JP2008097075A - Restricted printing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing method that ensures preventing printing unintended by a user who requests printing. <P>SOLUTION: A key management server 2 retains key information used to decrypt encrypted print information in association with key identification information identifying the key information. When receiving an input associating the encrypted print information with the key identification information about key information used to decrypt the print information, a printer 3 sends the received key identification information to the key management server. The key management server 2 sends the key information associated with the key identification information received from the printer 3 to the printer 3 on a predetermined condition. The printer 3 decrypts the received print information with the key information received from the key management server 2, prints the decrypted print information, and erases the key information used for the decryption from the apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing system that performs printing based on a print job. In particular, the job creator intends when the job creator who created the print job is different from the print person who performs printing based on the print job. As described above, the present invention relates to a technique for preventing printing by a printing person.

  Conventionally, a print job for printing a document based on document data is generated by a computer, and the document is printed by using the print job by a printing apparatus.

The following inventions have been proposed as inventions related to printing.
An invention has been proposed in which unlimited printing is prevented by adding to the electronic information the number of times the electronic information to be printed can be printed, and controlling the electronic information to be printed in excess of the number of times that can be printed. (See Patent Document 1).

The printing device generates a pair of encryption key and decryption key, transmits the encryption key to the client, and the client encrypts the job using the received encryption key and provides it to the printing device having the corresponding decryption key Thus, an invention for preventing wiretapping of communication between the printing apparatus and the client has been proposed (see Patent Document 2).
JP 2001-184184 A Japanese Patent No. 3281235

  In recent years, a document creator stores a print job for printing a document in a file format on an external recording medium such as a magneto-optical disk (MO) and provides it to a printer, and requests the printer to print the document. Things have been done. In this case, even if the creator of the document intends to limit printing by the printing company to a certain number of times, the document can be reused and printed many times unless the printing company discards the file. End up.

  Here, Patent Document 1 discloses a technique for preventing unlimited printing, but electronic information is recorded because printing is restricted by adding the number of printable times to the electronic information (print job) itself. There is a problem that printing restrictions are effectively invalidated by electronically copying the file itself and submitting it to a printer a plurality of times or submitting it to a plurality of printers.

  The present invention has been made in view of the above-described conventional circumstances, and an object of the present invention is to provide a printing method that guarantees that printing more than intended by a user who has requested printing is not performed.

  According to the present invention, a restricted printing system includes a key management device having a decryption key management unit and a decryption key transmission unit, an encrypted job input unit, a decryption key acquisition unit, a decryption unit, a printing unit, and a decryption key deletion unit. It can be realized as a restricted printing system including a printing apparatus having the same, and can be realized as a method executed by the restricted printing system.

  The key management device holds, in the decryption key management means, key information used for decrypting encrypted print information for printing a document and key specifying information for specifying the key information in association with each other. Then, when the printing apparatus accepts an input in which the encrypted print information is associated with the key specifying information of the key information used for decrypting the print information, the decryption key obtaining unit In order to acquire key information corresponding to the received key specifying information, the key specifying information is transmitted to the key management apparatus, and the key management apparatus receives the key specifying information from the printing apparatus by the decryption key transmitting unit. In response, key information corresponding to the key identification information is transmitted to the printing apparatus, and the printing apparatus acquires the received print information from the key management apparatus corresponding to the transmitted key identification information by the decrypting unit. Decryption is performed using the key information, and printing is performed on the basis of the decrypted print information by the printing unit, and the key information used for the decryption is erased from the own apparatus by the decryption key erasing unit.

That is, the key management apparatus centrally manages key information used for decryption, and the printing apparatus acquires key information from the key management apparatus for each input of print information and uses the key information for decryption. Erase from own device.
In this way, since the key information is used up once, even if the same print information is input to the printing device, the key information used in the past cannot be reused, and the printing device obtains the key information again from the key management device. Therefore, the number of times of printing can be limited by performing transmission control of key information by the key management device. Further, since the key information is centrally managed by the key management apparatus, even if print information having the same content is input to a plurality of printing apparatuses, the number of printing can be limited by performing transmission control of the key information by the key management apparatus.

