JP2002158865A - Method and system for processing image information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent watermark information from being copied easily and to determine whether printing is performed properly by a specified print means or not based on the watermark information. SOLUTION: When the image information of a digital content is printed on a printer 5, print means detection data containing inherent information stored in an inherent information memory 24 is encrypted, at a tampering detection data generating section 30, by a secrete key incorporated in the printer to generate tampering detection data. The tampering detection data is added to the print means detection data to obtain electronic watermark information which is embedded in the image information of a digital content at an electronic watermark inserting section 32 before being delivered to the printer 5 and printed on a print sheet. The image information is read out from the printed sheet by means of a scanner 6 and the print means detection data is separated from the tampering detection data by a data separating means. Properness of the printer is determined by decrypting the separated tampering detection data using a public key of the printer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and an image processing apparatus capable of judging the validity of image information printed on paper when image information of digital content is printed.

[0002]

2. Description of the Related Art In recent years, the spread of the Internet has made it possible to effectively utilize digital contents by storing, copying, and processing them. It is desired that it is possible to easily determine whether or not the print has been made along the route.

As an image processing apparatus for embedding additional information in input image data, for example, an image processing apparatus described in Japanese Patent Application Laid-Open No. H11-4337 is known. The image processing apparatus adds predetermined watermark information such as a user ID code to image data read by an image scanner by a watermark information inserter, and supplies the image data with the watermark information to a printer. It has a configuration for printing out.

[0004]

However, in the above-mentioned prior art, since the watermark information is directly added to the image data read by the image scanner, the image data printed out on paper must be analyzed. Allows the watermark information to be separated and detected,
By adding the separated watermark information to other image data, it is possible to easily print out the image data to which the watermark information has been added, thereby ensuring the copyright and the validity of the printed image data. There is an unsolved problem that cannot be done.

Accordingly, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and has been made to prevent the watermark information from being easily copied, and to provide a printing means based on the watermark information. It is an object of the present invention to provide an image processing method and an image processing apparatus capable of confirming whether or not a print is specified and legitimately printed.

[0006]

According to a first aspect of the present invention, there is provided an image processing method comprising the steps of: (a) identifying a printing unit when printing image information of digital content on a sheet by a printing unit; The information is used to form falsification detection data using a secret key built in the printing means, and the falsification detection data is added to the unique information to create printing means detection data. Is added to the image information of the digital content in a digital watermark format and printed on paper.

According to the first aspect of the present invention, a printing means such as a printer and a facsimile is connected to a network. Unique information for specifying the printing means is created using the secret key built into the printing means to create tampering detection data, and this tampering detection data is added to the unique information to create printing means detection data. Since the print unit detection data is added to the digital content image information in the form of a digital watermark, even if the digital watermark information is separated from the printed paper, it is valid based on the tampering detection data decrypted using the public key. Sex determination can be made accurately.

According to a second aspect of the present invention, there is provided the image information processing method, wherein when printing the image information of the digital content on the paper by the printing means, the private information identifying the printing means is stored in a secret key contained in the printing means. To create falsification detection data, add the falsification detection data to the unique information to create printing means detection data, and apply the printing means detection data to the digital content image information in a digital watermark format. The image information printed on the paper is read by the image information reading means, the digital watermark information is extracted from the read image information, and the electronic watermark information is used for falsification detection using the public key of the printing means. It is characterized in that the data is decoded to determine the validity of the print image information.

According to the second aspect of the present invention, in addition to the operation of the first aspect, image information printed on a sheet is read by image information reading means such as an image scanner or an electronic still camera, and the read image information is read from the read image information. Since the digital watermark information is extracted and the falsification detection data is decrypted by using the public key of the printing means, it is possible to confirm from the decryption result that the image information is valid image information printed by the specific printing means.

Further, in the image information processing method according to a third aspect, in the invention according to the first or second aspect, the unique information for specifying the printing unit is set by combining a model of the printing unit, a serial number, and the number of times of printing. It is characterized by being. In the invention according to claim 3, the model of the printing means,
Since the selection is made by combining the serial number and the number of prints, in particular, by setting the serial number, the printing unit can be accurately specified, and by additionally setting the number of prints, the printing of the print unit can be performed. If the history is stored, the printed matter can be specified accurately.

According to a fourth aspect of the present invention, in the image processing method according to any one of the first to third aspects of the present invention, the printing unit detecting data includes printing unique information for specifying a printing unit and current time information. It is characterized by being created by encryption based on the secret key of the means. According to the fourth aspect of the present invention, since the unique information for specifying the printing unit and the current time information are encrypted with the secret key of the printing unit as the printing unit detection data, the printing unit detection data always changes. Thus, the digital watermark printed on the paper changes with the passage of time, and the forgery of the printing unit detection data can be prevented.

