwriting information at the time of handwriting input of an individual signature is recorded, and personal authentication is performed based on whether or not the handwriting information matches.

In addition, as disclosed in Patent Document 3 below, in recent years, personal authentication is performed based on not only two-dimensional handwriting information but also three-dimensional handwriting position information.

JP 2007-226703 A JP 2012-48281 A JP 2012-220972 A

However, in the conventional electronic signature system, in the case of a system that generates a signed document by superimposing the handwritten image of the input electronic signature on the signature column of the signature document, the third party who has obtained the signed document image Can copy and copy the signature handwriting image on the image, so that a forged signed document impersonating a malicious third party can be easily created.

The present invention has been made in view of such problems, and it is possible to create a counterfeit signed document even when generating a signed document in which a handwritten image of an electronic signature is superimposed on the signature column of the signed document. It is an object of the present invention to provide an electronic signature management system that can prevent the occurrence of an electronic signature.

In order to solve the above-described problems, an electronic signature management system according to the present invention includes an electronic signature management system that manages an electronic signature input by handwriting with a pen input device or a touch input device, and a display and an original signature of the electronic signature. Correlation between a deterioration sign handwriting image generation unit that generates a deterioration sign handwriting image obtained by irreversibly degrading a handwriting image, information on the electronic signature, and a pixel color that is a color of a pixel constituting the display screen And a pixel color conversion table storage unit for recording a pixel color conversion table for recording, and simple sign information relating to the electronic signature including the deteriorated signature handwriting image without including the original signature handwriting image is encrypted with a first encryption key. And the pixel color change A pixel color code generation unit that generates a pixel color code that is a collection of the pixel colors by converting the pixel color with reference to a table, the deteriorated signature handwriting image, and the pixel color code of the signature document A signed document image generation unit that generates a signed document image superimposed at a predetermined position, and the pixel color code of the signed document image in order to easily verify the authenticity of the signed document image. And a simple certifying unit that restores the simple sign information by decrypting with reference to the pixel color conversion table and decrypting with the first decryption key.

The electronic signature management program according to the present invention is an electronic signature management program for causing a computer to manage an electronic signature input by handwriting with a pen input device or a touch input device. A deteriorated signature handwriting image generation step for generating a deteriorated signature handwriting image that has been deteriorated automatically, and the simplified sign information relating to the electronic signature including the deteriorated signature handwriting image without including the original signature handwriting image, And converting to the pixel color by referring to a pixel color conversion table that records the association between the information related to the electronic signature and the pixel color that is the color of the pixels constituting the display screen, A collection of pixel colors A pixel color code generating step for generating a pixel color code, and a signed document image generating step for generating a signed document image in which the deteriorated signature handwriting image and the pixel color code are superimposed on a predetermined position of the signature document; In order to easily verify the authenticity of the signed document image, the pixel color code of the signed document image is decrypted with reference to the pixel color conversion table and decrypted with a first decryption key. Thus, the computer is caused to execute a simple proof step for restoring the simple signature information.

An electronic signature management method according to the present invention is an electronic signature management method for managing an electronic signature input by handwriting with a pen input device or a touch input device with a computer.
A deteriorated signature handwriting image generation step for generating a deteriorated signature handwriting image obtained by irreversibly degrading an original signature handwriting image of the electronic signature, and the electronic signature including the deteriorated signature handwriting image without including the original signature handwriting image The simple sign information related to the signature is encrypted with the first encryption key, and the pixel color conversion table that records the correspondence between the information related to the electronic signature and the pixel color that is the color of the pixels constituting the display screen is referred to. A pixel color code generating step of generating a pixel color code that is an aggregate of the pixel colors by converting to the pixel color; and the deteriorated signature handwriting image and the pixel color code at a predetermined position of the signature document Generate a signed document image superimposed on In order to easily verify the authenticity of the signed document image and the signed document image generation step, the pixel color code of the signed document image is decoded with reference to the pixel color conversion table, and And a simple proof step of restoring the simple signature information by decrypting with the first decryption key.

