JPH06124178A - Security system for print data - Google Patents

Abstract

PURPOSE:To exactly ensure security by preventing the content of security objective data existing in a spool queue from being known even when the third person tries to look in at the security objective data through a display or the like. CONSTITUTION:A print data preparing device 1 is equipped with a ciphered data preparing part 12 which ciphers print data, adds a user ID, key code, and ciphered ID to the ciphered data, and transfers the data to a printer side. A printer 2 is equipped with a ciphered data deciphering part 23 which deciphers the ciphered data based on the user ID or the like. The ciphered data transferred to the printer 2 are temporarily stored in a spool queue 22, and at the time of printing, the ciphered data are deciphered by the ciphered data deciphering part 23, and outputted, only when a pass word is matched. The ciphered data are stored in the spool queue 22, so that only the lump of the meaningless data can be seen even when the third person tries to look in at the content, and the content of the print data can be prevented from being known.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print data security system in a printing system.

[0002]

2. Description of the Related Art FIG. 10 is a diagram showing a state in which a host computer and a printer are connected to a network.
In FIG. 10, 100 is a network and 101 to 10
Reference numeral 5 is a printer, and 111 to 113 are host computers. The printers 101 to 105 are the network 100.
And output data from a plurality of host computers 111 to 113 connected to the network 100 is printed.

When the printer is shared by a plurality of users as described above, if the printer is directly output to the outside, the printed output data may be seen by a third party.
Confidentiality cannot be maintained. For this reason, a print data security method has been conventionally proposed in which measures are taken to maintain confidentiality. In the conventional general print data security method, normal print data is transferred to a printer with a password. The printer holds the transferred print data together with the password in the spool queue. When printing it, request the password from the operator and execute the printing only when the entered password matches the stored password to ensure security. I have to.

Prior art documents relating to such a print data security system include, for example, Japanese Patent Laid-Open Nos. 61-269729 and 62-3322.
Japanese Patent Laid-Open No. 159724/1989 and the like.

[0005]

[Problems to be Solved by the Invention]

(Problem) However, in the above-described conventional technique, when print data exists in the spool queue, a third party can see the content through a display or the like, and it is not possible to securely maintain the confidentiality of the data. There was a problem that it could not be done.

(Explanation of Problems) In the conventional method, the data cannot be printed unless the password is known, but the print data itself is normal data. Thus, when it is held in the spool queue, it is possible to see the contents of the data through a display attached to the printer if you wish to see it. Therefore, the confidentiality of the data cannot be surely maintained. An object of the present invention is to solve the above problems.

[0007]

In order to solve the above-mentioned problems, in the print data security system of the present invention,
The print data generation device has an encrypted data generation unit that encrypts the print data and adds the user ID, the key code, and the encryption ID to the encrypted print data and transfers the encrypted print data to the printer. After confirming that the spool queue storing the encrypted data and the password match, the encrypted data is taken out from the spool queue and decrypted and decrypted based on the user ID, key code and encrypted ID. It was decided to provide an encrypted data decryption unit that sends data to the print data output side.

[0008]

[Operation] The encrypted data generator of the print data generator encrypts all print data before transferring it to the printer. On the other hand, on the printer side, it is possible to prevent the print output from being output by a third party because the print output is performed after confirming the agreement of the passwords. Moreover, the encrypted print data can only be decrypted
It is time to print out, and the transferred data is stored in the spool queue as it is. Therefore, even if there is security target data in the spool queue, all the data is encrypted, and even if you try to view it through a display etc., you will see a group of data that has no meaning. The contents are not known to the three parties. Therefore, the confidentiality of the data can be surely maintained.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an outline of the present invention. In FIG. 1, 1 is a print data generation device, and 1
1 is a data print application, 12 is an encrypted data generation unit, 13 is an encrypted information storage unit, 14 is a magnetic disk, 2 is a printer, 21 is a data input unit, 22 is a spool queue, 23 is an encrypted data decryption unit, Reference numeral 24 is a decryption information storage unit, 25 is a key data processing unit, 26 is a magnetic disk, 27 is a print data output unit, and 28 is a recording unit.

