JP2005252891A - Watermark information authentication system and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a watermark information authentication system capable of authenticating watermark information on the basis of an imperfect watermark information on a recording paper, even if the watermark information is not correctly printed on the recording paper. <P>SOLUTION: At an image forming apparatus, a recording portion outputs a watermark information, acquired from a server by a watermark information acquiring portion, to a recording paper (S5). From an image on the recording paper and read by an image reading portion (S6), a watermark information extracting portion extracts a watermark information (S7). A detecting portion detects missing in the watermark information (S8). A missing information transmitting portion transmits the detected missing information to the server (S9). At the server, a control unit stores into a watermark information area a new watermark information composed of the missing information transmitted from the image forming apparatus and a watermark information previously sent out to the image forming apparatus, as an object of authentication with a watermark information transmitted subsequently from the image forming apparatus. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a digital watermark information authentication system and an image forming apparatus that perform holding and authentication of digital watermark information and outputting the digital watermark information onto a recording sheet.

Conventionally, as an electronic watermark information authentication system, for example, there is one as disclosed in Patent Document 1. In this digital watermark information authentication system, when a user inputs various data for purchasing a product to the multipurpose terminal 2, the input data is transmitted from the multipurpose terminal 2 to the host computer 1. It is determined whether to allow the user to sell the product. When the host computer 1 permits the sale of the product, the laser printer 5 prints (outputs) a certificate in which electronic watermark information that is difficult to see is embedded. In addition, when digital watermark information is printed on a paper medium by an electrophotographic method or the like, the original digital watermark information may not be accurately printed on the recording paper. The image of the printed matter to be discharged is read, and the personal computer 4 compares the digital watermark data included in the image read from the original with the original digital watermark data, and detects whether or not they match. It has become.
JP 2000-151979 A

  The above-described digital watermark information authentication system can authenticate digital watermark information only when the digital watermark information is accurately printed on the printed matter and the accurate digital watermark information printed on the printed matter is read. is there. Therefore, the user has to repeat printing again until the printed matter on which the digital watermark information is printed correctly is discharged. The comparison of the digital watermark information by the personal computer 4 is performed in order to discharge the printed matter in which the original digital watermark information is printed correctly, and the printed matter in which the digital watermark information is not printed correctly is discharged. In this case, this is detected so that the user can recognize that the printed matter is defective.

  The present invention has been made to solve the above problem, and even when the digital watermark information is not correctly printed on the recording paper, based on the incomplete digital watermark information on the recording paper, It is an object of the present invention to provide a digital watermark information authentication system and an image forming apparatus that can authenticate digital watermark information.

According to a first aspect of the present invention, there is provided a server for holding and authenticating digital watermark information, outputting digital watermark information acquired from the server onto a recording sheet, and a server for digital watermark information read from a document. An electronic watermark information authentication system comprising an image forming apparatus that transmits
The image forming apparatus includes: an electronic watermark information acquisition unit that acquires electronic watermark information from the server; an output unit that outputs the electronic watermark information acquired by the electronic watermark information acquisition unit to a recording paper; An image reading unit that reads an image on recording paper to which watermark information is output, and the digital watermark information included in the image on the recording paper read by the image reading unit is extracted and acquired from a server by the digital watermark information acquisition unit A detection unit that detects a lack of the extracted digital watermark information by comparison with the digital watermark information that has been extracted, and a missing unit that transmits to the server missing information indicating the lack of the digital watermark information detected by the detection unit An information transmission means,
The server stores at least one or more digital watermark information as an object of authentication with the digital watermark information transmitted from the image forming apparatus; and the electronic watermark information storage unit stores the electronic watermark information to the image forming apparatus. An electronic watermark information transmitting means for transmitting electronic watermark information stored in the watermark information storage means, missing information transmitted from the missing information transmitting means of the image forming apparatus, and the image forming apparatus from the electronic watermark information transmitting means Control means for storing, in the digital watermark information storage means, new digital watermark information composed of the digital watermark information sent to the digital watermark information as an authentication target with the digital watermark information transmitted from the image forming apparatus. Is.

  In this configuration, in the image forming apparatus, the digital watermark information acquired from the server by the digital watermark information acquisition unit is output to the recording paper by the output unit, and the detection unit performs digital watermarking from the image on the recording paper read by the image reading unit. Information is extracted, the lack of the extracted digital watermark information is detected, and the missing information transmission means transmits the detected missing information to the server. The server transmits the electronic watermark information stored in the electronic watermark information storage means to the image forming apparatus by the electronic watermark information transmitting means, and the control means is transmitted from the missing information transmitting means of the image forming apparatus. The new digital watermark information composed of the missing information and the digital watermark information sent from the digital watermark information sending means to the image forming apparatus is subject to authentication with the digital watermark information sent from the image forming apparatus. It is stored in digital watermark information. Thus, even if the digital watermark information acquired from the server cannot be output accurately on the recording paper by the output unit of the image forming apparatus, as long as the detection unit detects the lack, even if there is missing digital watermark information, The server can function as digital watermark information to be authenticated.

The invention according to claim 2 is the digital watermark information authentication system according to claim 1, wherein the image forming apparatus includes a document reading unit that reads an image on a document and the digital watermark information extraction unit. And electronic watermark information transmitting means for transmitting electronic watermark information extracted from the image on the original read by the original reading means to the server,
An authentication unit configured to authenticate whether or not the digital watermark information transmitted from the digital watermark information transmission unit of the image forming apparatus is the digital watermark information stored in the digital watermark information storage unit; When the authentication by the authentication unit is established, output permission information for permitting the output unit to output the document image read by the document reading unit of the image forming apparatus is sent to the image forming apparatus. Output permission information sending means for
The image forming apparatus includes an output permission information receiving unit that receives the output permission information transmitted from the output permission information transmitting unit of the server, and when the output permission information is received from the server by the output permission information receiving unit. And an operation control means for causing the output means to output the original image read by the original reading means.

