Print data validity verification method and printing system

Abstract

To generate a print data file for variable printing using personal information, and then verify the validity of contents of each piece of variable data included in the print data file without using the personal information.SOLUTION: On a PDF generation side, for each record, variable data of a use field is extracted from a variable data file and a first hash value is calculated according to a predetermined calculation rule (S100). Also, on the PDF generation side, the variable data of the use field in the variable data file is arranged on a corresponding page to generate a print data file (S200). Thereafter, on an inspection side, the variable data is extracted from the print data file and a second hash value is calculated according to the predetermined calculation rule, and it is inspected whether or not the second hash value matches the first hash value calculated on the PDF generation side (S300).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for verifying the validity of data included in a print data file for variable printing. [Background technology]

[0002] In recent years, variable printing, which prints different content on each page of a specified format, such as for printing invoices or direct mail, has become popular. When performing variable printing, an operator first creates a template that specifies the content to be printed on all pages and the placement of variable data, which can vary in content (data values) from page to page. A variable data file containing multiple records of variable data is then prepared, and a submission data file for variable printing is generated by arranging each variable data item in the variable data file on a page based on the template. A CSV file, a text data file in which multiple pieces of text data are separated by commas (,), is typically used as the variable data file.

[0003] Incidentally, PDF files (Portable Document Format files) are sometimes used to submit print data to printing companies. Submitting print data as a PDF file is called "PDF submission." PDF submission offers the advantages of reducing the possibility of printing problems such as layout corruption and reducing the size of the submitted data. Therefore, PDF submission is sometimes used when performing the variable printing mentioned above. In the following, PDF files used as submission data files for variable printing will be referred to as "variable PDF files."

[0004] The generation of a variable PDF file will be explained with reference to Figure 26. Note that here, an example will be given in which a CSV file is used as the variable data file, and in addition to the variable data contained in the CSV file, an image is also placed on each page. In the following explanation of the variable data file (CSV file), a field named "Z" will be referred to as the "Z field." For example, a field named "Address" will be referred to as the "Address field."

[0005] 26, the variable data file 91 contains variable data for multiple records. The name of each field is written on the first line. Each record is made up of multiple variable data such as name and address. In this example, three images 92(1) to 92(3) are prepared. Each record is associated with one of the three images 92(1) to 92(3) by the image field of the variable data file 91. When the process of generating the variable PDF file 93 starts, first, the variable data of the first record (the record whose number field data value is "1") in the variable data file 91 is arranged on the first page based on the template, and image 92(1) is arranged on the first page based on the template and the data value of the image field of the first record in the variable data file 91. Next, the variable data of the second record (the record whose number field data value is "2") in the variable data file 91 is arranged on the second page based on the template, and image 92(3) is arranged on the second page based on the template and the data value of the image field of the second record in the variable data file 91. Thereafter, the same process is repeated up to the last record in the variable data file 91. This completes the generation of the variable PDF file 93. Note that the contents of the variable PDF file 93 are shown in schematic form in FIG.

[0006] A variable PDF file is generated as described above. However, because personal information is printed during variable printing, it is important to verify the validity of the content of the variable PDF file. This is because it is necessary to prevent unacceptable events, such as a printed document with a person's personal information being sent to another person or an invoice with an incorrect amount being sent to a customer. In the example of variable PDF file 93 shown in Figure 26, as shown in Figure 27, it is necessary to verify whether the name is printed correctly (see the arrow marked with symbol 95), whether the address is printed correctly (see the arrow marked with symbol 96), and whether the image is printed correctly (see the arrow marked with symbol 97).

[0007] Three conventional methods (first to third conventional methods) for verifying the validity of the contents of a variable PDF file are described below. Note that the first conventional method and the second conventional method are often used together.

[0008] The first conventional method is a method that uses barcodes. In this method, when generating a variable PDF file, the variable data to be placed on each page is converted into a barcode, and the barcode is embedded in the variable PDF file. Then, during verification, the data value obtained by decoding the barcode embedded in the variable PDF file is compared with the data value contained in the variable data file from which the variable PDF file was generated. Note that QR codes (a registered trademark in Japan) are sometimes used instead of barcodes.

[0009] The second conventional method is a visual comparison. In this method, the contents of the variable PDF file and the contents of the variable data file from which the variable PDF file was generated are displayed on a computer display, and the two are compared visually. Sometimes, one file is printed and the printed copy is compared visually with the display screen, or both files are printed and the printed copies are compared visually.

[0010] The third conventional method is to extract variable data (typically character strings) from a variable PDF file. In this method, the variable data located on each page of the variable PDF file is extracted, and the data values ​​of the extracted variable data are compared with the data values ​​contained in the variable data file from which the variable PDF file was generated.

[0011] In relation to the present invention, Japanese Patent Application Laid-Open No. 2013-156907 discloses a printing system that can prevent the creation of unintended prints when variable printing is performed. According to this system, authentication information is added to the variable data when variable print data is generated, and the printing device detects the authentication information from the variable data and determines whether the variable data is legitimate based on the authentication information. Then, only if the variable data is determined to be legitimate is printing performed based on composite data obtained by combining the variable data and format data. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-156907 Summary of the Invention [Problem to be solved by the invention]

[0013] The first and third conventional methods compare variable data (typically character strings) without relying on layout information, making it impossible to detect errors such as placing a phone number where an address should be (column misalignment in a CSV file serving as a variable data file). The second conventional method raises concerns about long verification times and the possibility of overlooking errors. Furthermore, all of the first to third conventional methods require the variable data file from which the variable PDF file was generated to verify the validity of the content of the variable PDF file. Because the variable data file contains personal information, there is a high security risk, such as the leakage of personal information. Thus, the conventional methods (the first to third conventional methods) require personal information for verification, resulting in a high security risk. While the invention disclosed in Japanese Patent Laid-Open Publication No. 2013-156907 does not require personal information to determine whether the variable data is authentic, it does not guarantee that the data values ​​of each variable data included in the variable print data match the data values ​​of the corresponding data from the variable print data generator. In other words, the validity of the content of each variable data is not guaranteed.

[0014] Therefore, the present invention aims to enable verification of the validity of the contents of each variable data contained in a print data file for variable printing (typically, a variable PDF file) after generating the print data file using personal information, without using personal information. [Means for solving the problem]

[0015] A first invention is a method for verifying the validity of data included in a print data file for performing variable printing based on variable data whose data value may differ for each page and fixed data that is common to all pages, using a computer, comprising: a hash value calculation step of extracting variable data for a usage field that is a field used for variable printing from a variable data collection that stores the variable data for each of a plurality of records, and calculating a first hash value using the extracted variable data in accordance with a predetermined calculation rule; a print data file generating step of arranging the variable data for the used fields in the variable data collection for each of the plurality of records on a corresponding page based on layout information that associates field names with coordinates, and generating the print data file including information on the variable data arranged on each page; a print data file inspection step of extracting the variable data from the print data file based on the used field information and the layout information for each of the plurality of records, calculating a second hash value using the extracted variable data in accordance with the predetermined calculation rule, and inspecting whether the second hash value matches the first hash value; Including, The print data file inspection step is performed by a second computer different from a first computer that performs the hash value calculation step and the print data file generation step.