The key management apparatus can perform transmission control of key information by various methods.
For example, the decryption key management means stores the number of times key information used for decryption can be transmitted in association with the key information, and the number of times the decryption key transmission means transmits key information corresponds to the key information. This can be realized by transmitting the key information when the number of times attached is not reached.
Further, for example, the key management device can be realized by further including a transmitted decryption key erasure unit that erases the key information transmitted by the decryption key transmission unit from the decryption key management unit. In this case, the decryption key management unit When the number of times the key information can be transmitted is held in association with the key information, and the transmitted decryption key erasing means reaches the number of times the key information is transmitted corresponding to the key information. The key information may be deleted.

  The key management device includes key generation means for generating key information used for decryption in the key management device itself, in addition to obtaining key information used for decryption from another device and holding it in the decryption key management means. The generated key information can be held in the decryption key management means. The key generation means generates asymmetric key generation for generating a set of key information (encryption key) used for encryption and key information (decryption key) used for decrypting print information encrypted using the encryption key. Processing may be performed, and target key generation processing for generating key information (encryption / decryption key) used in common for encryption and decryption may be performed.

  Then, the key management apparatus can cause the decryption key management unit to hold the generated key information used for decryption and the key specifying information of the key information acquired by the process exemplified below.

  As processing corresponding to both the asymmetric key generation processing and the symmetric key generation processing, for example, a print job reception unit that receives print information from the user, and a key that receives the received print job from the key management device in correspondence with the print job Encrypting means for encrypting using information (encryption key or encryption / decryption key), and encryption by associating the encrypted print information with job specifying information (job ID) for specifying the print information as key specifying information A client device comprising: an encrypted job output means for outputting to the job input means; and a key management device, wherein the key management device receives the print information when the client device accepts the print information. And encryption key transmitting means for transmitting key information (encryption key or encryption / decryption key) used for encryption to the client device. It means for holding the job identification information of the print information that the client device has received (job ID) as the key identification information.

  Further, for example, the key management device encrypts the received print information using the print job reception unit that receives print information from the user and the generated key information (encryption key or encryption / decryption key) used for encryption. An encryption unit; an encrypted job output unit that outputs the encrypted print information to be input to the encrypted job input unit in association with job identification information (job ID) that identifies the print information as key identification information; The decryption key management means holds the job specifying information (job ID) of the received print information as key specifying information.

  As processing corresponding to the asymmetric key generation processing, for example, print job reception means that receives print information from the user, and key information (encryption key) that receives the received print job from the key management apparatus corresponding to the print job are used. Encryption means for encrypting the encrypted data, and an encrypted job to be output for input to the encrypted job input means by associating the encrypted print information with the key information (encryption key) used for the encryption as key specifying information A restricted printing system, and the key management device receives the generated key information (encryption key) used for encryption in response to reception of print information by the client device. The apparatus further comprises an encryption key transmitting means for transmitting to the apparatus, and the decryption key managing means retains the transmitted key information (encryption key) used for encryption as key specifying information.

  Also, for example, a print job receiving unit that receives print information from a user, an encryption unit that encrypts the received print information using the generated key information (encryption key), and An encrypted job output unit that outputs the encrypted print information to be input to the encrypted job input unit in association with the key information (encryption key) used for the encryption as the key specifying information. The key management means holds the key information (encryption key) used for the encryption as key specifying information.

  The key management device further includes client management means for holding client device identification information for identifying a client device to which key information used for encryption is to be transmitted, and the encryption key transmission means stores the client device identification information in the held client device identification information. When the corresponding client device receives print information, key information used for encryption of the print information may be transmitted to the client device.

  The key management device further includes a printing device management unit that holds printing device identification information for identifying a printing device to which key information used for decryption is transmitted, and the decryption key transmission unit holds the printing device When the key specifying information is received from the printing apparatus corresponding to the identification information, the key information corresponding to the key specifying information may be transmitted to the printing apparatus.

  The present invention accepts an input in which encrypted print information and key specifying information for specifying key information used for decrypting the print information are associated with each other, and accepts the print information as key information corresponding to the key specifying information. A communication unit that performs communication with a printing apparatus that decrypts and prints the key information used for the decryption from the own apparatus, and uses the key information and the key used to decrypt the encrypted print information. Decryption key management means for associating and holding key identification information of information, and decryption key transmission for transmitting key information corresponding to the key identification information to the printing apparatus in response to reception of the key identification information from the printing apparatus And a program that configures the key management apparatus by causing the computer to execute the program.

