JP4751632B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile that can back up data stored in a storage device such as a built-in hard disk device.

  In Patent Document 1, when backing up data in a built-in hard disk device, the time required for backup is predicted so as not to impair energy saving, and the backup is performed by the estimated time from the transition timing to the sleep mode. Copiers that start are described.

  Japanese Patent Laid-Open No. 2004-268832 discloses a security policy holding unit, a security policy rewriting unit, and an operation control according to the security policy so that the document can be managed based on the security policy describing the document handling rules. An image forming apparatus having a means is described.

JP 2004-148609 A JP2004-166241

In the copying machine described in Patent Document 1, there is no description relating to confidentiality of backed up data, and there is a risk of data leaking easily to those other than those involved.
In the image forming apparatus described in Patent Document 2, the data in the information system (image forming apparatus) is managed based on the security policy, but there is a description regarding the confidentiality of the backup data recorded on the removable recording medium. And there is a risk of data leaking easily to non-related parties.

An object of the present invention is to provide an image forming apparatus capable of maintaining the confidentiality of backup data in which data in a built-in storage device is recorded on a removable recording medium.
Another object of the present invention is to provide an image forming apparatus that can reproduce data only by an information recording / reproducing apparatus that has performed recording, and can maintain confidentiality of backup data recorded on a recording medium.

Another object of the present invention is to provide an image forming apparatus capable of reproducing data from a recording medium recorded by another information recording / reproducing apparatus when another information recording / reproducing apparatus is damaged.
Another object of the present invention is to provide an image forming apparatus capable of maintaining the confidentiality of backup data even if the encryption is decrypted.

In order to achieve the above object, an invention according to claim 1 is an image forming apparatus having a storage device for storing inputted data and an information recording / reproducing device for recording / reproducing data in the storage device on a recording medium. The information recording / reproducing apparatus encrypts the data when recording the data on the recording medium and records the data on the recording medium, and reproduces the data from the recording medium when reproducing the data from the recording medium. and decoding means for decoding the data, used for the encryption and the decryption, to the information recording and reproducing apparatus and a means for storing a specific encryption key, another of the information recording and reproducing apparatus is damaged The information recording / reproducing apparatus has storage means for storing an encryption key unique to the information recording / reproducing apparatus. Means for storing the manufacturing number of the apparatus and means for storing data unique to the information recording / reproducing apparatus, and encrypts the manufacturing number of the information recording / reproducing apparatus and the unique data and records them on the recording medium. The encrypted manufacturing number recorded on the recording medium and the unique data are decrypted, the decrypted manufacturing number and the manufacturing number stored in the information recording / reproducing apparatus match, and When the decrypted unique data matches the unique data stored in the information recording / reproducing device, the data reproduced from the recording medium is decrypted and input to the storage device, and the damaged separate A unique encryption key of the information recording / reproducing apparatus is additionally stored in the storage means, and the storage means stores a plurality of unique encryption keys in addition .

According to the present invention, it is possible to maintain confidentiality of backup data in which data in a built-in storage device is recorded on a removable recording medium.
According to the present invention, data can be reproduced only by the information recording / reproducing apparatus that performed the recording, and the confidentiality of the backup data recorded on the recording medium can be maintained.
According to the present invention, when another information recording / reproducing apparatus is damaged, data can be reproduced from the recording medium recorded by the other information recording / reproducing apparatus.
According to the present invention, confidentiality of backup data can be maintained even if the encryption is decrypted.

  FIG. 1 shows an image forming apparatus according to an embodiment of the present invention. In this embodiment, a scanner 1 that optically reads a document, a printer 2 that prints and outputs image data on paper, a network interface 3 for connecting to an external computer via a network, and a modem connected to a telephone line 4, a hard disk device 5 as a storage device for accumulating data read by the scanner 1, an optical disk device 7 for recording / reproducing data of the hard disk device 5 on an optical disk 6 as a recording medium, and the image forming apparatus by a user. An operation unit 8 including a button and a touch panel for operation, a liquid crystal display device for displaying characters and images, a CPU (Central Processing Unit) 9 for controlling the operation of the image forming apparatus, and an access by the CPU 9 RAM (Rando) that temporarily stores data And Access Memory) 10, ROM (Read Only Memory) 11 for storing control programs and fixed data such as the present image forming apparatus is connected to the system bus 12. Accordingly, the image forming apparatus functions as a facsimile, a copier, a scanner, a printer, and a data server.