[0016] The second invention is the first invention, In the hash value calculation step, a hash value file is generated that includes information on the used fields and the first hash value for each of the plurality of records; In the print data file generating step, the layout information is included in the print data file as metadata; The hash value file and the print data file are transmitted separately from the first computer to the second computer.

[0017] The third invention is the first invention, In the print data file generation step, the layout information, the information on the used fields, and the first hash value for each of the plurality of records calculated in the hash value calculation step are included in the print data file as metadata.

[0018] The fourth invention is the first invention, information on the used field is transmitted from the first computer to the second computer; When the second hash value is calculated in the print data file inspection step, the predetermined calculation rule is derived from information in the used field.

[0019] The fifth invention is the first invention, A plurality of fields are set as the used fields, The hash value calculation step a variable data reading step of reading the variable data in the variable data collection; a used field information acquisition step of acquiring information on the used field; a string generation step of generating a string by combining the variable data for the plurality of fields in the variable data collection based on the information of the used fields; a calculation step of calculating a hash value of the character string generated in the character string generation step as the first hash value; The present invention is characterized by comprising:

[0020] The sixth invention is the fifth invention, the hash value calculation step further includes a sorting step of sorting the plurality of fields using field names as keys after the used field information acquisition step, In the character string generating step, the variable data for the plurality of fields is combined in the order of the plurality of fields after being sorted in the sorting step.

[0021] The seventh invention is the first invention, In the hash value calculation step, the first hash value is calculated using the extracted variable data and coordinates associated with each field by the layout information.

[0022] The eighth invention is the first invention, In the hash value calculation step, in addition to the variable data for the used field, the variable data for an unused field that is a field not used for variable printing is extracted, and the first hash value is calculated using the variable data for the used field and the variable data for the unused field; In the print data file generating step, the variable data for the unused fields is included in the print data file; In the print data file inspection step, the second hash value is calculated using the variable data for the used field extracted from the print data file and the variable data for the unused field extracted from the print data file.

[0023] A ninth aspect of the present invention is the first aspect of the present invention, In the hash value calculation step, the first hash value is calculated for each field, In the print data file inspection step, the second hash value is calculated for each field, and it is inspected whether or not the second hash value matches the first hash value for each field.

[0024] A tenth aspect of the present invention is the ninth aspect of the present invention, If a field in which the second hash value and the first hash value do not match is found in the print data file inspection step, the second computer outputs a message identifying the field in which the second hash value and the first hash value do not match.

[0025] An eleventh aspect of the present invention is the first aspect of the present invention, A field for storing character data, a field for storing numeric data, and a field associated with image data and for storing the file name of the image data can be set as the use field.

[0026] A twelfth invention is any one of the first to eleventh inventions, The print data file is a portable document format file.

[0027] The thirteenth invention is any one of the first to eleventh inventions, The variable data collection is characterized in that it is a text data file.

[0028] A fourteenth aspect of the present invention is a method for verifying, using a computer, the validity of data included in a print data file for performing variable printing based on variable data whose data value may differ for each page and fixed data that is common to all pages, the method comprising: a checksum calculation step of extracting variable data for a usage field that is a field used for variable printing from a variable data collection that stores the variable data for each of a plurality of records, and calculating a first checksum using the extracted variable data in accordance with a predetermined calculation rule; a print data file generating step of arranging the variable data for the used fields in the variable data collection for each of the plurality of records on a corresponding page based on layout information that associates field names with coordinates, and generating the print data file including information on the variable data arranged on each page; a print data file inspection step of extracting the variable data from the print data file based on the used field information and the layout information for each of the plurality of records, calculating a second checksum using the extracted variable data in accordance with the predetermined calculation rule, and inspecting whether the second checksum matches the first checksum; Including, The print data file checking step is performed by a second computer different from the first computer that performs the checksum calculation step and the print data file generation step.

[0029] A fifteenth aspect of the present invention is a printing system capable of performing variable printing based on variable data whose data value may differ for each page and fixed data that is common to all pages, comprising: a first computer that performs a hash value calculation process that extracts, for each of a plurality of records, variable data for a used field that is a field used in variable printing from a variable data collection that stores the variable data, and calculates a first hash value using the extracted variable data in accordance with a predetermined calculation rule; and a print data file generation process that arranges, for each of the plurality of records, the variable data for the used field in the variable data collection on a corresponding page based on layout information that associates field names with coordinates, and generates a print data file that includes information on the variable data arranged on each page; a second computer that performs a print data file inspection process for extracting the variable data from the print data file based on the used field information and the layout information for each of the plurality of records, calculating a second hash value using the extracted variable data in accordance with the predetermined calculation rule, and inspecting whether the second hash value matches the first hash value; The present invention is characterized by comprising: [Effects of the Invention]

[0030] According to the first aspect of the present invention, a first computer calculates a first hash value in accordance with a predetermined calculation rule using variable data for a used field in a variable data collection (e.g., a text data file or a database). A print data file containing information on the variable data arranged on each page is generated in the first computer. A second computer calculates a second hash value in accordance with the same calculation rule as that used to calculate the first hash value, using variable data extracted from the print data file generated in the first computer. The second computer checks whether the second hash value matches the first hash value calculated in the first computer for each of a plurality of records. The data (data value of the used field) from which the first hash value was generated cannot be restored from the first hash value. The second computer does not use a variable data collection to calculate the second hash value. In other words, personal information is not used to calculate the second hash value in the second computer. The variable data collection is not required to check whether the second hash value matches the first hash value. In this way, the process performed by the second computer to verify the validity of the content of each variable data included in the print data file does not require a variable data collection. As a result, after generating a print data file using personal information, it is possible to verify the validity of the content of each variable data included in the print data file without using personal information.

[0031] According to the second aspect of the present invention, the process of generating the hash value file is separated from the process of generating the print data file, thereby reducing the possibility of problems occurring when generating the first hash value.

[0032] According to the third aspect of the present invention, the number of files that need to be transmitted from the first computer to the second computer is reduced, making operation easier.

[0033] According to the fourth aspect of the present invention, it is possible to calculate the second hash value according to the same calculation rule as that used when calculating the first hash value, without requiring complex processing.

[0034] According to the fifth aspect of the present invention, one first hash value is calculated for each record, so that it is possible to determine the validity of the contents of the print data file for each record.

[0035] According to the sixth aspect, the amount of information to be transmitted from the first computer to the second computer can be reduced.

[0036] According to the seventh aspect, it is possible to verify the validity of the layout position of variable data on a page that constitutes a print data file.

[0037] According to the eighth aspect of the present invention, it is possible to more accurately verify the validity of the contents of each variable data included in the print data file.

[0038] According to the ninth aspect, it is possible to verify the validity of the contents of the variable data for each field.

[0039] According to the tenth aspect, when invalid data is included in a print data file, the user can easily identify the invalid data.

[0040] According to the eleventh aspect, it is possible to verify the validity of character data, numeric data, and image data in the contents of the print data file without using personal information.

[0041] According to the twelfth invention, after generating a PDF file (portable document format file) as a print data file using personal information, it becomes possible to verify the validity of the contents of each variable data included in the PDF file without using personal information.

[0042] According to the thirteenth aspect of the present invention, the same effects as those of the first aspect of the present invention can be obtained.

[0043] According to the fourteenth aspect of the present invention, the same effects as those of the first aspect of the present invention can be obtained.

