JP2003223435A - Document printing device, document authentication device, document printing method, document authentication method, document authentication system, program, and storage media - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish techniques for using certificates or the like utilizing the characteristics of printed documents (paper documents) by correctly verifying signatures from signature information recorded on printed documents and from the printed documents. <P>SOLUTION: A document printing device for printing documents prints document designating information for designating electronic documents and signature information for the document designating information, along with the electronic documents. The signature information comprises a digital signature created by use of an encryption key. A document authentication device reads the document including the document designating information and the signature information of the document designating information, and document verification information is output by a retrieval means and an authentication means. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for printing a document such as a certificate and authenticating the document.

[0002]

2. Description of the Related Art The electronic signature law came into effect on October 1, 2000 in the United States. With this, electronic signature (digital signature)
Is now recognized as a legally valid signature. Similarly, in Japan, the law concerning electronic signatures and certification operations came into effect in April 2001, and electronic signatures have been recognized as legally valid. In Japan, it is said that the certifier or the contractor has consented to the contents of those documents by the signature and seal of the certificate or contract (hereinafter referred to as the certificate etc.) that the certifier or contractor makes. Was legally regarded. With the enforcement of this law, it is expected that electronic signatures will be increasingly used for transactions on the Internet in the future.

On the other hand, it is natural that information literacy will not be fully spread, and that it will continue to exist without a method of consenting to sign and stamp a paper document as in the past. However, it can be said that the reason is not necessarily limited to the limits of information literacy. This can be understood by considering the characteristics of paper documents as information transmission / recording media. Information such as characters, figures, and photographs recorded on paper is transmitted to the human brain by direct human eyes. For that purpose, electronic equipment such as a computer is not required. Also, if it is not such a large amount of information, the necessary information can be recorded on several paper documents, and it can be carried as an information transmission medium that allows you to confirm the contents with the naked eye at any time. Storage media, flexible disk, CD
-This is a great advantage over electronic storage media such as ROM, Sony Memory Stick, Compact Flash (registered trademark) card, and smart card.

The contents can be kept secret by putting them in a sealed letter. The nature of this concealment is that if information is stolen, it can "know" the very fact that it has been stolen. On the other hand, in the case of an electronic storage medium, it may be difficult to know the fact that information has been stolen. Furthermore, the physical size that can be folded and stored on paper is variable, such as fountain pen, ballpoint pen,
The advantage is that you can easily record additional memos without using an electronic device, such as with a pencil, brush, or highlighter. Although it is not a casual memo to write certificates,
It is common practice to write thin notes with a pencil.

Due to such consideration, a certificate based on a paper document with a signature and a seal (hereinafter referred to as a paper certificate or the like) will be used in the future.
It is expected that the digital certificate and the electronic certificate with the electronic signature will be used together. Here, the electronic signature may include a digital signature and image data of a handwritten signature in some cases, but in the following description, the electronic signature is limited to the digital signature. Here, the digital signature means a signature using a public key cryptosystem such as RSA (registered trademark), elliptic curve cryptography, and ElGamal cryptography. For a detailed explanation, see, for example, "Modern Cryptography," written by Tatsuaki Okamoto and Hirosuke Yamamoto (first edition June 30, 1997, published by Industrial Books, ISBN4-7828-
5353-X).

RSA will be briefly described below. In RSA, d (or a pair of p and q) is used as a secret key and e and n pair is used as a public key. Here, p and q are prime numbers, and d is calculated from p and q. n = p * q
(The product of p and q), and letting λ be the least common multiple of p-1 and q-1, then e is appropriately selected from integers smaller than λ that are coprime to λ. Is. d is calculated by d = 1 / e mod λ. Here, if the prime numbers p and q are sufficiently large, it is extremely difficult to factor p out of n = p * q to obtain p and q. It is practically impossible to obtain q).
To encrypt the data m, c calculated by c = ^me mod n is the encrypted data. Conversely, the decoding is calculated by m = c ^d mod n, m is obtained. Further, when m is encrypted with the secret key d, c = ^md mod n, and the original key m can be obtained by using this public key e as m = ^ce mod n. The digital signature can be realized as follows because of the property that what is encrypted with this private key can be decrypted with the public key. Ie SH
When s = h (m) ^d mod n is obtained from the plaintext m using the one-way hash function h (x) such as A, this s becomes the signature data. That is, the ^{h (m) = s e mod} n, but it should h (m) is obtained, this is exactly what h
The signature can be verified depending on whether it is equal to (m).

