JP7730701B2 - System, information processing device and control method thereof - Google Patents

Description

The present invention relates to technology that uses blockchain to ensure the authenticity of printed materials.

Blockchain technology is known for its excellent resistance to tampering, making it virtually impossible to delete or alter registered data. It is known that the use of blockchain can prevent unauthorized changes to electronic data (see Patent Document 1).

JP 2018-128823 A

One possible service would involve an image forming device equipped with a scanner and printer linking with a blockchain service to guarantee the authenticity of printed materials. In one example of such a service, the image forming device registers document identification information and evidence information for the printed material (such as when and who printed it) with the blockchain service. The image forming device embeds the document identification information in the print data and then prints it. In this example, the recipient of the printed document can extract the document identification information from the document and query the blockchain service to confirm the document's authenticity.

In a service that uses blockchain to guarantee the authenticity of printed materials, image forming devices need the ability to embed information in print data and to link with blockchain services. However, there are image forming devices already in use that do not have these functions, and such devices cannot perform the above-mentioned authenticity-guaranteed printing.

The present invention aims to ensure the authenticity of data from image forming devices even if they do not have the functionality to directly link with blockchain services.

In order to solve the above problem, a system is provided which is composed of an information processing device and a blockchain device, wherein the information processing device has a virtual driver and a printer driver, and the virtual driver causes the information processing device to execute an embedding instruction means which instructs an external device to embed identification information in print data, a receiving means which receives identification information related to the print data and the print data in which the identification information is embedded from the external device, and a registration instruction means which instructs the blockchain device to register the identification information related to the print data in a transaction, and causes the information processing device to execute a sending means which sends a print job of the print data in which the identification information is embedded, received from the external device, to an image forming device, and the blockchain device has a registration means which generates a transaction based on the identification information and registers it in a block, and the virtual driver and the printer driver work together so that a printed material can be generated and a block related to the generated printed material can be registered with a single print instruction from a user.

It is possible to guarantee the authenticity of data from image forming devices even if they do not have the functionality to directly connect to blockchain services.

FIG. 1 is a diagram illustrating a system configuration. FIG. 2 is a diagram illustrating a hardware configuration of an image forming apparatus. FIG. 1 illustrates a hardware configuration of an information processing apparatus and a document management apparatus. FIG. 2 is a diagram illustrating a software configuration of the information processing device. FIG. 2 is a diagram illustrating a software configuration of the print data generating device. FIG. 1 is a diagram illustrating the software configuration of a blockchain device. FIG. 10 is a diagram illustrating the data structure of a blockchain device. 10 is an example of a screen for installing a virtual driver that issues credentials. FIG. 10 is a sequence diagram of credential issuance in the first embodiment. 10 is a flowchart showing a credential issuing process of the print data generating device according to the first embodiment. This is an example of a virtual driver and printing app screen. FIG. 10 is a sequence diagram of printing to guarantee authenticity in the first embodiment. 4 is a flowchart showing a print data generation process of the print data generating device according to the first embodiment. 10 is a flowchart showing a transaction registration process of the block chain device according to the first embodiment. This is an example of a verification app screen. FIG. 10 is a sequence diagram of verification in the first embodiment. 10 is a flowchart showing information extraction processing of the print data generating device. 10 is a flowchart showing the ledger reference process of a blockchain device. FIG. 10 is a sequence diagram of printing to guarantee authenticity in the second embodiment. 10 is a flowchart showing a print data generation process of a print data generating device according to a second embodiment. FIG. 11 is a sequence diagram of credential issuance in the third embodiment. 11 is a flowchart showing a print data generation process of a print data generating device according to a third embodiment. FIG. 11 is a sequence diagram of verification in the third embodiment. 10 is a flowchart showing a transaction registration process of a block chain device according to a fourth embodiment. 10 is a flowchart showing a verification process of a blockchain device according to a fourth embodiment.

[Example 1]
First, we will explain the service that guarantees the authenticity of data and printed materials. Guaranteeing authenticity in this service means proving that electronic data or printed materials are genuine based on information that uniquely identifies them. Information about electronic data or printed materials includes evidence of when, who, what, and how, as well as document content information when the evidence information is saved. Information about electronic data and printed materials is used to prove authenticity, so it must be highly tamper-resistant. Therefore, this service manages information about electronic data and printed materials using blockchain, which is known to be highly tamper-resistant. One benefit of this service is that a third party (this service) guarantees information about electronic data and printed materials, allowing the owners of the electronic data and printed materials to prove their authenticity. Furthermore, users who receive electronic data or printed materials can confirm that they are genuine.

The following describes an embodiment of the present invention with reference to the drawings. Figure 1 is an overall view of a printing system in this embodiment. An image forming device 101, an information processing device 102, and a document management device 103 are connected to a LAN 100 and exist within an intranet, communicating with a print data generation device 111 and a block chain device 112 via the Internet 110. The image forming device 101 is a device equipped with printing and scanning functions. The information processing device 102 is a device operated by a user, and accepts instructions for authenticating printing (hereinafter referred to as authenticity-guaranteed printing) and verifying printed materials, requests processing from each device via the LAN 100, and provides the user with the function of displaying results and errors. The document management device 103 is a device that stores electronic data generated by the image forming device 101 and information processing device 102, and provides document management services.

When the print data generation device (external device) 111 receives a request to generate print data, it issues document identification information to be registered in the blockchain device 112 and provides a service of embedding the document identification information into the print data. Furthermore, when it receives a request to extract information (extraction instruction), it provides a service of extracting the embedded information from the electronic data.

The blockchain device 112 is a device that stores and provides document identification information (identification information) that uniquely identifies electronic data and printed materials in blockchain format, and provides a blockchain service to ensure the authenticity of documents. The services provided by the blockchain device 112, document management device 103, and print data generation device 111 may be provided by virtualizing multiple computers into a single device. Therefore, when we refer to a blockchain system, document management system, or print data generation system, we are referring to a system made up of one or more devices.

Furthermore, in this embodiment, two types of network configurations, the Internet 110 and LAN 100, are used, but all devices may be connected to either one of the networks, and there are no restrictions on configurations using other network types.

Figure 2 is a block diagram showing the hardware configuration of the image forming apparatus 101. A control unit 200 including a CPU 201, which is a central processing unit, controls the overall operation of the image forming apparatus 101. The CPU 201 reads control programs stored in a ROM 202, which is read-only memory, and performs various controls such as reading control and transmission control. A RAM 203, which is random access memory, is used as a temporary storage area such as the main memory and work area of the CPU 201. A HDD 204, which is a hard disc drive, stores image data, various programs, and various data described below. The image forming apparatus 101 has the hardware configuration of an information processing apparatus, but in addition to this, it also has the following hardware configuration.

The operation unit I/F 205 connects the operation unit 209 and the control unit 200. The printer I/F 206 connects the printer 210 and the control unit 200. Image data to be printed by the printer 210 is transferred from the control unit 200 via the printer I/F 206 and printed on a recording medium by the printer 210. The scanner I/F 207 connects the scanner 211 and the control unit 200. The scanner 211 reads an image on a document, generates image data, and inputs it to the control unit 200 via the scanner I/F 207.

The network I/F 208 connects the control unit 200 (image forming apparatus 101) to the LAN 100. The network I/F 208 transmits image data and information to external devices on the LAN 100, and receives various information from external devices on the LAN 100.

Figure 3 is a block diagram showing the hardware configuration of the information processing device 102, document management device 103, print data generation device 111, and blockchain device 112. The CPU 302 controls the entire device. The CPU 302 executes application programs and the OS stored in the HDD 305, and controls the temporary storage of information, files, etc. required for program execution in the RAM 303. The ROM 304 is a storage unit that stores various data such as basic I/O programs. The RAM 303 is a temporary storage unit that functions as the main memory, work area, etc. for the CPU 302. The HDD 305 is one of the external storage units that functions as a large-capacity memory and stores applications, the OS, related programs, etc.

The display 306 is a display means that displays commands entered from the keyboard/mouse 307, which is an instruction input unit. The interface 308 is an external device I/F that connects printers, USB devices, and peripheral devices. The system bus 301 controls the flow of data within the device. The network interface card (hereinafter referred to as NIC) 309 exchanges data with external devices via the LAN 100 and the Internet 110.

