KR101837831B1 - Electronic signature display and verification methods with enhanced security - Google Patents

Abstract

The present invention relates to an electronic signature display and verification method with enhanced security, and a method for displaying an electronic signature according to the present invention is characterized in that when a signature for confirmation or authentication of a created electronic document is input, ; A second step of encrypting contents information of the electronic document and unique information of a terminal used to generate a cipher text and generating authentication information using the fixed color modulation information or the additive color modulation information; Processing the authentication information to modulate a portion or the entirety of the signature image so that an average color of a particular region of the signature image is modulated to converge to a color that contrasts with a line color of the signature image, A third step of generating a second signal; And a fourth step of transmitting and storing the authentication information to an authentication server and displaying the authenticated signature image on a predetermined signature area on the electronic document
According to another aspect of the present invention, there is provided an electronic signature verification method comprising: a step of reading an authenticated signature image in a predetermined signature area on an electronic document; A step of inquiring authentication information of the authenticated signature image from an authentication server; Comparing the cipher text extracted from the authenticated signature image with the cipher text of the authentication information to display whether the authenticated signature image is up / modulated; Decrypting the cipher text of the authentication information or the cipher text extracted from the authenticated signature image to extract the content information of the electronic document and comparing the extracted content information with the content information of the electronic document to display whether the content is up / do.

Description

[0001] DESCRIPTION [0002] Security-enhanced electronic signature display and verification methods [

The present invention relates to an electronic signature display and verification method, and more particularly, to an electronic signature display and verification method that is difficult to be stolen / altered or stolen, and can verify an electronic document or verify an electronic signature.

Traditionally, certificates for documents such as contracts, commerce documents, and archives were usually provided through a seal or a registered seal, handprint, or handwritten signature. After confirming that it was not tampered with, it was able to accomplish certain purposes such as document authentication, document authentication and non-repudiation.

In order to provide the purpose and function of a traditional seal or a registered seal in a digital environment, a method of authenticating a user or a digital message using an electronic signature based on an authorized and a private certificate is required to be certified (authenticity) Integrity, and non-repudiation. However, it is based on Active X, so it is inconvenient to use in a mobile environment using a smartphone or a tablet PC. Also, an elderly person There is a problem in that it is difficult to apply it.

In addition, when a timestamp is given to an electronic document from a public authority that has been certified as a standard time, it is used as a means of ensuring the integrity of the document, so that it is possible to check forgiveness, but there is no function of preventing the image from being stolen, There is a problem in that there is no public confidence in the time stamp issuance time.

Unlike a signature on a paper, there is a problem that authentication (authenticity), integrity, and anti-repudiation effects are limited in the case of an electronic signature performed for confirmation or authentication of an electronic document. The quality of digital signature images is improving and the risk of theft is also increasing. A signature image inputted to a terminal or the like using a touch pen or the like may be used for a contract or other electronic document having no relation with a signer when it is leaked for reasons such as hacking and can be abused and in such a case, There is a problem in that it can not be performed.

Thus, when an electronic signature is displayed in an electronic document, it can be used even for users who are not accustomed to the elderly or other electronic documents, while meeting the requirements of authentication (authenticity), integrity, and non-repudiation. There has been a demand for measures that can be secured.

Korean Registered Patent No. 10-0729600 (Jun. 12, 2007)

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an electronic signature display and verification method capable of overcoming the above-described problems.

Another object of the present invention is to provide a security-enhanced digital signature display and verification method that can satisfy the requirements of authentication (authenticity), integrity, and non-repudiation of an electronic document.

It is still another object of the present invention to provide an electronic signature display and verification method capable of blocking forgery or forgery of a signature image and having a handwriting confirmation function.

It is another object of the present invention to provide an electronic signature display and verification method that can be easily used by anyone and can secure reliability.

According to another aspect of the present invention, there is provided a method for displaying an electronic signature, the method comprising the steps of: inputting a signature for verification or authentication of a created electronic document using a tool or a finger; Comprising: A second step of encrypting the content information of the electronic document and the unique information of the terminal used to generate a cipher text and processing the cipher text into a plurality of fixed color modulation information or an enhancement color modulation information to generate authentication information; Processing the authentication information to modulate a portion or the entirety of the signature image so that an average color of a particular region of the signature image is modulated to converge to a color that contrasts with a line color of the signature image, A third step of generating a second signal; Transmitting the authentication information to an authentication server and storing the authentication information, and displaying the authenticated signature image on a predetermined signature area on the electronic document.