Further, in the image information processing method according to a fifth aspect, the printing unit detection data is created by encrypting unique information for specifying a printing unit and data of the number of prints with a secret key of the printing unit. It is characterized by: Also in the invention according to the fifth aspect, the printing means increases the number of prints data each time the paper is printed, so that the digital watermark printed on the paper changes over time, and the printing means detection data Forgery can be prevented.

According to a sixth aspect of the present invention, there is provided an image information processing apparatus, comprising: printing means for printing image information of digital content; unique information storing means for storing unique information for specifying the printing means; When printing the image information of the content, the unique information is created by the tampering detection data creation unit that creates the tampering detection data by using the secret key built in the printing unit, and the tampering detection data creation unit. Printing means detection data creation means for creating printing means detection data by adding the falsification detection data to the unique information, and digitally watermarking the printing means detection data created by the printing means detection data creation means. A digital watermark information inserting unit that embeds the information in the image information of the digital content and supplies the information to the printing unit.

According to the sixth aspect of the invention, the same operation as that of the first aspect can be obtained. The image information processing apparatus according to claim 7, further comprising: a printing unit that prints image information of the digital content; a unique information storage unit that stores unique information that specifies the printing unit; When printing information, falsification detection data creation means for creating falsification detection data using a private key built in the printing means, and falsification detection created by the tampering detection data creation unit. Means for adding printing data to the unique information to create printing means detection data, and printing means detection data created by the printing means detection data creation means as digital watermark information. A digital watermark information insertion unit that embeds the digital content in image information and supplies the digital watermark information to the printing unit, and reads image information of a sheet printed by the printing unit Image information reading means, falsification detection data separation means for separating falsification detection data from the image information read by the image information reading means, and printing the falsification detection data separated by the falsification detection data separation means. And a validity judging means for judging the print information based on the decrypted data for falsification detection using the public key of the means.

According to the seventh aspect of the invention, the same operation as that of the second aspect is obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention. In the figure, reference numeral 1 denotes an information processing apparatus including a personal computer or the like connected to the Internet and a roll area network. A keyboard 2, a mouse 3, a display 4, a printer 5 and an image scanner 6 as printing means
Is connected.

As shown in FIG. 2, the information processing apparatus 1 includes an arithmetic control unit 10 and a system bus 1
A keyboard control unit 12 for controlling a keyboard 2 connected via the mouse 1; a mouse control unit 13 for controlling a mouse 3;
Display control unit 14 for controlling display 4, printer 5
, An input / output interface unit 16 for the image scanner 6, a communication control unit 17 connected to a communication line accessible to the Internet, and a local area network 19 to which a database server 18 is connected. A LAN control unit 20 is provided.

Then, the information processing apparatus 1 accesses a WWW (World Wide Wed) for accessing the Internet.
b) Browser software, a network driver, a printer driver, an image scanner driver, etc. are installed, and by accessing a desired homepage on the Internet with WWW browser software,
Displaying the desired digital content on the display 4,
The displayed digital content is configured to be stored on a hard disk or printed by the printer 5.

As shown in FIG. 3, the printer 5 is provided with an image processing section 21. The image processing section 21 receives color image information of digital contents as print data from the information processing apparatus 1, In the color image information, printer identification data is created by encrypting unique information for specifying the printer, and the printer detection data is supplied to the printer unit 22 as color image information embedded as invisible digital watermark information. It is configured to perform color printing on printing paper.

Here, the image processing section 21 includes a print information memory 23 for storing image information of digital contents inputted from the information processing apparatus 1, and a model name, a serial number, a printing order, and the like of the printer itself. A unique information memory 24 for storing unique information, a secret key memory 25 for storing a secret key unique to the printer, a built-in clock section 26 for outputting current time information, and a print counter for counting the number of prints of the printer section 22 27, the unique information stored in the unique information memory 24, the print count data counted by the print count counter 27, and the current time information generated by the built-in clock section 26 are input, and unique information is created by combining these. By applying a predetermined function such as a hash function to the unique information created by the unique information creating unit 28. , Message digest (Mess
age Digest)
A message creating code that encrypts the message digest created by the digest creating unit 29 using the secret key stored in the secret key memory 26 (Message Authentication code).
Code), a tampering detection data creating unit 30 for creating tampering detection data consisting of
A printing means detecting data creating section 31 for creating the printing means detecting data by adding the falsification detecting data created by the above to the unique information created by the unique information creating section 28; and a printing means detecting data creating section 31 The printing unit detection data created in step (1) and the digital content image information stored in the print information memory 23 are input, and image information in which the printing unit detection data is embedded in the image information as digital watermark information is created. And a digital watermark insertion unit 32 that outputs the digital watermark to the printer unit 22.