  For example, when a facsimile destination number is input from the operation unit 8, the CPU 9 causes the scanner 1 to read the transmission original in the facsimile transmission mode, and stores the read data on the hard disk by the hard disk device 5, and then stores the data in the modem 4. Facsimile transmission is performed by transmitting via. In the facsimile reception mode, the CPU 9 stores facsimile reception data received by the modem 4 on the hard disk by the hard disk device 5 and prints it out by the printer 2 to perform facsimile reception.

  In the copy mode, the CPU 9 stores the original image data read by the scanner 1 on the hard disk by the hard disk device 5 and repeatedly outputs it to the printer 2 for the required number of sheets and prints it on paper, thereby causing it to function as a copier. . Further, in the data server mode, the CPU 9 stores the document image data read by the scanner 1 in the hard disk by the hard disk device 5, and the document image data is downloaded from an external computer via the network interface 3, or By sending it as an e-mail to a computer, it is used as a scanner for a computer.

  Also, image and document data input from an external computer via the network interface 3 is stored in the hard disk by the hard disk device 5, and then the data is output to the printer 2 and printed, thereby the printer for the computer. Let it be used as Furthermore, since the data stored in the hard disk by the hard disk device 5 can be accessed from a plurality of external computers via the network interface 3, it can also be used as a data server for sharing business data in an office or the like. The data stored in the hard disk of the hard disk device 5 is recorded on the optical disk 6 by the optical disk device 7 for backup.

  FIG. 2 shows the configuration of the optical disk device 7. A spiral or concentric track is formed on the optical disc 6 which is a recording medium for recording information, and data is recorded along this track. The track of the optical disc 6 is slightly wobbled at a constant period, and addresses over the entire surface of the optical disc 6 are recorded in advance by the change in frequency and phase. The optical disk 6 is rotated by a motor 13. The optical head 14 incorporates an optical system including a laser diode and a lens and a photoelectric conversion element, and irradiates the optical disk 6 with laser light from the laser diode through the lens and the like, and marks corresponding to data on the optical disk 6. The recorded mark is scanned with the laser beam, and the reflected light is received by the photoelectric conversion element to output an electrical signal. The electrical signal output from the optical head 14 is amplified by the operational amplifier circuit 15, and a reproduction signal corresponding to the mark on the optical disk 6 and a focus error indicating whether the laser beam is focused on the recording surface of the optical disk 6. A signal, a tracking error signal indicating whether or not the laser beam is scanned along the track of the optical disc 6, a signal corresponding to the meandering of the track, and the like are output.

  The servo circuit 16 controls the lens in the optical head 14 and the motor 13 by the focus error signal from the operational amplifier circuit 15, the tracking error signal, and the signal corresponding to the meandering of the track, thereby focusing the laser beam on the optical disc 6. The optical disk 6 is rotated at a constant linear velocity or a constant angular velocity. Although not shown, a mechanism for searching the data on the optical disk 6 by moving the optical head 14 in the radial direction of the optical disk 6 is also provided. The above is the operation for recording and reproducing marks on the track of the optical disc 6.

  Next, data processing at the time of recording / reproduction of the optical disc apparatus 7 will be described. First, the bus interface circuit 17 detects the input data from the system bus 12 to the optical disk device 7 by the built-in address decoder at the time of data recording to record data on the optical disk 6, and encrypts and decrypts the data. 18 When reproducing data from the optical disc 6, the bus interface circuit 17 outputs the data output from the encryption / decryption circuit 18 to the system bus 12.