  According to this configuration, in the image forming apparatus, the electronic watermark information transmitting unit transmits the electronic watermark information extracted by the electronic watermark information extracting unit from the image on the original read by the original reading unit to the server. In the server, the authentication unit authenticates whether or not the digital watermark information transmitted from the digital watermark information transmission unit of the image forming apparatus is the digital watermark information stored in the digital watermark information storage unit. When the authentication is established, the output permission information sending unit sends output permission information permitting the output unit to output the document image read by the document reading unit of the image forming apparatus to the image forming apparatus. Further, in the image forming apparatus, when the output permission information receiving unit receives the output permission information sent from the output permission information sending unit of the server, the operation control unit outputs the document image read by the document reading unit to the output unit. Let Thereby, even if the digital watermark information output on the original is missing compared to the original complete digital watermark information, the server, based on the missing digital watermark information, It is possible to determine whether or not to permit output of the document image to the output unit of the image forming apparatus.

The invention according to claim 3 is the digital watermark information authentication system according to claim 1 or 2, wherein the image forming apparatus is a personal identification information input means for inputting personal identification information by a user. And personal identification information transmitting means for transmitting the personal identification information input to the personal identification information input means to the server,
The control unit of the server includes personal identification information transmitted from the personal identification information transmission unit of the image forming apparatus, missing information transmitted from the missing information transmission unit of the image forming apparatus, and the digital watermark information. New digital watermark information composed of digital watermark information sent from the sending means to the image forming apparatus is stored in the digital watermark information storage means.

  According to this configuration, in the image forming apparatus, when personal identification information is input to the personal identification information input unit by the user, the personal identification information transmission unit transmits the personal identification information to the server. In the server, the control unit includes the personal identification information transmitted from the personal identification information transmitting unit of the image forming apparatus, the missing information transmitted from the missing information transmitting unit of the image forming apparatus, and the digital watermark information transmitting unit. New digital watermark information including the digital watermark information sent to the image forming apparatus is stored in the digital watermark information storage means. As a result, when the digital watermark information is authenticated, the server also determines whether the personal identification information matches or does not match, so only the person having the specific personal identification information is allowed to output by the output unit of the image forming apparatus. It becomes possible to restrict output more strictly.

According to a fourth aspect of the present invention, in the digital watermark information authentication system according to the third aspect, the personal identification information transmitting unit of the image forming apparatus uses an image on the document read by the document reading unit. When the electronic watermark information transmitting means transmits the electronic watermark information extracted by the electronic watermark information extracting means to the server, the personal identification information input to the personal identification information input means is transmitted to the server. And
In the server, the authentication unit is configured to generate the electronic watermark based on the personal identification information transmitted from the personal identification information transmission unit of the image forming apparatus and the electronic watermark information transmitted from the electronic watermark information transmission unit. Authentication with the electronic watermark information stored in the watermark information storage means is performed, and the output permission sending means reads by the document reading means by the output means of the image forming apparatus when authentication by the authentication means is established. Output permission information indicating permission to output the original document image to the image forming apparatus,
The image forming apparatus includes an output permission information receiving unit that receives the output permission information transmitted from the output permission information transmitting unit of the server, and when the output permission information is received from the server by the output permission information receiving unit. And an operation control means for causing the output means to output the original image read by the original reading means.

  According to this configuration, in the image forming apparatus, when the digital watermark information transmitting unit transmits the digital watermark information extracted by the digital watermark information extracting unit, the personal identification information input to the personal identification information input unit is transmitted. The means transmits to the server. In the server, based on the digital watermark information and personal identification information transmitted from the image forming apparatus side, the authentication unit authenticates the digital watermark information stored in the digital watermark information storage unit, and this authentication is performed. If it is established, the output permission information sending means sends output permission information permitting the output means to output the document image read by the document reading means of the image forming apparatus to the image forming apparatus. Further, in the image forming apparatus, when the output permission information receiving unit receives the output permission information sent from the output permission information sending unit of the server, the operation control unit outputs the document image read by the document reading unit to the output unit. Let As a result, when the digital watermark information is authenticated, the server also determines whether the personal identification information matches or does not match, so only the person having the specific personal identification information is allowed to output by the output unit of the image forming apparatus. It becomes possible to limit output more strictly.

  The invention according to claim 5 is the digital watermark information authentication system according to claim 4, wherein the authentication means is transmitted from the personal identification information transmission means of the image forming apparatus to the server. The personal information is obtained when authentication of the digital watermark information stored in the digital watermark information storage unit is performed based on the personal identification information and the digital watermark information transmitted from the digital watermark information transmission unit. When authentication is not established only for identification, personal identification information storage means for storing the personal identification information is provided.

  According to this configuration, in the server, when authentication of only the personal identification information is not established at the time of digital watermark information authentication by the authentication unit, the personal identification information storage unit stores the personal identification information. As a result, when a person who does not have appropriate personal identification information tries to illegally copy a document with digital watermark information output, the inappropriate personal identification information is stored. It becomes possible to specify the person who used the etc.

The invention according to claim 6 is an image forming apparatus for holding and authenticating digital watermark information and outputting the digital watermark information onto a recording sheet,
Digital watermark information storage means for storing at least one digital watermark information;
Output means for outputting electronic watermark information stored in the electronic watermark information storage means to a recording paper;
Image reading means for reading an image on a recording paper on which digital watermark information is output by the output means;
The digital watermark information included in the image on the recording paper read by the image reading unit is extracted, and the extracted digital watermark information is compared with the digital watermark information acquired from the server by the digital watermark information acquisition unit. A detecting means for detecting the omission;
The new watermark information comprising the missing information indicating the missing of the watermark information detected by the detecting means and the watermark information to be output on the recording paper by the output means is authenticated as the watermark information. And a control means for storing in the digital watermark information storage means.