The authentication method according to claim 1, further comprising: combining the color modulation method or the false information in the second step, the third step, or the second step and the third step to form the authentication information, So as to configure the mobile communication terminal.

In the second step, the step of configuring the fixed color modulation information or the enhancement / color modulation information may further include the step of classifying the colors of the modulation object and processing them using different fixed color modulation methods or an additive / .

The method may further include generating vector image information of the signature using the input signature in the first step and adding the vector image information in generating the cipher text in the second step.

And transmitting the hash value of the authenticated signature image to the server after the third step.

According to another embodiment of the present invention, there is provided a digital signature verification method comprising: a step of reading an authenticated signature image in a predetermined signature area on an electronic document; A step of inquiring authentication information of the authenticated signature image from an authentication server; Comparing the cipher text extracted from the authenticated signature image and the cipher text of the authentication information to display whether the authenticated signature image is up / modulated; Decrypting the cipher text of the authentication information or the cipher text extracted from the authenticated signature image to extract the content information of the electronic document and comparing the extracted content information with the content information of the electronic document to display whether the content is up / do.

Checking the hash value of the authenticated signature image from the authentication server after the first step, and comparing the hash value of the authenticated signature image displayed in the electronic document with the hash value of the authenticated signature image, and displaying the result.

And restoring the original signature image using the authentication information and the authenticated signature image when the color modulation information of the authentication information is composed only of the enhancement color modulation information after the second step, .

If the authentication information includes vector image information of the signature after the second step, the step of restoring and displaying the original signature image using the vector image information may further include the step of displaying the original signature image.

According to the present invention, since the signature inputted for the confirmation or authentication of the electronic document is modulated up to the pixel unit by using the ciphertext and the color modulation information including the content information of the document and the context information at the time of signature and attached to the electronic document, It is difficult to extract only the image separately, which has the effect of weakening the will to steal. In addition, even in the modulated state, each pixel constituting the margin of the signature is configured to be in contrast with the line color of the signature through a juxtaposition of colors, so that the handwriting of the signature can be confirmed and, if necessary, the authentication information and the authenticated signature image The original signature image can be restored without loss, enabling more sophisticated handwriting confirmation. In addition, the signature image is combined with the content information of the encrypted electronic document and the context information at the time of signature so that it is possible to verify whether the authenticated signature image and the content information of the electronic document are tampered with or not through the authentication information. Therefore, an electronic document to which an authenticated signature image is attached has authentication (authenticity), integrity, and anti-repudiation effect.

In addition, since the authentication and verification method is intuitive, it is possible to easily authenticate and verify electronic documents even in the case of the elderly who are not familiar with smart phones or tablet PCs, and can easily use them.

1 is a diagram illustrating a system for storing and retrieving authentication information according to the present invention.
FIG. 2 is a schematic block diagram of a security-enhanced digital signature display and verification method according to an embodiment of the present invention,
3 is a flowchart illustrating an electronic signature display and verification method according to an exemplary embodiment of the present invention,
4 to 6 are examples of a digital signature input and display method,
7 is an example of the structural features of the color of the digital signature image,
8 to 22 illustrate the characteristics of a color modulation method constituting authentication information, the construction of color modulation information using the color modulation method, and the processing of a signature image using the color modulation information,
Figures 23-24 are for implementation and application examples of authenticated signature images,
25 and 28 are examples of verification and restoration methods of electronic documents and signature images.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings without intending to intend to provide a thorough understanding of the present invention to a person having ordinary skill in the art to which the present invention belongs.

1 is a diagram illustrating a system for storing and retrieving authentication information according to the present invention.

Referring to FIG. 1, the authentication information storage and retrieval system includes a client terminal 310 and an authentication information server 320.