Note that the configuration of each device is an example and is not limited to the configuration examples shown in Figures 2 and 3. For example, the storage location of data and programs can be changed to ROM 304, RAM 303, HDD 305, etc. depending on the characteristics of the data and programs. Unless otherwise specified in this embodiment, various processes are realized by loading programs stored in ROM 304, etc. into RAM 303, etc. and executing them with CPU 302.

Figure 4 is a block diagram showing the software configuration related to the present invention in the information processing device 102. The communication unit 401 provides the function of communicating with other devices on the LAN 100. The print processing unit 402 uses the services of the print data generation device 111 and the block chain device 112 via the communication unit 401 and provides the function of issuing print instructions to the printer driver 403. The print processing unit 402 can be provided as a virtual printer driver (hereinafter referred to as a virtual driver) or a print app.

The printer driver 403 sends a print job to the image forming device 101 via the communication unit 401 in response to a print instruction. The verification processing unit 404 uses the services of the print data generation device 111 and the blockchain device 112 via the communication unit 401 to provide a function for verifying the authenticity of electronic data. The verification processing unit 404 can be provided as a verification app. The verification processing unit 404 may also be provided as one of the functions of the aforementioned print app.

The credential DB 405 provides the function of managing credential information for the print data generation device 111 and the blockchain device 112. When the print processing unit 402 and the verification processing unit 404 use their respective services, the information managed by the credential DB 405 is used for authentication. The credential DB 405 may be prepared as a DB managed by each of the print processing unit 402 and the verification processing unit 404.

In this embodiment, the print processing unit 402 and verification processing unit 404 are provided to the user as functions of a virtual driver or app, and issue credentials for using each service during installation or when using the print verification function. When issuing credentials, in order to authenticate the virtual driver or app as authentic, the credentials for each service are embedded in the virtual driver or app beforehand and provided to the user. In this explanation, these credentials are assumed to be common credentials (hereinafter referred to as common credentials) for the virtual driver and apps. Common credentials are managed in the credential DB 405.

Note that common credentials do not need to be common across all virtual drivers and apps. For example, common credentials could be issued and embedded for each version of the virtual driver, and the service could fail authentication if the credential version is too old.

In addition to common credentials, the credential DB 405 manages credentials for using services obtained by issuing credentials (hereinafter referred to as service usage credentials). Service usage credentials are credentials issued by each service for each virtual driver or application, and each service registers user information when they are issued.

When issuing service usage credentials, the credentials held by the user (hereinafter referred to as user credentials) are used to register the user. User credentials are issued when the user applies to use a service, and the user manages the user credentials on the information processing device 102 or an accessible file server (not shown). A user can apply to use a service using a standard method, so a description of this method will be omitted.

We have explained the credentials managed by the information processing device 102, but the procedure for issuing service usage credentials using common credentials and user credentials will be described later.

An example of information stored in credential DB 405 is shown in Table 1.

The credential information table in Table 1 consists of "destination," "purpose," "ID," and "authentication information." In order to manage credentials for multiple services, the credentials for the service to be used are determined by the "destination."

As mentioned above, the credential DB 405 stores common credentials used for credential issuance and service usage credentials for service usage, and uses them differently depending on the "purpose."

"ID" is information that allows a service to uniquely identify a user. "Authentication information" is information that allows a service to authenticate a user. "ID" and "authentication information" are information issued by each service and are used in the authentication process of each service. In this embodiment, they are managed in a single information table, but separate credential information tables can also be created and managed for each connection destination or purpose.

Figure 5 is a block diagram showing the software configuration related to the present invention in the print data generation device 111. The communication unit 501 provides the function of communicating with other devices via the Internet 110. The processing control unit 502 provides the function of executing processing in each processing unit in response to requests received from external devices via the communication unit 501, and transmitting the processing results to the external devices via the communication unit 501.

The authentication unit 503 is composed of an authentication processing unit 504 and a user information DB 505. The authentication processing unit 504 provides a function for authenticating users who use the service. The user information DB 505 provides a function for storing user information, which is information about users who use the service. An example of user information stored in the user information DB 505 is shown in Table 2.

The user information table in Table 2 consists of "ID," "authentication information," and "user." "ID" is information used to uniquely identify a user. "Authentication information" is information used to authenticate a user. "User" is information used to identify the user of "ID," and one user may be linked to multiple IDs. For example, the aforementioned user credentials and service usage credentials are registered as the same user.

The document identification information embedding unit 506 provides the function of generating document identification information and embedding the document identification information in print data. The document identification information is information for uniquely referencing the registered content in the blockchain. The document identification information extraction unit 507 provides the function of extracting embedded information from electronic data.

Figure 6 is a block diagram showing the software configuration related to the present invention in the blockchain device 111. The communication unit 601 provides the function of communicating with other devices via the Internet 110. The processing control unit 602 provides the function of executing processing in each processing unit in response to requests received from external devices via the communication unit 601, and transmitting the processing results to the external devices via the communication unit 601.

The authentication unit 603 is composed of an authentication processing unit 604 and a user information DB 605. The authentication processing unit 604 provides a function for authenticating users who use the service. The user information DB 605 provides a function for storing user information. An example of user information stored in the user information DB 605 is shown in Table 3.

In this embodiment, the configuration of the user information table in Table 3 is the same as that in Table 2. The block data management unit 606 performs blockchain processing such as transaction generation, block generation, writing to the distributed ledger 607, and referencing the distributed ledger 607. The distributed ledger 607 provides the function of storing blocks. Generally, in a blockchain, the ledger is managed by multiple nodes (computers), and the block data management unit 606 may be composed of multiple units.

The information that may be included in the DBs that manage the credential information and user information described in Tables 1, 2, and 3 is not limited to this. For example, the issuance date and expiration date of the credential may also be managed.

Furthermore, the credential information may be a digital certificate, a key pair consisting of a private key and a public key, or a predetermined data value; there are no restrictions on the actual form of the credential information. In this embodiment, the credentials of the print data generation device 111 and the blockchain device 112 are the same, but they may be different for each device.

Figure 7 is a block diagram showing the blocks held by the distributed ledger 607 and the transactions that constitute the blocks. In this embodiment, transaction 701 includes three pieces of information. As mentioned above, document identification information 702 is information for uniquely referencing the registered content of the blockchain. When registering printed matter, document identification information 702 is generated by hashing the electronic data to be printed, the registration date and time, and information about the registrant. In other words, even if the same electronic data is printed, document identification information 702 will be different each time it is printed. When registering electronic data, information generated by hashing the electronic data is registered as document identification information 702. In other words, the same electronic data cannot be registered multiple times. By doing this, if the contents of the electronic data are tampered with, the hash generated from the electronic data will be different, making it impossible to refer to the registered content before the tampering. Therefore, the authenticity of tampered electronic data cannot be proven.

In this embodiment, the document identification information 702 is generated differently for printed matter and electronic data, but it may be the same. Furthermore, there are no restrictions on how the document identification information 702 is generated, as long as it is unique information. For example, it may be a list and concatenation of information such as date and time or registrant information without hashing, or it may be a combination of partially hashed information and a list.

The next two pieces of information are information about the evidence of electronic data and printed materials. Registration date and time 703 is information indicating the time of registration. Registrant 704 is information about the user who made the registration, such as the user in Table 3.

While the information included in the transaction in this embodiment has been described, the information that may be included is not limited to this. For example, information regarding the period for which the registered content is guaranteed, information regarding the number of pages to confirm that all pages of the printed material are included, and information regarding the electronic data that is the source of the printed material (hereinafter referred to as the original document) may also be included. Examples of information regarding the original document include a hashed value of the electronic data of the original document, and if it is registered as electronic data in the blockchain, its document identification information. Furthermore, the amount of information used when generating a transaction may be limited to only the document identification information and the registration date and time.

Next, the structure of a block that holds transactions 701 will be explained using block 705. This is a schematic representation of a typical blockchain structure. Block 705 holds multiple transactions 701(a) to 701(c) and a block hash value 706 calculated from these transactions 701. Although the number of transactions 701 included in a block is three, this does not limit the number of transactions.