According to the present invention, even when a signed document is generated by superimposing an input handwritten image of an electronic signature on a signature field of a signed document, unauthorized copying of the signed handwritten image is prevented, and a forged signature has been created. Document creation can be prevented and the authenticity of the signed document can be verified.

FIG. 1 is a schematic diagram schematically showing a configuration of an electronic signature management system according to an embodiment of the present invention. FIG. 2 is a schematic diagram schematically showing the configuration of the electronic signature management terminal according to the embodiment of the present invention. FIG. 3 is a block diagram schematically showing functions of the electronic signature management system according to the embodiment of the present invention. FIG. 4 is a schematic diagram schematically showing the configuration of the electronic signature management server according to the embodiment of the present invention. FIG. 5 is a diagram for explaining an image in the signature column of the signed document image according to the embodiment of the present invention. FIG. 6 is a flowchart showing the flow of electronic signature registration processing in the electronic signature management system according to the embodiment of the present invention. FIG. 7 is a flowchart showing the flow of the electronic signature certification process in the electronic signature management system according to the embodiment of the present invention.

Hereinafter, an electronic signature management system according to an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, a case where a patient undergoing surgery manages an electronic signature signed on a surgical consent form on a PC terminal using a digital pen as a pen input device will be described as an example of the electronic signature management system.

FIG. 1 is a schematic diagram schematically showing a configuration of an electronic signature management system according to the present embodiment. FIG. 2 is a schematic diagram schematically showing the configuration of the electronic signature management terminal according to the present embodiment. FIG. 3 is a block diagram schematically showing functions of the electronic signature management system according to the present embodiment. FIG. 4 is a schematic diagram schematically showing the configuration of the electronic signature management server according to the present embodiment. FIG. 5 is a diagram for explaining an image in the signature column of the signed document image according to the present embodiment.

As shown in FIG. 1, the electronic signature management system 1 includes an electronic signature management terminal 10 used by a patient who signs and a management server 50. The electronic signature management terminal 10 and the management server 50 are communicably connected via a network 5 such as a LAN or the Internet.

As shown in FIG. 2, the electronic signature management terminal 10 includes a PC main body 11, a display 40 that displays output information from the PC main body 11, and an input device 42 for inputting information to the PC main body 11. Yes.

The PC main body 11 includes an arithmetic device 12 such as a CPU (Central Processing Unit) for performing various calculations, an HDD (Hard Disc Drive) for storing various information, and a RAM (Random) used as a work area for arithmetic processing. And a storage device 13 such as “Access Memory”.

The storage device 13 stores a program storage unit 131 for storing programs such as an OS (operating system), an electronic signature registration program, and an electronic signature simple certification program installed in the PC main body 11 and a signed document image. A signed document image storage unit 132, a pixel color conversion table storage unit 133, a key storage unit 134, and a video memory 135 that temporarily holds screen contents to be displayed on the display 40.

The pixel color conversion table recorded in the pixel color conversion table storage unit 133 is a correspondence relationship between predetermined information and the color (pixel color) of each pixel (dot) constituting the screen of the display 40 (video memory 135). Is a table in which is recorded. Pixels that make up the screen are determined by RGB values of 256 tones, and can take 16,777,216 colors. Therefore, by using a pixel color conversion table, one pixel can theoretically be used. 16,777,216 types of information can be recorded.

In the present embodiment, the pixel color code is an aggregate of pixel colors (pixel colors) that are colored with the color (color) obtained by converting information based on the pixel color conversion table. It is a collection of 2,500 pixel colors in a square shape of 50 pixels vertically and 50 pixels horizontally. Of course, the size, shape, number of dots, etc. of the pixel color code can be changed as appropriate, and may be a circular or triangular pixel color code.

The key storage unit 134 records an encryption key for encryption and a decryption key for decryption. Specifically, an encryption key A, which is a first encryption key used when encrypting simple sign information, which will be described later, and a decryption key A, which is a first decryption key used when decrypting the simple sign information, An encryption key B, which is a second encryption key used when encrypting detailed signature information described later, is recorded in the key storage unit 134.