[0044] According to the fifteenth aspect of the present invention, the same effects as those of the first aspect of the present invention can be obtained. [Brief explanation of the drawings]

[0045] [Figure 1] 1 is a block diagram showing the overall configuration of a printing system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing a hardware configuration of a computer that functions as a variable PDF generation device or a variable PDF inspection device in the first embodiment. [Figure 3] FIG. 2 is a diagram for explaining a functional configuration in the first embodiment. [Figure 4] 10 is a flowchart showing an outline of a series of processes relating to verification of the validity of print data in the first embodiment. [Figure 5] FIG. 10 is a diagram showing an example of a variable data file in the first embodiment. [Figure 6] FIG. 2 is a diagram schematically showing the contents of a hash value file in the first embodiment. [Figure 7] FIG. 10 is a diagram showing an example of a print result when printing is performed based on a variable PDF file in the first embodiment. [Figure 8] FIG. 2 is a diagram showing an example of a template in the first embodiment. [Figure 9] FIG. 2 is a diagram for explaining the configuration of a variable PDF file in the first embodiment. [Figure 10] 10 is a flowchart showing a detailed procedure of a first hash value calculation process in the first embodiment. [Figure 11]FIG. 10 is a diagram for explaining sorting of used fields in the first embodiment. [Figure 12] FIG. 10 is a diagram for explaining string joining in the first embodiment. [Figure 13] 10 is a flowchart showing a detailed procedure of a variable PDF file generation process in the first embodiment. [Figure 14] FIG. 2 is a block diagram for illustrating details of a variable PDF inspection unit in the first embodiment. [Figure 15] 10 is a flowchart showing a detailed procedure of a variable PDF file inspection process in the first embodiment. [Figure 16] FIG. 10 is a diagram illustrating a functional configuration according to a second embodiment of the present invention. [Figure 17] FIG. 11 is a diagram for explaining the configuration of a variable PDF file in the second embodiment. [Figure 18] 10 is a flowchart showing an outline of a series of processes relating to verification of the validity of print data in the second embodiment. [Figure 19] 10 is a flowchart showing a detailed procedure of a variable PDF file generation process in the second embodiment. [Figure 20] FIG. 11 is a block diagram for illustrating details of a variable PDF inspection unit in the second embodiment. [Figure 21] FIG. 13 is a diagram schematically showing the contents of a hash value file in a third modified example. [Figure 22] FIG. 13 is a diagram showing an example of a print result when printing is performed based on a variable PDF file in a fourth modified example. [Figure 23] FIG. 13 is a diagram showing an example of a variable data file in the fourth modified example. [Figure 24] FIG. 13 is a diagram for explaining sorting of used fields in the fourth modified example. [Figure 25]FIG. 13 is a diagram illustrating character string concatenation in the fourth modified example. [Figure 26] FIG. 10 is a diagram illustrating generation of a variable PDF file in a conventional example. [Figure 27] FIG. 10 is a diagram illustrating verification of the validity of the contents of a variable PDF file in a conventional example. DETAILED DESCRIPTION OF THE INVENTION

[0046] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the printing system according to each embodiment, variable printing is performed based on variable data whose data value can vary from page to page and fixed data that is common to all pages.

[0047] <1. First embodiment> <1.1 Overall configuration of the printing system> FIG. 1 is a block diagram showing the overall configuration of a printing system according to a first embodiment of the present invention. This printing system includes a variable PDF generation device 10 that generates a variable PDF file, which is a print data file for variable printing and is a portable document format file; a variable PDF inspection device 20 that checks (verifies) the validity of the data in the variable PDF file; a RIP device 30 that performs RIP processing on the print data that constitutes the variable PDF file; and an inkjet printing device 40 that prints based on the print data after RIP processing by the RIP device 30. The variable PDF generation device 10, the variable PDF inspection device 20, the RIP device 30, and the inkjet printing device 40 are connected to each other via a LAN 5. The variable PDF generation device 10 serves as a first computer, and the variable PDF inspection device 20 serves as a second computer.

[0048] As mentioned above, personal information is used in variable printing. Since personal information cannot be leaked to the public, this printing system allows only specific individuals to use the personal information. Specifically, personal information can be used on the PDF generation side in FIG. 1, but not on the inspection side in FIG. 1. In other words, personal information can only be used in the variable PDF generation device 10.

[0049] In this printing system, the variable PDF file generated by the variable PDF generation device 10 is transmitted to the variable PDF inspection device 20 via the LAN 5, but the present invention is not limited to this. For example, the variable PDF file generated by the variable PDF generation device 10 may be stored in a file server via the LAN 5, and then the variable PDF inspection device 20 may obtain the variable PDF file from the file server via the LAN 5. Also, a configuration in which the variable PDF generation device 10 and the variable PDF inspection device 20 are not connected via the LAN 5 may be adopted. In such a configuration, the variable PDF file generated by the variable PDF generation device 10 may be provided to the variable PDF inspection device 20 via, for example, a communication line other than the LAN 5 (such as a dedicated line or the Internet) or a computer-readable recording medium such as a DVD-ROM.

[0050] <1.2 Computer hardware configuration> FIG. 2 is a block diagram showing the hardware configuration of a computer 500 functioning as the variable PDF generation device 10 or the variable PDF inspection device 20. The computer 500 shown in FIG. 2 includes a main body 510, an auxiliary storage device 521, an optical disk drive 522, a display unit 523, a keyboard 524, and a mouse 525. The main body 510 includes a CPU 511, a memory 512, a first disk interface unit 513, a second disk interface unit 514, a display control unit 515, an input interface unit 516, and a network interface unit 517. The CPU 511, the memory 512, the first disk interface unit 513, the second disk interface unit 514, the display control unit 515, the input interface unit 516, and the network interface unit 517 are connected to one another via a system bus. The auxiliary storage device 521 is connected to the first disk interface unit 513. The auxiliary storage device 521 is a magnetic disk device or the like. The optical disk drive 522 is connected to the second disk interface unit 514. An optical disk 59 serving as a computer-readable recording medium such as a CD-ROM or DVD-ROM is inserted into the optical disk drive 522. A display unit (display device) 523 is connected to the display control unit 515. The display unit 523 is a liquid crystal display or the like. The display unit 523 is used to display information desired by the operator. A keyboard 524 and a mouse 525 are connected to the input interface unit 516. The keyboard 524 and the mouse 525 are used by the operator to input instructions to the computer 500. The network interface unit 517 is connected to the LAN 5.

[0051] The auxiliary storage device 521 stores programs to be executed by the computer 500. The CPU 511 realizes various functions by reading the programs stored in the auxiliary storage device 521 into the memory 512 and executing them. The memory 512 includes a RAM and a ROM. The memory 512 functions as a work area for the CPU 511 to execute the programs stored in the auxiliary storage device 521. The programs are provided by being stored in, for example, the computer-readable recording medium (non-transitory recording medium). In this embodiment, the auxiliary storage device 521 of the computer 500 functioning as the variable PDF generation device 10 stores a variable PDF file generation program and a hash value calculation program, and the auxiliary storage device 521 of the computer 500 functioning as the variable PDF inspection device 20 stores a variable PDF file inspection program. The processes realized by executing the variable PDF file generation program, the hash value calculation program, and the variable PDF file inspection program will be described later.