Next, the operation of the first embodiment will be described. Now, by accessing the desired homepage via the Internet in the information processing apparatus 1, the image information of the paid digital content is read, or the evidential ability is requested by accessing the database server via the local area network 19. Read the image information of digital contents such as a notarized deed, seal certificate, family register, etc., and print the image information of the digital contents with the specified printer 5, so that the printed matter is printed through a regular route. Can be proved.

That is, the image information of the digital content read by the information processing device 1 is
5 to the printer 5. When the printer 5 receives the image information of the digital content, the image information is stored in the print information memory 23 of the image processing unit 21. on the other hand,
In the image processing unit 21, the unique information including the printer model and serial number stored in the unique information memory 24 and the current time information generated by the built-in clock unit 25 are supplied to the unique information creating unit 28. The information creating unit 28 creates a unique information ID for specifying the printing unit by combining the unique information and the current time information.

When the unique information ID for specifying the created printing means is input to the message digest creating unit 29, a message digest code MD is created using a hash function, and the created message digest code MD is created. The MD is input to the tampering detection data creating unit 30 and the message digest code MD is encrypted using the secret key stored in the secret key memory 26, thereby obtaining the tampering detection data MAC consisting of the message authentication code. Create

By inputting the created falsification detection data MAC and the unique information created by the unique information creation unit 28 to the printing unit detection data creation unit 31, the tampering detection data MAC is added to the unique information ID. By generating printing means detection data and inputting the printing means detection data PD to the digital watermark insertion unit 32 to which the image information of the digital content stored in the print information memory 23 is input, the image information of the digital content is obtained. Forming image information in which the data PD for falsification detection added with the data MAC for falsification detection is embedded in a digital watermark format, and inputting this image information to the printer unit 22, the data PD for printing means detection Prints the image information of the digital content in a state where is invisible.

Therefore, when the image information of the digital content printed on the printing paper is visually recognized, the image information of the digital content can be visually recognized, but the data for detecting the printing means cannot be visually recognized. In order to confirm whether or not the image information of the digital content printed on the printing paper is that printed by the regular printer 5, the image information printed on the printing paper is read by the image scanner 6, and the image information is read. The image information of digital contents and the data PD for printing means detection are separated from the image information, and the tampering detection data MA added to the separated data PD for printing means detection.
C, the falsification detection data MAC is used to decrypt the message digest code with the public key, while the printing means detection data is generated by the message digest creation unit to create a message digest code, and the two are compared. If they match, it is confirmed that the data has not been tampered with, and if the printing unit detection data at this time is unique information indicating a specific printer, the image information of the digital content printed on the printing paper is not authorized. It can be confirmed that the print has been performed through the route of.

According to the first embodiment, the message digest code MD is created only for the printing means detection data, and the message digest code MD is used as the falsification detection data MAC by using the secret key of the printer 5. Since it is created, it is possible to reliably detect the duplication or tampering of the image information with a smaller data amount as compared with the case where the tampering detection data MAC is created for the entire image information.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, a print image information confirming unit capable of confirming whether or not the image has been printed through a regular path based on image information printed on a print sheet is added. . That is, in the second embodiment, as shown in FIG. 4, the information processing apparatus 1 is provided with the print image information confirmation unit 41.

The print image information confirmation unit 41 receives image information of digital contents printed on a print sheet read by the image scanner 6 and adds digital watermark information, that is, data for falsification detection MAC from the image information. The digital watermark reader 42 for extracting and analyzing the printing means detection data PD and the printing means detection data PD to which the falsification detection data MAC extracted by the digital watermark reader 42 are added are input. And unique information I
D, and a falsification detection data MAC separated by the data separation unit 43 is decrypted by using the public key of the printer 5 stored in the public key memory 44. A decrypting unit 45 for decrypting the message digest code MD, and a data separating unit 43
A message digest creation unit 46 for creating a message digest code MD 'using the hash function for the printing means detection data PD separated by the above-described method, and a message digest code M decrypted by the decryption unit 45.
D ′ is compared with the message digest MD created by the message digest creation unit 46 to determine whether or not the two match, and a comparison result of the comparison and determination unit 47 is a message digest. When the MD and MD 'match, it is determined that the data has not been tampered with, and the printing unit detection data is output to the information processing apparatus 1 as display information, and the message digest MD
When MD and MD 'do not match, a message indicating that tampering has been performed is output to the information processing apparatus 1.