The input device 42 includes a keyboard 43, a mouse 44, and a pen tablet 46 that is a pen input device. The pen tablet 46 is composed of a flat tablet main body 47 and a digital pen 48. When a patient who signs is holding the digital pen 48 and moving it on the tablet main body 47, a tertiary on the time axis at the tip of the digital pen 48 is obtained. Original (XYZ coordinate) trajectory information is input to the PC main body 11 and recorded in the storage device 13.

Of the trajectory information of the digital pen 48, the height (Z-axis) information from the tablet body 47 at the tip of the digital pen 48 is the tablet body when the tip of the digital pen 48 is away from the tablet body 47. When the tip of the digital pen 48 is in contact with the tablet main body 47, the contact pressure (writing pressure) is obtained.

That is, by writing a signature in the same way as a patient signs on paper using the pen tablet 46, the trajectory information of the digital pen 48 including time information is input from the pen tablet 46 to the PC body 11, and this time axis From the above sign trajectory information, a handwriting image (black and white) of a patient's signature can be generated, and sign stroke information on the time axis can be generated.

Focusing on the function, as shown in FIG. 3, the PC main body 11 of the electronic signature management terminal 10 includes a deteriorated signature handwriting image generation unit 21, a pixel color code generation unit 22, a signed document image generation unit 23, The detailed sign information generation unit 24 and the simple proof unit 31 are provided. The functions of these units are realized by the arithmetic device 12 executing various programs stored in the program storage unit 131.

The deterioration signature handwriting image generation unit 21 generates a deterioration signature handwriting image in which the image quality of the handwriting image of the patient's signature input from the pen tablet 46 is irreversibly deteriorated. The deteriorated signature handwriting image is displayed in a signature column of a signed document image to be described later.

The deteriorated signature handwriting image is a small image having a rough image quality of the original signature handwriting image generated based on the locus information of the digital pen 48 received from the tablet main body 47. For example, in an original signature handwriting image, every 16 pixels area of 4x4 pixels (dots) is replaced with either the dominant white or black color in that area, thereby deteriorating the signature handwriting. An image is generated.

FIG. 5 is a view for explaining the display of the signature column of the signed document image according to the present embodiment. FIG. 5A is a diagram illustrating a deteriorated signature handwritten image to which a pixel color code displayed in the signature column is added, and FIG. 5B is a diagram illustrating an enlarged pixel color code. FIG. 5C shows an original signature handwriting image.

As shown in FIG. 5, compared with the original signature handwriting image, the deteriorated signature handwriting image can be seen at a glance that it is not the original handwriting, but it maintains the image quality to the extent that it can be seen whether the signer is his or her own signature. is doing.

Of course, the deterioration method at the time of generating the deterioration signature handwriting image can be changed as appropriate, and if it is an irreversible deterioration method, a method of reducing the image and thinning the dots and then expanding it to the original size, A combination of degradation methods may be used. In addition, the image quality of the deteriorated signature handwriting image can be changed as appropriate, and it is deteriorated at a glance that it is not the original signature handwriting, and at the same time the signer can see that it is a deteriorated image of his / her signature Any image quality is acceptable.

In the present embodiment, the deterioration signature handwriting image generation unit 21 generates a deterioration signature handwriting image in real time even during the signing of the patient, and displays the deterioration signature handwriting image in the middle of the signature in the signature column of the signature document as needed. To do. Of course, the deterioration signature handwriting image in the middle of the signature may not be displayed.

The pixel color code generation unit 22 generates a pixel color code displayed beside the deteriorated signature handwriting image in the signed document image based on the electronic signature information input from the pen tablet 46 by the patient.

The pixel color code stores the name of the signature document signed by the patient (surgical consent form), the date of signing, a deteriorated signature handwriting image, and detailed signature information, which will be described later, as simple signature information about the input electronic signature. Includes location information.