[0052] <1.3 Verification method for print data validity> <1.3.1 Overview> In this printing system, as shown in Figure 3, functional components involved in verifying the validity of print data include a variable PDF generation unit 11 and a first hash value calculation unit 12 on the PDF generation side, and a variable PDF inspection unit 21 on the inspection side. Below, a summary of the steps in a series of processes involved in verifying the validity of print data will be explained with reference to the flowchart shown in Figure 4. Note that this embodiment assumes that a CSV file is used as a variable data file that stores multiple records of variable data used for variable printing. It is also assumed that this embodiment assumes that fields that store character data and fields that store numeric data can be set as used fields (fields used for variable printing among the fields that make up the variable data file 110).

[0053] First, on the PDF generation side, the first hash value calculation unit 12 performs a first hash value calculation process (step S100). The first hash value calculation process is realized by the CPU 511 in the computer 500 functioning as the variable PDF generation device 10 executing a hash value calculation program. For each of a plurality of records included in the variable data file 110 storing variable data, the first hash value calculation unit 12 extracts variable data for the used fields in the variable data file 110 based on layout information 120 that associates the names of the used fields with coordinates on the pages constituting the variable PDF file 140, and calculates a hash value using the extracted variable data in accordance with a predetermined calculation rule. There are various types of hash functions for calculating hash values, but for example, SHA-256 (Secure Hash Algorithm 256-bit) can be used. For convenience, the hash value calculated by the first hash value calculation unit 12 is referred to as the "first hash value." The first hash value calculation unit 12 also generates a hash value file 150 that compiles the first hash values ​​calculated for each of the multiple records and information on the fields used.

[0054] Next, on the PDF generation side, variable PDF generation unit 11 performs variable PDF file generation processing (print data file generation processing) (step S200). The variable PDF file generation processing is realized by CPU 511 in computer 500 functioning as variable PDF generation device 10 executing a variable PDF file generation program. Based on variable data file 110, the above-mentioned layout information 120, and template 130 that defines the content to be printed commonly on all pages and the layout position of the variable data, variable PDF generation unit 11 arranges variable data for the used fields in variable data file 110 for each of multiple records included in variable data file 110 on the corresponding page, and generates variable PDF file 140 as a print data file including information on the variable data arranged on each page. At this time, layout information is included in variable PDF file 140 as metadata. For convenience, the layout information given to the variable PDF generation unit 11 and the first hash value calculation unit 12 is denoted by the symbol 120, whereas the layout information included in the variable PDF file 140 is denoted by the symbol 1421 (see FIG. 9).

[0055] In this way, the PDF generation side generates the variable PDF file 140 and the hash value file 150. In this embodiment, the variable PDF file 140 and the hash value file 150 are separately transmitted from the PDF generation side to the inspection side (transmitted from the variable PDF generation device 10 to the variable PDF inspection device 20).

[0056] Thereafter, on the inspection side, the variable PDF inspection unit 21 performs a variable PDF file inspection process (print data file inspection process) (step S300). The variable PDF file inspection process is realized by the CPU 511 in the computer 500 functioning as the variable PDF inspection device 20 executing a variable PDF file inspection program. For each of the multiple records, the variable PDF inspection unit 21 extracts variable data from the variable PDF file 140 based on the used field information included in the hash value file 150 and the layout information 1421 included in the variable PDF file 140, and calculates a hash value using the extracted variable data in accordance with a predetermined calculation rule. For convenience, the hash value calculated by the variable PDF inspection unit 21 is referred to as a "second hash value." The variable PDF inspection unit 21 further inspects whether the second hash value for each of the multiple records matches the first hash value included in the hash value file 150, and outputs an inspection result 61.

[0057] As described above, the first hash value calculation process and the variable PDF file generation process are executed by the variable PDF generation device 10 on the PDF generation side, whereas the variable PDF file inspection process is executed by the variable PDF inspection device 20 on the inspection side. That is, the variable PDF file inspection process (the process of step S300) is executed by a computer different from the computer that executes the first hash value calculation process (the process of step S100) and the variable PDF file generation process (the process of step S200).

[0058] The calculation of the hash value (first hash value) by the first hash value calculation unit 12 and the calculation of the hash value (second hash value) by the variable PDF inspection unit 21 are performed according to the same calculation rules. Therefore, by comparing the first hash value and the second hash value, it is possible to verify the validity of the content of each variable data included in the variable PDF file 140.

[0059] In this embodiment, step S100 realizes a hash value calculation step, step S200 realizes a print data file generation step, and step S300 realizes a print data file inspection step.

[0060] In this embodiment, the variable PDF file generation process is performed after the first hash value calculation process, but the present invention is not limited to this. The first hash value calculation process may be performed after the variable PDF file generation process, or the first hash value calculation process and the variable PDF file generation process may be performed in parallel.

[0061] <1.3.2 Files used in processing> FIG. 5 is a diagram showing an example of a variable data file 110. As described above, in this embodiment, a CSV file is used as the variable data file 110. A CSV file is a file in which multiple pieces of text data are separated by commas (,), and FIG. 5 shows the display content of the CSV file (variable data file 110) when displayed using well-known spreadsheet software. The names of each field are written in the lines indicated by arrows labeled with reference numeral 111. In the portion labeled with reference numeral 112, one line of data constitutes one record. As shown in FIG. 5, the variable data file 110 used for variable printing stores multiple records, each containing multiple pieces of variable data. In this embodiment, a variable data collection is realized by this variable data file 110.

[0062] Incidentally, the variable data file 110 contains a large amount of personal information. In this regard, as described above, in this embodiment, the personal information can be used only in the variable PDF generation device 10. In other words, the variable data file 110 can be referenced from the variable PDF generation device 10, but the variable data file 110 cannot be referenced from the variable PDF inspection device 20. This is how the settings are made.

[0063] Fig. 6 is a diagram schematically showing the contents of the hash value file 150. As shown in Fig. 6, the hash value file 150 includes information on the used fields (see part A) and information on the first hash value for each of a plurality of records (see part B). The information on the used fields in the hash value file 150 shown in Fig. 6 indicates that the hash value of a character string obtained by combining the data value of the customer ID field, the data value of the name field, the data value of the postal code field, the data value of the address field, the data value of the bank account field, and the data value of the amount field for each record is calculated as the first hash value.

[0064] 7 is a diagram showing an example of the print result of the first record of the variable data file 110 shown in FIG. 5 (i.e., the print result of the first page) when printing is performed based on the variable PDF file 140. Note that this variable PDF file 140 is generated based on the template 130 shown in FIG. 8. As shown in FIG. 7, on the page, the data value of the postal code field of the variable data file 110 is placed at the position marked with reference numeral 41, the data value of the address field of the variable data file 110 is placed at the position marked with reference numeral 42, the data value of the name field of the variable data file 110 is placed at the position marked with reference numeral 43, the data value of the customer ID field of the variable data file 110 is placed at the position marked with reference numeral 44, the data value of the amount field of the variable data file 110 is placed at the position marked with reference numeral 45, and the data value of the bank account field of the variable data file 110 is placed at the position marked with reference numeral 46. The variable data is placed at each position with reference to the layout information 120. Note that, although the following description is given assuming that one record of the variable data file 110 corresponds to one page of the variable PDF file 140, one record of the variable data file 110 may correspond to multiple pages of the variable PDF file 140.

[0065] 9 is a diagram illustrating the configuration of a variable PDF file 140. The variable PDF file 140 includes actual data 141 that is actually displayed or printed, and metadata, which is various information other than the actual data. In this embodiment, the above-mentioned layout information 1421 is included in the variable PDF file 140 as metadata. The layout information 1421 is information that indicates the layout position on the page of the data values ​​of each field of the variable data file 110 (more specifically, information on the coordinates of the origin, width, and height).

[0066] <1.3.3 First hash value calculation process> The first hash value calculation process will be described in detail. FIG. 10 is a flowchart showing the detailed steps of the first hash value calculation process. After the first hash value calculation process starts, variable data included in the variable data file 110 is first read (step S110). In step S110, data for all fields is read. Next, information on used fields is acquired based on the layout information 120 (step S120). In this regard, as described above, the layout information 120 is information that associates the names of used fields (fields used for variable printing) among the fields that make up the variable data file 110 with coordinates on the pages that make up the variable PDF file 140. Therefore, information on used fields can be acquired from this layout information 120. After acquiring the information on used fields, the used fields are sorted (step S130). More specifically, a process is performed to sort the multiple fields identified in step S120 using the field names as a key. In this embodiment, the multiple fields are sorted in ascending order of the Japanese character code. For example, if the order of the used fields in the variable data file 110 is as shown in part A of Figure 11 (note that the Japanese character code of each field is written in the part indicated by the arrow labeled 64), the order of the used fields after sorting will be as shown in part B of Figure 11. Note that in this embodiment, the used fields are sorted as described above, but the present invention is not limited to this. If the order of multiple fields that are used fields can be uniquely determined, the multiple fields may be arranged, for example, in the order in which they appear.

[0067] After sorting the used fields, the following steps S140 to S160 are repeated a number of times equal to the number of records contained in variable data file 110. In step S140, for the record being processed, data values ​​of the multiple fields that are used fields are obtained from variable data file 110 in the order obtained in step S130. Next, a character string is generated by concatenating the multiple data values ​​(data values ​​of the multiple fields) obtained in step S140 (character string concatenation is performed) (step S150). In this regard, it is assumed that three fields (X field, Y field, Z field) are used fields and that the order of these three fields after sorting is "Y field, Z field, X field." In this case, if the data value of the X field is "ABC," the data value of the Y field is "HIJK," and the data value of the Z field is "123," the character string generated in step S150 is "HIJK123ABC." Therefore, for example, if the data values ​​of the multiple fields that are used fields for the record to be processed are as shown in part A of Figure 12, a character string as shown in part B of Figure 12 will be generated in step S150 (see also Figure 11). After the character string is generated in step S150 in this way, a hash value of the character string is calculated as a first hash value (step S160). In this way, a first hash value is calculated for each of the multiple records included in the variable data file 110.

[0068] After the processing of steps S140 to S160 is completed for all of the multiple records included in the variable data file 110, a hash value file 150 is generated (step S170) that includes information on the used fields and information on the first hash value for each of the multiple records. This completes the first hash value calculation process.

[0069] As can be seen from the above process, in this embodiment, the first hash value is calculated using the calculation rule of "calculating the hash value of a character string generated by combining the data values ​​of multiple fields that are used fields in the order obtained by sorting them using the field names as a key."

[0070] In this embodiment, step S110 implements the variable data reading step, step S120 implements the used field information acquisition step, step S130 implements the sorting step, step S150 implements the string generation step, and step S160 implements the calculation step.

[0071] <1.3.4 Variable PDF file generation process> The variable PDF file generation process will be described in detail. Fig. 13 is a flowchart showing the detailed procedure of the variable PDF file generation process. After the variable PDF file generation process starts, first, the layout information 120 is read (step S210). Next, for example, the template 130 shown in Fig. 8 is read (step S220).

[0072] After the template 130 is read, the following steps S230 to S240 are repeated a number of times equal to the number of records included in the variable data file 110. In step S230, multiple pieces of variable data (data values ​​of multiple fields that are used fields) for the record to be processed are read from the variable data file 110. Then, in step S240, while referencing the layout information 120 read in step S210, the multiple pieces of variable data read in step S230 are arranged on the corresponding pages based on the template 130 read in step S220. That is, the variable data is arranged on the pages that make up the variable PDF file 140.

[0073] After the processing of steps S230 to S240 is completed for all of the multiple records included in the variable data file 110, the variable PDF file 140 is generated by adding metadata including layout information 1421 to the actual data 141 obtained by the processing of step S240 for the multiple records (step S250). This completes the variable PDF file generation processing.

[0074] <1.3.5 Variable PDF file inspection processing> The variable PDF file inspection process will be described in detail. Fig. 14 is a block diagram for describing the details of the variable PDF inspection unit 21 that performs the variable PDF file inspection process. The variable PDF inspection unit 21 is provided with a variable PDF file 140 as shown schematically in Fig. 9 and a hash value file 150 as shown schematically in Fig. 6. The variable PDF file 140 includes actual data (variable data) 141 and metadata 142 including layout information 1421. The hash value file 150 includes used field information 151 and a first hash value 152.

[0075] The variable PDF inspection unit 21 is composed of a second hash value calculation unit 211 and a comparison unit 213. Based on layout information 1421, the second hash value calculation unit 211 obtains data values ​​at positions (positions on a page) corresponding to each field of each record constituting actual data 141 in the variable PDF file 140. Then, for each record, the second hash value calculation unit 211 combines data values ​​of multiple fields based on used field information 151, and calculates a hash value of the resulting character string as a second hash value 212. The comparison unit 213 compares the first hash value 152 included in the hash value file 150 for each record with the second hash value 212 calculated by the second hash value calculation unit 211, and outputs an inspection result 61.

[0076] 15 is a flowchart showing the detailed steps of the variable PDF file inspection process. After the variable PDF file inspection process starts, the layout information 1421 included in the variable PDF file 140 is first read (step S310). Then, the following steps S320 to S350 are repeated a number of times equal to the number of records of the actual data 141 included in the variable PDF file 140.

[0077] In step S320, for the record to be processed, layout information 1421 is referenced to read data values ​​at positions corresponding to each field on a page constituting the variable PDF file 140. Because multiple fields are used fields, multiple data values ​​are read in step S320. Next, a character string is generated by combining the multiple data values ​​read in step S320 (character string combination is performed) (step S330). In step S330, used field information 151 is referenced to combine the data values ​​of the multiple fields in the same order as when the character string was generated in the first hash value calculation process (see FIG. 10). That is, the data values ​​of the multiple fields are combined in the order obtained by sorting the multiple fields using the field names as a key. Thereafter, the hash value of the character string generated in step S330 is calculated as a second hash value 212 (step S340). Then, the second hash value 212 calculated in step S340 is compared with the first hash value 152 included in the hash value file 150 (step S350). In other words, for the record to be processed, it is checked whether the second hash value 212 calculated in step S340 matches the first hash value 152 included in the hash value file 150.

[0078] After the processing of steps S320 to S350 is completed for all records, the inspection result 61 is output (step S360). For example, if there is a record in which the second hash value 212 and the first hash value 152 do not match, a message indicating that an error has occurred in the page containing that record is displayed on the display unit 523 of the computer 500 functioning as the variable PDF inspection device 20. When the inspection result 61 is output, the variable PDF file inspection process ends.

