JP2007257527A - Printing system and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control output of secret information in each used printer. <P>SOLUTION: When a secret portion is selected from data generated by an application 102, a print data generation part 103 encrypts the portion by an encryption key acquired from the usable printer. A non-secret portion, the secret portion encrypted in each the printer, and substitutional data designated for output by the other printer are stored as print data. In time of printing, the secret information encrypted by the encryption key acquired from the printer of an output destination is selected in a print data selection part 106, and is transmitted to the printer 109 together with non-secret information. When the corresponding secret information is absent, the substitutional data are transmitted. The printer 109 decrypts the encrypted secret portion by a stored decryption key, and prints it. When cannot decrypt it, the secret portion is replaced with the substitutional data, and is printed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing system, and more particularly to a printing system that changes print data output by a printer that performs printing. The present invention also relates to a printing control apparatus and a printing apparatus that constitute the printing system.

  As a configuration of a printing system in which a host computer and a printer that is an example of an image forming apparatus are connected, there are a stand-alone connection that directly connects the host computer and the printer, and a network connection that connects the host computer and the printer via a network. . Among these configurations, with a network connection, a large high-speed printer or an expensive color printer can be shared by a plurality of terminal devices (host computers), or printing can be performed using printers at remote locations. There is an advantage.

On the other hand, in the case of network connection, the print data is transmitted from the host computer to the printer through the network, so that the print data may be wiretapped. Therefore, a technique for encrypting print data has been proposed in order to prevent eavesdropping of print data when printing is performed via a communication network such as the Internet (see, for example, Patent Document 1).
JP 2004-86894 A

  However, a printer connected to the network (called a network printer) may be used by an unspecified person. Therefore, depending on the location where the network printer is installed, the printed matter that is output may be seen by a user who is not originally authorized to view the contents.

  For example, in the case where important data such as confidential information is printed at a customer who is connected to the Internet, or a salesperson on the go prints on the nearest printer, the output result can be seen. It will be very troublesome. Therefore, the user must print data including confidential information using a printer near the user or a printer that can be used only by a specified user in the company. When printing with a printer installed at a location other than that, the user needs to correct the data prior to printing by deleting confidential information from the data of the document or the like to be printed. . For this purpose, it is necessary to find all the relevant parts in the document, and the burden on the user is heavy.

  There is also a technique called direct printing in which printing is performed from a printer without using a host computer. In direct printing, data stored in an application is supplied to the printer as it is, for example, via a recording medium or communication medium interface provided in the printer. Communication media used for direct printing include those using a wireless interface such as Bluetooth (registered trademark). Even with direct printing using such a wireless interface, if confidential information is printed carelessly, there is a risk of allowing unauthorized users to access the confidential information.

  The present invention has been made in view of the above problems, and an object thereof is to solve the above problems. In particular, a printing system in which confidential information is encrypted when data including it is encrypted, and the encrypted confidential information is decrypted and printed by a specific printer, while the confidential information cannot be printed by other printers, and a control method therefor The purpose is to provide.

In order to achieve the above-described object, the present invention has the following configuration. That is, a print data generation device connected to a printer,
Encryption means for generating encrypted confidential data obtained by encrypting a confidential portion designated in data to be printed by a method that can be decrypted by a printer that can be used by the computer;
The encrypted confidential data encrypted by the encryption means is associated with the identification information of a printer that can decrypt the encrypted confidential data, and both the substitute data substituting the confidential portion and the non-sensitive data other than the confidential portion Data storage means for storing print data;
If the print data stored by the data storage means includes encrypted confidential data encrypted by a method that can be decrypted by the printer to which the print data is sent, the encrypted confidential data is selected and included. If not, there is provided transmission means for selecting the alternative data and transmitting the selected data and the non-confidential data to the destination printer.

Alternatively, a printer device connected to a computer,
Determining means for determining whether or not the encrypted data is included in the print data received from the computer;
Generating means for decrypting the encrypted data and generating plain text print data together with the unencrypted portion when it is determined by the determining means that the encrypted data is included; ,
Printing data generated by the generating means, or printing means for printing the print data received from the computer when it is determined that the data encrypted by the determining means is not included. And

  According to the present invention, confidential information can be printed only by a specific printer, and confidential information can be protected.