  The present invention holds key information used for decrypting encrypted print information and key specifying information for specifying the key information in association with each other, and receives the key specifying information in response to receiving the key specifying information. Encryption that accepts an input that associates communication means for communicating with a key management device that returns key information corresponding to the key information, and key specification information of the encrypted print information and key information used to decrypt the print information Job input means, decryption key acquisition means for transmitting the key specifying information to the key management device in order to acquire key information corresponding to the received key specifying information, and the received key specification for the received print information The decryption means for decrypting using the key information acquired from the key management apparatus corresponding to the information, the print means for performing printing based on the decrypted print information, and the key information used for the decryption. Decryption erased from the device And erasing means, also realized as a printing device equipped with, also, it can be realized as a program constituting the printing apparatus is executed by the computer.

  According to the present invention, since the printing apparatus acquires key information used for decrypting the print job from the key management apparatus and uses it for decryption, the printing apparatus deletes the key information from the own apparatus. Unless the key information is transmitted from the key management device, the print information cannot be decrypted and printed, and the number of times of printing can be limited by the key information transmission control by the key management device. Therefore, even if print information having the same content is input to the printing device a plurality of times or input to a plurality of printing devices, the key management device controls the transmission of the key information and prints based on the printing information. The number of printings can be limited, and printing can be limited as intended by the user who requested printing.

The present invention will be specifically described based on an example.
FIG. 1 shows the system configuration of a restricted printing system according to the present invention. The restricted printing system of this example is a client 1 that encrypts print information (print job) received from a user, an encryption key, and a decryption key. A key management server 2 that performs key generation management and a printer 3 that decrypts and prints an encrypted print job (encrypted job) are provided. The restricted printing system of this example includes a plurality of clients 1 and printers 3, which are omitted in FIG.

  The client apparatus 1 includes a job reception unit 11 that receives a print job from a user, an encryption key acquisition unit 12 that acquires the encryption key by transmitting the job ID of the print job to the key management server 2, and acquires a print job from the key management server 2. Encryption means 13 for encrypting using the encryption key, and encryption job output means 14 for outputting the job ID of the print job in association with the job ID of the print job as key specifying information to the encrypted job obtained by encrypting the print job. Yes.

  The key management server 2 includes a key generation unit 22 that generates a pair of an encryption key and a decryption key, and an encryption key transmission unit that transmits the generated encryption key to the client device 1 in response to receiving a job ID from the client device 1. 21, a key management table (decryption key management means) 23 that holds a decryption key corresponding to the transmitted encryption key in association with the received job ID, and a decryption corresponding to the job ID received from the printer 3 Decryption key transmission means 24 for obtaining a key from the key management table 23 and transmitting it to the printer 3, and transmitted transmitted decryption key erasure means 25 for erasing the transmitted decryption key from the key management table 23 under a predetermined condition. .

  As shown in FIG. 2A, the key management table 23 includes a job ID of the print job, a decryption key corresponding to the encryption key used for encrypting the print job, and the number of times the decryption key can be transmitted. Are associated with the key data. As will be described later, the number of times in the key data is input from the user when the client apparatus 1 accepts the print job and transmitted together with the job ID of the print job, and restricts the transmission of the decryption key. Used for.

Further, the key management table 23 holds a target printer ID for identifying the printer 3 to be managed, as shown in FIG. 4B, and the decryption key transmission means 24 is the printer 3 corresponding to the printer ID. A decryption key is transmitted when a job ID is received from.
Further, as shown in FIG. 3C, the key management table 23 holds a target client ID for identifying the client 1 to be managed, and the encryption key transmitting unit 25 stores the client 1 corresponding to the client ID. An encryption key is transmitted when a job ID is received from.

  The printer 3 includes an encrypted job input unit 31 that receives an input in which an encrypted job and a job ID are associated, an input job spool 32 that stores the input encrypted job, and an encrypted job to be processed from the input job spool 32. The job management means 33 for picking up one by one, the decryption key obtaining means 34 for obtaining the decryption key by transmitting the job ID associated with the extracted encrypted job to the key management server 2, and the encryption using the obtained decryption key. A decrypting unit 35 for decrypting the encrypted job, a printing unit 36 for performing printing based on the print job obtained by decrypting the encrypted job, and a decrypting key erasing unit 37 for erasing the decryption key used for the decryption. ing.