First, the pixel color code generation unit 22 stores the signature document name, the deteriorated signature handwriting image, the signature date, and the detailed signature information storage location information, which are simple signature information, stored in the key storage unit 134. The encrypted simple sign information is converted into a pixel color for each pixel while referring to the pixel color conversion table recorded in the pixel color conversion table storage unit 133 after being encrypted with A. Generate a pixel color code of 50x50 pixels.

The signed document image generation unit 23 uses the deteriorated sign handwriting image generated by the deterioration sign handwriting image generation unit 21 and the pixel color code generated by the pixel color code generation unit 22 for simple proof including simple sign information. Generate a signed document image. This signed document image is a file in a general lossless compression image file format such as bitmap (BMP) or PNG, and can be opened and displayed by a general image browsing application or browser.

The reason why the signed document image file is set to the lossless compression image file format is that, if the image file format is a lossy compression format, the image quality deteriorates and the pixel color code cannot be decoded in the proof processing described later. is there.

Specifically, the signed document image generation unit 23 superimposes the deteriorated signature handwriting image and the pixel color code on the signature column of the surgical agreement that is a document displayed on the display 40 when performing electronic signature. Generate the displayed signed document image. The deteriorated signature handwriting image is displayed in a superimposed manner in the signature field portion of the image of the surgical consent document, and the pixel color code is displayed in the vicinity of the lower right side of the deteriorated signature handwritten image (see FIG. 5). The generated signed document image file is recorded in the signed document image storage unit 132.

The detailed sign information generation unit 24 generates detailed sign information including the original signature handwriting image for detailed certification, and records it in the detailed sign information storage unit 532 of the management server 50. Specifically, the detailed signature information generation unit 24 generates signature handwriting information as the detailed signature information from the original signature handwriting image of the electronic signature and the above-described signature trajectory information on the time axis.

The detailed sign information generation unit 24 encrypts the original signature handwriting image and the sign stroke information on the time axis, which is the generated detailed sign information, with the encryption key B stored in the key storage unit 134, The detailed signature information storage unit 532 records the detailed signature information. The sign stroke information including the time information can be reproduced as a moving image on the real time axis by the detailed certification unit 58 described later.

The simple certifying unit 31 decrypts the above-mentioned simple sign information and displays it on the display 40 in order to easily prove the authenticity of the signed document image. Specifically, the simple certification unit 31 first acquires the pixel color code in the signed document image displayed on the display 40 from the video memory 135.

Thereafter, the simple certifying unit 31 decrypts the pixel color code by using the decryption key A recorded in the key storage unit 134, and easily proves the authenticity of the signed document image among the decrypted information. Information necessary for the display is displayed on the display 40.

As shown in FIG. 4, the management server 50 includes an arithmetic device 52 such as a CPU (Central Processing Unit) for performing various calculations, an HDD (Hard Disc Drive) for storing various information, and a work area for arithmetic processing. And a storage device 53 such as a RAM (Random Access Memory).

The storage device 53 stores a program storage unit 531 for recording various programs such as an OS (operating system) and an electronic signature detailed certification program installed in the management server 50, and detailed signature information of the electronic signature. A detailed sign information storage unit 532 and a key storage unit 534 in which the decryption key B is recorded are provided.

Further, as shown in FIG. 3, when focusing attention on the function, the management server 50 includes a detail certification unit 58 for proving the authenticity of the signed document image in detail with the administrator authority. The detailed certification unit 58 decrypts the detailed signature information using the decryption key B stored in the key storage unit 534 in order to explain the authenticity of the signed document image in detail.

When acquiring the detailed signature information, the detailed certification unit 58 stores the detailed signature information of the management server 50 based on the storage location information of the detailed signature information included in the simple signature information decrypted from the pixel color code by the simple certification unit 31. The unit 532 is accessed.

The decrypted detailed signature information is displayed on a display directly connected to the management server 50, or transmitted to the electronic signature management terminal 10 via the network 5 and displayed on the display 40. The detailed sign information includes the original sign handwriting image and the sign handwriting information, and the detailed certification unit 58 displays the original sign handwriting image and the sign handwriting animation that is the movement of the tip of the digital pen 48 at the time of signing. Can do.