If s thus calculated is added to the electronic document data m as signature data, signature verification is performed by the above signature verification method as long as the signer keeps the secret key secret. If s is successful, s cannot be created by anyone other than the signer, so it is guaranteed that the signer has just created the signature data and that the electronic document data m has not been modified after signing. What if m
This is because if is changed after the signature, the one-way function h (x) has a different value and the above verification is not successful.

The digital signature of the electronic document thus made causes an essential difference in strictness from the signature method of signature-printing a paper document.

In Japan, in Article 167 of the Criminal Code, "A person who forges a seal or signature of another person for the purpose of exercising (forgery and improper use of private seal) shall be punished by imprisonment with work for not more than three years. 2 Any person who improperly uses a seal or signature of another person or uses a counterfeit seal or signature is the same as the preceding paragraph. "The law only prohibits the forgery of the seal and the seal stamp Forgery is not technically difficult, and certificates and the like are forged.

When a signature is stamped on a paper document, creating a seal stamp that imitates the signature and can imprint the same shadow from the shadow of the stamp is compared with the difficulty of obtaining the private key from the public key in the above digital signature. It's much easier.

As an invention to make up for the drawbacks of the paper certificate and the like, for example, Ralph C. Merkle, Da of US Pat. No. 5,157,726 is cited.
n S. Bloomberg, John S. Brown et al.
CUMENTCOPY AUTHENTICATION ". According to the invention, "a process of making an authenticable copy of an original document supplied from an entity, in which a hard copy of the original document is made and a digital representation of the original document and the entity is identified. A process consisting of including a signature in the document ".

Also, Christopher of US Pat. No. 5,912,974
Invention by J. Holloway "APPARATUS AND METHOD FOR AU
There is "THENTICATING OF PRINTED DOCUMENTS". According to the invention, "a device for authenticating a hardcopy document, wherein the means for digitizing the information content of the hardcopy document and the means for editing the digital format of the information content of the hardcopy document are the same. Means for producing an edited digital form of the information content of the hardcopy document, producing a second digital form essentially the same as the edited digital form from the hardcopy document; Means for encrypting a digital format to generate a digital signature, means for generating an authentication code from the edited digital format and the digital signature, means for attaching the authentication code to the hardcopy document, and the authentication Device comprising means for proving the authenticity of said hardcopy document using a code ". .

There is also Japanese Patent No. 2875450, "Printing Device and Printing Verification Device for Electronic Approval Information" by Takashi Okamoto and Koichi Sakurai (filed on April 21, 1993). According to the present invention, in a printing device for electronic approval information for electronically stamping electronic information, public information generating means for generating public information from secret information of a stamper, and registration means for previously registering the public information in a database. And a stamp information generating unit that generates stamp information using secret information for electronic information, a stamp information converting unit that converts the stamp information generated by the stamp information generating unit into a print format, and the stamp information conversion. Stamp information printing means for printing the stamp information converted by the means,
A device for printing electronic approval information, electronic information input means for reading information of a printed matter on which electronic information is printed, and electronic information for converting the information read by the electronic information input means into electronic information Reverse conversion means, seal information input means for reading information of printed matter on which seal information is printed, seal information reverse conversion means for converting the information read by the seal information input means into seal information, and taking out public information from the database An electronic approval information print verification device characterized by comprising a search means and a stamp verification means for verifying electronic information using the stamp information and the public information in the database ". .

[0014]

In the future, it is expected that electronic certificates with electronic signatures will be used in Internet transactions and paper certificates will be used as usual. While it is difficult to forge a digital certificate or the like, the fact that a paper certificate or the like is easily forged is a problem because the convenience of paper documents described above cannot be fully utilized. Forgery is as difficult as a certificate. In contrast, US Patent 5,157,726 and US Patent
There are inventions of 5,912,974 and Japanese Patent No. 2875450,
These have the following problems.

First, in US Pat. No. 5,157,726, a digital signature is created from a document digitized by being scanned by a copier by a document digitizer means, and the digital signature is merged with a copy of the document to produce a copy document with a digital signature. A method of creating a copy document with a digital signature and authenticating the digital signature by a copying machine is disclosed. Although there is no technical disclosure about a specific method of digitization and a method of printing a digital signature, in order to digitally sign a document copied by a copying machine,
The method of digitizing a document is to create an image format consisting of pixel data, or use OCR (Opt
ical Characiter Reader: An optical character recognition device) is used for character encoding. However, it is difficult or rather impossible to obtain the same digitized data for each scanning by the copier by either method. In the case of the image format, the same digital data cannot be obtained due to dust adhering to the surface of the glass surface on which the document of the copying machine is placed, or variations in the reading light intensity. Furthermore, regarding the result of OCR,
Correct recognition results cannot be obtained due to these uncertain factors. Therefore, even if the content of the document is not modified, the wrong result that the authentication fails in the check of the digital signature is caused.