The print data generating device 1 is a device having a function of generating print data, such as a host computer, a workstation, a personal computer and a word processor. The generated print data is temporarily stored in the magnetic disk 14. The data print application 11 activates the encrypted data generation unit 12 and gives an instruction as to which data of the print data stored in the magnetic disk 14 is to be processed. The encrypted data generation unit 12 encrypts the print data stored in the magnetic disk 14 based on the key code, the encryption ID, the encryption method, etc. stored in the encrypted information storage unit 13, and the printer Transfer to 2.

The data input unit 21 of the printer 2 stores the encrypted data in the spool queue 22 among the data transferred from the print data generating apparatus 1. The key data processing unit 25 extracts and holds the user ID, the encrypted ID, and the key code from the transferred data. The encrypted data decryption unit 23 receives the encrypted data from the spool queue 22, the corresponding user ID, encrypted ID, and key code from the key data processing unit 25, and further decrypts the encrypted data from the decryption information storage unit 24. It receives the decryption information such as the method and decrypts the encrypted data. The magnetic disk 26 temporarily holds the decrypted print data and then delivers it to the print data output unit 27.

FIG. 2 is a diagram showing an example of data stored in the encrypted information storage unit. FIG. 2A shows a key code / encryption ID storage table in which a plurality of key codes and encryption IDs to be used are stored for each user ID. FIG. 2B is an encryption method storage table that stores the encryption method corresponding to each encryption ID.

FIG. 3 is a diagram showing an example of data stored in the decryption information storage unit. FIG. 3A shows a security target user ID storage unit that stores user IDs of users who need to keep print data confidential. FIG. 3B is a user ID storage table,
For each logon class, the user ID of the user who is permitted to print out in that logon class is stored.
FIG. 3C is a cryptanalysis method storage table, which stores cryptanalysis methods corresponding to each encrypted ID. These decryption methods have a one-to-one correspondence with the encryption methods stored in the encryption method storage table of FIG. The "logon class" is used to distinguish the files that can be accessed and the programs that can be started when operating the printer according to the user. The number of files and programs that can be started increases.

Next, the contents of data transferred from the print data generating device 1 to the printer 2 will be described. FIG. 4 is a diagram showing an example of a transfer data format according to the present invention. This data is generated by the encrypted data generation unit 12 of the print data generation device 1, and the user ID, the encrypted ID, and the key code are added to the encrypted data.

Next, the operation of the present invention will be described with reference to the flow chart. The print data generation device 1
It is assumed that the respective data in the encrypted information storage unit 13 in the above and the decryption information storage unit 24 in the printer 2 are set in advance. First, the print data generation device 1
A procedure for encrypting print data and transferring it to the printer 2 in the encrypted data generation unit 12 will be described.

FIG. 5 is a flowchart showing an example of a procedure for encrypting and transferring print data. Step 1 ... The user ID input by the user is set to the portion A of the transfer data (see FIG. 4, hereinafter the same). Step 2 ... One of the plurality of key codes corresponding to the user ID in the encryption code storage table 13 (see FIG. 2A) is randomly selected. , At the location C of the transfer data. Step 3 ... One of the plurality of encrypted IDs corresponding to the key code of the encrypted information storage unit 13 and the user ID in the encrypted ID storage table (same as above) is randomly selected to transfer the transfer data. Set it at point B.

Step 4 ... Read the print data specified by the data print application 11 from the magnetic disk 14. Step 5: The print data is encrypted based on the encryption method corresponding to the encryption ID selected in Step 3 in the encryption method storage table of the encryption information storage unit 13 (see FIG. 2B). To do. Step 6 ... Set the encrypted data at the location D of the transfer data and transfer the data to the printer 2.

Next, the encrypted data decryption unit 2 of the printer 2
3, the procedure for decrypting the encrypted data and starting printing will be described. This procedure is started after the operator who wants to print out specifies the data to be printed and the logon class. FIG. 6 is a flowchart showing an example of a procedure for decrypting encrypted data and starting printing. Step 1 ... Acquires the user ID corresponding to the data to be printed from the key data processing unit 25. Step 2 ... Is the user ID obtained in Step 1 among the user IDs corresponding to the logon class designated by the operator in the user ID storage table of the decryption information storage unit 24 (see FIG. 3B)? Check whether or not. Step 3: If not, it means that the user is not permitted to print in the logon class. Therefore, a message prompting you to change the logon class is displayed on the display connected to the printer, and input is awaited. Step 4 ... User I acquired in Step 1 in the user ID corresponding to the changed logon class in the user ID storage table of the decryption information storage unit 24 (same as above)
Check if D is present. Step 5 ... When not present, it means that printing is not permitted even in the modified logon class. In that case, an error message is displayed on the display connected to the printer, and the process ends without printing.

Step 6 ... When there is a user ID in Steps 2 and 4, the user ID obtained in Step 1 is stored in the security target user ID storage unit of the decryption information storage unit 24 (see FIG. 3A). Check if there is. Step 7 ... If so, it means that it is necessary to keep the confidentiality of the print data. Therefore, in order to confirm whether or not the operator who is currently trying to print is the user who sent the print data, a message prompting the operator to enter the password is displayed on the display connected to the printer. , Wait for input. Step 8 ... It is determined whether or not the entered password matches the previously registered password. Step 9 ... If they match, the encrypted ID is acquired from the key data processing unit 25. Step 10 ... Then, the key code is acquired from the key data processing unit 25. Step 11: The decryption method corresponding to the encrypted ID obtained in step 9 is acquired from the decryption method storage table of the decryption information storage unit 24 (see FIG. 3C). Step 12 ... Decrypt the encrypted data. Step 13 ... The decoded print data is sent to the print data output unit 27 via the magnetic disk 26 to start printing.

In this way, first of all, it is possible to prevent a third person from printing out with the password. In addition, since the data stored in the spool queue is encrypted data, even if there is security data in the spool queue, all the data is encrypted and you can see it even if you try to view it through a display etc. Is a chunk of data that has no meaning,
There is no fear that a third party will know the contents. As a result, the confidentiality of the data is surely maintained. Further, not only the password but also the combination with the logon class is used to judge the permission / prohibition of print output, so that higher security can be secured. Furthermore, since the encryption method and the key code are randomly selected from a plurality of ones, even if the same data is encrypted, the probability that the first and second encrypted data will be the same is low, Data hiding is more sophisticated.

In the above embodiment, even if the logon class is changed in step 4, there is no user ID obtained in step 1 among the corresponding user IDs, or the password matches in step 8. When not
I displayed an error and did not print. However, in such a case, the encrypted data can be printed as it is without displaying an error. FIG. 7 is a flowchart showing another example of the procedure for decrypting encrypted data and starting printing. This flowchart is different from FIG. 6 in that when NO is determined in Steps 4 and 7, Step 5 (error display) in the flowchart of FIG. 6 is omitted and Step 12 (print start) is executed. 6 and the other procedures are the same. By doing this, for example, even if the passwords do not match, printing is executed, but the data is printed without decryption, so the data that is output is meaningless and the print data is confidential. Is retained.

In the above embodiments, the user ID in the transfer data format corresponds to an individual. However, it is also possible to handle it corresponding to the group. FIG. 8 is a diagram showing another example of data stored in the encryption information storage unit, and FIG. 9 is a diagram showing another example of data stored in the decryption information storage unit. FIG. 8A shows a group user ID storage table.
A user ID belonging to the group is stored for each group user ID. 8 (b) and 8 (c)
The table is similar to that shown in FIGS. 2A and 2B. 9 (a), 9 (b), and 9 (c) are similar to FIG.
(A), FIG. 3 (b) and FIG. 3 (c) have the same contents, but only the group user ID is set together with the user ID in the user ID storage table of FIG. 9 (b). They are different.

That is, the points of FIGS. 8 and 9 are different from those of FIGS. 2 and 3 in the print data generating apparatus 1 side for the group user I for a plurality of user IDs.
This is the point that defines D. Further, the printer 2 side also sets the group user ID in each logon class.

In this case, the user ID is also input as the ID to be input when performing the process in the print data generating apparatus 1. When the user ID is entered, FIG.
Based on the group user ID storage table of (a),
The group user ID to which the user belongs is acquired.
Then, the group user ID is set at the location A (see FIG. 4) of the transfer data. B of transfer data,
An encrypted ID and a key code corresponding to the user ID are set in the areas C, respectively. When performing the decryption on the printer 2 side, the group user ID
Are treated the same as user IDs.

Further, as shown in FIG. 10, when a plurality of host computers 111 to 113 and printers 101 to 105 are connected on the network, the user I
Instead of D, the machine ID of each host computer can be used to set whether or not printing is possible in host computer units. In that case, it is not always necessary that the host computer and the machine ID have a one-to-one correspondence.
One machine ID for multiple host computers
There is no problem even if it is given.

[0026]

As described above, the print data security system of the present invention has the following effects. First, the password can prevent a third party from printing out. Furthermore, since the data stored in the spool queue is encrypted data, even if there is security data in the spool queue, all of that data is encrypted and even if you try to view it through a display etc. There is no fear that the contents will be known to the three parties, and the confidentiality of the data is surely maintained. Further, as in the embodiment, if it is determined not only the password but also the logon class whether or not the print output is possible, higher security can be secured. Furthermore, if one of the encryption methods and the key code is randomly selected, the probability that the first encrypted data and the second encrypted data will be the same will be low even if the same data is encrypted. The hiding of will be more advanced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of the present invention.

FIG. 2 is a diagram showing an example of data stored in an encrypted information storage unit.

FIG. 3 is a diagram showing an example of data stored in a decryption information storage unit.

FIG. 4 is a diagram showing an example of a transfer data format according to the present invention.

FIG. 5 is a flowchart showing an example of a procedure for encrypting and transferring print data.

FIG. 6 is a flowchart showing an example of a procedure for decrypting encrypted data and starting printing.

FIG. 7 is a flowchart showing another example of a procedure for decrypting encrypted data and starting printing.

FIG. 8 is a diagram showing another example of data stored in the encrypted information storage unit.

FIG. 9 is a diagram showing another example of data stored in the decryption information storage unit.

FIG. 10 is a diagram showing a state in which a host computer and a printer are connected to a network.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Print data generation device, 11 ... Data print application, 12 ... Encrypted data generation part, 13 ... Encrypted information storage part, 14 ... Magnetic disk, 2 ... Printer,
21 ... Data input unit, 22 ... Spool queue, 23 ... Encrypted data decryption unit, 24 ... Decryption information storage unit, 25 ...
Key data processing unit, 26 ... Magnetic disk, 27 ... Print data output unit, 28 ... Recording unit, 100 ... Network, 101-105 ... Printer, 111-113 ... Host computer

Claims (1)

[Claims] 1. A print data generation device has an encrypted data generation unit that encrypts print data and adds a user ID, a key code, and an encrypted ID to the encrypted print data and transfers the print data to a printer. , The printer is
A spool queue that stores the transferred encrypted data,
After confirming that the passwords match, the encrypted data is taken out from the spool queue, decrypted based on the user ID, key code, and encrypted ID, and the decrypted data is sent to the print data output side. A print data security method having a copy section.