The configuration of the electronic signature management system 1 has been described above. Next, the flow of electronic signature registration processing in the electronic signature management system 1 will be described. FIG. 6 is a flowchart showing a flow of electronic signature registration processing in the electronic signature management system according to the present embodiment.

First, in S10, the electronic signature management terminal 10 displays the surgery agreement on the display 40 in order to show the contents of the surgery agreement to the patient who performs the electronic signature. When the patient agrees with the contents of the surgical consent form, the patient moves the cursor of the display 40 to the signature section of the surgical consent form and starts the electronic signature by holding the digital pen 48 and moving it on the tablet body 47 ( S11).

When the digital pen 48 is moved on the tablet main body 47, information on the movement of the tip of the digital pen 48 (three-dimensional trajectory information on the time axis) is transmitted from the pen tablet 46 to the PC main body 11, and the time is stored in the storage device 13. It is temporarily recorded as sine trajectory information on the axis (S12).

In S12, when the sign trajectory information starts to be recorded, the deterioration sign handwriting image generation unit 21 generates a deterioration sign handwriting image in the middle from the sign handwriting information up to the present time in a predetermined cycle (for example, every 1 s). Then, it is superimposed and displayed in the signature column of the surgical consent form displayed on the display 40 (S13). Thereby, the patient can perform an electronic signature while seeing a signature in the middle of writing.

When the patient who has finished writing the electronic signature inputs through the input device 42 that the electronic signature has been completed (S14), the process proceeds to S15, and the pixel color code generation unit 22 generates a pixel color code. As described above, the pixel color code includes, as simple signature information, a signature document name (operation agreement), a signature date, a deteriorated signature handwriting image, and detailed signature information storage location information. The pixel color code generation unit 22 generates the pixel color code after encrypting the simple sign information with the encryption key A.

In S16, the signed document image generation unit 23 generates a signed document image in which the completed deteriorated signature handwriting image and the pixel color code are superimposed and displayed at a predetermined position on the image of the surgical consent document, and the display 40 is displayed. At the same time, the generated signed document image is recorded in the signed document image storage unit 132.

Subsequently, in S 18, the detailed sign information generation unit 24 generates detailed sign information and records it in the detailed sign information storage unit 532 of the management server 50. As described above, the detailed signature information includes the original signature handwriting image of the electronic signature and the signature stroke information, and the detailed signature information is encrypted with the encryption key B. This completes the electronic signature registration process.

Next, the flow of processing for proving that the signed document image is genuinely signed electronically by the patient based on the registered electronic signature information using the electronic signature management system 1 will be described. FIG. 7 is a flowchart showing the flow of certification processing in the electronic signature management system according to the present embodiment.

In the present embodiment, simple simple proof using simple signature information recorded in the pixel color code included in the signed document image recorded in the signed document image storage unit 132 and the detailed signature information storage unit 532 Detailed proof using the recorded detailed signature information is performed.

As a scene where the authenticity of the signed document image is necessary, when a patient who has registered an electronically signed surgical consent form in the electronic signature management system 1 There may be a case where the patient has a signed surgical consent form (signed document image) displayed on the display 40 to explain that the patient has consented to the surgical content before the surgery.

First, in S20, the hospital staff operates the electronic signature management terminal 10 with the patient, searches the signed document image storage unit 132, and selects the signed document image electronically signed by the patient. And displayed on the display 40. Here, the signed document image is displayed by the browser installed in the PC main body 11 and recorded in the program storage unit 131.

Then, although it is a deteriorated sign handwriting image with a low resolution, a surgical consent form in which the sign handwriting image signed by the patient is drawn in the signature section is displayed on the display 40, so that the hospital staff can Thus, it can be explained that the patient consented to the operation content before the operation.

If the patient is satisfied with the contents of the operation, the process ends here. On the other hand, if the patient argues that this signed surgical consent form is a fake copy of my signature, and claims that I have not signed this surgical consent form, , The process proceeds to S21 to start the simple certification process.