Also in US Pat. No. 5,912,974, a means for digitizing the information content of a hardcopy document is used. As a means for this, a method is adopted in which a document is captured by an image scanner and digitized by OCR. However, the recognition accuracy of OCR is not perfect, and erroneous recognition always occurs, as described above. For example, even if the surface of a document is stained, it is easy to understand that no matter how accurate the OCR is, misrecognition occurs. The patent utilizes a means of editing the digital format of the information content of the hardcopy document and may be construed as including a method of editing the misrecognition to correct it to the correct character. . However, this involves manual correction work,
Not efficient. In addition, it is almost impossible to correct the parts other than the characters such as figures and photographs.

According to Japanese Patent No. 2875450,
The stamp information (which can be understood as a digital signature) applied to the electronic information is converted into a print format, and the stamp information is printed. Then, by the electronic information input means, the printed matter is read and converted into electronic information, and the stamp information is read from the print format,
It is disclosed that public information (which can be understood as a public key) is taken out from a database, and electronic information is verified using the stamped information and the public information. Then, it is described that OCR or the like is used as the electronic information input means.
However, it is a drawback of the present invention that erroneous recognition of OCR poses a problem and that no method for inputting a figure or a photograph and converting it back to the same electronic data as the original electronic information is disclosed at all. Therefore, in verification of printed matter, data tampering due to inverse conversion is always performed,
The result is that the verification is not successful. Furthermore, there is no disclosure of a method for automatically obtaining search information for retrieving public information from a database. According to the present invention, there is no means other than that the person who verifies the printed matter obtains the key information for designating the public information by being taught by the person who created the stamp information and searches the database.

As described above, in any of the above inventions, it is practically impossible to read the digital signature recorded in the print document and verify the signature correctly from the content of the print document.

Therefore, the purpose of the invention in this patent application is to verify the signature correctly from the signature information recorded in the print document and the print document, and to provide a certificate or the like that makes the best use of the characteristics of the print document (paper document). It is about establishing utilization technology. At this time, it is possible to eliminate manual work as much as possible.

[0020]

[Means for Solving the Problems] In the coming electronic contract society, a paper certificate, etc. is not unrelated to the electronic certificate, etc. Normally, there is an electronic certificate, etc. It is expected that certificates and other information will be output, and the mechanism of signature creation and signature authentication will be operated in cooperation with the "paper" and "electronic" media. In addition, the development of technology on the premise of such cooperation is considered to be the source of activating the electronic contract society. Therefore, original document → Create signature data → Output paper document → Print signature data on paper document → Read paper document / signature →
In the flow of signature authentication (see FIG. 1), making the original document a paper document causes difficulty due to the incomplete digitization of the paper document described above. In the invention, the original document is an electronic document. Further, the verification of the signature based on all the information of the paper document is similarly difficult due to the incomplete digitization of the paper document when the signature verification is performed. Therefore, in the invention according to the present patent application, the target of signature authentication is limited to the information that specifies the document, partial authentication is performed, and the document confirmation information is output so that the coincidence between the paper document and the electronic document can be confirmed. did.

Therefore, the present invention is characterized in that the document designating information designating the electronic document and the signature information of the document designating information are printed together with the electronic document. The signature information is a digital signature created using an encryption key. Further, the document including the document designation information and the signature information of the document designation information is read, the digitized data of the document designation information and the signature information is fetched, the electronic document is searched by the document designation information, and the fetched. The signature is authenticated based on the document designation information and the signature information, and the document confirmation information is output from the electronic document related to the document designation information. In the search, the encryption key is searched together with the electronic document from the document designation information,
The signature authenticating means authenticates using the encryption key. Further, it is characterized by comprising printing means for printing the electronic document and outputting the document together with the document designation information for designating the electronic document associated with the signature information.
Also, the signature information is created by digitally signing the electronic document with an encryption key. Further, the document including the document designation information for designating the electronic document associated with the signature information is read, the digitized data of the document designation information is fetched, and the electronic document and the signature information are searched by the document designation information, A signature is authenticated from the electronic document and the signature information, and document confirmation information is output from the electronic document related to the document designation information.
Further, in the search, an encryption key is searched from the document designation information together with the electronic document and the signature information, and the signature authenticating unit authenticates using the encryption key. Further, in a document authentication system comprising a terminal and a server connected to the terminal via a network, the terminal includes a terminal input means and a terminal transmission means, and the server has a server reception means, a search means, and a storage means. And an authentication unit, a generation unit, and a server transmission unit, wherein the terminal inputs the document designation information by the terminal input unit, and the terminal transmission unit transmits the document designation information to the server via a network, The server receives the document designation information by the server receiving unit, searches the electronic document and signature information stored in the storage unit by the search unit based on the document designation information, and retrieves the electronic document and the signature information from the electronic document and the signature information. The signature is authenticated by the authentication means, the document confirmation information is generated from the electronic document by the generation means, and the document verification information is generated. By the server transmission means information, and transmits over the network to the terminal.