Block 705 also holds the hash value 707 of the previous block to link blocks. The hash value of block 708 is stored in the hash value 707 of the previous block, indicating that the blocks are related. When the block next to block 705 is generated, the value of the block's hash value 706 is set as the hash value of the previous block in the next block. By repeating this process, blocks are linked together, making it difficult to tamper with transaction data. In this embodiment, the hash value of the previous block is used, but it is also possible to manage the hash value of the subsequent block, or to manage the hash values of both the previous and subsequent blocks.

The procedure for issuing credentials will be explained. The print processing unit 402 uses the common credentials obtained from the credential DB 405 and the user credentials specified by the user to request each service to issue service usage credentials. Below, the procedure for issuing credentials will be explained using the example of installing a virtual driver or app that has the functions of the print processing unit 402.

Figure 8 is an example of an installation screen when issuing credentials. The installation screen 801 is an installer screen that provides the functionality of installing a virtual driver or app that has the functionality of the print processing unit 402. The blockchain service credential selection field 802 is a field for selecting user credentials for the blockchain service. The print data generation service credential selection field 803 is a field for selecting user credentials for the print data generation service. The issue button 804 is a button for starting the credential issuance process.

Figure 9 is a sequence diagram of credential issuance in Example 1. This sequence is initiated when the user presses the aforementioned issue button 804, and the print processing unit 402, print data generation device 111, and blockchain device 112 work together to perform processing to obtain service usage credentials for each device.

In step S901, the user presses the issue button 804 to instruct the issuance of service usage credentials. Upon receiving the instruction to issue the service usage credentials, the print processing unit 402 requests the print data generating device 111 to perform credential issuance processing in step S902. Upon receiving the issuance request, the print data generating device 111 performs service usage credential issuance processing and provides the generated service usage credential to the print processing unit 402. Details of the credential issuance processing in step S902 will be explained later using the flowchart in Figure 10. Next, in step S903, the print processing unit 402 stores the service usage credentials received from the print data generating device 111 in the credential DB 405.

Next, the print processing unit 402 requests the blockchain device 112 to perform credential issuance processing in step S904. Upon receiving the issuance request, the blockchain device 112 performs processing to issue a service usage credential and provides the generated service usage credential to the print processing unit 402. Details of the credential issuance processing in step S904 will be explained later using the flowchart in Figure 10. Next, in step S905, the print processing unit 402 stores the service usage credential received from the blockchain device 112 in the credential DB 405.

In step S906, the print processing unit 402 notifies the user of the results of the credential issuance and ends this sequence. The user is notified by displaying a dialog box containing a message indicating successful issuance and any error messages received from the device (described below). The dialog boxes used for these notifications are standard dialog boxes provided by the OS, and therefore will not be described here.

Figure 10 is a flowchart showing the credential issuance process of the print data generating device 111. This flowchart is started when the print data generating device 111 receives the credential issuance request described above. The process control unit 502 is executed on the CPU 301 via the communication unit 501. When this flowchart is started, the process control unit 502 receives the common credential and the ID and authentication information of the user credential from the print processing unit 402. The process control unit 502 passes the received credential to the authentication processing unit 504, which then executes the following process.

In step S1001, the ID and authentication information of the common credentials received from the print processing unit 402 at startup are compared with the information in the user information DB 505 to determine whether authentication was successful. In step S1002, if authentication was successful, the process proceeds to step S1003; if authentication was unsuccessful, the process passes an error message to the process control unit 502 and proceeds to step S1007.

In step S1003, the ID and authentication information of the user credentials received from the print processing unit 402 at startup are compared with the information in the user information DB 505 to determine whether authentication was successful. In step S1004, if authentication was successful, the process proceeds to step S1005; if authentication was unsuccessful, the process passes an error message to the process control unit 502 and proceeds to step S1007.

In step S1005, service usage credentials are issued. First, an ID and authentication information are generated. There are no restrictions on how the generated ID is generated, as long as it is unique in the user information table managed by the user information DB 505. There are also no restrictions on the authentication information generated. Next, the user is obtained from the user information DB 505 based on the ID in the user credentials. The generated ID, authentication information, and the obtained user are registered in the user information DB 505. The authentication processing unit 504 passes the issued service usage credential information to the processing control unit 502, and the process proceeds to step S1006.

In step S1006, the process control unit 502 transmits the issued credential information to the print processing unit 402 via the communication unit 501. If the process control unit 502 receives an error message, in step S1007 it transmits the error message to the print processing unit 402 via the communication unit 501. After the transmission process to the print processing unit 402 is completed in step S1006 or step S1007, this flowchart ends.

The flowchart for the credential issuance process of the blockchain device 112 is the same as that of the print data generation device 111. The communication unit 501, processing control unit 502, authentication processing unit 504, and user information DB 505 of the print data generation device 111 correspond to the communication unit 601, processing control unit 602, authentication processing unit 604, and user information DB 605 of the blockchain device 112, respectively.

The procedure for issuing credentials has been explained above, but this is merely an example and does not limit other procedures up to the time when the print processing unit 402 possesses service usage credentials. For example, a common credential may not be embedded in the print processing unit 402 in advance, and a user credential may be specified in the print processing unit 402 to be newly issued. Alternatively, a service usage credential may be embedded in the print processing unit 402 in advance.

As mentioned above, if the verification processing unit 404 is provided as a separate application (verification application) from the print processing unit 402 and credential information is managed separately, service usage credentials may be issued using a similar procedure when the verification application is installed.

This section explains authentic printing. In authentic printing, the user operates a screen provided by the print processing unit 402 to start printing. This section explains, using diagrams, example screens when the print processing unit 402 is provided as a virtual driver or print app, and the process flow for authentic printing.

Figure 11 shows example screens for a virtual driver and printing app. Figure 11(a) is the print properties screen for the virtual driver. The user opens the electronic data they want to print using a general application that can display, edit, and print electronic data, and when executing the print job, selects the virtual driver and prints, which displays the print properties shown in Figure 11(a). Applications that open electronic data, allow driver selection, and have printing functions are general, so they are not shown in the figure.

The function selection tab 1101 is a tab for selecting functions. At startup, "Basic Settings" is selected in the function selection tab 1101, and a screen for making basic settings related to printing is displayed.

The printer driver setting field 1102 is a field for selecting the printer driver to be used for printing. There are no restrictions on the printer driver that can be specified here, and the driver that is normally used for printing can be selected. When printing, the print job is sent to the image forming device 101 via the printer driver selected here. The print properties button 1103 is a button that displays the print properties screen of the selected printer driver. The properties displayed when the print properties button 1103 is pressed are not shown in the figure because they are the properties screen of a general printer driver. The print button 1104 is a button for starting authenticity-guaranteed printing. The cancel button 1105 is a button for canceling the print instruction and closing the print properties screen of the virtual driver.

The aforementioned service usage credentials can also be issued from the virtual driver's properties screen. Figure 11(b) shows the credential management screen for selecting the user credentials required to issue service usage credentials. Selecting "Credential Management" in the function selection tab 1101 displays the credential management screen shown in Figure 11(b).

The blockchain service credential selection field 1106 is a field for selecting user credentials for the blockchain service. The print data generation service credential selection field 1107 is a field for selecting user credentials for the print data generation service. After setting the necessary information in each field, when the print button 1104 is pressed, the credential issuance sequence shown in Figure 9 above is initiated before authenticity-guaranteed printing begins. The use of the credential management screen in Figure 11(b) is not limited to issuing credentials. For example, functions for reissuing, updating, and deleting credentials may be added.

Figure 11(c) is an example screen when the print processing unit 402 is provided as a print application. When the print application is launched, the top menu screen 1108 in Figure 11(c) is displayed. The authenticity assurance print selection button 1109 is a button that transitions to a screen for authenticity assurance printing. The verification selection button 1110 is a button that transitions to a screen for verification. The verification screen will be described later in Figure 15. The credential management selection button 1111 is a button that transitions to a credential management screen. In this embodiment, only the functions for authenticity assurance are shown on the top menu screen 1108, but the authenticity assurance function may also be provided as an addition to the normal printing and image editing functions that a typical print application has.