  According to this configuration, the digital watermark information stored in the digital watermark information storage unit is output to the recording paper by the output unit, and the detection unit extracts the digital watermark information from the image on the recording paper read by the image reading unit. Detecting the missing of the extracted digital watermark information, the control means, the new digital watermark information consisting of the missing information and the digital watermark information to be output to the recording paper by the output means, The digital watermark information is stored as a target for digital watermark information authentication. As a result, even if the output unit cannot accurately output the digital watermark information to the recording paper, as long as the detection unit detects the lack, even if the digital watermark information is missing, the digital watermark information to be authenticated It becomes possible to function as.

The invention according to claim 7 is the image forming apparatus according to claim 6, wherein the document reading unit reads an image on the document,
Digital watermark information extracting means for extracting digital watermark information from an image on a document read by the document reading means;
Authentication means for authenticating whether the digital watermark information extracted by the digital watermark information extraction means is digital watermark information stored in the digital watermark information storage means;
The apparatus further includes an operation control unit that causes the output unit to output a document image read by the document reading unit when authentication by the authentication unit is established.

  According to this configuration, in the image forming apparatus, the digital watermark information extracted by the digital watermark information extraction unit from the image on the document read by the document reading unit is stored in the digital watermark information storage unit. Whether the digital watermark information is authenticated or not is verified. If the authentication is established, the operation control means causes the output means to output the original image read by the original reading means. As a result, even if the digital watermark information output on the document is missing compared with the original digital watermark information in the original state, the digital watermark information is output to the output means based on the missing digital watermark information. It is possible to determine whether or not to permit output of a document image.

  According to the first and sixth aspects of the present invention, even if the output means of the image forming apparatus cannot output the digital watermark information to the recording paper correctly, as long as the detection means detects the lack, It is possible to make certain digital watermark information function as digital watermark information to be authenticated. Therefore, it is possible to guarantee with high accuracy that the printed material is genuine while eliminating the effort of repeating the output until the complete digital watermark information is output on the recording paper. This has a remarkable effect in the case where the original electronic watermark information is not accurately printed on the recording paper due to the printing by the electrophotographic method being influenced by the surrounding environment or the like.

  According to the second and seventh aspects of the present invention, even when the digital watermark information output on the original is missing compared to the original complete digital watermark information, Based on the missing digital watermark information, it is possible to determine whether or not to permit the output unit of the image forming apparatus to output the document image.

  According to the third and fourth aspects of the invention, the server determines whether the personal identification information matches or does not match when the digital watermark information is authenticated. Only the output by the output unit of the image forming apparatus can be allowed to be stricter.

  According to the invention described in claim 5, when a person who does not have appropriate personal identification information tries to illegally copy a document on which digital watermark information is output, the inappropriate personal identification information is Since it is stored, it becomes possible to specify a person who used an illegal copy or the like.

  Hereinafter, a digital watermark information authentication system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram showing an outline of an electrical configuration of a digital watermark information authentication system according to an embodiment of the present invention. The digital watermark information authentication system 1 includes an image forming apparatus 2 and a server 3 connected to the image forming apparatus 2 via a network such as the Internet. In the digital watermark information authentication system 1, the server 3 holds and authenticates the digital watermark information, and the image forming apparatus 2 outputs the digital watermark information acquired from the server 3 onto the recording paper and is included in the image read from the document. The digital watermark information to be transmitted is transmitted to the server 3. In FIG. 1, a state in which each part of the image forming apparatus 2 communicates with each part of the server 3 is indicated by a plurality of signal lines. However, as described above, both of them realize communication through a network such as the Internet. To do.

  The image forming apparatus 2 includes a control unit 21, an image processing unit 22, an image memory 23, a personal identification information input unit 24, an image reading unit 25, a document reading unit 26, and a recording unit 27. .

  The personal identification information input unit (personal identification information input means) 24 includes a display panel or a keyboard having a touch panel function, and is personal identification information (ID unique to each user, etc. given to each user by operation by the user). , Information for specifying each user) is input.

  The image reading unit (image reading unit) 25 includes an optical scanner or the like, and reads an image on the recording paper after the output (recording or printing) by the recording unit 27 is completed. The image reading unit 25 is provided downstream of the recording unit 27 in the document conveying direction and upstream of a discharge tray (not shown) from which recorded recording paper is discharged.

  The document reading unit (document reading means) 26 is composed of an optical scanner or the like, and is composed of a flatbed scanner or a scanner having an ADF function. The document reading unit 26 reads an image on a document that is an object to be copied when the image forming apparatus 2 performs copying. The document reading unit 26 is provided separately from the image reading unit 25 described above.

  The recording unit (output unit) 27 forms an image read by the document reading unit 26 on a recording sheet, and includes, for example, an electrophotographic mechanism including a charging unit, an exposure unit, a developing unit, a transfer unit, and the like. It is done.

  The image memory 23 includes a recording paper image storage unit 231 and a document image storage unit 232. The recording paper image storage unit 231 temporarily stores the image on the recording paper read by the image reading unit 25. The document image storage unit 232 temporarily stores an image on the document read by the document reading unit 26.