The client terminal 310 may be a user computer, a notebook, a tablet, a handheld PC, a personal digital assistant (PDA), a smart phone, or the like, has an electronic document creation or inquiry function, have.

When there is an authentication information storage request, the authentication information server 320 stores the authentication information in the authentication information DB. If there is an inquiry about the authentication information, the authentication information server 320 inquires the authentication information and provides the authentication information to the client terminal 310.

The authentication information server 320 is a comprehensive concept including all the configurations for storing and inquiring authentication information by receiving the authentication information storing and inquiring message from the client terminal 310 having the storing and inquiring authority.

That is, although the authentication information server 320 is shown as one hardware device in FIG. 1, the authentication information server 320 may be a set of a plurality of server devices connected through a network.

The electronic document described below may be an electronic document that is created through a client terminal such as a PC, a tablet PC, or a smart phone, and may be displayed through a display screen of the client terminal, and may include an electronic document type contract, , Card application, real estate contract, bank business contract, various agreement, various reports, various payment documents, various documents of public office, various agreements of hospital, registration documents and documents related to the delivery of courier services, And all the electronic documents that require the signature of the person concerned for identification or authentication, including those related to the advancement of the performance.

When an electronic document is created through the client terminal, signature input is required to confirm or authenticate the electronic document. Typically, the signature input is made by the client terminal recognizing the signature of the person concerned through the touch screen. In addition, it is possible to receive a signature via a signer in a manner well known to a mouse or other conventional technician.

For example, when a contract is created in a client terminal such as a tablet PC in the case of a product purchase contract or an insurance contract, and the creation of the contract is completed, the signature of the contractor is input to the confirmation and authentication means. In this case, The signature is input to the client terminal when the contractor makes a signature as in a general document. In this case, the signature can be recognized and input through a pressure sensor incorporated in the client terminal or the like.

4, when the signature is input 131 through the client terminal, the signature image generating unit 130 generates an image of the signature 132 as shown in FIG. 5 . The signature image 132 may be in the form of an image separated by a background (margin) and a line portion (or letter portion) of the signature. The signature image 132 may be implemented in the form of an image in the same shape as a signature performed on a general document.

As shown in FIG. 4, when the signature is inputted 131 through the client terminal, the signature image generating unit 130 may generate a vector image 133 of the signature as shown in FIG.

7, the signature image 132 is a signature image in which the color constituting the signature image is either achromatic color 134a or color 134b, 134c of one of R, G, and B, or one of R, G, Having only two colors, if the values of the two colors are the same (134d), the color scheme of the signature image can have a certain rule.

The authentication information generation unit 140 may encrypt the content information of the electronic document and the unique information of the terminal to be used, and may configure the authentication information by combining the encrypted information and the color modulation information.

Wherein the content information of the electronic document includes at least one of document format information of the electronic document, description content information of the electronic document, time information relating to completion of creation of the electronic document or input of a signature, And may include at least any one piece of information.

The document format information of the electronic document is information on the format of the electronic document, for example, whether it is a document using a Korean-language document creating program with an extension of HWP, a document using an MS-WORD program, And the document description information of the electronic document may include information on the entire contents described in the electronic document, compression information, and the like.

The time point information related to the completion of creation of the electronic document or the input of the signature may include information on the creation completion time point of the electronic document, the start time of the signature input, and the completion time of the signature input. The location information related to the signature location of the electronic document includes information on the location where the actual electronic document is created (the place where the contract was made), the location where the signature was made, and the like. The location information for the GPS sensor mounted on the terminal, Position information recognized through a router, position information recognized through a repeater relaying communication of the terminal, and the like.

In addition, the unique information of the terminal may include a unique number of a terminal assigned to the used terminal, a model name, and the like. And other information that can be determined to be unique information of the terminal.

The color modulation information may be a fixed color modulation method 142a for replacing the color of the modulation object 141 with a fixed color as shown in FIG. 8, or may be a fixed color modulation method 142a for replacing R And adding or subtracting (adding a negative number) the G and B color values 143a and 144a respectively to obtain the modulated colors 143b and 144b.