The simple certification process is performed by starting a simple certification program (simple certification unit 31) installed in the PC main body 11 (S22). When the simple proof program is activated and the simple proof program is instructed to decode the pixel color code, the simple proof unit 31 decodes the pixel color code in S25.

In the decryption in S25, first, the simple certifying unit 31 refers to the video memory 135 and searches for and recognizes the pixel color code displayed on the display 40. In S20, since the pixel color code is displayed in the signed document image displayed by the browser, the pixel color code is recognized by the simple certification unit 31.

In the present embodiment, since the signed document image is displayed on the display 40 with the same resolution, the simple proof unit 31 can acquire the pixel color code information from the video memory 135, but the signed document image has been signed. When the document image is enlarged or reduced and displayed on the display 40, the simple certification unit 31 needs to directly acquire the pixel color code information from the signed document image storage unit 132.

The simple certification unit 31 refers to the pixel color conversion table recorded in the pixel color conversion table storage unit 133, decodes the pixel color code, and decodes the simple sign information in the encrypted state.

Specifically, for each pixel included in the pixel color code, it is converted into information associated with the color, and the simple sign information of the encrypted state is restored. Subsequently, the simple certifying unit 31 decrypts the simple sign information in the encrypted state by using the decryption key A recorded in the key storage unit 134 to restore the simple sign information.

By decoding the pixel color code in this way, the simple certifying unit 31 can restore the signature document name, the signature date, the deteriorated signature handwriting image, and the detailed signature information storage location information, which are simple signature information. it can.

In S26, the simple certification unit 31 displays information (signed document name, signature date, deteriorated signature handwriting image) necessary for the simple certification on the display 40 among the decrypted simple signature information.

If the simplified sign information displayed on the display 40 completely matches the contents of the signed document image displayed on the display 40, the signed handwriting image obtained by the signed document image is copied illegally. It is possible to easily prove that the image is not a falsified signed document image.

If this simple proof confirms that the patient has agreed to the surgical procedure in advance, the explanation to the patient will be completed. On the other hand, if the patient is still not convinced by the simple proof, the process proceeds to S30 to start the detailed proof.

In the present embodiment, the detailed certification is configured so that only a system administrator having the administrator authority of the electronic signature management system 1 can perform. Therefore, if the hospital staff is not a person who has administrator authority, it is necessary to call the system administrator when performing the detailed certification.

In this embodiment, the detailed certification program for performing the detailed certification is installed only in the management server 50, and the system administrator who is present with the patient and the staff of the hospital gives the administrator authority to the management server 50 from the electronic signature management terminal 10. The detailed certification is performed while remotely operating the management server 50.

Of course, the operation rules for detailed proof can be changed as appropriate. When performing detailed proof instead of remote operation, the system administrator and the patient go to the location where the management server 50 is located and operate the management server 50 directly. The detailed certification program may be installed in the electronic signature management terminal 10 and the detailed certification can be performed in the electronic signature management terminal 10, but only the system administrator can install the detailed certification program. You may comprise so that it can be used.

In S31, first, the system administrator accesses the management server 50 from the electronic signature management terminal 10 and starts the detailed certification program (detail certification unit 58). Subsequently, in S <b> 32, the detailed certification unit 58 uses the decryption key B recorded in the key storage unit 534 to decrypt the detailed signature information that has been encrypted and recorded in the detailed signature information storage unit 532.

In S33, the detailed signature information decrypted by the detailed certification unit 58 is transmitted to the electronic signature management terminal 10 and displayed on the display 40. Detailed signature information includes original signature handwriting images with no degradation in image quality and signature stroke information, and these detailed signature information that can only be decoded by system administrators ensures the authenticity of signed document images. can do.

In particular, the sign stroke information is sign trajectory information on the time axis, and it is possible to play a movie while frame-by-frame advancement or temporary playback is stopped. By seeing this, the patient is a document signed by himself / herself. I have to be convinced.