  The image processing unit 22 includes a detection unit (detection unit) 221, a digital watermark information extraction unit (digital watermark information extraction unit) 222, and an image composition unit 223. The detection unit 221 extracts digital watermark information from the image on the recording paper read by the image reading unit 25, and the digital watermark information acquisition unit 215 outputs the extracted digital watermark information from the server 3 for output by the recording unit 27. Compared with the acquired digital watermark information, the lack of digital watermark information extracted from the image on the recording paper is detected. The digital watermark information extraction unit 222 extracts digital watermark information included in the image from the image on the document read by the document reading unit 26. The image combining unit 223 combines the digital watermark information acquired from the server by the digital watermark information acquisition unit 215 with the image on the document read by the document reading unit 26.

  The control unit 21 includes an output permission information receiving unit (output permission information receiving unit) 211, a personal identification information transmitting unit (personal identification information transmitting unit) 212, a missing information transmitting unit (missing information transmitting unit) 213, a digital watermark An information transmission unit (digital watermark information transmission unit) 214, a digital watermark information acquisition unit (digital watermark information acquisition unit) 215, an operation control unit (operation control unit) 216, and a digital watermark information request transmission unit 217 are provided. ing.

  The output permission information receiving unit 211 receives output permission information (instruction for permitting execution of the output operation by the recording unit 27) from the server 3. The personal identification information transmission unit 212 transmits the personal identification information input from the user to the personal identification information input unit 24 to the server 3. The missing information transmission unit 213 transmits the missing information detected by the detection unit 221 to the server 3. The digital watermark information transmission unit 214 transmits the digital watermark information extracted by the digital watermark information extraction unit 222 to the server 3. The digital watermark information acquisition unit 215 receives and acquires digital watermark information from the server 3 and sends it to the image composition unit 223. The operation control unit 216 controls operation of each unit of the image forming apparatus 2. The digital watermark information request transmission unit 217 transmits an instruction to the server 3 to request transmission of digital watermark information to be embedded in the image output on the recording paper by the recording unit 27. Note that data communication between the image forming apparatus 2 and the server 3 is performed via interfaces provided in the image forming apparatus 2 and the server 3, respectively, but the interface is not shown in FIG. Yes.

  The display unit 28 is controlled based on information received from the server (for example, output permission information or output non-permission information received by the output permission information receiving unit 211 from the server 3) under the control of the operation control unit 216. The authentication result of the digital watermark information in the authentication unit 317 of the server 3 and the availability of output by the recording unit 27 are displayed.

  The server 3 includes a control unit 31 and a data storage unit 32. The control unit 31 includes an output permission information sending unit (output permission information sending unit) 311, a personal identification information receiving unit (personal identification information receiving unit) 312, a missing information receiving unit (missing information receiving unit) 313, and an electronic watermark Information receiving unit (digital watermark information receiving unit) 314, digital watermark information sending unit (digital watermark information sending unit) 315, control unit (control unit) 316, authentication unit (authentication unit) 317, digital watermark information request A receiving unit 318.

  The personal identification information receiving unit 312 receives personal identification information from the personal identification information transmitting unit 212 of the image forming apparatus 2. The personal identification information receiving unit 312 sends the received personal identification information to the authentication unit 317 during the digital watermark information authentication process, and stores the personal identification information in the digital watermark information storage unit 322 as part of the digital watermark information. When performing the processing, the electronic watermark information is sent to the electronic watermark information storage unit 322.

  The missing information receiving unit 313 receives missing information from the missing information transmitting unit 213 of the image forming apparatus 2. The missing information receiving unit 313 sends the received missing information to the digital watermark information storage unit 322. The digital watermark information receiving unit 314 is digital watermark information (the digital watermark information included in the document image and extracted by the digital watermark information extracting unit 222) from the digital watermark information transmitting unit 214 of the image forming apparatus 2. Is sent to the authentication unit 317. The digital watermark information transmission unit 315 performs image formation on the digital watermark information read from the digital watermark information storage unit 322 by the control unit 316 according to the digital watermark information request from the image forming apparatus 2 received by the digital watermark information request reception unit 318. Send to device 2. The control unit 316 manages operation control of each unit of the server 3.

  The digital watermark information request reception unit 318 receives an instruction to request transmission of digital watermark information from the digital watermark information request transmission unit 217 of the image forming apparatus 2. The output permission information sending unit 311 is a result of authentication by the authentication unit 317 between the digital watermark information received from the image forming apparatus 2 by the digital watermark information receiving unit 314 and the digital watermark information stored in the digital watermark information storage unit 322. Accordingly, either output permission information or output non-permission information is sent to the image forming apparatus 2.

  The authentication unit 317 determines whether the digital watermark information received from the digital watermark information transmission unit 214 of the image forming apparatus 2 by the digital watermark information reception unit 314 matches the digital watermark information stored in the digital watermark information storage unit 322. Authenticate whether or not. The digital watermark information storage unit 322 stores the digital watermark information a that is to be output onto the recording paper by the recording unit 27 of the image forming apparatus 2, but the missing information receiving unit 313 receives the information from the image forming apparatus 2. When missing information is received, a combination of the digital watermark information a and the missing information is stored as new digital watermark information b.

  At the time of authentication by the authentication unit 317, the digital watermark information received by the digital watermark information receiving unit 314 from the image forming apparatus 2 is missing compared to the digital watermark information a stored in the digital watermark information storage unit 322. Even if the missing information matches the missing information received by the missing information receiving unit 313 and stored in the digital watermark information storage unit 322, the electronic watermark information receiving unit 314 receives the electronic information received from the image forming apparatus 2. When the watermark information matches the digital watermark information b stored in the digital watermark information storage unit 322, the digital watermark information received by the digital watermark information reception unit 314 from the image forming apparatus 2 and the digital watermark information storage unit 322 It is assumed that authentication with the digital watermark information stored in is established.

  The digital watermark information storage unit 322 stores the personal identification information receiving unit 312 when the missing information receiving unit 313 receives the missing information from the image forming apparatus 2 and the personal identification information receiving unit 312 receives the personal identification information from the image forming apparatus 2. The combination of the digital watermark information a and the missing information and personal identification information is stored as new digital watermark information c.

  When the digital watermark information receiving unit 314 authenticates the digital watermark information received from the image forming apparatus 2, the authentication unit 317 compares the received digital watermark information with the digital watermark information c, and receives the received digital watermark information. Unless the personal identification information and the personal identification information included in the digital watermark information c match, the digital watermark information is not authenticated.

  If the authentication of the digital watermark information by the authentication unit 317 is established, the output permission information sending unit 311 sends the output permission information to the image forming apparatus 2.

  The data storage unit 32 includes a personal identification information storage unit (personal identification information storage unit) 321 and a digital watermark information storage unit (digital watermark information storage unit) 322. The personal identification information storage unit 321 includes the personal identification information received by the personal identification information reception unit 312 by the authentication unit 317 and the personal identification information included in the digital watermark information c stored in the digital watermark information storage unit 322. When authentication is performed, both digital watermark information matches (after considering missing information), but when it is determined that both personal identification information do not match, the personal identification information that does not match is stored. To do. In addition, the personal identification information storage unit 321 may store the date and time information of the personal identification information that has not been matched by the personal identification information receiving unit 312 together with the personal identification information that has not been matched.

  The digital watermark information storage unit 322 stores one or a plurality of digital watermark information a. The digital watermark information a is read from the digital watermark information storage unit 322, transmitted from the digital watermark information transmission unit 315 to the image forming apparatus 2, and formed as a latent image on the recording paper by the recording unit 27 in the image forming apparatus 2. Used as digital watermark information. The digital watermark information storage unit 322 stores the missing information received by the missing information receiving unit 313 from the image forming apparatus 2 in association with the digital watermark information a, and a new combination of the missing information and the digital watermark information is stored. Stored as digital watermark information b. Further, when the personal identification information is transmitted together with the missing information from the image forming apparatus 2, the digital watermark information storage unit 322 displays a combination of the missing information and the personal identification information and the digital watermark information a. Stored as new digital watermark information c.

  In connection processing and information communication between the image forming apparatus 2 and the server 3, safety is ensured by using a protocol such as a challenge response code or IPsec.

  A first embodiment of processing for outputting an image including digital watermark information (latent image) on a recording sheet by the digital watermark information authentication system 1 will be described. FIG. 2 is a flowchart showing a first embodiment of a process for forming an image including digital watermark information (latent image) on a recording paper by the digital watermark information authentication system 1, and FIG. FIG. 4 is a diagram schematically illustrating a state in which digital watermark information is combined with an image, and FIG. 4 is a diagram illustrating an example of a digital watermark information embedding position on a recording sheet.

  The case where a document is copied by the image forming apparatus 2 will be described. When an image including digital watermark information is formed on a recording sheet, when the document reading unit 26 reads the document image (S1), a digital watermark information request is transmitted. The unit 217 transmits an instruction to request transmission of digital watermark information to the server 3 (S2).

  In the server, when the digital watermark information request receiving unit 318 receives a transmission request instruction for the digital watermark information (SV1), the control unit 316 reads the digital watermark information from the digital watermark information storage unit 322 (SV2). The read digital watermark information is transmitted to the image forming apparatus 2 by the digital watermark information sending unit 315 (SV3).

  In the image forming apparatus 2, when the digital watermark information acquisition unit 215 receives the digital watermark information from the server 3 (S3), the digital watermark information acquisition unit 215 sends the digital watermark information to the image synthesis unit 223, and the image synthesis unit 223 combines the digital watermark information with the original image read by the original reading unit 26 in S1, and generates an image to be output on the recording paper by the recording unit 27 (S4).

  An example of image composition processing by the image composition unit 223 will be described. The digital watermark information is embedded as a latent image in an image formed on a document. For example, different types of dither patterns are used for the latent image portion which is digital watermark information and the background portion other than that, and the pattern density of one of them is determined as the resolution at the time of document reading by the image reading unit 25 and the document reading unit 26. And the other pattern density less than the resolution at the time of reading the document by the image reading unit 25 and the document reading unit 26. At this time, even if the original document is viewed, it is impossible for a person to visually recognize the digital watermark information. However, when the information is output by the recording unit 27, the image reading unit 25 and the document reading unit 26 can read the watermark information on the document. If the image is optically read, the detection unit 221 or the digital watermark information extraction unit 222 can determine the digital watermark information from the read image.

  The image synthesized by the image synthesis unit 223 as described above is sent to the recording unit 27, and the recording unit 27 outputs the image on the recording paper (S5).

  When the output from the recording unit 27 is completed, the image reading unit 25 reads the image on the recording paper in the process of being conveyed from the recording unit 27 to the discharge tray (S6). The image read by the image reading unit 25 is sent to the detection unit 221 via the recording paper image storage unit 231. The detection unit 221 determines whether a barcode indicating digital watermark information or a latent image using a different dither pattern is embedded in the image, and extracts the digital watermark information from the image. (S7). Further, the detection unit 221 compares the extracted digital watermark information with the digital watermark information acquired by the digital watermark information acquisition unit 215 in S3, and the digital watermark information acquired by the digital watermark information acquisition unit 215 is obtained. For the information, a missing portion generated in the extracted digital watermark information is detected (S8). Missing information indicating missing that has occurred in the extracted digital watermark information is transmitted to the server by the missing information transmitting unit 213 (S9).

  The missing information detected by the detection unit 221 may be as follows. For example, as shown in FIG. 4, the image composition unit 223 divides the output (recording) area on the recording paper into 15 blocks A to O, and the same digital watermark information is embedded in every block. The electronic watermark information acquired from the server 3 is combined with the image read by the document reading unit 26. If the detection unit 221 cannot detect the digital watermark information in any of the blocks, information indicating the block in which the digital watermark information can be detected and the block in which the digital watermark information cannot be detected is set as missing information. Also good. This missing information is stored in the digital watermark information storage unit 322 in the same manner as described above, and the authentication unit 317 of the server 3 does not recognize this block even if the digital watermark information cannot be authenticated in any block. As long as the digital watermark information undetectable block information indicated by the missing information stored in the digital watermark information storage unit 322 matches the digital watermark information received from the image forming apparatus 2 and the digital watermark information storage unit 322. It is assumed that authentication with the digital watermark information stored in is established. In this case, it is preferable that at least one of the digital watermark information embedded in the plurality of blocks can be authenticated by the authentication unit 317.

  Further, in consideration of the development characteristics of the recording unit 27, for the blocks divided into A to O, digital watermark information that cannot be visually and reliably detected is embedded in the output area A, and the O area is embedded. As approaching, if the development characteristics are affected, the digital watermark information may be embedded so that the detection becomes difficult, so that the use of embedded information may change from time to time.

  Returning to FIG. 2, in the server 3, when the missing information receiving unit 313 receives the missing information from the image forming apparatus 2 (SV 4), the control unit 316 previously sends the digital watermark sent from the digital watermark information sending unit 315 in SV 3. The information a is associated with the missing information, and the combination of the missing information and the digital watermark information is stored as new digital watermark information b in the digital watermark information storage unit 322 (SV5).

  Next, processing when the digital watermark information is authenticated by the digital watermark information authentication system 1 will be described. FIG. 5 is a flowchart showing processing when the digital watermark information is authenticated by the digital watermark information authentication system 1.

  The case where a document is copied in the image forming apparatus 2 will be described. When the document reading unit 26 reads a document to be copied (S11), the electronic watermark information extracting unit 222 performs electronic recording from the read image of the document. Watermark information is extracted (S12). The digital watermark information transmission unit 214 transmits the extracted digital watermark information to the server 3 (S13).

  In the server 3, when the digital watermark information receiving unit 314 receives the digital watermark information from the image forming apparatus 2 (SV11), the authentication unit 317 authenticates the received digital watermark information (SV12). In this authentication, the authentication unit 317 determines whether or not the digital watermark information received from the image forming apparatus 2 is the same as the digital watermark information a stored in the digital watermark information storage unit 322. It is also performed by determining whether or not the new digital watermark information b including the above-described missing information and digital watermark information is the same. That is, even when the digital watermark information received from the image forming apparatus 2 by the digital watermark information receiving unit 314 is missing compared to the digital watermark information a stored in the digital watermark information storage unit 322, If the missing data matches the missing information stored as a part of the digital watermark information b in the digital watermark information storage unit 322, the digital watermark information received from the image forming apparatus 2 by the digital watermark information receiving unit 314 It is assumed that authentication with the digital watermark information stored in the digital watermark information storage unit 322 has been established.

  When the authentication unit 317 authenticates the received digital watermark information and the digital watermark information stored in the digital watermark information storage unit 322 (YES in SV13), the output permission information transmission unit 311 outputs the output permission. Information (instruction for permitting the recording unit 27 to output the information read by the document reading unit 26) is transmitted to the image forming apparatus 2 (SV14). In the image forming apparatus 2, when the output permission information receiving unit 211 receives the output permission information from the server 3 (S14), the operation control unit 216 puts the image read by the document reading unit 26 on the recording unit 27 recording paper. Output (S15).

  If the authentication by the authentication unit 317 is not established (NO in SV13), the output permission information sending unit 311 sends output non-permission information to the image forming apparatus 2 (SV15). In the image forming apparatus, when the output permission information receiving unit 211 receives the output non-permission information (S16), the operation control unit 216 outputs the image read by the document reading unit 26 on the recording unit 27 recording paper. The processing is stopped (S17).

  2 and 5 is performed, only the incomplete electronic watermark information is embedded in the image on the original, or the electronic watermark information is accurately obtained due to the change in performance of the original reading unit 26 over time. Even if it is not read, the server 3 can authenticate the digital watermark information. Further, since the authentication unit 317 of the server 3 authenticates the digital watermark information based on the missing information received from the image forming apparatus 2, even if the digital watermark information received from the image forming apparatus 2 is incomplete. The digital watermark information stored in the digital watermark information storage unit 322 can be compared with high accuracy.

  Next, a second embodiment of processing for outputting an image including digital watermark information (latent image) on recording paper by the digital watermark information authentication system 1 will be described. FIG. 6 is a flowchart showing a second embodiment of a process for forming an image including digital watermark information (latent image) on a recording sheet by the digital watermark information authentication system 1. Note that the same processes as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the first embodiment, the combination of the missing information transmitted from the image forming apparatus 2 and the original digital watermark information stored in the digital watermark information storage unit 322 is used as new digital watermark information b. Although it is stored in the watermark information storage unit 322 for authentication, it is stored in the personal identification information, the missing information, and the digital watermark information storage unit 322 transmitted from the image forming apparatus 2 to the server 3. The combination of the original digital watermark information may be stored as new digital watermark information c in the digital watermark information storage unit 322 for authentication.

  The case of copying in the image forming apparatus 2 will be described. For example, in the image forming apparatus 2, when the copying operation starts, the user is requested to input personal identification information, and the personal identification information is input to the personal identification information input unit 24 from the user. When input is made (YES in S21), document reading by the document reading unit 26 is started (S1). Then, processing similar to S2 to S8 and SV1 to SV3 in FIG. 2 of the first embodiment is performed, and the missing information detected in S8 is transmitted to the server 3 by the missing information transmitting unit 213, and personal identification information is input in S21. The personal identification information transmission unit 212 transmits the personal identification information input to the unit 24 to the server 3 (S22).

  In the server 3, when the missing information receiving unit 313 and the personal identification information receiving unit 312 receive the missing information and the personal identification information (SV21), the control unit 316 forms an image in the SV3 with the personal identification information and the missing information. A combination with the digital watermark information (original digital watermark information) sent to the apparatus 2 is stored in the digital watermark information storage unit 322 as new digital watermark information c (SV22).

  The digital watermark information authentication process by the digital watermark information authentication system 1 corresponding to the second embodiment of the process for outputting the image including the digital watermark information (latent image) onto the recording paper will be described. FIG. 7 is a flowchart showing authentication processing of the digital watermark information by the digital watermark information authentication system 1. Note that the same processes as those shown in FIG.

  The case of copying in the image forming apparatus 2 will be described. When starting the copying operation, the image forming apparatus 2 requests the user to input personal identification information, and sends the personal identification information to the personal identification information input unit 24. Is input (YES in S31), the image reading unit 25 reads the original image (S11), the digital watermark information extracted by the digital watermark information extraction unit 222, and the personal identification input to the personal identification information input unit 24 Both the information are transmitted to the server 3 by the digital watermark information transmission unit 214 and the personal identification information transmission unit 212 (S32).

  In the server 3, when the digital watermark information receiving unit 314 and the personal identification information receiving unit 312 receive the digital watermark information and the personal identification information from the image forming apparatus 2 (SV31), the authentication unit 317 includes the received digital watermark information, Authentication with digital watermark information stored in the digital watermark information storage unit 322 (in addition to authentication with the digital watermark information a and b, authentication with new digital watermark information c including missing information and personal identification information is also included. (SV32). When this authentication is established (YES in SV13), the output permission information sending unit 311 sends output permission information to the image forming apparatus 2 (SV14).

  Further, when the authentication by the authentication unit 317 is not established (NO in SV13), the authentication unit 317 receives the received digital watermark information and the digital watermark information stored in the digital watermark information storage unit 322. If it is determined that the personal identification information received from the image forming apparatus 2 does not match the personal identification information that is a part of the digital watermark information c stored in the digital watermark information storage unit 322 (SV33). The control unit 316 stores the personal identification information received from the image forming apparatus 2 and information such as the date and time when the personal identification information is received from the image forming apparatus 2 in the personal identification information storage unit 321 (SV34). ). Thereafter, the output permission information sending unit 311 sends output non-permission information to the image forming apparatus 2 (SV15).

  By performing such processing, in addition to the digital watermark information, the personal identification information received from the image forming apparatus 2 and the personal identification that is a part of the digital watermark information c stored in the digital watermark information storage unit 322 Whether the information matches or not is also an element for determining whether or not copying by the image forming apparatus 2 is permitted. Therefore, only the person having specific personal identification information can output the recording unit 27 of the image forming apparatus 2. Can be allowed, and more strict output restrictions are possible. In addition, when a person who does not have appropriate personal identification information tries to illegally copy a document in which digital watermark information is embedded in an image, the image forming apparatus displays the inappropriate personal identification information and personal identification information. Since the date and time received from 2 is stored, it is possible to identify the person who used the illegal copy or the like, and the point in time when the illegal copy or the like was attempted.

  The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, in each of the embodiments described above, the server 3 performs digital watermark information retention and authentication. However, the image forming apparatus 2 performs the electronic watermark information retention and authentication and the output of the digital watermark information on the recording paper. It is good also as a structure which performs both. In this case, the units provided in the image forming apparatus 2 and the server 3 shown in FIG. 1 for transmitting and receiving various data between the image forming apparatus 2 and the server 3 are not required.

  1 illustrates the configuration of the digital watermark information authentication system 1 including the image forming apparatus 2 and the server 3. However, the image forming apparatus 2 and the server 3 are not necessarily limited to the configuration illustrated in FIG. . For example, when executing the processing described with reference to FIGS. 2 to 7, it may not be provided if there is an unnecessary part.

It is a functional block diagram which shows the outline of the electrical constitution of the digital watermark information authentication system which concerns on one Embodiment of this invention. 5 is a flowchart illustrating a first embodiment of a process for forming an image including digital watermark information (latent image) on a recording sheet by the digital watermark information authentication system. It is a figure which represents typically a mode that an electronic watermark information is synthesize | combined with the image used as the output object to a recording paper. It is a figure which shows the example of the electronic watermark information embedding position on a recording paper. It is a flowchart which shows the process in the case of authenticating electronic watermark information by an electronic watermark information authentication system. It is a flowchart which shows 2nd Embodiment of the process which forms the image containing digital watermark information (latent image) on a recording paper by a digital watermark information authentication system. It is a flowchart which shows the authentication process of the said digital watermark information by the digital watermark information authentication system corresponding to 2nd Embodiment of the process which outputs the image containing digital watermark information (latent image) on a recording paper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Information authentication system 2 Image forming apparatus 3 Server 21 Control unit 211 Output permission information receiving part 212 Personal identification information transmission part 213 Missing information transmission part 214 Digital watermark information transmission part 215 Digital watermark information acquisition part 216 Operation control part 217 Digital watermark information Request transmission unit 22 Image processing unit 221 Detection unit 222 Digital watermark information extraction unit 223 Image composition unit 23 Image memory 231 Recording paper image storage unit 232 Original image storage unit 24 Personal identification information input unit 25 Image reading unit 26 Original reading unit 27 Recording Unit 31 control unit 311 output permission information transmission unit 312 personal identification information reception unit 313 missing information reception unit 314 digital watermark information reception unit 315 digital watermark information transmission unit 316 control unit 317 authentication unit 318 digital watermark information request reception unit 32 data storage unit 321 individuals Another information storage unit 322 information storage unit