As shown in FIG. 7, when the modulation object 141 is an achromatic color 134a or one of R, G, and B colors 134b and 134c or two colors of R, G, and B, If the values are the same (134d), the colors 143b and 144b modulated using the add / drop color modulation methods 143a and 144a are converted into the R, G, and B signals by the add / drop color modulation methods 143a and 144a and RG, The relative distances between the B values can be the same.

9, by using the RG and RB values of the modulation result 145 as shown in FIG. 9, the additive color modulation method (FIG. 146a can be specified, and the original color 145a can be derived by inverse-processing the addition / subtraction color modulation method 146a.

As shown in FIG. 10, in modulating the color using the additive / subtracted color modulation method, the modulation is performed so that the maximum value (255) of each of R, G, and B is exceeded in the modulation process (145a) A plurality of enhancement color modulation methods can converge to one color modulation result when the modulation 145b is performed so as to be less than the minimum value (0) of the color modulation result (hereinafter referred to as overflow).

As shown in FIG. 11, the additive color modulation method may have the same color modulation method (147a, 147b, 147c / 148a, 148b) in which the relative distances between the R, G, and B values are the same.

Therefore, in order to modulate the original image using the additive / subtracted color modulation method and the specific information, and to restore the information and the original image from the modulated image without loss, the original image should be modulated without overflow, 12, the authentication information generation unit 140 may generate a plurality of modulation methods for the modulation data 149a and 149d corresponding to the plurality of modulation methods 149a and 149d, Modulation methods 149b and 149e are applied according to the colors of the modulation objects 149a and 149d so that the modulation results 149c and 149f in which overflow does not occur can be derived .

FIG. 13 shows an example of an additive color modulation method set 150a, 150b, 150c, 150d, and 150e in which no conflict occurs due to overflow, And the modulation object equal to or more than the intermediate value may be configured so as to reduce the combination (add a negative number), and add the combination to a value less than the intermediate value.

The intermediate values 128, 128 and 128 are merely examples, and the color of the modulation object may be divided into a value larger or smaller than the intermediate value, thereby forming a set of the additive color modulation method.

When the values of R, G, and B are added or subtracted by combining values of the remaining two colors from 0 to 128 by fixing one of the values of R, G, and B to 0, the examples (150a, 150b, and 150c) And an example of a set of the enhancement color modulation method using the characteristic that no conflicts due to isomorphism occur between the combinations.

In the examples 150d and 150e, one of R, G, and B is fixed to 0, and one of the remaining two color values is always larger than the other one (150d: if G = 0 then G < (150d: if G = 0 then G> R> B, 150e: if B) is added so that one of the remaining two color values is always smaller than the other = 0 then G < R &lt; B) to reduce (add a negative number) by using the characteristics of the additive color modulation method.

There may be no conflict between examples 150a and 150d or 150a and 150e of the additive color modulation method set.

When a set of the additive color modulation method in which the conflict does not occur is displayed in the R, G, and B coordinate systems, the symbols 150a and 150d are distributed as shown in FIG. 14. The symbols 150a and 150e 151b.

Since the set of the additive color modulation method in which the conflict does not occur is distributed with a symmetrical structure, a set of the additive and color modulated method in which conflicts do not occur, such as 151a, 151b, 151c, 151d, 151e and 151f, can be constituted.

The enhancement color modulation information 152a may be composed of a set of one or more enhancement color modulation methods ("A", "B", etc. of 152a) corresponding to each signal as shown in FIG.

The add / drop color modulation method set ("A", "B", etc.) of the add / drop color modulation method set 152a may be configured by one or two or more enhancement color modulation methods for exclusively modulating a modulation object of a specific color. For example, the set of the additive and deconvolution color modulation methods 152c having two enhancement color modulation methods with the gray values 128, 128, and 128 as intermediate values may be set such that each of the enhancement color modulation methods includes a region where the modulation object is RGB (128, 128, 128) (127, 127, 127) or less, and can be exclusively modulated.

The fixed color modulation information 152b may consist of a set of one or more fixed color modulation methods ("A", "B", etc., of 152b) corresponding to each signal as shown in FIG.

The set of fixed color modulation methods ("A "," B ", etc.) of the fixed color modulation method may be configured with one or more fixed color modulation methods that exclusively modulate the modulation object of a specific color.