  The encryption / decryption circuit 18 encrypts input data from the bus interface circuit 17 with an encryption key unique to the optical disk device 7 at the time of data recording for recording data on the optical disk 6, and then an error correction encoding / decoding circuit 19. Output to. The encryption / decryption circuit 18 decrypts the encrypted data from the error correction coding / decoding circuit 19 by using the same key as that at the time of data recording when reproducing the data from the optical disc 6 and performs bus interface. Output to the circuit 17.

  The error correction encoding / decoding circuit 19 adds data for performing error correction to the encrypted data from the encryption / decryption circuit 18 at the time of data recording to record data on the optical disc 6, thereby modulating and demodulating circuit 20 output. The error correction coding / decoding circuit 19 performs error correction decoding using the data added to the data from the modulation / demodulation circuit 20 at the time of data reproduction for reproducing data from the optical disc 6, thereby correcting the error. The subsequent data is output to the encryption / decryption circuit 18.

  When recording data on the optical disc 6, the modulation / demodulation circuit 20 sets the data inversion interval to a predetermined rule so that the DC component of the recording signal is reduced and the frequency component of the signal has a predetermined characteristic. At the same time, the data from the error correction coding / decoding circuit 19 is converted so as to meet the above conditions, and at the same time, a synchronization signal is inserted into the data and output to the laser driving circuit 21. The data conversion here is a process generally called RLL (Run Length Limited) modulation. At the time of data reproduction for reproducing data from the optical disk 6, the binary data from the data detection circuit 22 is converted (demodulated) by the synchronization signal from the data detection circuit 22, which is the reverse of the above data conversion.

  The laser drive circuit 21 records the mark and space corresponding to the binary data modulated by laser light irradiation on the optical disk 6 as a recording medium. A signal for driving the diode is generated. At the time of data reproduction for reproducing data from the optical disc 6, the reproduction signal output from the operational amplifier circuit 15 is subjected to waveform equalization by the waveform equalization circuit 23 to reduce errors when binarized by a threshold value. It is corrected as follows.

  Thereafter, the reproduction signal from the waveform equalization circuit 23 is binarized by the binarization circuit 24 at a predetermined threshold value. The data detection circuit 22 detects a synchronization signal from the output signal of the binarization circuit 24, and further generates a clock signal synchronized with data by a PLL circuit built in the data detection circuit 22. The data detection circuit 22 detects and outputs the binarized signal from the binarization circuit 24 as binary data of 0 and 1 based on the generated clock signal. Thereafter, the output signal of the data detection circuit 22 is demodulated by the modulation / demodulation circuit 20, error correction / decoding by the error correction coding / decoding circuit 19, and decryption of the cipher by the encryption / decryption circuit 18, and the bus interface circuit. 17 and output from the optical disc apparatus 7.

  Each circuit of the optical disk device 7 described above is connected to a system bus 28 together with a CPU 25, a RAM 26, and a ROM 27 for controlling the operation of the optical disk device 7. The system bus 12, the CPU 9, the RAM 10, and the ROM 11 illustrated in FIG. 1 are components in the image forming apparatus. In addition to these, the optical disc apparatus 7 includes a system bus 28, a CPU 25, a RAM 26, and a ROM 27 as components. A DVD + RW is used as the optical disk 6 and a laser diode having a laser beam wavelength of 650 nm is used as the optical head 14. As the optical head 14, a blue laser capable of recording at a higher density may be used, and a phase change optical disk corresponding to the laser wavelength (for example, 405 nm) may be used.

  FIG. 3 shows the internal configuration of the encryption / decryption circuit 18. The encryption / decryption circuit 18 holds an encryption circuit 29, a decryption circuit 30, a data selector 31 for switching data input to the encryption circuit 29, and various data set by the CPU 25 via the system bus 28. Registers 32-35 as storage devices, and registers 37, 38 as storage devices for holding data to be read by the CPU 25, and an address decoder for detecting the addresses of the registers 32-35, 37, 38 are incorporated. The bus interface circuit 39 controls the data transfer between the CPU 25 and the registers 32-35, 37, 38.