[0022]

2 and 3 are block configuration diagrams of a preferred embodiment of the present invention, FIG. 2 is a block configuration diagram of a document printing device, and FIG. 3 is a block configuration diagram of a document authentication device. Is. A storage unit 201 is a database in which the document designation information, the encryption key, and the electronic document are stored in association with each other. The electronic document is electronic document data created by word processing software of a computer or Acrobat.
It may be electronic document data in an electronic distribution format such as PDF (registered trademark) or electronic document data in an image format such as TIFF or JPEG. The document designation information is data for uniquely identifying the electronic document in the database, and is, for example, a document code composed of alphabets and numbers. The encryption key is
This is an encryption key used for authentication. For example, if the database is a resident card database of a local government, the electronic document is data obtained by digitizing the resident card, and the document designation information is a management number for managing the resident card.
Further, the encryption key is an encryption key for authenticating the signature of a person (usually the mayor etc.) who makes a digital signature to prove the resident's card. When the digital signature is made by the public key cryptosystem, the encryption key is a public key. It is also possible to use a common key cryptosystem for the digital signature, and in this case, the encryption key is a common key. However, in this case, the common key must be managed secretly as appropriate.

For example, when a person who applies for the receipt of a resident card presents an address and a name, by searching a management number database that associates an address / name (not shown) with a management number (document designation information) of the resident card. , The document designation information 204, which is a management number, is obtained.

Reference numeral 207 is a search means for searching the storage means 201 for a related electronic document and encryption key using the document designation information as a key. However, when there is one electronic document stored in the storage unit 201, the search unit 207 is not necessary. Reference numeral 202 denotes a signature creating means, for example, in the method based on the public key cryptosystem of RSA, the secret key of the signer (the mayor's secret key in the case of the above-mentioned residence certificate issuing device) is used, and the signature information is changed from the document designation information 204. 205 (digital signature data) is created by the signature creating means 202. Reference numeral 203 denotes a printing unit, which prints an electronic document related to the document designation information 204 on paper or the like, and prints a document 206.
To create. However, at this time, the document designation information 204
Then, the signature information 205 is superimposed (206a, 206b) on the electronic document in a re-digitizable print format and printed. For example, since the data amount of the document designation information 206a is small, the print format can be an OCR-B font, and the signature information 206b can be a barcode, a two-dimensional barcode or the like. FIG. 4 is a diagram showing an example of the printed document. Also, the document designation information 206a and the signature information 2
06b may be embedded in the document 206 as a digital watermark.

The processing of the document printing apparatus will be described below with reference to the flowchart of FIG. In step S601, the document specifying information (for example, the document code) is set to the signer's private key (RSA).
A signature information 205, which is signature data, is created by digitally signing with a private key (public key cryptosystem). Next, in step S602, an electronic document corresponding to the document designation information is searched and obtained. Then, in step S603, the document designating information is superposed on a predetermined position of a blank portion such as a header or footer of the electronic document, for example, in the OCR-B font, and a bar code print pattern obtained by converting the signature information into a bar code is overlaid. The printed document 206 is created and output.

In FIG. 3, reference numeral 301 denotes an electronic means, which reads the document 206 printed by the document printing apparatus shown in FIG. 2, digitizes the document designation information 206a and the signature information 206b again, and serves as document designation information. If there is no falsification, it is converted into the same document designation information 307 as the document designation information 204, and if there is no falsification as the signature information, the signature information 205
It is converted into the same signature information 306 as the above. For example, the computerization means 301 reads the document 206 with an image scanner, converts it into a bitmap image, cuts out the document designation information 402 (FIG. 4) at a predetermined position, and recognizes the character to obtain a character code. Here, when the document designation information is included as a digital watermark, it is converted into a character code even when the digital watermark is read. Further, the digitizing means 301 uses the signature information 403 located at a predetermined position from the bitmap image.
The barcode or digital watermark data shown in FIG. 4 is read and converted into signature information data. Reference numeral 303 denotes a search unit that searches using the document designation information 307 converted and output by the computerization unit 301 as a key, and stores the encryption key 308 and the electronic document 309 related to the document designation information 307 in the storage unit 201.
Take out from. Next, 302 is an authentication means, which authenticates the digital signature with the signature information 306, the document designation information 307, and the encryption key 308. Specifically, hash data is created from the document designation information 307 by a predetermined one-way hash function, and the signature information 306 is created.
It is checked whether the data decrypted by the encryption key 308 and the hash data match. If they match, it means that the authentication has succeeded and issues an output instruction to the output means 305. If they do not match, an authentication error is displayed by a message display means (not shown).