In order to secure the visibility of the authenticated signature image, the authentication information generation unit 140 may be configured to restrict the color used in the fixed color modulation method or the color modulation used in the enhancement color modulation method, The range can be limited. For example, if the line color of the signature image is black and the margins are white, the color used for the fixed color modulation method is R, G , The average value of B is 200 or more, or the range of subtraction of the R, G and B values of the additive color modulation method can be limited to 50 or less.

The authentication information generating unit 140 may generate a plurality of sets of additive and color modulation methods 153a and 153b or sets of fixed color modulation methods 154a and 154b for each signal as shown in FIG. ) So that security can be enhanced.

The authentication information generation unit 140 generates a cipher text using the content information of the electronic document and the unique information of the used terminal, using a hash function and an encryption function, converts the cipher text into a code, It is possible to generate authentication information in combination with the information 152a and 152b.

The cipher text may include vector image information 133 of the signature.

The authentication information generating unit 140 or the signature image processing unit 150 may be configured so that the average color of a specific region of the signature image is modulated so as to converge to a color that contrasts with the line color of the signature image, As shown, it can be processed to have a homogeneous blank.

If the collation color of the specific area of the processed authentication information is deflected to specific colors 157a and 159a as shown in FIG. 18 or 19, correction values 157b and 159b for correcting the color deviation are added So as to form target colors 157c, 159c, and 159d. For example, the specific area 158 where the specific color deflection 159a was present is cured through the color correction 159b so that the modulation object of the enhancement color modulation information 158 is black (0 , 0,0), the region is changed to a deep gray 159d through a juxtaposition and when the modulation object of the enhancement color modulation information 158 is white 255,255,255, the region is converted to a light gray 159c Can be seen.

The correction values 157b and 159b may be a fixed color modulation method or an additive color modulation method that is not overlapped with the color modulation method of the authentication information or the forgery and falsification of the color modulation method. For example, one set can be used for authentication information generation and one for color correction or false information generation in the set of enhancement color modulation methods (150a and 150d or 150a and 150e) known to be free of such forgery .

The signature image processing unit 150 may process the signature image 161 into an authenticated signature image 164 using the authentication information 162 and 163 as shown in FIG.

The authentication information generating unit 140 or the signature image processing unit 150 may perform a color modulation method corresponding to the dense signal when the specific signal is dense in a specific region and color distortion occurs as shown in FIG. It is possible to add a process of processing false ciphertext 166b with improved security and visibility by adding false information 165b that makes contrast. For example, when the specific signal "1" is continuously present in 166a in Fig. 21, according to the combination for signal "1" in 156a, G (G, , The B side can be concentrated in a specific area. Therefore, among the false information 165b, it is possible to process the signal "G" of the false information having the largest red shift and the signal "B" of the false information having a small difference in the lightness.

The authentication information generating unit 140 or the signature image processing unit 150 may include a case 168a in which a specific signal composed of two or more color modulation method sets is concentrated in a specific region as shown in FIG. It is possible to add a process of processing the cipher text 166d having improved visibility by using the color modulation methods 168b and 168c that are in contrast to each other among the color modulation methods corresponding to the specific signal. For example, when the specific signal "1" is continuously present at 168a in Fig. 22, the bright region (e.g., RGB (128, 128, 128) , The red, green, and blue shifts occur in 168b, 168c, and 168c, respectively. Therefore, the two can be processed by cross-combining to improve the visibility of the signature image after the modulation.

The signature image display unit 180 displays the authenticated signature image 167 in a predetermined signature area on the electronic document. Generally, the authenticated signature image 167 is displayed in a signature area where a signature is made in a general paper document or an electronic document. It is possible to print or store the electronic document in which the authenticated signature image 167 is displayed, or to store it as another file for transfer or possession.

Signature image verification and original signature image restoration may be restricted when the signature image display unit 180 compresses and displays the signature image in a manner such that loss occurs (JPG or the like) or prints on paper or the like.