  In addition, although each function means with which the key management server 2 of this example is provided is comprised by making a computer run the program which concerns on this invention, you may make it comprise with a dedicated circuit element. In addition, each functional unit included in the printer 3 of the present example is configured by causing a computer to execute the program according to the present invention, but may be configured by a dedicated circuit element.

Encryption processing by the restricted printing system of this example will be described with reference to FIG.
When the job receiving unit 11 receives a print job and the number of times the print job can be printed from the user (step S11), the encryption key obtaining unit 12 receives the job ID of the received print job and the received job. Is transmitted to the key management server 2 (step S12).

  When the key management server 2 receives the job ID and the number of times from the client 1, the key generation unit 22 generates a pair of the encryption key and the decryption key (step S13), and transmits the generated encryption key to the client 1. (Step S14) The received job ID and the number of times and the generated decryption key are associated with each other and stored in the key management table 23 as key data (Step S15). It should be noted that a pair of encryption and decryption keys may be generated in advance, and transmission of the encryption key and association storage of the decryption key may be performed in response to reception of the job ID.

  When the client 1 acquires the encryption key from the key management server 2, the encryption unit 13 encrypts the print job using the acquired encryption key (step S16), and the encryption job output unit 14 encrypts the print job. The encrypted encryption job and the job ID of the print job are output in association with each other (step S17). The encrypted job may be directly output to the printer 3 using, for example, LPR (Line PRinter daemon protocol), IPP (Internet Printing Protocol), or the like. May be input to the printer 3 by loading the external recording medium into the printer 3.

Decryption processing by the restricted printing system of this example will be described with reference to FIG.
When the encrypted job input unit 31 receives an input in which the encrypted job and the job ID are associated with each other (step S21), the printer 3 stores the input in the input job spool 32. Then, the job management unit 33 takes out encrypted jobs one by one as a processing target, and the decryption key acquisition unit 34 transmits the job ID associated with the encrypted job to the key management device 34 (step S22). .

  When the key management server 2 receives the job ID from the printer 3, the decryption key transmission means 24 acquires the decryption key in the key data corresponding to the job ID from the key management table 23 and transmits it to the printer 3 (step S23), the transmitted key deletion unit 25 determines whether or not the key data satisfies the deletion condition, and deletes the key data when the deletion condition is satisfied (step S24). That is, even if the job ID is received after the erasure process, the decryption key is not transmitted because the corresponding key data does not exist. In this example, every time the decryption key is transmitted, the number of times in the key data is reduced by 1. When the number of times becomes 0, it is determined that the erasure condition is satisfied, and the data is erased. The number of transmissions is counted every time, and when the number of transmissions matches the number of times in the key data, it is determined that the erasure condition is satisfied, and erasure is performed.

  When the printer 3 receives the decryption key from the key management server 2, the decryption means 35 decrypts the encrypted job using the received decryption key (step S25), and the printing means 36 obtains the decryption key. Printing is performed based on the print job, and the decryption key deleting unit 37 deletes the decryption key used for the decryption and the decrypted print job (step S27).

  Therefore, since the decryption key is erased by one decryption process, for example, even when the same encrypted job is decrypted by the same printer 2, the decryption key must be obtained from the key management server 2 again. Printing can be surely restricted by the transmission control of the decryption key by the management server 2. In addition, since the key management server 2 manages the decryption key in a unified manner, even when the same encryption job is input to a plurality of printers 2, printing can be reliably restricted by the decryption key transmission control by the key management server 2. It becomes like this.

Note that the decryption key transmission control by the key management server 2 is not limited to the above-described method, and can be realized by other methods.
For example, the decryption key transmission means 24 determines whether or not to transmit by comparing the number of times of transmission of the key decryption key and the number of times in the corresponding key data, for example, without having the number of times in the key data, This can be realized by always deleting the key data once transmitted.

In addition, paper information for designating paper to be used for printing is associated with the print job, and for example, printing is performed by printing on paper such as a predetermined pattern (watermark) that appears on the copy destination paper. Document copying may be prevented.
A plurality of key management servers 2 are provided, and server identification information such as the IP address of the key management server 2 is associated with the print job, and each printer 3 receives a decryption key from the key management server 2 specified by the server identification information. May be obtained.