Therefore, according to the second embodiment, the image information of the digital contents printed by the authorized printer 5 is extracted by the digital watermark reader 42 because the image information read by the image scanner 6 is not disturbed. By inputting the printing unit detection data PD to which the falsification detection data MAC has been added to the data separation unit 43, the falsification detection data MAC and the unique information ID are separated. Then, by inputting the falsification detection data MAC to the decryption unit 45, the message digest code MD created from the original print unit detection data is decrypted using the public key, while the data separation unit 43 separates the message digest code MD. The generated unique information is input to the message digest code creation unit 46, and a message digest code MD 'is created using a mesh function, and the decoded message digest code MD and the created message digest code MD' are combined. By comparing and judging by the comparison judging unit 47, the two coincide with each other, and it can be confirmed that they have not been tampered with. By outputting the printing unit detection data to the information processing apparatus 1 as display information, The model, serial number, number of prints, and print time are displayed on the display 4 of the information processing apparatus 1. By being, it can be confirmed that the image information printed in the printer 5 of the regular.

However, when the image information of the digital contents is printed by another printer other than the regular printer 5, and when this printer cannot embed the digital watermark information, the digital watermark reader 42 extracts the digital watermark information. Since it is in a state where it cannot be performed, it is possible to easily confirm that the image is not printed by an authorized printer.

Further, when printing is performed by a printer other than the authorized printer 5, this printer can embed digital watermark information, and creates printing means detection data such as a model, a serial number, and the number of times of printing. However, even if the message digest code MD is created, the secret key for creating the falsification detection data MAC cannot be matched from the message digest code MD. M
An AC is created and added to the unique information ID to create printing means detection data PD. The printing means detection data PD is embedded in digital content image information as an electronic watermark format, and the printing unit 5 , The image information of the digital contents on the printing paper is read by the image scanner 6, the data for falsification detection is separated, and the message digest code MD decrypted by the decryption unit 45 using the public key is read. Does not match the unique information ID with the message digest code MD 'created by the message digest creation unit 46, the comparison determination unit 47 determines that the two do not match, and the digital content printed by the authorized printer 5 Is not image information.

Further, when the image information of the digital contents printed by the authorized printer 5 is copied by a copying machine to create a duplicate product, or when read by an image scanner and printed by another printer, Since the image information of the digital content displayed in the above section will be distorted or changed in dot, the image information of this duplicated product is read by the image scanner 6, the data for falsification detection is separated and decoded by the decoding unit 45. Sometimes, the message digest code MD matches the regular message digest code MD, but the message digest code MD 'created by using the hash function in the message digest creation unit 46 to generate the separated unique information. Since it will change for the legitimate message digest code Comparing and determining unit 47 a message digest code MD 'and created the message digest code MD decoded in is determined to be a mismatch,
It can be determined that the product is a duplicate.

In the second embodiment, the case where the print image information confirmation unit 31 is provided in the information processing apparatus 1 has been described. However, the present invention is not limited to this. A confirmation unit 31 may be provided. In the second embodiment, the case where the image information is read by the image scanner 6 when determining whether the image information of the digital content printed on the printing paper is the one printed by the authorized printer 5 will be described. However, the present invention is not limited to this. After image information of digital content printed on printing paper is captured by an electronic still camera, and the captured image information is converted into image information corresponding to the size of the printing paper, Print image information confirmation unit 31
In other words, means capable of reading image information of digital content printed on printing paper as electronic information can be applied.

[0034]

As described above, according to the first and sixth aspects of the present invention, the printing means is connected to the network, and the printing means acquires and prints paid digital contents from the database server. In this case, the falsification detection data is created by using the secret key built in the printing means with the unique information for specifying the printing means, and the falsification detection data is added to the unique information to generate the printing means detection data. Creates and adds this printing means detection data to the digital content image information in digital watermark format, so even if the digital watermark information is separated from the printed paper, the falsification detection data decrypted using the public key Thus, it is possible to obtain an effect that the validity can be accurately determined based on the information.

According to the second and seventh aspects of the present invention, in addition to the effect of the first aspect, the image information printed on the paper can be read by image information reading means such as an image scanner or an electronic still camera. Since the digital watermark information is extracted from the read image information and the falsification detection data is decrypted using the public key of the printing means, the image data is valid image information printed by the specific printing means based on the decryption result. Can be confirmed.