  The encryption key used for encryption and decryption is stored in nonvolatile storage means such as ROM 27 or EEPROM, and is set in the register 32 by the CPU 25. The encryption circuit 29 and the decryption circuit 30 receive the encryption key set in the register 32, and perform encryption and decryption of data using the encryption key, respectively. In addition to the encryption key, the serial number of the optical disk device 7 and data unique to the optical disk device 7 (hereinafter referred to as unique data) are also stored in a non-volatile storage means such as the ROM 27, and each is registered in the register 33 by the CPU 25. , 34 can be set.

  The encryption circuit 29 is manufactured by the data selector 31 from the hard disk device 5 via the system bus 12 and the bus interface circuit 17 (input data shown in FIG. 3) and the registers set in the registers 33 and 34. The number and unique data are switched and input. The data selector 31 performs the switching based on the data selector control data set in the register 35 by the CPU 25. For example, the data selector 31 uses the data selector control data as 2-bit data, and when the data selector control data is “00” and “11”, selects the input data from the bus interface circuit 17 to the encryption circuit 29. When the data selector control data is “01”, the serial number of the optical disk device 7 is selected and input to the encryption circuit 29. When the data selector control data is “10”, the unique data is selected and the encryption circuit is selected. 29. Thereby, the input data of the encryption circuit 29 is switched.

The decryption circuit 30 uses the same encryption key set in the register 32 as that used during data recording to reproduce the data from the optical disc 6 and reproduces the encrypted data from the error correction encoding / decoding circuit 19. Decode the serial number and unique data. The serial number and unique data in the output data of the decryption circuit 30 are held in registers 37 and 38, respectively. Thereby, the CPU 25 reads the serial number and unique data recorded on the optical disc 6 from the registers 37 and 38.
In this embodiment, since the same encryption key (shared encryption key) is used for encryption and decryption, the encryption method of the encryption circuit 29 is an AES (Advanced Encryption) which is a standard encryption method in the United States as an example. Standard) should be used.

  FIG. 4 is a diagram for explaining a method of using an encryption key for protecting the confidentiality of backup data recorded on the optical disk 6 when the data from the hard disk device 5 of the present embodiment is recorded on the optical disk 6 for backup. It is. First, in each of the optical disk devices 7 (hereinafter referred to as 7a and 7b) incorporated in the image forming apparatuses 40a and 40b of the present embodiment, a unique encryption key is stored in a nonvolatile storage means such as a ROM 27 or an EEPROM, respectively. 6 (hereinafter referred to as 6a and 6b), the encryption circuit 29 encrypts the data using the encryption key. Accordingly, data recorded on the optical disks 6a and 6b can be reproduced only by the recorded optical disk apparatus, and cannot be reproduced by another optical disk apparatus or an optical disk apparatus incorporated in another image forming apparatus. Here, this encryption key is called a recording / playback encryption key.

Originally, the purpose of backup is to record data reproduced from a hard disk of a hard disk device built in a specific image forming apparatus on an external recording medium (here, an optical disk), and return (record) it to the hard disk of the hard disk device again Therefore, there is no problem even if the data recorded on the optical disk cannot be reproduced by an optical disk apparatus other than the optical disk apparatus that recorded the data. As a result, the recorded data of the optical disk cannot be played back by an optical disk device other than the recorded optical disk device, so that the backup data can be kept confidential.
However, if the optical disk device is replaced with another optical disk device, for example, because the optical disk device is damaged, the recorded data of the optical disk recorded before the damage is damaged by the damaged optical disk device. Cannot play. Or, when the image forming apparatus itself in which the built-in optical disk apparatus is damaged is replaced with a new image forming apparatus having the same configuration as the image forming apparatus, the optical disk apparatus incorporated in the new image forming apparatus is damaged. Therefore, the backup data recorded by the damaged optical disk device cannot be reproduced by another optical disk device.