Figure 11 (d) is an example of a screen for performing authenticity-guaranteed printing. Pressing the authenticity-guaranteed printing selection button 1109 displays the authenticity-guaranteed printing screen 1112. The back button 1113 is a button for returning to the top menu screen 1110. The preview 1114 displays a preview of the selected file. The file selection button 1115 is a button for transitioning to a screen for selecting electronic data for authenticity-guaranteed printing by referencing the storage within the device or external storage on a network, etc. The screen for selecting electronic data is not shown in the figure, as it is a screen provided by a general printing app.

The printer selection button 1116 transitions to a screen for selecting the device to use for printing. Here, like a typical printing app, image forming devices are searched for using Bluetooth or Multicast DNS. When using Bluetooth, image forming devices are searched for by receiving a Bluetooth beacon from an image forming device within the Bluetooth communication range. The received beacon contains the printer's IP information, and the obtained IP information is used for IPP (Internet Printing Protocol) communication or IPPS communication. Detailed information such as the device name is obtained from the printer via IPP or IPPS communication, and the obtained information is displayed in a list on the search results screen for the number of image forming devices found. If the image forming device supports TLS (Transport Layer Security), detailed information is obtained via IPPS communication. An image forming device can be selected from the list of image forming device search results and set as the print destination. The image forming device search screen and selection screen are not shown in the figure as they are screens provided by general printing apps.

The print property setting button 1117 is a button that transitions to a screen for setting the print properties of the printer selected with the printer selection button 1116. As described above, the print property screen is displayed based on detailed printer information obtained via IPP or IPPS communication. The printer property setting screen is not shown in the figure, as it is a screen provided by a general printing application. The print button 1118 is a button for starting authenticity-guaranteed printing.

Figure 11 (e) is a credential management screen for selecting the user credentials required to issue service usage credentials. Pressing the credential management selection button 1111 displays the credential management screen 1119. The blockchain service credential selection button 1120 is a button that transitions to a screen for selecting user credentials for the blockchain service. The print data generation service credential selection button 1121 is a button that transitions to a screen for selecting user credentials for the print data generation service. The credential selection screen is not shown in the figure as it is a general screen that allows you to select a file by referencing the device's internal storage or external storage such as on a network.

The Apply button 1122 is a button that saves the settings of the selected user credentials. When the Print button 1118 is pressed, the saved user credentials are used to start the credential issuance sequence shown in Figure 9 before authenticity-assured printing begins. Alternatively, the Apply button 1122 may be used as a credential issuance button to start credential issuance. The use of the credential management screen in Figure 11(e) is not limited to issuing credentials. For example, functions for reissuing, updating, and deleting credentials may be added.

Figure 12 is a sequence diagram of authenticity-guaranteed printing in Example 1. Figure 12(a) is a sequence diagram when the print processing unit 402 is provided as a virtual driver. This sequence is started when the user presses the print button 1104, and the print processing unit 402, printer driver 403, image forming device 101, print data generation device 111, and blockchain device 112 work together to perform authenticity-guaranteed printing.

In step S1201, the user presses the print button 1104 to send a print instruction to the print processing unit 402. Upon receiving the print instruction, the print processing unit 402 sends print data to the print data generation device 111 and requests print data generation processing. In step S1202, the print data generation device 111 performs print data generation processing and sends the generated document identification information and print data to the print processing unit 402. Details of the print data generation processing in step S1202 will be explained later using the flowchart in Figure 13.

Next, the print processing unit 402 sends the document identification information and a registration instruction to the blockchain device 112. Upon receiving the registration request, the blockchain device 112 performs transaction registration processing in step S1203 and sends the results to the print processing unit 402. Details of the transaction registration processing in step S1203 will be explained later using the flowchart in Figure 14.

Next, the print processing unit 402 instructs the printer driver 403 specified in the printer driver setting field 1102 to print the print data received from the print data generation device 111, i.e., to generate a print job.

Upon receiving the print instruction, the printer driver 403 performs print job generation processing in step S1204 and transmits the print job to the image processing device 101. The image forming device 101, which has received the print job, performs print processing in step S1205, ending this sequence. The print job generation processing of the printer driver 403 and the print processing of the image forming device 101 are general printer driver and image forming device processing, so a description of these will be omitted. If the print processing unit 402 receives an error message (described below) from the print data generation device 111 or the block chain device 112, the user is notified using a dialog box that the OS provides as standard (not shown).

Figure 12(b) is a sequence diagram when the print processing unit 402 is provided as a print application. This sequence is started when the user presses the print button 1118 mentioned above, and the print processing unit 402, image forming device 101, print data generation device 111, and blockchain device 112 work together to perform processing and perform authenticity-guaranteed printing.

Steps S1211 to S1213 perform the same processing as steps S1201 to S1203 described in the sequence for authenticity-guaranteed printing in the virtual driver in Figure 12(a). In step S1214, the print processing unit 402 instructs the image forming device 101 selected using the printer selection button 1116 to print the print data received from the print data generation device 111, i.e., to generate a print job. The image forming device 101, having received the instruction to generate a print job from the print processing unit 402, generates a print job and performs printing processing. If the print processing unit 402 receives an error message (described below) from the print data generation device 111 or the block chain device 112, it notifies the user using a dialog box that the OS provides as standard (not shown).

Figure 13 is a flowchart showing the print data generation process of the print data generation device 111. This flowchart is started when the communication unit 501 receives the print data generation request described above in the print data generation device 111, and is first executed by the process control unit 502 on the CPU 301. When this flowchart is started, the process control unit 502 receives the ID and authentication information of the service usage credentials and print data from the print processing unit 402. The process control unit 502 passes the received service usage credentials to the authentication processing unit 504, and step S1301 is executed by the authentication processing unit 504.

In step S1301, the authentication processing unit 504 compares the ID and authentication information of the service usage credentials with the information in the user information DB 505 and determines whether the authentication was successful. If the comparison is successful, the information of the user of the service usage credentials is obtained from the user information DB 505 and temporarily stored in RAM 303.

In step S1302, the authentication result is confirmed, and if authentication is successful, the process proceeds to step S1303. If the process proceeds to step S1303, the process returns to the process control unit 502, which then passes the print data received from the print processing unit 402 to the document identification information embedding unit 506, which then executes the document identification information embedding unit 506. If authentication is unsuccessful, an error message is passed to the process control unit 502, and the process proceeds to step S1306.

In step S1303, the document identification information embedding unit 506 generates document identification information. In this step, three pieces of information are hashed: the print data received from the process control unit 502, the date and time information in the print data generating device 111, and the user information saved in RAM 303 in step S1301, to generate document identification information.

In step S1304, the document identification information embedding unit 506 embeds the document identification information issued in step S1303 into the print data received from the process control unit 502. In the embedding process, the document identification information is converted into a format (e.g., a barcode) that can be read by scanning or photographing during verification, as described below, and then embedded. The embedding method may be either visible information that the user can see, or invisible information that the user cannot see, and any form of embedded information that can be embedded in the printed material is acceptable. If you want to explicitly indicate to the user that the information has been registered on the blockchain, it is best to embed it as visible information; for example, a two-dimensional barcode can be used. Alternatively, if you do not want to impair the appearance of the document, it is best to embed it as invisible information. For example, it is possible to embed it as invisible information in the document by printing a pattern of tiny dots of toner or ink that are invisible to the user. The document identification information embedding unit 506 passes the document identification information and the print data in which that information is embedded to the process control unit 502, and the process proceeds to step S1305.

In step S1305, the process control unit 502 transmits the generated document identification information and the print data in which that information is embedded to the print processing unit 402 via the communication unit 501. If the process control unit 502 receives an error message, in step S1306 it transmits the error message to the print processing unit 402 via the communication unit 501. After the transmission process to the print processing unit 402 is completed in step S1305 or step S1306, this flowchart ends.