  In this example, the job ID is used as key specifying information, but an encryption key can also be used as key specifying information. That is, the key management table 23 holds the encryption key and the decryption key generated in pairs in association with each other, and the encrypted job output unit 14 encrypts the print job and the encryption used for the encryption. The key may be output in association with the key. Accordingly, the printer 3 receives an input in which the encryption job and the encryption key are associated with each other, and can transmit the encryption key to the key management server 2 to obtain the corresponding decryption key, thereby decrypting the encryption job. . In this case, encryption can be performed using a different encryption key for each page of the print job.

  In this example, the key generation means 22 performs an asymmetric key generation process for generating a pair of an encryption key and a decryption key, but a target key generation process for generating an encryption / decryption key used in common for encryption and decryption. Can also be configured. That is, the encryption key transmitting means 21 transmits the encryption / decryption key instead of the encryption key to the client 1 to perform encryption with the encryption / decryption key, and causes the key management table 23 to perform encryption / decryption instead of the decryption key. The decryption key may be held in association with the job ID, and the decryption key transmission unit 24 may transmit the encryption / decryption key to the printer 3 to perform decryption using the encryption / decryption key.

FIG. 5 shows the configuration of a restricted printing system according to another embodiment of the present invention.
The restricted printing system of this example has a configuration in which the client 1 has the key generation management function of the key management server 2 in FIG. 1, and the key generation unit 22 in FIG. 1 corresponds to the key generation unit 15 in FIG. The key management table 23 in FIG. 1 corresponds to the key management table 16 in FIG. 4, the decryption key transmission means 24 in FIG. 1 corresponds to the decryption key transmission means 17 in FIG. 4, and the transmitted decryption key deletion in FIG. The means 25 corresponds to the transmitted decryption key erasing means 18 shown in FIG.

  That is, when the job receiving unit 11 receives a print job from the user, the key generating unit 15 generates a pair of an encryption key and a decryption key, and the encryption unit 13 encrypts the print job using the encryption key. The encrypted job output unit 14 outputs the encrypted job obtained by encrypting the print job in association with the job ID of the print job. The generated decryption key is stored in the key management table 16 in association with the job ID of the print job. When the decryption key transmitting unit 17 receives the job ID from the printer 3, the decryption key corresponding to the job ID is stored. Is transmitted to the printer 3, and the transmitted key erasure unit 18 determines whether or not the transmitted decryption key satisfies the erasure condition. If the erasure condition is satisfied, the decryption key is erased.

  Note that the printer 3 is the same as the printer 3 described with reference to FIG. 1 except that the client 1 is the destination to which the decryption key acquisition unit 34 transmits the job ID to acquire the decryption key, and thus description thereof is omitted. .

  In this example, the job ID is used as key specifying information, but an encryption key can also be used as key specifying information. That is, the key management table 16 holds the encryption key and the decryption key generated in pairs in association with each other, and the encrypted job output unit 14 encrypts the print job and the encryption used for the encryption. The key may be output in association with the key. Accordingly, the printer 3 receives an input in which the encrypted job and the encryption key are associated with each other, and can transmit the encryption key to the client 1 to obtain the corresponding decryption key, thereby decrypting the encrypted job.

  In this example, the key generation unit 15 performs an asymmetric key generation process for generating a pair of an encryption key and a decryption key, but a target key generation process for generating an encryption / decryption key used in common for encryption and decryption. Can also be configured. That is, the encryption unit 13 encrypts the print job with the encryption / decryption key instead of the encryption key, and holds the encryption / decryption key in association with the job ID in the key management table 16 instead of the decryption key. The decryption key transmitting means 17 may transmit the encryption / decryption key to the printer 3 and perform decryption using the encryption / decryption key.

It is a figure which shows the structure of the restriction | limiting printing system which concerns on one Example of this invention. It is a figure explaining the information which the key management server which concerns on one Example of this invention manages. It is a figure explaining the encryption process which concerns on one Example of this invention. It is a figure explaining the decoding process which concerns on one Example of this invention. It is a figure which shows the structure of the restriction | limiting printing system which concerns on the other Example of this invention.