  Only when replacing such an optical disk apparatus or image forming apparatus, a new model of image formation is performed using the recording / reproducing encryption key of the damaged optical disk apparatus 7b or the optical disk apparatus 7b incorporated in another image forming apparatus as a reproduction-only encryption key. In addition to the recordable non-volatile storage means of the optical disk apparatus 7a replaced from the optical disk apparatus 7a or other image forming apparatus 40b in the apparatus, the information is stored. The number of read-only keys that can be added to the recordable nonvolatile storage means is not limited to one, but a plurality of keys can be added. By doing so, the data of the optical disc 6 recorded by the optical disc device before replacement can be reproduced by the optical disc device after replacement. Discard the optical disk device before replacement.

  In FIG. 4, the image forming apparatus after replacing the optical disk apparatus and the optical disk apparatus replaced after being damaged are the image forming apparatus 40a and the optical disk apparatus 7a. The optical disk device before the replacement of another image forming apparatus and the other image forming apparatuses are the optical disk device 7b and the image forming apparatus 40b. The optical disk devices 7a and 7b store the recording / reproducing encryption keys 1 and 2 in the nonvolatile storage means. At this stage, the data recorded on the optical disks 6 and 6a by the respective optical disk devices 40a and 40b can be reproduced only by the recorded optical disk device. When discarding the damaged optical disk device 7b to the new model image forming device 40a by replacement, or the optical disk device 7b not damaged and replaced, the nonvolatile memory such as the ROM 27 in the optical disk device 7b is discarded. The recording / reproducing encryption key 2 stored in the storage means is added as a reproduction-only encryption key 1 to the nonvolatile storage means in the optical disc device 40a. By doing so, the recording data of the optical disk 6b can be reproduced by the image forming apparatus 40a and the optical disk apparatus 7a.

  FIG. 5 shows a processing flow when data is reproduced from the optical disk 6 on which data encrypted by the recording / reproducing encryption key is recorded when the serial number of the optical disk apparatus 7 and data unique to the optical disk device 7 are not used. Show. First, the encrypted data (data reproduced from the optical disk 6) encrypted from the error correction coding / decoding circuit 19 by the decryption circuit 30 with the recording / reproducing encryption key stored in the ROM 27 in the optical disk device 7 in step S 1. Decrypted. At this time, the CPU 25 sets the recording / reproduction encryption key in the ROM 27 in the register 32, and the decryption circuit 30 is encrypted from the error correction coding / decryption circuit 19 using the recording / reproduction encryption key from the register 32. By decrypting the data, the data encrypted and recorded on the optical disc 6 is decrypted. In steps S2 and S3, the CPU 25 displays a part of the decoded data on the liquid crystal display device of the operation unit 8 via the system bus 12 in FIG. 1, thereby allowing the user to confirm the data.

  When decrypting the encrypted data recorded on the optical disc 6, it is impossible to mechanically detect whether the decrypted data is abnormal even if a different encryption key is used. Whether or not the converted data is abnormal is visually confirmed by a human from the display data of the liquid crystal display device of the operation unit 8. If the data is normal as a result of the confirmation, the user presses a display button such as “OK” on the touch panel of the operation unit 8 or the like. If the data is abnormal, the user presses a display button such as “NG”. If the “OK” button is pressed, the CPU 25 causes the optical disk device 7 to reproduce data from the optical disk 6 in accordance with an input signal from the “OK” button, and the decoding circuit 30 to the bus interface circuit 17 in step S4. The data is input to the hard disk device 5 to be recorded on the hard disk, and the process is terminated.

  When the “NG” button is pressed, the CPU 25 determines whether the reproduction-only encryption key is stored in the non-volatile storage means such as the ROM 27 in the optical disc apparatus 7 in step S5 according to the input signal from the “NG” button. If the reproduction-only encryption key is not stored in the non-volatile storage means such as the ROM 27, the CPU 25 determines that “data cannot be reproduced” on the liquid crystal display device of the operation unit 8 in step S10. A warning is displayed and the process is terminated.