Figure 14 is a flowchart showing the transaction registration process of the blockchain device 112. This flowchart is started when the communication unit 601 receives the above-mentioned request to register the document identification information in the blockchain device 112, and is first executed by the process control unit 602 on the CPU 301. When this flowchart is started, the process control unit 602 receives the ID, authentication information, and document identification information of the service usage credentials from the print processing unit 402. The process control unit 602 passes the received service usage credentials to the authentication processing unit 604, and step S1401 is executed by the authentication processing unit 604.

In step S1401, the authentication processing unit 604 compares the ID and authentication information of the service usage credentials with the information in the user information DB 605 and determines whether the authentication was successful. If the comparison is successful, the information of the user of the service usage credentials is obtained from the user information DB 605 and temporarily stored in RAM 303.

In step S1402, the authentication result is confirmed, and if authentication is successful, the process proceeds to step S1403. If the process proceeds to step S1403, the process returns to the process control unit 602, which then passes the document identification information received from the print processing unit 402 to the block data management unit 606, which then executes the block data management unit 606. If authentication is unsuccessful, an error message is passed to the process control unit 602, and the process proceeds to step S1408.

In step S1403, the block data management unit 606 determines whether the document identification information 702 passed from the process control unit 602 can be registered in the blockchain. In this embodiment, the document identification information is information that uniquely references the registration content, so if the information has already been registered, it is deemed not to be registerable. If it is determined that registration is possible, the process proceeds to step S1404; if it is determined that registration is not possible, the process passes an error message to the process control unit 602 and proceeds to step S1408.

In step S1404, a transaction 701 is generated. The document identification information 702 is specified as the document identification information received by the process control unit 602 from the print processing unit 402. The registration date and time 703 is specified as the date and time information in the blockchain device at the time step S1404 is executed. The registrant 704 is specified as the information temporarily stored in RAM 303 in step S1401.

In step S1405, the block data management unit 606 generates a block and writes it to the distributed ledger 607. After the transaction is generated in step S1404, the block is not necessarily generated immediately; it is generated when the block generation conditions are met. For example, when a certain number of transactions to be registered in a block have been collected or after a certain amount of time has passed, a block is generated by combining all the transactions that are available. The block generation conditions differ depending on the type of blockchain and its settings. After the block is generated, it is written to the distributed ledger 607. In this example, the block is generated when the conditions are met, but this is merely an example of one form of blockchain and does not limit the method of block generation.

In step S1406, if block generation and writing to the distributed ledger 607 are successful, a completion notification is passed to the processing control unit 602 and the process proceeds to step S1407. If not, an error message is passed to the processing control unit 602 and the process proceeds to step S1408.

In step S1407, the process control unit 602 sends a registration completion message to the print processing unit 402 via the communication unit 601. If the process control unit 602 receives an error message, in step S1408 it sends the error message to the print processing unit 402 via the communication unit 601. After the transmission process to the print processing unit 402 is completed in step S1407 or step S1408, this flowchart ends.

The above has explained authenticity-guaranteed printing. The printed matter obtained through authenticity-guaranteed printing can be scanned by the image forming device 101 or photographed using the camera function of the information processing device 102, document identification information extracted from the electronic data, and queried with the blockchain device 112 to confirm the registered content. Confirming the registered content of a printed matter in this way is called verification. The verification method will be explained below.

Figure 15 shows an example screen when the verification processing unit 404 is provided as a function of a verification app or print app. Figure 15(a) shows the verification app screen. When the verification app is launched, a verification app screen 1501 is displayed. The verification file selection field 1502 is a field for selecting the file to be verified. The verification button 1503 is a button that starts verification of the specified file.

Verification result screen 1504 in Figure 15(b) is a screen that displays the verification results. Verification file 1505 displays the file name or path specified by the user in Figure 15(a). Verification result 1506 displays whether it is registered in the blockchain. In the example screen in Figure 15(b), OK is displayed as an example of when it is registered in the blockchain. If it is not registered, NG is displayed (not shown). If verification result 1506 is OK, the information registered in the blockchain may be displayed. In Figure 15(b), the registration date and time 703 included in transaction 701 is displayed as registration date and time 1507, and the registrant 704 is displayed as registrant 1508. By checking the verification results, the user who performed the verification can confirm the evidence of when and who printed the printed materials they own. Close button 1509 is a button that closes verification result screen 1504.

Figures 15(c) to (e) are example screens when the verification processing unit 404 is provided as one of the functions provided by a print app. Pressing the verification selection button 1110 on the top menu screen 1108 of the print app described above displays the verification menu screen 1510. The back button 1511 is a button that transitions to the top menu screen 1108. The select file and verify button 1512 is a button that transitions to a screen for selecting and verifying a file. The take a photo with a camera and verify button 1513 is a button that transitions to a screen for setting up and verifying a file with a camera.

Figure 15 (d) is a screen for selecting and verifying a file. By selecting a file and pressing the verify button 1512, verification screen 1514 is displayed. The back button 1515 is a button that transitions to verification menu screen 1510. The file selection button 1516 is a button that transitions to a screen that references the device's internal storage or external storage, such as on a network, and selects the electronic data to be verified. The verify button 1517 is a button that starts verification of the specified file.

Figure 15(e) shows a screen for photographing and verifying a printed matter with a camera. Pressing the "Take a photo with a camera and verify" button 1513 displays the verification screen 1518. Camera image 1519 displays an image captured from a camera built into or connected to the device running the print app. Pressing the "Verify" button 1520 while the printed matter is visible in the camera image 1519 captures a still image and starts verification of the captured data. When photographing and verifying a printed matter with a camera, the portion of the printed matter photographed varies depending on the method of embedding the document identification information. If the entire printed matter must be photographed to extract the embedded information, the entire matter must be photographed. However, if information such as a two-dimensional barcode is embedded, verification can be performed by photographing only that portion. In this embodiment, photographing and verification begins by pressing the "Verify" button 1520. However, the photographed data may be saved and then verified by selecting the photographed data with the "File selection" button 1516 in Figure 15(d).

The verification results in the print app can be notified to the user by displaying a verification result screen as a pop-up, as shown in Figure 15(b). When verifying by taking a photo with a camera, the information displayed in the verification file 1505 will display the save destination if the captured image is automatically saved, and will not display anything if the captured image is not saved.

Figure 16 is a sequence diagram of verification in this embodiment. This sequence is started by pressing one of the verification buttons 1503/1517/1520, and performs verification through cooperation between the verification processing unit 404, print data generation device 111, and blockchain device 112.

In step S1601, pressing one of the verification buttons 1503/1517/1520 instructs the verification processing unit 404 to perform verification. In step S1602, upon receiving the verification instruction, the verification processing unit 404 reads the specified file or a captured image. The electronic data obtained by reading it is passed to the print data generation device 111, and a request is made to perform information extraction processing.

In step S1603, the print data generation device 111 performs information extraction processing and sends the extracted document identification information to the verification processing unit 404. Details of the information extraction processing will be explained later in Figure 17.

The verification processing unit 404, which has received the document identification information from the print data generation device 111, confirms the registered contents of the document identification information with the blockchain device 112. In step S1604, the blockchain device 112, which has received an inquiry from the verification processing unit 404, references the distributed ledger 607 and sends the reference results to the verification processing unit 404. Details of the ledger reference process will be explained later in Figure 18.

In step S1605, the verification processing unit 404 receives the result of the reference to the distributed ledger 607 from the blockchain device 112, displays a screen like that shown in Figure 15(b) to the user as the verification result, and ends this sequence. Errors in this sequence are displayed using a dialog box that the OS provides as standard (not shown).

Figure 17 is a flowchart showing the information extraction process of the print data generating device 111. This flowchart is started when the communication unit 501 receives a request to extract the embedded information described above in the print data generating device 111, and is first executed by the process control unit 502 on the CPU 301. When this flowchart is started, the process control unit 502 receives the ID and authentication information of the service usage credential and data to extract information from the verification processing unit 404 via the communication unit 501. The process control unit 502 passes the received service usage credential to the authentication processing unit 504, and step S1701 is executed by the authentication processing unit 504.