Explanation of symbols

1: Client 2: Key management server
3: Printer, 11: Job accepting means,
12: Encryption key acquisition means, 13: Encryption means,
14: encrypted job output means, 21: encryption key transmission means,
15, 22: Key generation means, 16, 23: Key management table,
17, 24: Decryption key transmission means 18, 25: Transmitted decryption key deletion means,
31: Encrypted job input means 32: Input job spool
33: Job management means 34: Decryption key acquisition means,
35: Decoding means, 36: Printing means,
37: Decryption key erasing means

Claims (18)

In a restricted printing system comprising: a printing device that performs printing based on print information for printing a document; and a key management device that communicates with the printing device.
The key management device is
Decryption key management means for holding key information used for decrypting encrypted print information and key specifying information for specifying the key information in association with each other;
In response to receiving the key specifying information from the printing apparatus, a decryption key transmitting means for transmitting key information corresponding to the key specifying information to the printing apparatus,
The printing device is
An encrypted job input means for receiving an input in which the encrypted print information and the key specifying information of the key information used for decrypting the print information are associated with each other;
Decryption key acquiring means for transmitting the key specifying information to the key management device in order to acquire key information corresponding to the received key specifying information;
Decrypting means for decrypting the received print information using the key information acquired from the key management device corresponding to the transmitted key specifying information;
Printing means for performing printing based on the decrypted print information;
Decryption key erasure means for erasing the key information used for the decryption from its own device;
A restricted printing system comprising: The restricted printing system according to claim 1,
The decryption key management means holds the number of times the key information can be transmitted in association with the key information,
The restricted printing system, wherein the decryption key transmission means transmits the key information when the number of times the key information is transmitted is less than the number associated with the key information. The restricted printing system according to claim 1,
The restricted printing system, wherein the key management device further comprises a transmitted decryption key erasure unit that erases key information transmitted by the decryption key transmission unit from the decryption key management unit. The restricted printing system according to claim 3.
The decryption key management means holds the number of times the key information can be transmitted in association with the key information,
The transmitted decryption key erasure unit erases the key information when the number of times the key information is transmitted reaches the number associated with the key information. The restricted printing system according to any one of claims 1 to 4,
The key management device further includes key generation means for generating key information used for decryption,
The restricted printing system, wherein the decryption key management means holds the generated key information. The restricted printing system according to claim 5,
The key generation unit further generates key information used for encrypting the print information, and the key information used for the decryption generated by the key generation unit is encrypted using the key information used for the encryption. A restricted printing system, which is key information used for decrypting a print job. The restricted printing system according to claim 5,
The restricted printing system, wherein the key information generated by the key generation means is key information that is commonly used for encryption and decryption of a print job. The restricted printing system according to claim 6 or 7,
The restricted printing system includes a client device that receives print information from a user,
The key management device further includes encryption key transmission means for transmitting the generated key information used for encryption to the client device in response to the client device receiving print information,
The decryption key managing means holds job specifying information for specifying print information received by the client device as key specifying information,
The client device is
Encryption means for encrypting print information received from a user using the key information received from the key management device corresponding to the print information;
An encrypted job output means for outputting the encrypted print information for associating the job specification information of the print information as key specification information and inputting it to the encrypted job input means;
A restricted printing system comprising: The restricted printing system according to claim 6 or 7,
The key management device includes:
Print job accepting means for accepting print information from a user;
Encryption means for encrypting the received print information using the generated key information used for encryption;
An encrypted job output means for outputting the encrypted print information to be input to the encrypted job input means in association with job specification information for specifying the print information as key specification information;
The restricted printing system, wherein the decryption key management unit holds job specifying information of the received print information as key specifying information. The restricted printing system according to claim 6, wherein
The restricted printing system includes a client device that receives print information from a user,
The key management device further includes encryption key transmission means for transmitting the generated key information used for encryption to the client device in response to the client device receiving print information,
The decryption key management means retains the transmitted key information used for encryption as key specifying information,
The client device is
Encryption means for encrypting print information received from a user using the key information received from the key management device corresponding to the print information;
An encrypted job output unit that outputs the encrypted print information to be input to the encrypted job input unit in association with the key information used for the encryption as the key specifying information;
A restricted printing system comprising: The restricted printing system according to claim 6, wherein
The key management device includes:
Print job accepting means for accepting print information from a user;
Encryption means for encrypting the received print information using the generated key information used for encryption;
An encrypted job output unit that outputs the encrypted print information to be input to the encrypted job input unit in association with the key information used for the encryption as the key specifying information;
The restricted printing system, wherein the decryption key management means holds key information used for the encryption as key specifying information. The restricted printing system according to claim 8 or 10,
The key management device further includes client management means for holding client device identification information for identifying a client device to which key information used for encryption is transmitted,