<Functional blocks of printing system>
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the entire print control system for carrying out the present invention. The host computer 101 is a general purpose computer connected to the network 207. The application 102 is an application program that creates data, such as a document processing program or a table creation program. The created data (application data) is transferred to the print data generation unit 103. The print data generation unit 103 converts input data (such as application data) into XML format data in this embodiment. At the time of the conversion, the print data generation unit 103 encrypts the portion designated as confidential information using an encryption key for each printer that can be used by the host computer 101. Here, the “available printer” is a printer having an encryption function and designated as a printer for printing confidential information by the user. Data to be replaced with confidential information (this is called substitute data) is generated as data to be output to other printers, that is, printers that do not have an encryption function, or printers that are not specified by the user. . The data to be replaced is designated from the application 104 through an operation by the user. That is, the print data generation unit 103 converts application data into XML for reproducing in a print format for a portion not designated as confidential information. For the portion designated as confidential information, encrypted data for each available printer and alternative data for output from a printer other than the available printer are also generated in XML format.

  The alternative data specification unit 104 specifies alternative data that the print data generation unit 103 generates as data that changes to confidential information. Therefore, a user interface for allowing the user to specify alternative data is provided. The printer information acquisition unit 107 acquires the printer ID and encryption key from the printer 109 and passes them to the print data generation unit 103. When public key cryptography is used, the encryption key is a public key. When the common key encryption is used, since the encryption key is a common key, it is necessary to encrypt and pass the key. The print data selection unit 106 selects data suitable for the data transmission destination printer from the data passed from the print data generation unit 103, and transmits the selected data as print data to the printer via the communication unit 108. To do. Data suitable for a printer includes unencrypted data and data corresponding to confidential information converted for each printer. The data corresponding to the confidential information converted for each printer is the confidential information data encrypted with the encryption key passed from the printer if the destination printer is the above-mentioned “available printer”. is there. If it is not “available printer”, it is alternative data. These data are transmitted to the printer in a format that can be reproduced as created by the application 102 (excluding confidential information).

  The printer 109 converts the print data received from the host computer 101 into an image and prints it. The print job acquisition unit 111 acquires print data via the communication unit 110. The print data is passed to the printer as a print job that is a set of data and commands described in the job control language. The printer information management unit 112 holds printer information such as a printer ID unique to the printer and key information for encryption communication, and provides printer information in response to a request from a host computer or the like. For example, if public key encryption is used, the key information includes a public key and a secret key. In this case, a public key is provided, and a private key is not provided. The print job analysis unit 113 analyzes the print data acquired by the print job acquisition unit 111. The encrypted data determination unit 115 determines whether the acquired print data includes encrypted data. If encrypted, the print data is passed to the encrypted data decryption unit 116. If it is not encrypted, the print data is transferred to the print mechanism unit 114 as it is. Only the encrypted portion may be passed to the encrypted data decryption unit 116. The encrypted data decryption unit 116 acquires the secret key from the printer information management unit 112 and decrypts the received data. The print job analysis unit 113 converts the XML-format print data, all in plain text, into a bitmap image while interpreting the XML tag, and passes the data to the print mechanism unit 114. The printing mechanism unit 114 prints the passed bitmap data.

<Computer and printer hardware>
FIG. 2 is a diagram showing the hardware configuration of the client 101 and the printer 109 of the present invention. In FIG. 2, a computer 101 includes a CPU 201 that executes software stored in a ROM 202 or a hard disk (HD) 204, and comprehensively controls each device connected to a system bus 206. This software includes an application program 102 and a printer driver 105. The hard disk 204 stores print data generated by the print data generation unit 103.

  The RAM 203 functions as a main memory, work area, and the like for the CPU 201. A network interface board (NIC) 205 corresponds to the communication unit 108 in FIG. 1, and exchanges data bidirectionally with other network devices or other PCs via the network 207.

  The printer 109 has almost the same hardware configuration. However, it has an engine unit 215 (printing mechanism unit 114) for performing printing. A program for realizing the print job acquisition unit 111, the print job analysis unit 113, and the like is stored in the ROM 212. The printer information is stored in the ROM 212. In order to change the printer information, it is desirable to use a rewritable ROM as the ROM 212. Of course, the printer 109 may be provided with a hard disk.