[0079] As can be seen from the above process, in this embodiment, the second hash value is calculated according to the calculation rule that "calculate the hash value of a character string generated by combining data values ​​of multiple fields that are used fields in the order obtained by sorting the data values ​​using the field names as a key." In other words, the first hash value and the second hash value are calculated according to the same calculation rule. In the variable PDF file inspection process, the above calculation rule is derived from the used field information 151.

[0080] <1.4 Effects> According to this embodiment, in the variable PDF generation device 10 that generates the variable PDF file 140 based on the variable data in the variable data file 110, a hash value calculation process is performed in which a hash value (first hash value 152) is calculated according to a predetermined calculation rule using variable data for used fields, which are fields used for variable printing among the fields included in the variable data file 110. In addition to the variable PDF file 140, the variable PDF generation device 10 transmits to the variable PDF inspection device 20 a hash value file 150 that includes information 151 on used fields and first hash values ​​152 for each of the multiple records included in the variable data file 110. Note that it is not possible to restore the data from which the first hash value 152 was generated (the data values ​​of the multiple fields that are used fields) from the first hash value 152. In the variable PDF inspection device 20, for each of the multiple records, variable data for the used fields is extracted from the variable PDF file 140 based on the used field information 151 and layout information 1421, and a hash value (second hash value 212) is calculated using the extracted variable data according to the same calculation rule as that used to calculate the first hash value 152. Furthermore, the variable PDF inspection device 20 checks whether the second hash value 212 matches the first hash value 152 included in the hash value file 150 for each of the multiple records.

[0081] Here, the variable data file 110 is not used to calculate the second hash value 212 in the variable PDF inspection device 20. In other words, personal information is not used to calculate the second hash value 212 in the variable PDF inspection device 20. Furthermore, the variable data file 110 is not required to check whether the second hash value 212 matches the first hash value 152. As described above, the variable data file 110 is not required for the process performed by the variable PDF inspection device 20 to verify the validity of the content of each variable data included in the variable PDF file 140.

[0082] As described above, according to this embodiment, after generating a variable PDF file 140 using personal information, it is possible to verify the validity of the contents of each variable data contained in the variable PDF file 140 without using personal information.

[0083] 2. Second embodiment A second embodiment of the present invention will be described below, focusing mainly on the differences from the first embodiment.

[0084] <2.1 Configuration etc.> Fig. 16 is a diagram for explaining the functional configuration of this embodiment. As shown in Fig. 16, in this embodiment, the first hash value calculation unit 12 is included in the variable PDF generation unit 11. That is, in the computer 500 functioning as the variable PDF generation device 10, the hash value calculation program is executed by being called from the variable PDF file generation program. Because the PDF generation side is configured in this way, a variable PDF file 160 including information equivalent to the information included in the hash value file 150 in the first embodiment is transmitted from the PDF generation side to the inspection side (from the variable PDF generation device 10 to the variable PDF inspection device 20).

[0085] 17 is a diagram illustrating the configuration of a variable PDF file 160 in this embodiment. The variable PDF file 160 includes actual data to be actually displayed or printed (see section A), layout information (see section B), used field information (see section C), and first hash value information for each of a plurality of records (see section D). The used field information and first hash value information are the information included in the hash value file 150 in the first embodiment. In this embodiment, the layout information, used field information, and first hash value information are included in the variable PDF file 160 as metadata.

[0086] <2.2 How to verify the validity of print data> With reference to the flowchart shown in Fig. 18, an outline of a series of processes related to verifying the validity of print data will be described. First, on the PDF generation side, a variable PDF file generation process is performed by the variable PDF generation unit 11 (step S400). In this embodiment, the variable PDF file generation process includes a first hash value calculation process performed by the first hash value calculation unit 12. In step S400, a variable PDF file 160 as shown schematically in Fig. 17 is generated. After the variable PDF file 160 is transmitted from the PDF generation side to the inspection side, a variable PDF file inspection process is performed by the variable PDF inspection unit 21 on the inspection side (step S500).

[0087] As described above, in this embodiment as well, the first hash value calculation process and the variable PDF file generation process are executed on the PDF generation side, while the variable PDF file inspection process is executed on the inspection side. That is, the variable PDF file inspection process is executed by a computer different from the computer that executes the first hash value calculation process and the variable PDF file generation process.

[0088] With reference to the flowchart shown in FIG. 19, the detailed procedure of the variable PDF file generation process in this embodiment will be described. After the variable PDF file generation process starts, first, the hash value calculation program is called from the variable PDF file generation program. This causes the first hash value calculation process to be performed (step S405). The first hash value calculation process is performed in the same manner as in the first embodiment (see FIG. 10). However, the process of step S170 in FIG. 10 (the process of generating a hash value file) is not performed. The processes of steps S410 to S440 are the same as the processes of steps S210 to S240 in the first embodiment (see FIG. 13). After the processes of steps S430 to S440 are completed for all of the multiple records included in the variable data file 110, the results of the first hash value calculation process are obtained (step S445). That is, in step S445, information on the first hash value for each of the multiple records included in the variable data file 110 is obtained. Thereafter, a variable PDF file 160 is generated (step S450) by adding metadata to the actual data obtained by the processing of step S440 for the multiple records included in the variable data file 110. At this time, the layout information, information on the used fields, and information on the first hash value obtained in step S445 are included in the metadata.

[0089] FIG. 20 is a block diagram for explaining details of the variable PDF inspection unit 21 that performs variable PDF file inspection processing. A variable PDF file 160 includes actual data (variable data) 161 and metadata 162 that includes layout information 1621, used field information 1622, and a first hash value 1623. In the first embodiment, the variable PDF inspection unit 21 obtained the used field information 151 and the first hash value 152 from the hash value file 150 (see FIG. 14). In contrast, in the present embodiment, the variable PDF inspection unit 21 obtains the used field information 1622 and the first hash value 1623 from the variable PDF file 160. Other points are the same as in the first embodiment. That is, the detailed procedure of the variable PDF file inspection processing in this embodiment (the processing of step S500 in FIG. 18) is the same as in the first embodiment (see FIG. 15).

[0090] <2.3 Effects> According to this embodiment, similar to the first embodiment, after generating a variable PDF file 160 using personal information, it is possible to verify the validity of the content of each variable data included in the variable PDF file 160 without using personal information. Also, in the first embodiment, the variable PDF file 140 and the hash value file 150 are transmitted from the PDF generation side to the inspection side, but in this embodiment, only the variable PDF file 160 is transmitted from the PDF generation side to the inspection side. Thus, according to this embodiment, the number of files that need to be handled is smaller than in the first embodiment, making operation easier.

[0091] <3. Modifications> The following describes modified examples.

[0092] <3.1 First modified example> In the above embodiments, hash values ​​(first hash value, second hash value) are calculated from a character string obtained by combining data values ​​of multiple fields that are used fields. In contrast, in this modified example, hash values ​​are calculated from a character string obtained by combining data values ​​of multiple fields that are used fields with additional information such as the coordinates of the multiple fields.

[0093] In this modification, when generating a character string for calculating a first hash value (step S150 in FIG. 10), data values ​​of multiple fields that are used fields and additional information such as coordinates of the multiple fields are combined in a predetermined order. Since the calculation of the second hash value and the calculation of the first hash value must be performed according to the same calculation rule, information on the calculation rule that specifies how the first hash value was calculated using variable data (data values ​​of multiple fields) and additional information is transmitted from the PDF generation side to the inspection side.