As described above, the electronic signature management system 1 according to the present embodiment has been described. However, according to the present embodiment, a deteriorated signature handwritten image with degraded image quality is displayed on a signed document image that is freely accessible. Even if the signed document image is illegally acquired by a third party, only a deteriorated signature handwriting image can be copied, so that it is possible to prevent forgery or falsification of the signed document by a malicious third party.

In addition, since the deteriorated signature handwriting image displayed on the signed document image is an image obtained by irreversibly degrading the original signature handwriting image, it is assumed that the data of the deterioration signature handwriting image is acquired by a malicious third party. Even the original signature handwriting image cannot be restored.

In addition, the signed document image is a file in a general image file format, and no dedicated browsing software is required, and if it is a general image display software, the signed document image can be displayed.

In addition to the deterioration of the signed document image, beside the signed document image, simple sign information for simply verifying the authenticity of the signed document image is encrypted with the encryption key A. If it is an environment having a decryption key A for decrypting it, the authenticity of the signed document image can be simplified by decrypting and displaying the simple sign information. Can prove.

In addition, the simple sign information is encrypted and recorded as a pixel color code. Even if the deteriorated sign handwriting image and the pixel color code are copied to a third party, they must have the decryption key A. Therefore, the simple signature information cannot be decoded, and information other than the deteriorated signature handwriting image is not obtained illegally.

Also, because the pixel color code is pasted beside the deteriorated signature handwriting image, even if the deteriorated signature handwriting image is pasted on another signed document and the signed document image is forged, the pixel color code is forged. Unless it is possible to do so, it is possible to easily reveal that the signed document image is not authentic by decoding the simple sign information from the pixel color code.

In addition, even if the simple sign information is illegally decoded from the pixel color code and stolen, the original sign handwriting image and sign stroke information are not included in the simple sign information. Important original signature handwriting images and signature stroke information are not stolen.

In addition, the original signature handwriting image and the signature stroke information, which are detailed signature information, are not recorded in the electronic signature management terminal 10 at all, and are encrypted as the detailed signature information using an encryption key B different from the encryption key A. In addition, it is recorded in the management server 50 accessible only by the system administrator, and it is very difficult to steal the original signature handwriting image or signature stroke information.

The embodiments of the present invention have been described above. However, the embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. . For example, the function of the electronic signature management terminal may be realized by cloud computing via a network.

In the above embodiment, the detailed signature information is stored and decrypted by the management server connected to the electronic signature management terminal via the network. However, the detailed signature information can be stored and decrypted in the electronic signature management terminal. You may comprise.

Further, in the above embodiment, the deteriorated signature handwriting image includes only the signature handwriting image, but when signing the signature document electronically, the signed date is input with a digital pen, and the date handwriting image is displayed. You may make it include in a deterioration signature handwriting image.

Also, the contents of simple sign information and detailed sign information can be changed as appropriate. In addition, the information included in the pixel color code of the simple sign information can be changed as appropriate, and it is not necessary to include all of the simple sign information in the pixel color code. In addition, the degraded sign handwriting image is not the image data itself. Information indicating image characteristics may be included in the pixel color code.

Also, since the encryption key can be decrypted over time, it is desirable to periodically change the encryption keys A and B and the decryption keys A and B. Further, the pixel color conversion table may record the association with the color for each of a plurality of pixel groups, not for each pixel.

Moreover, in the said embodiment, although the pen input device provided with a tablet main body and a digital pen was employ | adopted as an input device which inputs an electronic signature by handwriting, if an input device which can input an electronic signature by handwriting, another apparatus is used suitably. be able to. For example, you may employ | adopt touch input devices, such as a touch screen and a touchpad which can input a locus | trajectory by touching with a finger.