When the output means of 305 receives an output instruction from the authentication means, the electronic document of 309 is printed out and a print document is created as the document confirmation information 310 or displayed on the display device.

Next, according to the flow chart of FIG.
The processing procedure of the document authentication device will be described. First, step S
In step 701, the document 206 is read by an image scanner and converted into image data. Then, the image data of the document designation information and the image data of the signature information included in the predetermined position are cut out, and the image data of the document designation information is character-recognized to be digitized document designation information 307 which is code data. The barcode, which is the image data of the signature information, is converted into electronic signature information 306 which is numerical data. Then, in step S703, the document designation information 3
The encryption key 308 and the electronic document 309 associated with the document designation information are retrieved from the storage unit 201 using 07 as a key.
In step S704, the digital signature is authenticated using the signature information 306, the document designation information 307, and the encryption key 308. In step S705, the authenticity of the authentication is determined. If the authentication is true, step S
In step 706, the electronic document 309 is output as document confirmation information by printing or displaying. If the authentication is false, the process advances to step S707 to display an error message.

Now, the logic of the authentication performed by the above embodiment will be described as follows. First, it is assumed that the above-described document printing / authentication system including a document printing device and a document authentication device is operated and managed under appropriate security management by a certificate issuing organization that issues a document that is a certificate. A document 206 (hereinafter referred to as a certificate) created by the document printing apparatus includes document designation information 204 for identifying an electronic document (stored in the storage unit 201) certified by a prover, and the document designation information. The signature information 205, which is obtained by digitally signing the certificate with the private key (or common key) of the prover, is printed so that it can be re-digitized. The contents of the electronic document certified by the prover are also printed on the certificate. The certificate is submitted to a person (hereinafter referred to as a certifying confirmer) who wants the certified person to recognize the certification. The certificate confirmer generally understands what the certificate is about to certify from the printed contents of the certificate, and knows whether or not the certificate matches the purpose for which the certificate was submitted. be able to. However, the authenticity of the certificate has not yet been confirmed. Therefore, the certificate confirmer reads the certificate with the image scanner of the document authentication apparatus and executes authentication. Then, the document designation information 206a printed on the certificate is read, and the signature information 206b that should be the digital signature data of the document designation information is also read, and the signature information is the true digital signature of the document designation information. Is a certifier's encryption key (encryption key, public key or common key corresponding to the document designation information stored in the storage unit 201)
Confirmed in. Here, if it is possible to confirm that the signature information is a true digital signature of the document designation information, it is found that the document designation information of the document requested by the proveee is correct. Then, the electronic document corresponding to the document designation information is printed by the output unit 305 and the proof confirmer obtains the document confirmation information. The proof confirmer confirms the proof contents with the document confirmation information. Where certificate (document 206)
By comparing the contents of the above with the document confirmation information, the certification work can be carried out more easily.

Here, the information that is essentially necessary to authenticate with the information included in the certificate is the document designation information 206a.
And the signature information 206b, and the print content of the electronic document is in an auxiliary position in the sense of authentication. However, the printed contents of the certificate serve the purpose of "informing the certifier of the purpose of the certificate", and the certificate (Document 20
It is important that the proof work for comparing the content of 6) with the document confirmation information is made efficient. It can be said that these are exactly the mechanisms that can utilize the above-mentioned characteristics of paper documents.

Further, the document designation information 206a of the document 206
The accuracy of digitizing the signature information 206b by the digitizing means 301 will be described below.
Since the document designation information 206a is printed in the OCR-B font, it can be said that the recognition accuracy is practically no problem because it is an OCR-dedicated font. Further, since the signature information 206b is a bar code, the reading accuracy is higher, so there is no problem. If it is desired to further improve the accuracy, both may be barcodes, or the digitization of the document designation information may be manually input. Therefore, in the present embodiment, as compared with the conventional invention, the number of authentication failures due to poor digitization accuracy is far less.