<Application operation>
Next, the operation of the application 102 will be described with reference to FIG. FIG. 3 is a flowchart showing an operation in an application for creating data.

  First, in step S301, it is determined whether or not there is an instruction to save the created data from the user. If so, the process proceeds to step S306. If not, the process proceeds to step S302. In step S302, the user inputs data and creates data. In step S302, it is not necessary to create data. In step S303, it is determined whether or not there is an instruction whether to designate a range of a portion designated as confidential information (referred to as a confidential portion). If there is no instruction, the process returns to step S301. If there is an instruction, the range of the confidential part is designated in step S304. This designation is performed by, for example, designating the range after displaying data such as a document created by the user. FIG. 4 shows an example of the range designation of the confidential part. Of the document 402, a portion 402 surrounded by a rectangle is designated as a confidential portion.

  In step S305, alternative data used to replace the confidential part is created. The alternative data needs to be set in advance. For example, before the data is created, a window as shown in FIG. 5 is activated from the application 102, and the user inputs or designates alternative data (replacement data in the figure). In FIG. 5, only the outer frame can be printed, or a character string or the like can be designated as alternative data. The outer frame is a frame indicating the range of the confidential part, and the content is blank. When the alternative data is generated, the process returns to step S301.

  In step S306, it is determined whether or not there is a confidential part in the generated application data. If there is no confidential part, the process proceeds to step S310. If there is a confidential part, the process proceeds to step S307. In step S307, a printer that permits printing of this data is selected from printers installed in the host. That is, an available printer is selected. The selection is performed, for example, by the user specifying a printer from the printer list. In step S308, the printer ID and encryption key (for example, public key) of the printer are acquired from the printer selected in S307. In step S309, the confidential part specified in the application data is encrypted with the encryption key acquired in step S308. In step S310, data is saved and the process is terminated.

  The stored data is in the XML format as shown in FIG. In the example of FIG. 6, data encrypted with an encryption key of an available printer and alternative data are stored. Of course, parts other than the confidential part are also stored in the XML format. A printer ID holding the public key used for encryption is written in the encrypted data tag.

  In FIG. 6, a printer ID 601 of an available printer is written in the encryption tag 600 in the printer ID tag. An encrypted confidential portion 602 is described corresponding to the printer ID. The printer ID tags 601 and 603 are repeated for all available printers in the encryption tag 600. The alternative data 604 is described in the open data tag 605. In the example of FIG. 6, the character string “cannot be displayed” is described in the open data tag 605 as alternative data. The encryption tag 600 and the open tag 605 are described in the select tag 610. The select tag 610 is a tag that is selected by the print data selection unit 106. Although omitted in FIG. 6, the data other than the confidential portion is described in plain text together with the XML tag representing the format.

<Printer driver operation>
FIG. 7 is a flowchart showing the operation of the printer driver selected at the time of printing. First, in step S701, a printer ID is acquired from a printer corresponding to the printer driver. In step S702, it is determined whether the print data includes a printer ID that matches the printer ID acquired in step S701. The determination target is the printer ID described in the encryption tag 600 in the select tag 610 in FIG. If there is a printer ID in the select tag that matches the printer ID acquired in step S701, the process proceeds to step S703, and if not, the process proceeds to step S704. In step S703, the encryption data of the printer ID tag determined to have the printer ID of the printer used in step S702 described from the select tag 610 is selected. The selected encrypted data is transmitted to the printer in combination with a portion other than the confidential portion of the print data (that is, the portion not surrounded by the select tag). The confidential part is incorporated in the part other than the confidential part together with the encryption tag to indicate that the encrypted part is encrypted. For example, as shown in FIG. 8, the confidential portion encrypted with the public key of the corresponding printer is selected from the select tag and transmitted. In FIG. 8, portions other than the confidential portion are omitted. In step S704, the alternative data described in the open data tag in the select tag is selected and transmitted to the printer in combination with a portion other than the confidential portion of the print data. For example, as shown in FIG. 9, the alternative data “cannot be displayed” described in the open tag is selected and transmitted from the select tag. In FIG. 8, portions other than the confidential portion are omitted.