DESCRIPTION OF SYMBOLS 1 Electronic signature management system 10 Electronic signature management terminal 11 PC main body 12 Arithmetic device 13 Storage device 131 Program storage part 132 Signed document image storage part 133 Pixel color conversion table storage part 134 Key storage part (encryption keys A and B, decryption key A)
135 Video memory 21 Deteriorated signature handwriting image generation unit 22 Pixel color code generation unit 23 Signed document image generation unit 24 Detailed signature information generation unit 31 Simple proof unit 40 Display 42 Input device 43 Keyboard 44 Mouse 46 Pen tablet 47 Tablet main body 48 Digital Pen 50 Management server 52 Computing device 53 Storage device 531 Program storage unit 532 Detailed signature information storage unit 534 Key storage unit 58 Detailed certification unit 5 Network

Claims

In an electronic signature management system for managing an electronic signature input by handwriting with a pen input device or a touch input device,
Display,
A deteriorated signature handwriting image generation unit for generating a deterioration signature handwriting image obtained by irreversibly degrading the original signature handwriting image of the electronic signature;
A pixel color conversion table storage unit that records a pixel color conversion table that records information relating to the electronic signature and a pixel color that is a color of a pixel constituting the screen of the display;
Simple signature information about the electronic signature including the deteriorated signature handwriting image without including the original signature handwriting image is encrypted with a first encryption key and converted into the pixel color with reference to the pixel color conversion table. A pixel color code generation unit that generates a pixel color code that is an aggregate of the pixel colors;
A signed document image generation unit that generates a signed document image in which the deteriorated signature handwriting image and the pixel color code are superimposed on a predetermined position of the signature document;
In order to easily verify the authenticity of the signed document image, the pixel color code in the signed document image is decrypted with reference to the pixel color conversion table and decrypted with a first decryption key. A simple proof part for restoring the simple signature information,
An electronic signature management system comprising:
A detailed signature information generating unit that encrypts detailed signature information about the electronic signature with a second encryption key, including the original signature handwriting image and signature stroke information including time information of the electronic signature;
In order to prove the authenticity of the signed document image in detail, a detailed proof unit that restores the detailed sign information by decrypting the encrypted detailed sign information with a second decryption key;
The electronic signature management system according to claim 1, further comprising:
3. The electronic signature management system according to claim 2, wherein the simple signature information includes information relating to a storage location of the detailed signature information.
In an electronic signature management program for causing a computer to manage an electronic signature input by handwriting with a pen input device or a touch input device,
A deteriorated signature handwriting image generation step for generating a deterioration signature handwriting image obtained by irreversibly degrading the original signature handwriting image of the electronic signature;
Pixels constituting the screen of the display and the information related to the electronic signature and the simple signature information related to the electronic signature including the deteriorated signature handwritten image without including the original signature handwritten image and encrypted with a first encryption key A pixel color code generation step of generating a pixel color code that is a collection of the pixel colors by referring to a pixel color conversion table that records a correspondence with a pixel color that is a color of ,
A signed document image generation step of generating a signed document image in which the deteriorated signature handwriting image and the pixel color code are superimposed on a predetermined position of the signature document;
In order to easily verify the authenticity of the signed document image, the pixel color code of the signed document image is decrypted with reference to the pixel color conversion table and decrypted with a first decryption key. And a simple certification step for restoring the simple signature information,
An electronic signature management program that causes the computer to execute
In an electronic signature management method for managing an electronic signature handwritten by a pen input device or a touch input device with a computer,
A deteriorated signature handwriting image generation step for generating a deterioration signature handwriting image obtained by irreversibly degrading the original signature handwriting image of the electronic signature;
Pixels constituting the screen of the display and the information related to the electronic signature and the simple signature information related to the electronic signature including the deteriorated signature handwritten image without including the original signature handwritten image and encrypted with a first encryption key A pixel color code generation step of generating a pixel color code that is a collection of the pixel colors by referring to a pixel color conversion table that records a correspondence with a pixel color that is a color of ,
A signed document image generation step of generating a signed document image in which the deteriorated signature handwriting image and the pixel color code are superimposed on a predetermined position of the signature document;
In order to easily verify the authenticity of the signed document image, the pixel color code of the signed document image is decrypted with reference to the pixel color conversion table and decrypted with a first decryption key. And a simple certification step for restoring the simple signature information,
An electronic signature management method comprising: