JP2006237689A - Data management device and its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data management device high in security protection capability and capable of immediately reproducing an encryption key even if the encryption key is damaged. <P>SOLUTION: A control unit reads out a key (A) from an NVRAM 3, encrypts it by using a key (B), and writes it in an HDD 4 as a key (A1) when initializing the HDD 4. When job data are inputted from a host computer to the control unit via a communication part, the control unit encrypts the job data by using the key (A) in the NVRAM 3 and writes them in the HDD 4. When printing the job data in the HDD 4, the control unit reads out the encrypted job data in the HDD 4, decrypts them by using the key (A), and outputs them to an image forming part. When the key (A) is damaged due to errors in operation or the like, the control unit reads out the key (A1) from the HDD 4, decrypts it, and writes it in the NVRAM 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data management apparatus including a removable non-volatile storage device (such as a hard disk) such as a printer, a fax machine, a copier, a server, and a personal computer, and a program thereof.

In a printer or the like, font data and job data supplied from a host computer are stored in a hard disk (hereinafter referred to as HDD). Therefore, there is a problem that data is leaked when this HDD is taken away.
Conventionally, techniques described in Patent Documents 1 to 3 are known as techniques for preventing such data leakage. The technique of Patent Document 1 is that when video information and audio information are stored in a recording medium, a scramble process is performed using a key obtained by encrypting unique information in a recording / reproducing apparatus by an identifier of the recording medium. The technique of Patent Document 2 is to automatically delete a key after reproducing encrypted data stored on a recording medium such as a CD. The technique of Patent Document 3 encrypts a digital work based on device-specific information and stores it in a storage means such as a memory card.
JP 2002-260326 A JP 2003-303136 A JP 2003-131950 A

However, all of the techniques described in these patent documents have a drawback in that no consideration is given to breakage of a decryption key.
The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a data management device that has high security protection capability and can be immediately reproduced even when a decryption key is damaged, and a program thereof. It is to provide.

  The present invention has been made to solve the above-described problems. The invention according to claim 1 is directed to a removable storage device, a nonvolatile memory storing a first encryption key, and the storage device. Encryption means for encrypting data to be stored with the first encryption key; first writing means for writing data encrypted by the encryption means to the storage device; and data from the storage device First reading means for reading data, first decrypting means for decrypting data read by the first reading means with a first decryption key corresponding to the first encryption key, and Second encryption means for encrypting one decryption key, second write means for writing the first decryption key encrypted by the second encryption means to the storage device, and the storage First decryption key in the means Second reading means for reading, it is a data management apparatus according to claim comprising a second decoding means for decoding the first decryption key read by said second reading means.

  According to a second aspect of the present invention, there is provided a computer comprising a removable storage device and a non-volatile memory for storing a first encryption key. A first procedure for encrypting with a key; a second procedure for writing data encrypted by the first procedure into the storage device; a third procedure for reading data from the storage device; A fourth procedure for decrypting the data read by the procedure with a first decryption key corresponding to the first encryption key, and a fifth procedure for encrypting the first decryption key; , A sixth procedure for writing the first decryption key encrypted by the fifth procedure to the storage device, a seventh procedure for reading the first decryption key in the storage means, The first read by the procedure of 7 Is a program for executing an eighth step of decoding the decryption key.

  According to the present invention, the internal data can be protected even when the storage device is stolen, and even when the key for decrypting the data in the storage device is damaged, the data can be immediately reproduced. is there.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an image forming apparatus (printer) to which a data management apparatus according to an embodiment of the present invention is applied. In this figure, reference numeral 1 denotes a control unit constituted by a microprocessor and a ROM (Read Only Memory) in which a program of the processor is stored, and controls the entire apparatus. Reference numeral 2 denotes a RAM (random access memory) for temporary storage of data, 3 denotes an NVRAM (nonvolatile RAM), and the NVRAM 3 stores a key A for encrypting job data (print data). This key A is a unique key for each apparatus, and is set based on a serial number or the like. An HDD 4 stores font data and job data encrypted with the key A, and is configured to be removable. A communication unit 5 receives job data supplied from a host computer via a LAN (local area network) and outputs the job data to the control unit 1.

  Reference numeral 7 denotes an image forming unit which transfers a toner image onto a sheet using a photoconductor to form an unfixed toner image (unfixed image). As the material of the sheet, paper, plastic or the like is used. Reference numeral 8 denotes a mechanical drive unit that drives mechanical parts such as sheet feeding, paper discharge, and conveyance. A fixing unit 9 fixes the unfixed image on the sheet by the image forming unit 7. The fixing unit 9 heats and presses the sheet to fix the unfixed image. Further, the heat generation required for fixing an unfixed image is maintained even during standby. Thereby, it is possible to cope with an immediate start of image formation without warming up.

Next, the data writing / reading operation of the HDD 4 in the above-described image forming apparatus will be described with reference to FIGS.
First, the controller 1 reads the key A from the NVRAM 3 at the time of initialization of the HDD 4, encrypts it using the key B stored in advance in the internal ROM, and obtains it by encryption as shown in FIG. The key A1 is written to the HDD 4. Thereafter, when job data is input from the host computer to the control unit 1 via the communication unit 5, the control unit 1 encrypts the job data using the key A in the NVRAM 3 and writes it in the HDD 4. When printing job data in the HDD 4, the encrypted job data in the HDD 4 is read, decrypted using the key A, and output to the image forming unit 7. As described above, the key A is a unique key for each apparatus. Therefore, even if the HDD 4 is set in another image forming apparatus of the same standard, job data cannot be printed.

Next, when the key A is damaged due to an operation error or the like, the control unit 1 reads the key A1 from the HDD 4, decrypts it using the key B in the ROM, and is obtained by decryption as shown in FIG. The key A is written into the NVRAM 3.
As described above, in the above embodiment, job data is encrypted using the unique key A for each apparatus and stored in the HDD 4, so that even if the HDD 4 is stolen, the job data is printed by another apparatus. Security can be ensured. Further, according to the above embodiment, since the key A1 obtained by encrypting the key A with the key B in the control unit 1 is stored in the HDD 4, the key A1 is decrypted because there is no key B even if the HDD 4 is stolen. If the key A in the NVRAM 3 is damaged, the key A can be immediately reproduced by decrypting the key A1 in the HDD 4.

In the above embodiment, the encryption key and the decryption key are the same, but another key paired for encryption / decryption may be used. In this case, the key stored in the HDD 4 is a decryption key.
In the above embodiment, the HDD is used, but a memory card, an optical disk, a magneto-optical disk, or the like may be used instead.

  The present invention is used in an apparatus that processes electronic data such as a printer, a copier, a FAX, a server, and a personal computer.

It is a block diagram which shows the structure of the data management apparatus by one Embodiment of this invention. It is explanatory drawing for demonstrating the operation | movement of the embodiment. It is explanatory drawing for demonstrating the operation | movement of the embodiment.

Explanation of symbols

1 ... Control unit 2 ... RAM
3 ... NVRAM
4 ... HDD
5 ... Communication Department

Claims (2)

A removable storage device;
A non-volatile memory for storing the first encryption key;
Encryption means for encrypting data to be stored in the storage device with the first encryption key;
First writing means for writing the data encrypted by the encryption means to the storage device;
First reading means for reading data from the storage device;
First decryption means for decrypting data read by the first read means with a first decryption key corresponding to the first encryption key;
Second encryption means for encrypting the first decryption key;
Second writing means for writing the first decryption key encrypted by the second encryption means to the storage device;
Second reading means for reading the first decryption key in the storage means;
Second decryption means for decrypting the first decryption key read by the second read means;
A data management device comprising: A computer comprising a removable storage device and a non-volatile memory for storing a first encryption key;
A first procedure for encrypting data to be stored in the storage device with the first encryption key;
A second procedure for writing the data encrypted by the first procedure to the storage device;
A third procedure for reading data from the storage device;
A fourth procedure for decrypting the data read out by the third procedure with a first decryption key corresponding to the first encryption key;
A fifth procedure for encrypting the first decryption key;
A sixth procedure for writing the first decryption key encrypted by the fifth procedure into the storage device;
A seventh procedure for reading the first decryption key in the storage means;
An eighth procedure for decrypting the first decryption key read by the seventh procedure;
A program for running

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