In step S1701, the authentication processing unit 504 compares the ID and authentication information of the service usage credentials with the information in the user information DB 505 and determines whether authentication is successful. In step S1702, the authentication result is confirmed, and if authentication is successful, the process proceeds to step S1703. If proceeding to step S1703, the process returns to the process control unit 502, after which the process control unit passes the data received from the verification processing unit 404 to the document identification information extraction unit 507, which then executes. If authentication is unsuccessful, an error message is passed to the process control unit 502, and the process proceeds to step S1706.

In step S1703, the document identification information extraction unit 507 extracts the document identification information embedded in the data. In step S1704, it is confirmed whether the information extraction was successful. If the information extraction was successful, the document identification information extraction unit 507 passes the extracted document identification information to the process control unit 502, and the process proceeds to step S1705. If the information extraction failed, the document identification information extraction unit 507 passes an error message to the process control unit 502, and the process proceeds to step S1706.

In step S1705, the process control unit 502 transmits the document identification information received from the document identification information extraction unit 507 to the verification processing unit 404 via the communication unit 501. If the process control unit 502 receives an error message, in step S1706 it transmits the error message to the verification processing unit 404 via the communication unit 501. After the transmission process to the verification processing unit 404 is completed in step S1705 or step S1706, this flowchart ends.

Figure 18 is a flowchart of the ledger reference process in the blockchain device 112. This flowchart is started when the communication unit 601 receives confirmation of the above-mentioned registration details in the blockchain device 112, and is first executed by the process control unit 602 on the CPU 301. When this flowchart is started, the process control unit 602 receives the ID, authentication information, and document identification information of the service usage credentials from the verification processing unit 404 via the communication unit 601. The process control unit 602 passes the received service usage credentials to the authentication processing unit 604, and step S1801 is executed by the authentication processing unit 604.

In step S1801, the authentication processing unit 604 compares the ID and authentication information of the service usage credentials with the information in the user information DB 605 and determines whether the authentication was successful.

In step S1802, the authentication result is checked, and if authentication is successful, the process proceeds to step S1803. If the process proceeds to step S1803, the process returns to the process control unit 602, which then passes the document identification information received from the verification processing unit 404 to the block data management unit 606, which then executes the block data management unit 606. If authentication is unsuccessful, an error message is passed to the process control unit 602, and the process proceeds to step S1805.

In step S1803, the blockchain managed by the distributed ledger 607 is searched for transactions 701 that include the document identification information received from the process control unit 602. The search results indicate whether the transaction exists and, if so, the information included in the transaction 701. Since the processing in this step is a general blockchain ledger reference process, details will not be explained. The block data management unit 606 passes the search results to the process control unit 602 and proceeds to step S1804.

In step S1804, the process control unit 602 transmits the search results received from the block data management unit 606 to the verification processing unit 404 via the communication unit 601. If the process control unit 602 receives an error message, in step S1805 it transmits the error message to the verification processing unit 404 via the communication unit 601. After the transmission process to the verification processing unit 404 is completed in step S1804 or step S1805, this flowchart ends.

As described above, in Example 1, the print processing unit 402 works in conjunction with the print data generation device 111 and the block chain device 112, enabling authenticity-guaranteed printing by the image forming device 101. Furthermore, the verification processing unit 404 works in conjunction with the print data generation device 111 and the block chain device 112, enabling verification of printed materials obtained by authenticity-guaranteed printing.

[Example 2]
In the first embodiment, the print processing unit 402 cooperates with the print data generation device 111 and the block chain device 112 to perform authenticity-guaranteed printing. Because the print processing unit 402 cooperates with two services, there may be a large amount of processing content involved in communicating with the services and in error handling. The print processing unit 402 operates in an environment prepared by the user, so there may be a need to reduce the amount of processing and minimize the load on the print processing unit 402. Therefore, it is conceivable that the print processing unit 402 communicates only with the print data generation device 111, and the print data generation device 111 communicates with the block chain device 112.

In this embodiment, when performing authenticity-guaranteed printing, the print processing unit 402 provides service usage credentials to the print data generation device 111, and the print data generation device 111 then requests the blockchain device 112 to register the transaction 701.

The credentials managed in the credential DB 405 are the same as in Example 1, and the procedure for issuing credentials is also the same.

Table 4 shows an example of a user information table managed by the user information DB 505 of the print data generating device 111 in this embodiment.

The user information table in Table 4 consists of "ID," "authentication information," "user," "BC ID," and "BC authentication information." "ID," "authentication information," and "user" are the same as those described in Table 2. "BC ID" is user identification information used for authentication when using the blockchain device 112. "BC authentication information" is authentication information used for authentication when using the blockchain device 112.

Next, authenticity-guaranteed printing in this embodiment will be described. An example of a screen when the print processing unit 402 is provided to the user as a virtual driver or print app is the same as that shown in Figure 11. In this embodiment, the sequence of authenticity-guaranteed printing when the print processing unit 402 is provided as a virtual driver will be described.

Figure 19 is a sequence diagram of authenticity-guaranteed printing in this embodiment. This sequence is started when the user presses the print button 1104, and the print processing unit 402, printer driver 403, image forming device 101, print data generation device 111, and blockchain device 112 work together to perform authenticity-guaranteed printing.

In step S1901, the user issues a print instruction to the print processing unit 402 by pressing the print button 1104. Upon receiving the print instruction, the print processing unit 402 requests the print data generation device 111 to perform print data generation processing in step S1902. Upon receiving the request for print data generation processing, the print data generation device 111 performs the print data generation processing and requests the blockchain device 112 to register the transaction 701.

In step S1903, the blockchain device 112 that received the registration request performs transaction registration processing and notifies the print data generation device 111 of the results. Details of the transaction registration processing are the same as those in the flowchart described in Figure 14.

Upon receiving the registration notification from the block chain device 112, the print data generation device transmits the document identification information and print data to the print processing unit 402. Detailed processing by the print data generation device 111 will be described later in FIG. 20. Subsequent steps S1904 and S1905 are the same as steps S1204 and S1205 described in FIG. 12 of the first embodiment.

Figure 20 is a flowchart showing the print data generation process of the print data generation device 111 in this embodiment. This flowchart is started when the communication unit 501 receives the above-mentioned print data generation request in the print data generation device 111, and first the process control unit 502 is executed on the CPU 301. When this flowchart is started, the process control unit 502 receives the ID and authentication information of the service usage credentials of the print data generation device 111 and print data from the print processing unit 402 via the communication unit 501. Optionally, the process control unit 502 also receives the ID and authentication information of the service usage credentials of the block chain device 112 from the print processing unit 402. The process control unit 502 passes the information on the service usage credentials of the print data generation device 111, and, if received, the information on the service usage credentials of the block chain device 112, to the authentication processing unit 504, and the authentication processing unit 504 executes the following process.

In step S2001, the ID and authentication information of the service usage credentials of the print data generating device 111 are compared with the information in the user information DB 505 to determine whether authentication is possible. In step S2002, if authentication is successful, the process proceeds to step S2003. If authentication is unsuccessful, an error message is passed to the processing control unit 502, and the process proceeds to step S2011.

In step S2003, it is confirmed whether the service usage credentials of the blockchain device 112 have been received. If they have been received, proceed to step S2004; if they have not been received, proceed to step S2005.

In step S2004, for the ID authenticated in step S2001, the ID and authentication information of the service usage credentials of the blockchain device 112 are registered as the "BC ID" and "BC authentication information" information described in Table 4. In addition, the "BC ID" and "BC authentication information" are temporarily stored in RAM 303.

In step S2005, it is checked whether the "BC ID" and "BC authentication information" are registered in the user information table for the ID authenticated in step S2001. If they are registered, the "BC ID" and "BC authentication information" are temporarily stored in RAM 303, and the process proceeds to step S2006. If they are not registered, an error message is passed to the process control unit 502, and the process proceeds to step S2011. If the process proceeds to step S2006, the process returns to the process control unit 502, which then passes the print data received from the print processing unit 402 to the document identification information embedding unit 506, and the document identification information embedding unit 506 is executed.

The processing in steps S2006 and S2007 performed by the document identification information embedding unit 506 is the same as steps S1303 and S1304 described in FIG. 13. The document identification information embedding unit 506 passes the document identification information generated in steps S2006 and S2007 and the print data in which that information is embedded to the process control unit 502, and the process control unit 502 performs the following processing.

In step S2008, the document identification information is registered in the blockchain device 112. The "BC ID" and "BC authentication information" stored in RAM 303 in step S2004 or step S2005 are used as authentication information for the blockchain device 112. The processing in the blockchain device 112 in this step is the same as the flowchart explained in Figure 14. The explanation in Figure 14 describes a case where communication is performed with the print processing unit 402, but this can be replaced with the print data generation device 111. In step S2009, a result notification is received from the blockchain device 112, and if registration was successful, the process proceeds to step S2010, or if registration was unsuccessful, the process proceeds to step S2011.

In step S2010, the generated document identification information and the print data in which that information is embedded are sent to the print processing unit 402 via the communication unit 501. In step S2011, an error message is sent to the print processing unit 402 via the communication unit 501. After the transmission process to the print processing unit 402 is completed in step S2010 or step S2011, this flowchart ends.

Verification of printed matter can be performed using the same method as described in Example 1 or the same method as the verification in Example 3 described below.

As described above, in this embodiment, the print processing unit 402 communicates only with the print data generation device 111. This enables authenticity-guaranteed printing with less processing by the print processing unit 402 than in embodiment 1.

[Example 3]
In Example 2, the print processing unit 402 possessed service usage credentials for the blockchain device 112, but since the print processing unit 402 does not directly use the blockchain device 112, there may be cases where it does not possess service usage credentials for the blockchain device 112.

In this embodiment, when performing authenticity-guaranteed printing, the print data generation device 111 uses the service usage credentials of the blockchain device 112 that it manages to register a transaction 701 in the blockchain device 112.

In this embodiment, the credential DB 405 does not manage the service usage credentials of the blockchain device 112, but manages the common credentials in the same manner as in embodiment 1. The credential information table in the credential DB 405 has the same configuration as Table 1.

The structure of the user information table in the user information DB 505 of the print data generating device 111 is the same as Table 4. In this embodiment, unlike in embodiment 2, the "BC ID" and "BC authentication information" are registered when credentials are issued.

We will now explain how to issue credentials in this embodiment. The screen displayed when issuing credentials is the same as shown in Figure 8 above.

Figure 21 is a sequence diagram for issuing credentials in this embodiment. This sequence is initiated when the user presses the aforementioned issue button 804, and the print processing unit 402, print data generation device 111, and blockchain device 112 work together to perform processing, allowing the print processing unit 402 to obtain service usage credentials.

In step S2101, the user presses the issue button 804 to issue service usage credentials. Upon receiving the service usage credentials, the print processing unit 402 requests the print data generation device 111 to issue the credentials in step S2102.

In step S2102, the print data generation device 111, which has received the issuance request, performs the process of issuing the service usage credentials. In this step, the print data generation device 111 performs the processes from step S1001 to step S1005 described in Figure 10. Through this process, the generated ID, authentication information, and the acquired user are registered in the user information table in Table 4. After that, the block chain device 112 is requested to perform the credential issuance process in step S2103.

In step S2103, the blockchain device 112, which has received the request for credential issuance processing, issues a service usage credential and provides the issued credential to the print data generation device 111. Details of the processing in this step are the same as those in the flowchart described in Figure 10.

In step S2104, the print data generation device 111 that received the service usage credentials registers the ID and authentication information of the received credentials as the "BC ID" and "BC authentication information" of the service usage credentials issued in step S2102. Then, the "ID" and "authentication information" of the service usage credentials issued in step S2102 are sent to the print processing unit 402. In this embodiment, as described above, the print processing unit 402 does not communicate with the blockchain device 112, and therefore the credentials provided to the print processing unit 402 do not include the credentials of the blockchain device 112.

In step S2105, the print processing unit 402 stores the received service usage credentials in the credential DB 405. In step S2106, the print processing unit 402 notifies the user of the result of the credential issuance and ends this sequence. To notify the user, a message indicating successful issuance and an error message received from the device are displayed in a dialog. The dialogs used for these notifications are standard dialogs provided by the OS, so a description thereof will be omitted.

Next, authenticity-guaranteed printing in this embodiment will be described. An example of a screen when the print processing unit 402 is provided to the user as a virtual driver or print app is the same as in Figure 11. The sequence of authenticity-guaranteed printing is the same as in Figure 19. The processing of the print data generation device 111 differs from the processing of Figure 20 described in Example 2 in that, as credential registration in the blockchain device 112 is completed when the credential is issued as described above, steps S2003 and S2004 are not performed. The processing of the print data generation device 111 in this embodiment will be described below using figures.

Figure 22 is a flowchart showing the print data generation process of the print data generation device 111 in this embodiment. This flowchart is started when the communication unit 501 receives a print data generation request in the print data generation device 111, and first the process control unit 502 is executed on the CPU 301. When this flowchart is started, the process control unit 502 receives the ID and authentication information of the service usage credentials of the print data generation device 111, and print data from the print processing unit 402 via the communication unit 501. The process control unit 502 passes the information of the service usage credentials of the print data generation device 111 to the authentication processing unit 504, and the following process is executed by the authentication processing unit 504.

In step S2201, the ID and authentication information of the service usage credentials of the print data generating device 111 are compared with the information in the user information DB 505 to determine whether authentication is possible. In step S2202, the authentication result is confirmed, and if authentication is successful, the process proceeds to step S2203; if authentication is unsuccessful, an error message is passed to the processing control unit 502 and the process proceeds to step S2209.

In step S2203, it is checked whether the "BC ID" and "BC authentication information" are registered in the user information table for the ID authenticated in step S2201. If they are registered, the "BC ID" and "BC authentication information" are temporarily stored in RAM 303 and the process proceeds to step S2204. If they are not registered, an error message is passed to the process control unit 502 and the process proceeds to step S2209.

The processing in steps S2204 to S2209 is the same as that in steps S2006 to S2011. To authenticate the blockchain device 112 in step S2206, the "BC ID" and "BC authentication information" temporarily stored in RAM 303 in step S2203 are used.

Next, we will explain how to verify printed materials in this embodiment. The verification screen is the same as that described in Figure 15 of Example 1.

Figure 23 is a sequence diagram of verification in this embodiment. This sequence is started by pressing one of the verification buttons 1503/1517/1520, and performs verification through cooperation between the verification processing unit 404, print data generation device 111, and blockchain device 112.

In step S2301, pressing one of the verification buttons 1503/1517/1520 instructs the verification processing unit 404 to perform verification. In step S2302, upon receiving the verification instruction, the verification processing unit 404 reads the specified file or a captured image. The electronic data obtained by reading it is passed to the print data generation device 111, and a request is made to perform information extraction processing.

In step S2303, the print data generation device 111, which has received the verification request, performs an information extraction process and confirms the registered contents of the extracted document identification information with the blockchain device 112. Details of the information extraction process are the same as those described in Figure 17.

In step S2304, the blockchain device 112, having received confirmation of the registration contents from the verification processing unit 404, references the distributed ledger 607 and transmits the reference results to the print data generation device 111. Details of the ledger reference process are the same as those described in Figure 18. The print data generation device 111, having received the reference results of the distributed ledger 607 from the blockchain device 112, transmits the presence or absence of registration and the registration contents as verification results to the verification processing unit 404.

In step S2305, the verification processing unit 404 receives the verification results from the print data generation device 111, displays the verification results to the user on a screen like the one shown in Figure 15(b), and ends this sequence. Errors in this sequence are displayed using a dialog box that the OS provides as standard (not shown).

As a result, the print processing unit 402 and verification processing unit 404 can perform authenticity-guaranteed printing and verification without managing the service usage credentials of the blockchain device 112.

[Example 4]
In Examples 1 to 3, the print data generation device 111 issues and extracts document identification information and embeds it in the print data, but it is possible to consider a case where the blockchain device 112 issues and extracts document identification information and embeds it in the print data.

In this embodiment, we will explain a case where the print data generation device 111 is not provided, and the blockchain device 112 issues and extracts document identification information and embeds it in the print data. Since the print processing unit 402 and verification processing unit 404 communicate only with the blockchain device 112, the credential DB 405 only manages the common credentials and service usage credentials issued by the blockchain device 112.

For issuing credentials, the same procedure as in Example 1 is performed only for the blockchain device 112. In this example, the credential selection field 803 for the print data generation service is not required on the installer screen in Figure 8.

In authenticity-guaranteed printing in this embodiment, the processing by the print data generation device 111 described in step S1202 of FIG. 12 is not performed, and the print processing unit 402 requests the blockchain device 112 to register the transaction 701. At this time, the print processing unit 402 sends the print data and a registration instruction to the blockchain device 112. Details of the processing in step S1203 by the blockchain device 112 that receives the registration request will be explained in FIG. 24 below. After processing in step S1203, the blockchain device 112 sends the print data with embedded document identification information to the print processing unit 402. The subsequent processing from the print instruction to the printer driver 403 is the same as in embodiment 1.

Figure 24 is a flowchart showing the transaction registration process of the blockchain device 112 in this embodiment. This flowchart is started when the communication unit 601 receives the above-mentioned registration request, and is first executed by the processing control unit 602 on the CPU 301. When this flowchart is started, the processing control unit 602 receives the ID of the service usage credential, authentication information, and print data from the print processing unit 402 via the communication unit 601. The processing control unit 602 passes the received service usage credential to the authentication processing unit 604, and step S2401 is executed by the authentication processing unit 604.

In step S2401, the authentication processing unit 604 compares the ID and authentication information of the service usage credentials with the information in the user information DB 605 and determines whether the authentication was successful. If the comparison is successful, the information of the user of the service usage credentials is obtained from the user information DB 605 and temporarily stored in RAM 303.

In step S2402, the authentication result is confirmed, and if authentication is successful, the process proceeds to step S2403. If the process proceeds to step S2403, the process returns to the process control unit 602, which then passes the print data received from the print processing unit 402 to the block data management unit 606, which then executes the block data management unit 606. If authentication is unsuccessful, an error message is passed to the process control unit 602, and the process proceeds to step S2410.

In step S2403, document identification information is generated using the same method as the processing described in step S1303 of Figure 13. In step S2404, if the generated document identification information has already been registered in the distributed ledger 607, registration is deemed impossible and the process returns to the generation of document identification information in step S2403, where the document identification information is regenerated. If the generated document identification information has not been registered in the distributed ledger 607, registration is deemed possible and the process proceeds to step S2405.

In step S2405, document identification information is embedded in the print data using a method similar to the processing described in step S1304 of Figure 13. The processing in steps S2406 and S2407 is similar to that in steps S1404 and S1405 of Figure 14.

In step S2408, if block generation is successful, the process is passed to the process control unit 602 along with the print data in which information was embedded in step S2405, and the process proceeds to step S1407. If the process fails, an error message is passed to the process control unit 602, and the process proceeds to step S2410.

In step S2409, the process control unit 602 transmits the print data to the print processing unit 402 via the communication unit 601. If the process control unit 602 receives an error message, in step S2410 it transmits the error message to the print processing unit 402 via the communication unit 601. After the transmission process to the print processing unit 402 is completed in step S2409 or step S2410, this flowchart ends.

Next, we will explain how to verify printed materials in this embodiment. As with Example 1, we assume that printed materials have been converted into electronic data in advance. The verification screen is the same as that described in Figure 15 of Example 1.

The verification sequence will be explained, focusing on the differences from Example 1. The processing in the print data generation device 111 described in step S1603 of Figure 16 is not performed, and the verification processing unit 404 requests verification from the blockchain device 112. At this time, the verification processing unit 404 sends the file data read in S1602 to the blockchain device 112. The processing of the blockchain device 112 that receives the verification request will be explained using Figure 25.

Figure 25 is a flowchart of verification in this embodiment. This flowchart is started when the communication unit 601 receives the above-mentioned verification request in the blockchain device 112, and is first executed by the processing control unit 602 on the CPU 301. When this flowchart is started, the processing control unit 602 receives the ID and authentication information of the service usage credential and the data to be verified from the verification processing unit 404 via the communication unit 601. The processing control unit 602 passes the received service usage credential to the authentication processing unit 604, and step S2501 is executed by the authentication processing unit 604.

In step S2501, the authentication processing unit 604 compares the ID and authentication information of the service usage credentials with the information in the user information DB 605 and determines whether the authentication was successful.

In step S2502, the authentication result is checked, and if authentication is successful, the process proceeds to step S2503. If the process proceeds to step S2503, the process returns to the processing control unit 602, which then passes the data received from the verification processing unit 404 to the block data management unit 606, which then executes the block data management unit 606. If authentication is unsuccessful, an error message is passed to the processing control unit 602, and the process proceeds to step S2507.

In step S2503, the block data management unit 606 extracts the document identification information embedded in the data. In step S2504, the success or failure of the information extraction is confirmed. If the information extraction is successful, the process proceeds to step S2505. If the information extraction is unsuccessful, the block data management unit 606 passes an error message to the process control unit 602 and the process proceeds to step S2507.

In step S2505, the blockchain managed by the distributed ledger 607 is searched for transactions 701 that include the document identification information extracted in step S2503. The search results indicate whether the transaction exists and, if so, the information included in the transaction 701. Since the processing in this step is a general blockchain ledger reference process, details will not be explained. The block data management unit 606 passes the search results to the processing control unit 602 and proceeds to step S2506.

In step S2506, the processing control unit 602 transmits the search results received from the block data management unit 606 to the verification processing unit 404 via the communication unit 601. If the processing control unit 602 receives an error message, in step S2507 it transmits the error message to the verification processing unit 404 via the communication unit 601. After the transmission process to the verification processing unit 404 is completed in step S2506 or step S2507, this flowchart ends.

As described above, Example 4 has been shown as an example that can achieve the same effects as Example 1 without using a print data generation device 111.

[Other Examples]
In the first to fourth embodiments, when the print processing unit 402 is provided as a virtual driver, the virtual driver instructs the printer driver 403 to print, and the printer driver 403 generates a print job and transmits the print job to the image forming apparatus 101. The present invention can also be realized by implementing the printer driver 403 so that it has the functions of the print processing unit 402, and distributing the printer driver 403 to the user as a new driver or as an update.

The present invention can also be realized by performing the following process. That is, software (programs) that realize the functions of the above-described embodiments are supplied to a system or device via a network or various storage media. The computer (or CPU or MPU) of that system or device then reads and executes the program.

According to the embodiment described above, a service that provides the function of generating print data for authenticity assurance can be prepared, and an authenticity assurance service can be provided by an app or printer driver that works in conjunction with that service and the blockchain service.

Claims (5)

A system comprising an information processing device and a blockchain device,
the information processing device has a virtual driver and a printer driver,
The virtual driver
an embedding instruction means for instructing an external device to embed identification information in print data;
a receiving means for receiving, from the external device, identification information relating to the print data and the print data in which the identification information is embedded;
a registration instruction means for instructing the block chain device to register identification information related to the print data in a transaction, and causing the information processing device to execute the registration instruction means;
The printer driver
causing the information processing device to execute a transmission means for transmitting a print job of print data in which the identification information is embedded, received from the external device, to an image forming device;
The blockchain device is
a registration means for generating a transaction based on the identification information and registering it in a block;
A system characterized in that the virtual driver and the printer driver work together to generate a printed material and register blocks related to the generated printed material with a single print instruction from the user. The information processing device further comprises:
The system described in claim 1, characterized in that it has an inquiry means for inquiring of the blockchain device whether identification information extracted from scanned data of a printed material is registered in a block. The information processing device further comprises:
3. The system according to claim 2, further comprising extraction instruction means for instructing the external device to extract identification information from data obtained by scanning a printed material. A system as described in any one of claims 1 to 3, characterized in that after it is confirmed that the transaction has been registered in a block by instruction from the registration instruction means, the sending means, which receives an instruction sent from the virtual driver, sends a print job of the print data in which the identification information is embedded to the image forming device. The information processing device further comprises:
The system described in claim 4, characterized in that it has a management means for managing a first credential used to authenticate the external device and a second credential used to authenticate the blockchain device.