Further, according to the third aspect of the present invention, since the selection is made by combining the model of the printing means, the serial number, and the number of times of printing, the printing means can be specified accurately by setting the serial number. By setting the number of times of printing in addition to this, it is possible to obtain the effect that if the print history of the printing means is stored, the printed matter can be specified accurately.

According to the fourth aspect of the present invention, the unique information for specifying the printing means and the current time information are encrypted with the secret key of the printing means as the printing means detection data. Since the data for printing always changes, the digital watermark printed on the paper changes with the passage of time, and an effect is obtained that the forgery of the printing unit detection data can be prevented.

According to the fifth aspect of the present invention, the printing means increases the number of prints each time the paper is printed, so that the digital watermark printed on the paper changes over time. In addition, it is possible to prevent the forgery of the printing unit detection data.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating an internal configuration of the information processing apparatus of FIG. 1;

FIG. 3 is a block diagram illustrating an internal configuration of the printer in FIG. 1;

FIG. 4 is a block diagram illustrating an internal configuration of an information processing apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 information processing device 4 display 5 printer 6 image scanner 21 image processing device 22 printer unit 23 print information memory 24 unique information memory 25 built-in clock unit 26 secret key memory 27 print count counter 28 printing means detection data creation unit 29 message digest Creation unit 30 Falsification detection data creation unit 31 Data addition unit 32 Digital watermark insertion unit 41 Print image information confirmation unit 42 Digital watermark reader 43 Data separation unit 44 Public key memory 45 Decryption unit 46 Message digest creation unit 47 Comparison judgment unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/40 H04N 1/40 Z F-term (Reference) 2C061 AP01 AP03 CL10 5B057 AA11 CA01 CA12 CA16 CB12 CB16 CB19 CE08 DA04 5C076 AA14 BA02 BA06 BA09 5C077 LL14 LL20 MP08 PP19 PP23 PP65 TT02 TT06 5J104 AA08 AA14 LA03 LA05 NA02 PA14

Claims (7)

[Claims] When printing image information of a digital content on a sheet by a printing means, falsification detection data is formed using unique information for specifying the printing means by using a secret key built in the printing means. The falsification detection data is added to the unique information to create printing means detection data, and the printing means detection data is added to the digital content image information in a digital watermark format and printed on paper. An image information processing method comprising: 2. When printing image information of a digital content on a sheet by a printing unit, falsification detection data is created by using a secret key built in the printing unit with unique information for specifying the printing unit. Then, the falsification detection data is added to the unique information to create printing means detection data, the printing means detection data is added to the digital content image information in a digital watermark format, and printed on paper. The printed image information is read by the image information reading means, the electronic watermark information is extracted from the read image information, and the falsification detection data is decrypted by using the public key of the printing means, thereby verifying the validity of the printed image information. An image information processing method, characterized in that: 3. The image information processing method according to claim 1, wherein the unique information for specifying the printing unit is set by combining a model of the printing unit, a serial number, and the number of times of printing. 4. The printing unit detecting data according to claim 1, wherein the printing unit detecting data is created by encrypting unique information for specifying the printing unit and current time information with a secret key of the printing unit. An image information processing method according to any one of the above. 5. The printing unit detection data is created by encrypting unique information for specifying a printing unit and print number data with a secret key of the printing unit.
The image information processing method according to any one of claims 1 to 3. 6. A printing unit for printing image information of digital content, a unique information storage unit for storing unique information for specifying the printing unit, and a unique unit for printing image information of digital content by the printing unit. Falsification detection data creation means for creating tampering detection data using a secret key built in the printing means, and falsification detection data created by the tampering detection data creation unit added to the unique information Printing means detecting data creating means for creating printing means detecting data, and embedding the printing means detecting data created by the printing means detecting data creating means into the digital content image information as digital watermark information. An image information processing apparatus, comprising: electronic watermark information insertion means for supplying to the printing means. 7. A printing unit for printing image information of digital content, a unique information storage unit for storing unique information for specifying the printing unit, and a unique unit for printing image information of digital content by the printing unit. Falsification detection data creation means for creating tampering detection data using a secret key built in the printing means, and falsification detection data created by the tampering detection data creation unit added to the unique information Printing means detecting data creating means for creating printing means detecting data, and embedding the printing means detecting data created by the printing means detecting data creating means into the digital content image information as digital watermark information. Electronic watermark information insertion means for supplying to the printing means, image information reading means for reading image information of a sheet printed by the printing means, A falsification detection data separation unit that separates the falsification detection data from the image information read by the report reading unit; and a falsification detection data separated by the falsification detection data separation unit using the public key of the printing unit. An image information processing apparatus comprising: a decryption unit; and a validity determination unit configured to determine validity of the print information based on the decryption detection data.