FIG. 5 is an example of a hardware configuration diagram of the document printing apparatus and the document authentication apparatus. Reference numeral 501 denotes a CPU that controls the apparatus, and 502 denotes an R that stores a BIOS and the like.
OM, 503 is a RAM which is a work area of the program,
Reference numeral 504 is a hard disk that is the storage means 201 and stores the OS, 505 is a communication interface (not used in this embodiment), 506 is a keyboard and mouse for inputting various operations, 507 is a display controller, and 508. Is a display device for displaying various messages, 50
Reference numeral 9 is an I / O port, 510 is a printer which is the printing means 203, 511 is an interface, 512 is an image scanner for converting a document into image data by an electronic means, and 513 is a bus. 6 to 7 including various processing modules such as a program for the electronic means 301 to perform character recognition processing of image data, a search means 207/303, an authentication means 302, and a signature creation means.
This program is stored in the hard disk 504 and is executed by the CPU 501. Note that the document printing device and the document authentication device may be separate hardware.

In this embodiment, the signature information 205 is a digital signature created by a secret key, but it may be the hash data itself generated from the document designation information 204 by a predetermined hash function such as SHA, or The hash data may be a cryptographic key of a common key cryptosystem. When the signature information 205 is the hash data, the encryption key is unnecessary in the storage unit 201,
It is not necessary to use the encryption key 308 even in the authentication means 302 of FIG.

In the description of the above embodiment, it has been stated that the document designation information 206a and the signature information 206b may be embedded in the document 206 as a digital watermark, but the digital watermark technique may be visible or invisible.
JP-A-2000-151979, JP-A-2000-1968
57 and the like may be applied.

[Second Embodiment] In the first embodiment described above, the document designation information and the signature information are overlaid and printed on the document (document 206). Therefore, the information of the document 206 alone cannot serve as a certificate of signature or the like, and the signature can be confirmed by combining with the encryption key stored in the storage unit 201 and the information of the electronic document. Here, in the second embodiment, this is further advanced to present an example in which the information included in the document is minimized.

FIG. 8 is a block diagram of a document printing apparatus according to the second embodiment, in which 801 is document designation information, 802 is retrieval means, 803 is document designation information, an electronic document, signature information, and an encryption key. Storage means for storing in association with each other, 804 is an electronic document, 805 is printing means, 806
Is a document, and 806a is document designation information printed in an OCR-B font or a barcode included in the document 806. Here, the encryption key is a public key of public key cryptosystem such as RSA. The signature information is the encryption key (public key)
It is signature data generated by digitally signing the electronic document with the private key corresponding to. The encryption key may be a common key. In this case, the same encryption key is used for signature creation and signature authentication. Further, the storage means may not include the encryption key, and in this case, the signature information is hash data created from the electronic document by a hash function such as SHA. The hardware configuration of this document printing apparatus is shown in FIG.
Is the same as.

The processing of the document printing apparatus will be described with reference to the flowchart of FIG. In step S901, the searching unit 802 searches for and retrieves an electronic document related to the document designation information from the storage unit 803.
In step S902, the document designation information is printed together with the electronic document by the printing unit 805, and the document 806 including the printed document designation information 806a is output. Here, the document designation information may be embedded in the document 806 as a digital watermark.

FIG. 10 is a block diagram of the document authentication apparatus according to the second embodiment, in which 1001 is an electronic means, 1002 is document designation information, 802, 803, 80.
4, 806 and 806a are the same as those in FIG. 8, 1003 is an encryption key, 1004 is signature information, 1006 is an authentication means, 1
Reference numeral 007 denotes output means such as a printer or a display device, and 10
Reference numeral 08 is document confirmation information. The hardware configuration of this document authentication device is the same as in FIG.

Next, the description of the document authentication device will be given with reference to the flowchart of FIG. In step S701, the document 806 printed by the document printing apparatus is read by the image scanner 512 and converted into image data, and the RAM 50 is read.
Store in 3. Then, in step S702, the document designation information is read from a predetermined position of the image data,
The digitized data is converted into the digitized data by the OCR program or the bar code stored in the hard disk device 504 or the digital watermark reading program (digitizing means 1001). Next, in step S703, the search means 80 is used with the document designation information as the digitized data as a key.
The signature information 1004, the encryption key 1003 (not required if the signature information is hash data), and the electronic document 804 related to the document designation information are retrieved from the storage unit 803 by means of 2. Then, in step S704, the signature information 10
The data obtained by decrypting 04 with the encryption key 1003 is compared with the hash data created from the electronic document 804 to authenticate the signature. In step S705, if the comparison is coincident, that is, if the signature is true, the process proceeds to step S706, and the electronic document 804 is printed by the printer 510 or displayed on the display device 508 and output. If the comparison does not match, that is, if the signature is false, the process advances to step S707 to display a signature error message on the display device S.
Display at 508.

[Third Embodiment] FIG. 11 is a block diagram of a system showing a third embodiment. 1101 is a terminal (such as a personal computer) connected to a network such as the Internet, 1102 is a server, and 1103 is a network such as the Internet.

The terminal 1101 has terminal input means and terminal transmission means. As shown in FIG. 12, the server 1102 has a server receiving means 1201 and a server transmitting means 1202, as well as a search means 802, a storage means 803, which performs the same functions as those shown in FIGS.
It has an authentication means 1006 and a generation means 1007 (expressed as an output means in the second embodiment, but replaced by a generation means here).

In the second embodiment, the document is read by the image scanner, the document designation information is digitized by the digitizing means, and is passed to the searching means as a search key. The document specifying information is input to the terminal by the means, and the document specifying information is transmitted to the network 1103 by the terminal transmitting means. At this time, the document designation information is input to the terminal as in the second embodiment.
It may be computerized (assuming the image scanner of the terminal is connected), or a person may read the document designation information and type from the keyboard.

The server 1102 receives the document designation information by the server receiving means 1201, passes the document designation information to the search means of 802, and the document confirmation information of 1008 after that in the same manner as the second embodiment. To get In this case, the document confirmation information includes the image format (JPEG etc.) that enables the electronic document 804 to be displayed on the terminal 1101 or Acrobat PDF.
Format. The server 1102 transmits the document confirmation information to the terminal 1101 by the server transmission means 1202. At the terminal 1101, the contents can be confirmed by comparing the document confirmation information with the original document.

[0044]

[Effect of the Invention] In the future electronic contract society,
Digital signatures such as digital signatures are widely used, but considering the advantages of paper documents such as information transparency, transportability, and recordability, it is possible to create and sign certificates and contracts using documents such as paper media. There is no confirmation. However, the security robustness of a digital signature is far superior to that of a conventional signature such as a conventional signature or a seal, so that the same level of security robustness is required for a document. Therefore, according to the present invention, since the digital signature can be used for the document by linking the document and the electronic document, the advantage of the document and the robustness of the security can be provided, which is extremely convenient.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a conventional invention.

FIG. 2 is a block diagram of the document printing apparatus according to the first embodiment.

FIG. 3 is a block diagram of a document authentication device of the first exemplary embodiment.

FIG. 4 is a diagram showing an example of a document.

FIG. 5 is a hardware configuration diagram of a document printing apparatus and a document authentication apparatus.

FIG. 6 is a flowchart of processing of the document printing apparatus according to the first embodiment.

FIG. 7 is a flowchart of processing of the document authentication apparatus of the first embodiment.

FIG. 8 is a block diagram of a document printing apparatus according to a second embodiment.

FIG. 9 is a flowchart of processing of the document printing apparatus according to the second embodiment.

FIG. 10 is a block diagram of a document authentication device according to a second exemplary embodiment.

FIG. 11 is a system configuration diagram of a third embodiment.

FIG. 12 is a block diagram of a system according to a third embodiment.

[Explanation of symbols]

201: storage means, 202: signature creation means, 203: printing means, 204: document designation information, 205: signature information, 2
06: document, 206a: document designation information, 206b: signature information, 301: digitization means, 302: authentication means, 30
3: search means, 305: output means, 306: signature information,
307: document designation information, 308: encryption key, 309: electronic document, 310: document confirmation information, 401: document, 402:
Document designation information, 403: Signature information, 501: CPU, 50
2: ROM, 503: RAM, 504: hard disk device,
505: communication I / F, 506: keyboard & mouse, 5
07: display controller, 508: display device, 509:
I / O port, 510: printer, 511: I / F, 5
12: image scanner, 801: document designation information, 80
2: search means, 803: storage means, 804: electronic document,
805: printing means, 806: document, 806a: document designation information, 1001: digitization means, 1002: document designation information, 1003: encryption key, 1004: signature information, 100
6: authentication means, 1007: output means (generation means), 10
08: Document confirmation information, 1101: Terminal, 1102: Server, 1103: Internet, 1201: Server receiving means, 1202: Server transmitting means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B41J 29/40 G06F 3/12 K 5J104 G06F 3/12 G06K 9/00 S G06K 9/00 G09C 1/00 640D G09C 1/00 640 B41J 29/00 ZF term (reference) 2C061 AP01 CL10 HJ06 HQ17 JJ06 JJ14 2C087 BA01 BA05 BA06 BA14 BB10 BD01 BD02 DA13 5B009 RC13 SA11 5012B011

Claims (21)