The encryption key transmitting means transmits, when the client device corresponding to the client device identification information receives print information, the key information used for encrypting the print information to the client device. system. The restricted printing system according to any one of claims 1 to 12,
The key management device further includes printing device management means for holding printing device identification information for identifying a printing device to which key information used for decryption is transmitted,
The decryption key transmission unit transmits the key information corresponding to the key identification information to the printing apparatus when the key identification information is received from the printing apparatus corresponding to the printing apparatus identification information. system. In a key management device for managing key information used for decrypting encrypted print information for printing a document,
Accepts input in which encrypted print information and key specification information for specifying key information used for decryption of the print information are associated, and decrypts the print information using key information corresponding to the key specification information Communication means for performing communication with a printing apparatus that prints and deletes the key information used for the decryption from its own apparatus,
Decryption key management means for holding the key information used for decrypting the encrypted print information and the key specifying information of the key information in association with each other;
A decryption key transmitting means for transmitting key information corresponding to the key specifying information to the printing apparatus in response to receiving the key specifying information from the printing apparatus;
A key management device comprising: In a printing apparatus that performs printing based on print information for printing a document,
The key information used for decrypting the encrypted print information is held in association with the key specifying information for specifying the key information, and the key corresponding to the key specifying information is received in response to the reception of the key specifying information. A communication means for communicating with a key management device for returning information;
An encrypted job input means for receiving an input in which the encrypted print information and the key specifying information of the key information used for decrypting the print information are associated with each other;
Decryption key acquiring means for transmitting the key specifying information to the key management device in order to acquire key information corresponding to the received key specifying information;
Decrypting means for decrypting the received print information using the key information acquired from the key management device corresponding to the transmitted key specifying information;
Printing means for performing printing based on the decrypted print information;
Decryption key erasure means for erasing the key information used for the decryption from its own device;
A printing apparatus comprising: In a program that configures a key management device that manages key information used for decrypting encrypted print information for printing a document by a computer,
Accepts input in which encrypted print information and key specification information for specifying key information used for decryption of the print information are associated, and decrypts the print information using key information corresponding to the key specification information A communication function for communicating with a printing apparatus that prints and deletes the key information used for the decryption from its own apparatus,
A decryption key management function for holding key information used for decrypting encrypted print information and key specifying information of the key information in association with each other;
A decryption key transmission function for transmitting key information corresponding to the key identification information to the printing apparatus in response to receiving the key identification information from the printing apparatus;
A program configured by causing a computer to execute. In a program that configures a printing apparatus that performs printing based on print information for printing a document by a computer,
The key information used for decrypting the encrypted print information is held in association with the key specifying information for specifying the key information, and the key corresponding to the key specifying information is received in response to the reception of the key specifying information. A communication function for communicating with a key management device that returns information;
An encrypted job input function for receiving an input in which the encrypted print information and the key specifying information of the key information used for decrypting the print information are associated with each other;
A decryption key acquiring function for transmitting the key specifying information to the key management device in order to acquire key information corresponding to the received key specifying information;
A decryption function for decrypting the received print information using the key information acquired from the key management device corresponding to the transmitted key identification information;
A print function for performing printing based on the decrypted print information;
A decryption key erasure function for erasing the key information used for the decryption from its own device;
A program configured by causing a computer to execute. In a method implemented by a restricted printing system comprising: a printing device that performs printing based on print information for printing a document; and a key management device that communicates with the printing device.
The key management device includes a decryption key management unit and a decryption key transmission unit, and the printing device includes an encryption job input unit, a decryption key acquisition unit, a decryption unit, a printing unit, and a decryption key. And erasing means,
The key management device holds, in the decryption key management means, key information used for decrypting encrypted print information and key specifying information for specifying the key information in association with each other,
The printing apparatus accepts an input in which the encrypted print information is associated with key specification information of key information used for decrypting the print information by the encrypted job input unit, and the decryption key acquisition unit , Transmitting the key specifying information to the key management device to obtain key information corresponding to the received key specifying information,
In response to receiving the key specifying information from the printing device by the decryption key transmitting means, the key management device transmits key information corresponding to the key specifying information to the printing device,
The printing apparatus decrypts the received print information using the key information acquired from the key management apparatus corresponding to the transmitted key identification information by the decryption means, and the decryption means performs the decryption by the printing means. A restricted printing method, wherein printing is performed based on the printed information, and the decryption key erasure unit erases the key information used for the decryption from the own apparatus.

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