  If the reproduction-only encryption key is stored in the non-volatile storage means such as the ROM 27, the CPU 25 sets the reproduction-only encryption key in the register 32 in step S6, and again encrypts it from the error correction coding / decoding circuit 19. The decrypted data (data reproduced from the optical disc 6) is decrypted by the decryption circuit 30. In steps S7 and S8, the CPU 25 displays a part of the decrypted data on the liquid crystal display device of the operation unit 8, thereby confirming whether the decrypted data is abnormal to the user. Let If the “OK” button is pressed as a result of the confirmation, the CPU 25 jumps to step S4 in response to an input signal from the “OK” button, causes the optical disk device 7 to reproduce data from the optical disk 6 and decodes the decoding circuit. The data is output from 30 through the bus interface circuit 17 so that the data is input to the hard disk device 5 and recorded on the hard disk, and the process is terminated.

  When the “NG” button is pressed, the CPU 25 determines whether another reproduction-only encryption key is stored in the nonvolatile storage means such as the ROM 27 of the optical disc apparatus 7 in step S9, and the nonvolatile storage means. If another reproduction-only encryption key is stored in step S6, the process returns to step S6 to set the reproduction-only encryption key in the register 32 and decrypt the encrypted data from the error correction coding / decoding circuit 19 again. The decryption circuit 30 performs decryption.

  When the “NG” button is further pressed in step S8, the CPU 25 determines in step S9 whether another reproduction-only encryption key is further stored in the nonvolatile storage means such as the ROM 27 in the optical disc apparatus 7. Repeatedly, as long as there is a reproduction-only encryption key stored in the nonvolatile storage means such as the ROM 27, the process returns to step S6 until the “OK” button is pressed, and the reproduction-only encryption key is set in the register 32 and error correction is performed again. The encrypted data from the encoding / decoding circuit 19 is decoded by the decoding circuit 30. When there is no encryption key that can be normally decrypted in the nonvolatile storage means such as the ROM 27 in the optical disk device 7, the CPU 25 warns the liquid crystal display device of the operation unit 8 that "data cannot be reproduced" in step S10. Is displayed and the process is terminated.

  By doing so, it is possible to protect the confidentiality of the backup data recorded on the optical disk 6 when the data recorded on the hard disk in the hard disk device 5 built in the image forming apparatus is backed up to the optical disk 6. In addition, the recording / reproducing encryption key of another optical disk device can be stored in the non-volatile storage means as a reproduction-only encryption key, and the optical disk data recorded by the other optical disk device can also be reproduced. It can also be used when replacing equipment.

  In this case, since the optical disk 6 on which the backup data is recorded cannot be reproduced by another optical disk device, the backup data can be kept secret. However, the optical disk device is removed from the image forming apparatus, and the optical disk and the optical disk device are stolen. Backup data leaks to a third party. In view of this, a mechanical key may be used in combination for attaching and detaching the optical disk device 7 to and from the image forming apparatus of the present embodiment. This key is stored in a separate location from the image forming apparatus. Also, if the mechanical key has a built-in wireless tag and the key and the keyhole mechanism send and receive the encryption to release and lock the key, even if the key is duplicated mechanically, It is even better because the person cannot unlock the key.

  In the above case, only the data to be recorded on the optical disk is encrypted. However, the manufacturing number of the optical disk device 7 is also encrypted and recorded on the optical disk 6, and when the data is reproduced, the manufacturing number of the optical disk device 7 read from the optical disk 6 A case will be described below in which the production number of the optical disk device 7 that is being reproduced is compared and data is output only when the two match, thereby improving the security of the confidential maintenance of the backup data. In this case, even if a malicious third party steals the optical disc, obtains the same type of optical disc device as the optical disc device 7 and decrypts the encryption key of the optical disc, the stealed optical disc data is reproduced. There is an effect to make it impossible.

  First, the operation of encrypting and recording the serial number of the optical disk device 7 on the optical disk 6 will be described. As shown in FIG. 3, the CPU 25 sets the manufacturing number of the optical disk device 7 in the register 33, and sets data selector control data for the data selector 31 to select the manufacturing number of the optical disk device 7 in the register 35. The serial number of the optical disk device 7 set in the register 33 is selected by the data selector 31 by the data selector control data set in the register 35 and encrypted by the encryption circuit 29, and the error correction encoding / decoding circuit By being output to 19, it is recorded on the optical disc 6.

  The CPU 25 sets data selector control data for selecting input data from the data selector 31 in the register 35 when the input data from the bus interface circuit 17 is encrypted and recorded on the optical disc 6. Therefore, the input data from the bus interface circuit 17 is selected by the data selector 31 according to the data selector control data set in the register 35, encrypted by the encryption circuit 29, and output to the error correction coding / decoding circuit 19. As a result, the data is recorded on the optical disc 6.

  In FIG. 4, when the recording / reproducing encryption key 2 of the image forming apparatus 40b is added to the non-volatile storage means as the reproduction-only encryption key 1 of the image forming apparatus 40a, the serial number of the optical disk device 7b of the image forming apparatus 40b. Are also stored in addition to the non-volatile storage means of the optical disc apparatus 7a. In this way, the encryption key and manufacturing number unique to the optical disc apparatus 7a are used in pairs.

  FIG. 6 shows a processing flow when reproducing backup data from the optical disk 6 when a pair of encryption key and serial number unique to the optical disk device 7a is used. First, in step S11, the encrypted data (data reproduced from the optical disk) from the error correction coding / decoding circuit 19 by the decryption circuit 30 using the recording / reproduction encryption key stored in the ROM 27 in the optical disk device 7 is obtained. Decrypted. At this time, the CPU 25 sets the recording / reproduction encryption key in the ROM 27 in the register 32, and the decryption circuit 30 is encrypted from the error correction coding / decryption circuit 19 using the recording / reproduction encryption key from the register 32. The serial number of the optical disc device 7 is decrypted, and the decrypted serial number of the optical disc device 7 is held in the register 37. Next, in step S12, the CPU 25 compares the manufacturing number of the optical disk device 7 held in the register 37 with the manufacturing number of the optical disk device 7 stored in the nonvolatile storage means of the optical disk device 7, and the two match. If the two match, in step S13, the optical disk device 7 reproduces the data from the optical disk 6 and outputs it from the decoding circuit 30 via the bus interface circuit 17. The data is input to the hard disk device 5 and recorded on the hard disk, and the process is terminated.

  If they do not match, the CPU 25 determines whether or not the reproduction-only encryption key is stored in the nonvolatile storage means in the optical disk device 7 in step S14, and the CPU 25 determines that the reproduction-only encryption key is the optical disk device. If it is not stored in the nonvolatile storage means 7, a warning such as “Data cannot be reproduced” is displayed on the liquid crystal display device of the operation unit 8 in step S 18, and the process is terminated.

  If the reproduction-only encryption key is stored in the non-volatile storage means in the optical disk device 7, the CPU 25 sets the reproduction-only encryption key in the register 32 in step S15, and again from the error correction coding / decoding circuit 19 The serial number of the optical disc apparatus (reproduced from the optical disc 6) is decrypted by the decryption circuit 30. In step S16, the CPU 25 determines whether or not the decrypted serial number of the optical disc device matches the serial number of the optical disc device corresponding to the reproduction-only encryption key stored in the nonvolatile storage means in the optical disc device 7. If the two match, the process proceeds to step S13 where the optical disk device 7 reproduces the data from the optical disk 6 and outputs the data from the decoding circuit 30 via the bus interface circuit 17 to the hard disk device 5. The data is input and recorded on the hard disk, and the process ends.

  Further, if they do not match, the CPU 25 determines whether or not another reproduction-only encryption key is stored in the nonvolatile storage means of the optical disc apparatus 7 in step S17, and the nonvolatile storage in the optical disc apparatus 7 is determined. If another reproduction-only encryption key is stored in the means, the process returns to step S15, the reproduction-only encryption key is set in the register 32, and the encrypted optical disk device from the error correction encoding / decoding circuit 19 is again set. The serial number is decrypted by the decryption circuit 30.