[Claims] 1. A document printing apparatus for printing a document, wherein document specifying information for specifying an electronic document and signature information of the document specifying information are printed together with the electronic document. 2. The document printing apparatus according to claim 1, wherein the signature information is a digital signature created by using an encryption key. 3. A document authentication device for authenticating a document, comprising:
An electronic means for reading the document including the document designation information and the signature information of the document designation information and for fetching the digitized data of the document designation information and the signature information; and a retrieval means for searching an electronic document by the document designation information. A document authenticating device comprising: an authenticating unit for authenticating a signature from the document specifying information and the signature information taken in by the digitizing unit; and an outputting unit for outputting the document confirming information from the electronic document related to the document specifying information. 4. The document authentication apparatus according to claim 3, wherein the retrieval unit retrieves an encryption key from the document designation information together with the electronic document, and the authentication unit authenticates using the encryption key. . 5. A document printing apparatus for printing a document, comprising: printing means for printing the electronic document and outputting the document together with document designation information for designating an electronic document associated with signature information. Document printing device. 6. The signature information is created by digitally signing the electronic document with an encryption key.
Document printing device described. 7. A document authenticating device for authenticating a document, which comprises: electronic means for reading a document including document designation information for designating an electronic document associated with signature information and for fetching digitized data of the document designation information. Search means for searching the electronic document and the signature information by the document designation information,
A document authentication device comprising: an authentication unit that authenticates a signature from the electronic document and the signature information; and an output unit that outputs document confirmation information from the electronic document related to the document designation information. 8. The retrieval unit retrieves an encryption key from the document designation information together with the electronic document and the signature information, and the authentication unit authenticates using the encryption key. Document authentication device. 9. A method of printing a document, comprising the steps of creating signature information from document designation information designating an electronic document, and printing the electronic document together with the document designation information and the signature information. Document printing method. 10. The document printing method according to claim 9, wherein the signature information is a digital signature created by using an encryption key. 11. A document authentication method for authenticating a document, which comprises a step of reading a document including document designation information and signature information of the document designation information, and an electronic device for fetching digitized data of the document designation information and the signature information. Digitizing step, a searching step of searching an electronic document from the document designating information, an authenticating step of authenticating a signature from the document designating information and signature information fetched in the digitizing step, and A document authentication method comprising the step of outputting document confirmation information from an electronic document. 12. The document authentication method according to claim 11, wherein an encryption key is searched together with the electronic document from the document designation information in the search step, and authentication is performed using the encryption key in the authentication step. 13. A document printing method for printing a document, comprising a printing step of printing the electronic document and outputting the document together with document designation information for designating an electronic document associated with signature information. How to print documents. 14. The document printing method according to claim 13, wherein the signature information is created by digitally signing the electronic document with an encryption key. 15. A document authentication method for authenticating a document, comprising: inputting document designation information for designating an electronic document associated with signature information; and searching the electronic document and the signature information by the document designation information. A document authentication method comprising: a search step for performing the authentication, an authentication step for authenticating a signature from the electronic document and the signature information, and an output step for outputting document confirmation information from the electronic document related to the document designation information. 16. The encryption key is searched together with the electronic document and the signature information from the document specifying information in the search step, and the authentication step uses the encryption key to perform authentication. Document authentication method described. 17. A document authentication program for authenticating a document, comprising a step of reading a document including document designation information and signature information of the document designation information, and digitization of digitized data of the document designation information and the signature information. A step of retrieving an electronic document from the document specifying information, an authenticating step of authenticating a signature from the document specifying information and the signature information fetched in the digitizing step, and the electronic related to the document specifying information. A document authentication program for causing a computer to execute an output process of outputting document confirmation information from a document. 18. A document authentication program for authenticating a document, comprising the step of inputting document designation information for designating an electronic document associated with signature information, and searching the electronic document and the signature information by the document designation information. A document for causing a computer to execute a search step for performing the authentication, an authentication step for authenticating a signature from the electronic document and the signature information, and an output step for outputting document confirmation information from the electronic document related to the document designation information. Certification program. 19. A computer-readable storage medium storing the program according to claim 17. 20. A computer-readable storage medium storing the program according to claim 18. 21. A document authentication system comprising a terminal and a server connected to the terminal via a network,
The terminal includes terminal input means and terminal transmission means, and the server includes server reception means, search means, storage means, and
The terminal includes document specifying information by the terminal inputting means, the terminal transmitting means transmits the document specifying information to the server via the network, and The server receives the document designation information by the server receiving unit, searches the electronic document and signature information stored in the storage unit by the search unit according to the document designation information, and extracts the electronic document and the signature information from the electronic document and the signature information. The signature is authenticated by the authentication unit, the document confirmation information is generated from the electronic document by the generation unit, and the document confirmation information is transmitted to the terminal by the server transmission unit via the network. Document authentication system.