<Printer operation>
FIG. 10 is a flowchart showing the operation of the printer main body. There are cases where print data selected by the printer driver is transmitted to the printer main body, and data stored by the application is transmitted directly directly. First, in step S1001, reception of print data is awaited. If no data has been received, the process returns to step S1001 and waits for data to come. In step S1002, print data is received. In step S1003, it is determined whether there is encrypted data in the received data. Specifically, if the print data includes an encryption tag, it is determined that the data in the encryption tag is encrypted data. If encrypted data is not included, the process proceeds to step S1006. If encrypted data is included, the process proceeds to step S1004.

  In step S1004, it is determined whether the printer ID described in the encryption tag matches the printer ID of the printer performing the processing in FIG. If they do not match, the process proceeds to step S1006, and if they match, the process proceeds to step S1005. When print data including an encryption tag is received from the printer driver, the printer IDs do not match. On the other hand, when data stored by an application is received as it is, there is a case where even if there is encrypted data, it is encrypted with an encryption key that cannot be decrypted by the printer. In this case, the printer ID of the encryption tag includes a printer ID that does not match the printer ID stored in the printer information management unit 112.

  In step S1005, the encrypted confidential part is decrypted with the decryption key stored in the printer information management unit 112, and the process proceeds to step S1007. In the case of a public key cryptosystem, the decryption key is a secret key in this case. In step S1007, the print data including the decrypted confidential portion is printed. For example, as shown in FIG. 11, the confidential part is printed in plain text, that is, in a state created by the application 102. In step S1006, printing is performed by replacing the confidential portion with alternative data. For example, as shown in FIG. 12, a document in which the confidential information portion is replaced with alternative data “cannot be displayed” is printed.

  In the case of direct printing, there is a possibility that an encrypted confidential part (encryption tag) that cannot be decrypted by the printer is included in the print data. In this case, the select tag remains. Therefore, in step S1005, it is determined whether or not a select tag is included in the print data. If it is included, an encryption tag in which a printer ID that does not match the printer ID of the printer is described is deleted from the print data. Also delete open tags. Thereafter, the confidential information in the encryption tag in which the printer ID that matches the printer ID of the printer is described is decrypted.

  On the other hand, also in step S106, it is determined whether or not there is a select tag in the print data. Delete all other cryptographic tags. If there is no open tag, a predetermined symbol such as a frame line is inserted into the print data instead of the confidential information.

  The print data that can be directly printed is XML format data created in the same format as the host computer 101.

  In this embodiment, the data transmitted to the printer is in the XML format. However, the encrypted portion and the unencrypted portion can be clearly distinguished, and if the format at the time of printing can be specified, other data can be specified. It may be in the form of

  Note that the present invention can be applied to a system (for example, a copier, a facsimile machine, etc.) consisting of a single device even if it is applied to a system composed of a plurality of devices (eg, a host computer, interface device, reader, printer, etc.). You may apply. Another object of the present invention is to supply a recording medium recording a program code for realizing the functions of the above-described embodiments to a system or apparatus, and the system or apparatus computer reads out and executes the program code stored in the storage medium. Is also achieved. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  Further, according to the present invention, the operating system (OS) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. This is also included. Furthermore, the present invention is also applied to the case where the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. In that case, based on the instruction of the written program code, the CPU of the function expansion card or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing. .

1 is a block diagram showing a system configuration applicable to the present invention. It is a figure showing an internal configuration of a computer constituting the client or printer of the present invention. It is a flowchart which shows the print data generation process in an application. It is an example of a screen when a confidential part is designated in an application for creating data. It is a figure which shows the example of a screen of the window which designates the alternative data for replacing as non-secret data. It is a figure which shows the example of a data format when data is preserve | saved with an application. 5 is a flowchart illustrating print data selection processing in a printer driver. FIG. 4 is a diagram illustrating an example of a data format of data transmitted to a printer when encrypted data is selected by a printer driver. FIG. 4 is a diagram illustrating an example of a data format of data transmitted to a printer when non-confidential data is selected by a printer driver. 6 is a flowchart illustrating print processing in the printer main body. It is a figure which shows the example of a printing result when encryption data is printed. It is a figure which shows the example of a printing result when non-secret data is printed.