[0094] In the variable PDF file inspection process, the data values ​​and additional information of multiple fields are combined in a predetermined order by referring to the calculation rule information transmitted from the PDF generation side to the inspection side, and the hash value of the character string obtained thereby is calculated as a second hash value. Then, as in the above embodiments, for each record, it is checked whether the second hash value calculated in the variable PDF file inspection process matches the first hash value transmitted from the PDF generation side to the inspection side.

[0095] <3.2 Second modified example> In the above embodiments, hash values ​​(first hash value, second hash value) were calculated from character strings obtained by combining data values ​​from only the used fields. In contrast, in this modified example, hash values ​​are calculated from character strings obtained by combining data values ​​from the used fields and one or more unused fields (fields not used for variable printing).

[0096] In this modification, when the first hash value calculation process is performed, variable data for unused fields is extracted in addition to variable data for used fields.Then, the first hash value is calculated using the extracted variable data (variable data for used fields and variable data for unused fields).In more detail, the hash value of a character string obtained by combining data values ​​for multiple used fields and data values ​​for one or more unused fields in a predetermined order is calculated as the first hash value.

[0097] Since variable data for unused fields is also required to calculate the second hash value, the variable data for unused fields is included in the variable PDF file transmitted from the PDF generation side to the inspection side (i.e., the variable PDF file transmitted from the variable PDF generation device 10 to the variable PDF inspection device 20). In addition, information on a calculation rule that specifies how the first hash value is calculated using the variable data for used fields and the variable data for unused fields is transmitted from the PDF generation side to the inspection side.

[0098] In the variable PDF file inspection process, a second hash value is calculated using variable data for used fields and variable data for unused fields, with reference to calculation rule information transmitted from the PDF generation side to the inspection side. Then, as in the above embodiments, it is checked for each record whether the second hash value calculated in the variable PDF file inspection process matches the first hash value transmitted from the PDF generation side to the inspection side.

[0099] <3.3 Third modified example> In the above embodiments, hash values ​​(first hash value, second hash value) are calculated from a character string obtained by combining data values ​​of multiple fields that make up each record. That is, a hash value is calculated for each record. In this case, when the first hash value and the second hash value do not match, it is not possible to determine which field's data value is inconsistent. Therefore, in this modified example, a hash value is calculated for each field of each record. The following describes a case where this modified example is applied to the above first embodiment.

[0100] In this modification, hash values ​​are calculated for each field, so the first hash value calculation process does not require the process of rearranging the multiple fields that are used (step S130 in FIG. 10) or the process of combining data values ​​in the multiple fields to generate a character string (step S150 in FIG. 10). In step S160 in FIG. 10, a hash value (first hash value) is calculated for each of the multiple data values ​​(data values ​​of the multiple fields) acquired in step S140. That is, a first hash value is calculated for each field. Since a first hash value is calculated for each field in this manner, the contents of the hash value file 150 in this modification are schematically shown in FIG. 21. As shown in part B of FIG. 21, the hash value file 150 stores a first hash value for each field for each record.

[0101] After the first hash value calculation process and the variable PDF file generation process are completed, a variable PDF file 140 as shown schematically in Figure 9 and a hash value file 150 as shown schematically in Figure 21 are sent from the PDF generation side to the inspection side.

[0102] The variable PDF file inspection process does not require the process of combining multiple data values ​​to generate a character string (the process of step S330 in FIG. 15). In step S340 in FIG. 15, a hash value (second hash value) is calculated for each of the multiple data values ​​read in step S320. Then, in step S350 in FIG. 15, the second hash value calculated in step S340 is compared with the first hash value included in the hash value file 150 for each field. In other words, for the record to be processed, it is checked for each field whether the second hash value calculated in step S340 matches the first hash value included in the hash value file 150.

[0103] Incidentally, if there is a field in which the second hash value does not match the first hash value, a message identifying the field in which the second hash value does not match the first hash value may be displayed on the display unit 523 of the computer 500 functioning as the variable PDF inspection device 20. This allows the user to easily understand which field's data value has the mismatch when there is a field in which the second hash value does not match the first hash value. In other words, when invalid data is included in the variable PDF file 140, the user can easily identify the invalid data.

[0104] <3.4 Fourth Modification> In the above-described embodiments, it is assumed that the validity of character data and numeric data is verified, but it is not assumed that the validity of image data is verified. In contrast, in this modified example, it is assumed that the validity of image data is verified in addition to character data and numeric data.

[0105] When printing is performed based on the variable PDF file in this modified example, the print result of a certain record will be, for example, as shown in Figure 22. In Figure 22, an image is printed in the dotted line portion marked with reference numeral 81. Image data for printing such an image is stored in a specified folder. Figure 23 is a diagram showing an example of a variable data file 110 in this modified example. The figure field 82 of this variable data file 110 stores the file name of the image data. In other words, each record in the variable data file 110 and the image data stored in the specified folder are associated with each other by the file name stored in the figure field 82 of the variable data file 110.

[0106] In addition, in this modified example, in addition to fields that store character data and fields that store numerical data, the above-mentioned figure field (i.e., a field associated with image data that stores the file name of the image data) can be set as a used field.

[0107] With the above configuration, the above-mentioned figure field is included in the used fields. As a result, in step S130 of FIG. 10, in the first hash value calculation process, the used fields are sorted, including the figure field. In this regard, for example, if the order of the used fields in the variable data file 110 is as shown in part A of FIG. 24 (note that the Japanese character code of each field is written in the part indicated by the arrow with reference numeral 84), the order of the used fields after sorting will be as shown in part B of FIG. 24. Also, in step S150 of FIG. 10, string concatenation is performed, including the data values ​​of the figure field (in this modified example, the file name of the image data). In this regard, for example, if the data values ​​of multiple fields that are used fields for the record to be processed are as shown in part A of FIG. 25, a string such as that shown in part B of FIG. 25 is generated in step S150. In addition, in the variable PDF file generation process, in step S240 of FIG. 13 and step S440 of FIG. 19, image data in addition to character data and numeric data is placed on the page based on the template 130.

[0108] Since the file name of the image data is also required to calculate the second hash value, information on the file name of the image data placed on each page of the variable PDF file is sent from the PDF generation side to the inspection side (i.e., from the variable PDF generation device 10 to the variable PDF inspection device 20).

[0109] In the variable PDF file inspection process, in step S320 of Fig. 15, the file name transmitted from the PDF generation side to the inspection side is acquired for an image. Then, in step S330 of Fig. 15, string concatenation is performed, including the acquired file name. As a result, in step S340 of Fig. 15, a second hash value is calculated based on a character string similar to the character string from which the first hash value was calculated. Then, as in each of the above embodiments, it is inspected for each record whether the second hash value calculated in the variable PDF file inspection process matches the first hash value transmitted from the PDF generation side to the inspection side.

[0110] According to this modified example as described above, it is possible to verify the validity of image data as well as the validity of character data and numeric data regarding the contents of a variable PDF file without using personal information.

[0111] In this modified example, a hash value is calculated for a character string obtained by string concatenation that includes the file name of the image data (data value of the image field). However, a hash value for the RAW data of the image may also be calculated in addition to a hash value for a character string obtained by string concatenation that uses only data values ​​of fields other than the image field (i.e., fields that store character data and fields that store numeric data). In this case, the PDF generation side transmits the hash value of the character string and the hash value of the image (RAW data) as first hash values ​​to the inspection side. Then, in the variable PDF file inspection process, a check is made to determine whether the second hash value calculated on the inspection side matches the first hash value transmitted from the PDF generation side to the inspection side for each of the character string and the image.