Claims (7)

An electronic apparatus comprising: a server that holds and authenticates digital watermark information; and an image forming apparatus that outputs digital watermark information acquired from the server onto a recording sheet and transmits digital watermark information read from a document to the server. A watermark information authentication system,
The image forming apparatus includes: an electronic watermark information acquisition unit that acquires electronic watermark information from the server; an output unit that outputs the electronic watermark information acquired by the electronic watermark information acquisition unit to a recording paper; An image reading unit that reads an image on recording paper to which watermark information is output, and the digital watermark information included in the image on the recording paper read by the image reading unit is extracted and acquired from a server by the digital watermark information acquisition unit A detection unit that detects a lack of the extracted digital watermark information by comparison with the digital watermark information that has been extracted, and a missing unit that transmits to the server missing information indicating the lack of the digital watermark information detected by the detection unit An information transmission means,
The server stores at least one or more digital watermark information as an object of authentication with the digital watermark information transmitted from the image forming apparatus; and the electronic watermark information storage unit stores the electronic watermark information to the image forming apparatus. An electronic watermark information transmitting means for transmitting electronic watermark information stored in the watermark information storage means, missing information transmitted from the missing information transmitting means of the image forming apparatus, and the image forming apparatus from the electronic watermark information transmitting means Control means for storing, in the digital watermark information storage means, new digital watermark information composed of the digital watermark information sent to the digital watermark information as an authentication target with the digital watermark information transmitted from the image forming apparatus. Digital watermark information authentication system. The image forming apparatus includes a document reading unit that reads an image on a document, a digital watermark information extraction unit that extracts digital watermark information from an image on the document read by the document reading unit, and a digital watermark information extraction unit. Digital watermark information transmitting means for transmitting the extracted digital watermark information to the server,
An authentication unit configured to authenticate whether or not the digital watermark information transmitted from the digital watermark information transmission unit of the image forming apparatus is the digital watermark information stored in the digital watermark information storage unit; When the authentication by the authentication unit is established, output permission information for permitting the output unit to output the document image read by the document reading unit of the image forming apparatus is sent to the image forming apparatus. Output permission information sending means for
The image forming apparatus includes an output permission information receiving unit that receives the output permission information transmitted from the output permission information transmitting unit of the server, and when the output permission information is received from the server by the output permission information receiving unit. The digital watermark information authentication system according to claim 1, further comprising operation control means for causing the output means to output a document image read by the document reading means. The image forming apparatus includes: personal identification information input means for inputting personal identification information by a user; and personal identification information transmission means for transmitting the personal identification information input to the personal identification information input means to the server. Prepared,
The control unit of the server includes personal identification information transmitted from the personal identification information transmission unit of the image forming apparatus, missing information transmitted from the missing information transmission unit of the image forming apparatus, and the digital watermark information. 3. The digital watermark information authentication system according to claim 1, wherein new digital watermark information including digital watermark information sent from the sending means to the image forming apparatus is stored in the digital watermark information storage means. The personal identification information transmitting means of the image forming apparatus is configured to output the electronic watermark information extracted by the electronic watermark information extracting means from the image on the original read by the original reading means, and the electronic watermark information transmitting means to the server. Transmitting the personal identification information input to the personal identification information input means to the server,
In the server, the authentication unit is configured to generate the electronic watermark based on the personal identification information transmitted from the personal identification information transmission unit of the image forming apparatus and the electronic watermark information transmitted from the electronic watermark information transmission unit. Authentication with the electronic watermark information stored in the watermark information storage means is performed, and the output permission sending means reads by the document reading means by the output means of the image forming apparatus when authentication by the authentication means is established. Output permission information indicating permission to output the original document image to the image forming apparatus,
The image forming apparatus includes an output permission information receiving unit that receives the output permission information transmitted from the output permission information transmitting unit of the server, and when the output permission information is received from the server by the output permission information receiving unit. 4. The digital watermark information authentication system according to claim 3, further comprising operation control means for causing the output means to output a document image read by the document reading means.   In the server, the authentication unit is configured to generate the electronic watermark based on the personal identification information transmitted from the personal identification information transmission unit of the image forming apparatus and the electronic watermark information transmitted from the electronic watermark information transmission unit. Claims provided with personal identification information storage means for storing personal identification information when authentication with only the personal information identification is not established when authentication is performed with the digital watermark information stored in the watermark information storage means. Item 5. The digital watermark information authentication system according to Item 4. An image forming apparatus that holds and authenticates digital watermark information and outputs digital watermark information onto a recording sheet,
Digital watermark information storage means for storing at least one digital watermark information;
Output means for outputting electronic watermark information stored in the electronic watermark information storage means to a recording paper;
Image reading means for reading an image on a recording paper on which digital watermark information is output by the output means;
The digital watermark information included in the image on the recording paper read by the image reading unit is extracted, and the extracted digital watermark information is compared with the digital watermark information acquired from the server by the digital watermark information acquisition unit. A detecting means for detecting the omission;
The new watermark information comprising the missing information indicating the missing of the watermark information detected by the detecting means and the watermark information to be output on the recording paper by the output means is authenticated as the watermark information. An image forming apparatus comprising: a control unit that stores the electronic watermark information storage unit as a target of the above. An original reading means for reading an image on the original;
Digital watermark information extracting means for extracting digital watermark information from an image on a document read by the document reading means;
Authentication means for authenticating whether the digital watermark information extracted by the digital watermark information extraction means is digital watermark information stored in the digital watermark information storage means;
The image forming apparatus according to claim 6, further comprising an operation control unit that causes the output unit to output a document image read by the document reading unit when authentication by the authentication unit is established.

Images