Explanation of symbols

101 Host computer 109 Printer 201 CPU
202 ROM
203 RAM
204 HD
205 LAN
206 System bus 207 Network

Claims (11)

A program executed by a computer connected to a printer,
Encryption means for generating encrypted confidential data obtained by encrypting a confidential portion designated in data to be printed by a method that can be decrypted by a printer that can be used by the computer;
The encrypted confidential data encrypted by the encryption means is associated with the identification information of a printer that can decrypt the encrypted confidential data, and both the substitute data substituting the confidential portion and the non-sensitive data other than the confidential portion Data storage means for storing print data;
If the print data stored by the data storage means includes encrypted confidential data encrypted by a method that can be decrypted by the printer to which the print data is sent, the encrypted confidential data is selected and included. If not, the program selects the substitute data, and causes the computer to function as a transmission unit that transmits the selected data and the non-confidential data to the destination printer. The encryption unit generates encrypted confidential data corresponding to the printer using an encryption key acquired from the printer,
The program according to claim 1, wherein the storage unit stores the encrypted confidential data in association with a printer identifier acquired from the printer together with the encryption key.   The program according to claim 1, wherein the data storage unit stores data in an XML format. A print data generation device connected to a printer,
Encryption means for generating encrypted confidential data obtained by encrypting a confidential portion designated in data to be printed by a method that can be decrypted by a printer that can be used by the computer;
The encrypted confidential data encrypted by the encryption means is associated with the identification information of a printer that can decrypt the encrypted confidential data, and both the substitute data substituting the confidential portion and the non-sensitive data other than the confidential portion Data storage means for storing print data;
If the print data stored by the data storage means includes encrypted confidential data encrypted by a method that can be decrypted by the printer to which the print data is sent, the encrypted confidential data is selected and included. If not, the print data generation apparatus further comprises a transmission unit that selects the alternative data and transmits the selected data and the non-confidential data to the destination printer. The encryption unit generates encrypted confidential data corresponding to the printer using an encryption key acquired from the printer,
The print data generation apparatus according to claim 4, wherein the storage unit stores the encrypted confidential data in association with a printer identifier acquired from the printer together with the encryption key. A printer device connected to a computer,
Determining means for determining whether or not the encrypted data is included in the print data received from the computer;
Generating means for decrypting the encrypted data and generating plain text print data together with the unencrypted portion when it is determined by the determining means that the encrypted data is included; ,
Printing data generated by the generating means, or printing means for printing the print data received from the computer when it is determined that the data encrypted by the determining means is not included. Printer device.   The determination unit further determines whether or not the encrypted data included in the print data can be decrypted by the generation unit, and if the decryption is possible, passes the encrypted data to the generation unit and decrypts it. 7. The printer apparatus according to claim 6, wherein if it is not possible, substitute data is transferred to the generation unit in place of the encrypted data. Storage means for storing an encryption key and a printer ID;
8. The printer apparatus according to claim 6, further comprising a unit that transmits an encryption key and a printer ID stored in the storage unit to the computer in response to a request from the computer.   A printing system comprising: the print data generation apparatus according to claim 4 or 5; and the printer apparatus according to any one of claims 6 to 8. A control method for a print data generation apparatus connected to a printer,
An encryption step for generating encrypted confidential data in which a confidential portion designated in data to be printed is encrypted by a method that can be decrypted by a printer that can be used by the computer;
The encrypted confidential data encrypted by the encryption step is associated with the identification information of a printer capable of decrypting the encrypted confidential data, and both the substitute data substituting the confidential portion and the non-sensitive data other than the confidential portion A data storage process for storing print data;
If the print data stored by the data storage step includes encrypted confidential data encrypted by a method that can be decrypted by the printer to which the print data is sent, the encrypted confidential data is selected and included. A control method for a print data generation apparatus, comprising: a transmission step of selecting the alternative data if not, and transmitting the selected data and the non-confidential data to the destination printer. A method of controlling a printer device connected to a computer,
A determination step of determining whether encrypted data is included in the print data received from the computer;
A generating step of generating plain text print data together with the unencrypted portion by decrypting the encrypted data when it is determined by the determining step that the encrypted data is included; ,
A printing step of printing the print data received from the computer when it is determined that the print data generated by the generation step or the data encrypted by the determination step is not included. A control method of the printer device.

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