The authenticated signature image 167 is intended to satisfy both the authenticity of the signature, the integrity, and the requirement to be recognized as a true signature, such as a signer's rejection. Here, satisfying the true nature means that the corresponding signature in the electronic document is for the document (for example, the contract, etc.), and satisfying the integrity means that there is no forgery or alteration in the electronic document , Denial of denial may mean that the signing entity has been prepared for the possibility of denying the signature itself, that is, the signing entity has blocked the possibility of denying the signature itself.

In the case of the present invention, since the digital signature is modulated to the authenticated signature image 167 simultaneously with the input, that is, the digital signature is modulated and displayed using the authentication information simultaneously with the input, It can hardly be separated from the authentication information, and even if the authenticated signature image 167 is leaked by mistake or hacking, reuse becomes difficult.

In addition, the authenticated signature image 167 includes the contents information of the electronic document in the authentication information, so that it is possible to satisfy all the requirements of authenticity, integrity, and denial of rejection.

In the case of a contract, for example, since the contents of the contract and the signature are merged into a single authentication image, it is not possible to deny that the signature is related to the contract, and the authentication information includes the contract content, , And terminal information are stored. Thus, it is possible to know the context in which the contract is concluded, and it is possible to compare with the corresponding electronic document, so that the requirements such as integrity and denial of denial are secured.

When the digital signature inquiry unit 210 reads the authenticated signature images 232 and 235 in the predetermined signature area on the electronic document, the signature image verifying unit 230, as shown in FIG. 25 or 26, The cipher texts 233 and 236 can be extracted from the authenticated signature images 232 and 235 using the color modulation information 231 and 234 of the authentication information retrieved from the server 320. [

The signature image verifying unit 230 compares the extracted ciphertexts 233 and 236 with the ciphertexts of the authentication information retrieved from the authentication information server 320 and displays whether the ciphertexts are modulated or not through the verification result display unit 260 .

The signature image verifying unit 230 compares the hash code of the authenticated signature images 232 and 235 with the hash code of the authenticated signature image retrieved from the authentication information server 320 and outputs the verification result display unit 260 It can indicate whether it is up / modulated.

The electronic document verifying unit 240 decrypts the cipher text of the authentication information retrieved from the extracted ciphertext 233 or 236 or the authentication information server 320 to check the document content information and compares it with the content information of the electronic document , And the verification result display unit 260 can display the presence / absence of modulation / demodulation.

27, when the color modulation information 251 of the authentication information is constituted only by the additive color modulation method, the signature image restoring unit 250 restores the color modulation information 251 and the authenticated signature image 252 ) Can be used to extract the additive color modulation method set 253.

The signature image reconstruction unit 250 may reconstruct the original signature image 254 by inverting the set of the additive and color modulation method 253 to the authenticated signature image 252 as shown in FIG.

The signature image restoring unit 250 may restore the original signature image using the vector image information when the authentication information includes the vector image information of the signature.

The verification result display unit 260 may display the original signature image 261 restored by the signature image restoring unit 250 as shown in FIG.

When the authenticated signature image 167 is modulated using only the additive color modulation method, the original signature image can be restored using the inherent modulation characteristics and the authentication information of the additive color modulation method. On the other hand, when modulating the entire signature using a fixed color modulation method, the signature image is permanently impaired. Therefore, the vector image of the signature included in the authentication information can be restored and displayed.

If only margins are modulated using the fixed color modulation method, the original signature image can be restored by specifying the modulation by the fixed color modulation method as the authentication information and reducing it to the color of the original margin. However, have.

As described above, when the authenticated signature image 167 is generated and displayed as a method of displaying the digital signature, since the signature image 132 is contaminated up to the pixel unit using the authentication information, only the signature image is extracted separately So that it has the effect of weakening the intent to steal.

In addition, signature information of the signer is merged with content information of the electronic document included in the authentication information. The authentication information includes information such as the creation time and signature time of the electronic document, and the unique information of the used terminal Therefore, it is possible to grasp the context or situation related to the creation of the electronic document, and it can not be denied that the signature is the signature performed on the electronic document.