[0112] <3.5 Fifth Modification> In the above embodiments, the validity of the contents of a variable PDF file is verified using a hash value, but the present invention is not limited to this. The validity of the contents of a variable PDF file can also be verified using a checksum instead of a hash value. In this case, a first checksum is calculated on the PDF generation side, and a hash value file 150 sent from the PDF generation side to the inspection side contains information 151 about used fields and the first checksum for each of the multiple records. The inspection side also calculates a second checksum and checks whether the second checksum for each of the multiple records matches the first checksum included in the hash value file 150.

[0113] <4.Other> The present invention is not limited to the above-described embodiments (including modified examples), and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiments, a CSV file is used as the variable data file, but a file other than a CSV file can also be used as the variable data file. In this regard, for example, a TSV file, which is a text data file in which multiple pieces of text data are separated by tab characters, can be used as the variable data file. Also, variable data may be acquired from a database rather than from a variable data file. Furthermore, it is possible for all fields constituting the variable data file 110 to be used fields, and for the variable data file 110 to contain no unused fields. [Explanation of symbols]

[0114] 10...Variable PDF generator 11...Variable PDF generation section 12...First hash value calculation unit 20...Variable PDF inspection device 21...Variable PDF Inspection Department 110...Variable data file (CSV file) 120,1421,1621...Layout information 130...Template 140,160...Variable PDF file 150...Hash value file 151,1622...Field information used 152,1623...First hash value 211...second hash value calculation unit 212...Second hash value 213...Comparison section

Claims

1. 1. A method for verifying the validity of data included in a print data file for performing variable printing based on variable data whose data value may differ for each page and fixed data that is common to all pages, using a computer, comprising: a hash value calculation step of extracting variable data for a usage field that is a field used for variable printing from a variable data collection that stores the variable data for each of a plurality of records, and calculating a first hash value using the extracted variable data in accordance with a predetermined calculation rule; a print data file generating step of arranging the variable data for the used fields in the variable data collection for each of the plurality of records on a corresponding page based on layout information that associates field names with coordinates, and generating the print data file including information on the variable data arranged on each page; a print data file inspection step of extracting the variable data from the print data file based on the used field information and the layout information for each of the plurality of records, calculating a second hash value using the extracted variable data in accordance with the predetermined calculation rule, and inspecting whether the second hash value matches the first hash value; Including, 10. The method for verifying authenticity, wherein the print data file inspection step is executed by a second computer different from a first computer that executes the hash value calculation step and the print data file generation step.

2. In the hash value calculation step, a hash value file including information on the used fields and the first hash value for each of the plurality of records is generated, In the print data file generating step, the layout information is included in the print data file as metadata; 2. The method of verifying authenticity according to claim 1, wherein the hash value file and the print data file are transmitted separately from the first computer to the second computer.

3. 2. The method for verifying authenticity described in claim 1, characterized in that in the print data file generation step, the layout information, the information on the used fields, and the first hash values ​​for each of the plurality of records calculated in the hash value calculation step are included in the print data file as metadata.

4. information on the used fields is transmitted from the first computer to the second computer; 2. The method of claim 1, wherein the predetermined calculation rule is derived from information in the used field when the second hash value is calculated in the print data file inspection step.

5. A plurality of fields are set as the used fields, The hash value calculation step a variable data reading step of reading the variable data in the variable data collection; a used field information acquisition step of acquiring information on the used field; a string generation step of generating a string by combining the variable data for the plurality of fields in the variable data collection based on the information of the used fields; a calculation step of calculating a hash value of the character string generated in the character string generation step as the first hash value; 2. The method of claim 1, further comprising:

6. the hash value calculation step further includes a sorting step of sorting the plurality of fields using field names as keys after the used field information acquisition step, 6. The validity verification method according to claim 5, wherein in the character string generating step, the variable data for the plurality of fields is combined in the order of the plurality of fields after being sorted in the sorting step.

7. 2. The method for verifying validity according to claim 1, wherein in the hash value calculation step, the first hash value is calculated using the extracted variable data and coordinates associated with each field by the layout information.

8. In the hash value calculation step, in addition to the variable data for the used field, the variable data for an unused field that is a field not used for variable printing is extracted, and the first hash value is calculated using the variable data for the used field and the variable data for the unused field; In the print data file generating step, the variable data for the unused fields is included in the print data file; The authenticity verification method described in claim 1, characterized in that in the print data file inspection step, the second hash value is calculated using the variable data for the used field extracted from the print data file and the variable data for the unused field extracted from the print data file.

9. In the hash value calculation step, the first hash value is calculated for each field, 2. The method for verifying authenticity according to claim 1, wherein in the print data file inspection step, the second hash value is calculated for each field, and it is checked whether the second hash value matches the first hash value for each field.

10. 10. The method for verifying authenticity described in claim 9, characterized in that, if a field in which the second hash value and the first hash value do not match is found in the print data file inspection step, the second computer outputs a message identifying the field in which the second hash value and the first hash value do not match.

11. 2. The method for validating validity according to claim 1, wherein a field for storing character data, a field for storing numeric data, and a field associated with image data and for storing a file name of the image data can be set as the used field.

12. 12. The method of claim 1, wherein the print data file is a file in a portable document format.

13. 12. The method of claim 1, wherein the variable data collection is a text data file.

14. 1. A method for verifying the validity of data included in a print data file for performing variable printing based on variable data whose data value may differ for each page and fixed data that is common to all pages, using a computer, comprising: a checksum calculation step of extracting variable data for a usage field that is a field used for variable printing from a variable data collection that stores the variable data for each of a plurality of records, and calculating a first checksum using the extracted variable data in accordance with a predetermined calculation rule; a print data file generating step of arranging the variable data for the used fields in the variable data collection for each of the plurality of records on a corresponding page based on layout information that associates field names with coordinates, and generating the print data file including information on the variable data arranged on each page; a print data file inspection step of extracting the variable data from the print data file based on the used field information and the layout information for each of the plurality of records, calculating a second checksum using the extracted variable data in accordance with the predetermined calculation rule, and inspecting whether the second checksum matches the first checksum; Including, 10. The method for verifying authenticity, wherein the print data file checking step is executed by a second computer different from a first computer that executes the checksum calculation step and the print data file generation step.

15. A printing system capable of performing variable printing based on variable data whose data value may differ for each page and fixed data that is common to all pages, a first computer that performs a hash value calculation process that extracts variable data for a used field, which is a field used in variable printing, from a variable data collection that stores the variable data for each of a plurality of records, and calculates a first hash value using the extracted variable data in accordance with a predetermined calculation rule; and a print data file generation process that arranges the variable data for the used field in the variable data collection for each of the plurality of records on a corresponding page based on layout information that associates field names with coordinates, and generates a print data file including information on the variable data arranged on each page; a second computer that performs a print data file inspection process for extracting the variable data from the print data file based on the used field information and the layout information for each of the plurality of records, calculating a second hash value using the extracted variable data in accordance with the predetermined calculation rule, and inspecting whether the second hash value matches the first hash value; A printing system comprising:

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