And the authenticated signature image 167 described above is generated by modifying the handwriting of the signature to the authentication information at the same time the signer inputs the signature. Accordingly, even if the signature image 167 is copied to the authenticated signature image 167, If the hash value of the image and the authentication information are not duplicated, the signature image verification can not be passed. Even if the hash value and the authentication information are stolen or copied, verification of the document content to verify that the content information of the electronic document is equal to the authentication information value Can not pass the process, and therefore can not pass the verification unless it is a copy having the same content as the original or original. So there is no benefit of copying or theft.

Accordingly, the electronic document exists at the time of signing by the signer, and the signer himself / herself assures that he / she has agreed or confirmed the contents by inputting the signature. Thus, in the case of the electronic document to which the authenticated signature image 167 is attached, And the content information or other context information of the electronic document can be known by using the authentication information, thereby ensuring integrity.

According to the present invention, authentication and confirmation of an electronic document are performed through the authenticated signature image 167, so that an elderly person who is unfamiliar with a smart phone or a tablet PC can easily authenticate or verify an electronic document, There is an advantage that it can be used easily. In addition, it is difficult to extract or modify the authentication information, and the context information and the content information of the electronic document at the time of signing the electronic document are encrypted in the authentication information, and a plurality of verification processes are performed, There is an effect that can be.

The foregoing description of the preferred embodiments of the present invention has been provided for purposes of illustration only and is not to be construed as limiting the present invention. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the basic principles of the present invention.

130: signature image generation unit 140: authentication information generation unit
150: signature image processing unit 170: authentication information processing unit
180: signature image display unit 210:
220: authentication information inquiry unit 230: signature image verification unit
240: electronic document content information verification unit 250: signature image restoration unit
260: verification result display section 320: authentication information server

Claims (10)

A digital sign display method comprising:
A first step of generating a signature image when a signature for confirmation or authentication of the created electronic document is input using a tool or a finger;
A second step of encrypting the content information of the electronic document and the unique information of the terminal used to generate a cipher text and processing the cipher text into a plurality of fixed color modulation information or an enhancement color modulation information to generate authentication information;
Processing the authentication information to modulate a portion or the entirety of the signature image so that an average color of a particular region of the signature image is modulated to converge to a color that contrasts with a line color of the signature image, A third step of generating a second signal;
And transmitting the authentication information to an authentication server and storing the authentication information, and displaying the authenticated signature image on a predetermined signature area on the electronic document. The method of claim 1,
The authentication method according to claim 1, further comprising: combining the color modulation method or the false information in the second step, the third step, or the second step and the third step to form the authentication information, And displaying the digital signature on the display unit. The method of claim 1,
And configuring the fixed color modulation information or the additive color modulation information so that the color of the modulation object is divided and processed by using different fixed color modulation method or an additive color modulation method in the second step And displaying the digital signature. The method of claim 1,
Further comprising the step of generating vector image information of a signature using the input signature in the first step and adding the vector image information in generating the ciphertext in the second step, How to sign. The method of claim 1,
And transmitting the hash value of the authenticated signature image to the server after the third step. A digital signature verification method comprising:
A step of reading an authenticated signature image in a predetermined signature area on an electronic document;
A step of inquiring authentication information of the authenticated signature image from an authentication server;
Comparing the cipher text extracted from the authenticated signature image and the cipher text of the authentication information to display whether the authenticated signature image is up / modulated;
Decrypting the cipher text of the authentication information or the cipher text extracted from the authenticated signature image to extract content information of the electronic document, comparing the extracted content information with content information of the electronic document, and displaying whether the content is up / modulated;
And restoring the original signature image using the authentication information and the authenticated signature image if the color modulation information of the authentication information is constituted only by the additive color modulation information, . The method of claim 6,
Checking the hash value of the authenticated signature image from the authentication server after the first step, comparing the hash value of the authenticated signature image displayed in the electronic document with the hash value of the authenticated signature image, and displaying the result Signature verification method. The method of claim 6,
Further comprising the step of restoring and displaying the original signature image using the authentication information and the authenticated signature image if the color modulation information of the authentication information is constituted only by the additive color modulation information after the second step The digital signature verification method. The method of claim 6,
Further comprising the step of restoring and displaying the original signature image using the vector image information when the authentication information includes the vector image information of the signature after the second step. A computer-readable recording medium having recorded thereon a computer program capable of executing the method recited in claim 1 or 6.

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