  If the two further do not match in step S16, the CPU 25 repeatedly determines whether or not another read-only encryption key is stored in the nonvolatile storage means in the optical disk device 7 in step S17. As long as there is a reproduction-only encryption key stored in the non-volatile storage means, the process returns to step S15 to set the reproduction-only encryption key in the register 32 until the two further match in step S16, and error correction coding is performed again. The decryption circuit 30 decrypts the encrypted serial number of the optical disk device from the decryption circuit 19. If there is no encryption key in the non-volatile storage means in the optical disk device 7 that can normally decrypt the serial number of the optical disk device, the CPU 25 "cannot reproduce data" on the liquid crystal display device of the operation unit 8 in step S18. Is displayed, and the process is terminated.

  By doing so, even if the encryption is decrypted, the confidentiality of the backup data recorded on the optical disk 6 when the data recorded on the hard disk in the hard disk device 5 built in the image forming apparatus is backed up to the optical disk 6 can be protected. . Further, the recording / playback encryption key of another optical disk device is stored in the nonvolatile storage means of the optical disk device 7a as a reproduction-only encryption key, and the manufacturing number of the other optical disk device is also stored in the nonvolatile storage means of the optical disk device 7a. Therefore, the optical disk data recorded by another optical disk device can also be reproduced, and it is possible to cope with the replacement of the image forming apparatus and the optical disk device.

  Further, when data is reproduced from the optical disk, the serial number of the optical disk apparatus read from the optical disk is compared with the serial number of the optical disk apparatus performing the reproduction, and data is output only when the two match. Even if a malicious third party steals the optical disc, obtains another optical disc device of the same model, and decrypts the encryption key, the data of the stolen optical disc cannot be reproduced.

  In the above case, the serial number of the optical disk device is also encrypted and recorded on the optical disk. However, there is a possibility that the serial number of the optical disk device will be known to a third party. Therefore, a case will be described in which unique data is assigned to each optical disk device and the unique data is inserted into the data at regular intervals when the data is encrypted and recorded on the optical disk. In this case, at the time of data reproduction, the unique data inserted into the data read from the optical disk is compared with the unique data of the optical disk apparatus that is reproducing, and the data read from the optical disk is output only when both match. And improve the security of confidential maintenance of backup data. This is because even if a malicious third party steals an optical disc, obtains an optical disc device of the same model that is different from the optical disc device 7, and decrypts the encryption key and serial number, the data on the stolen optical disc is reproduced. There is an effect to make it impossible.

  First, the operation of inserting the unique data of the optical disc device 7 into the data to be recorded on the optical disc 6, encrypting it and recording it on the optical disc 6 will be described. As data unique to the optical disk device 7, for example, a 128-bit random number consisting of 1 and 0 is generated, assigned to each optical disk device, and stored in the nonvolatile storage means of the optical disk device 7. As shown in FIG. 3, the CPU 25 reads the unique data of the optical disc device 7 from the nonvolatile storage means of the optical disc device 7 and sets it in the register 34. Then, the CPU 25 switches the input so that the specific data is inserted into the data input from the hard disk device 5 via the system bus 28 and the bus interface circuit 17 at regular intervals. The data selector control data is set in the register 35. Therefore, the data selector 31 inserts the specific data of the optical disk device set in the register 34 at regular intervals with respect to the data input from the hard disk device 5 via the system bus 28 and the bus interface circuit 17. The output of the data selector 31 is encrypted with the encryption key set in the register 32 by the encryption circuit 29 and output to the error correction encoding / decoding circuit 19, thereby being recorded on the optical disk 6.

  As shown in FIG. 4, when the recording / reproducing encryption key 2 of the image forming apparatus 40b is added to the non-volatile storage means of the optical disc apparatus 7a as the reproduction-only encryption key 1 of the image forming apparatus 40a, the image forming apparatus 40b The unique data of the optical disk device 7b is also stored in addition to the nonvolatile storage means of the optical disk device 7a. In this way, the encryption key and unique data unique to the optical disc apparatus 7 are used in pairs.

  FIG. 7 shows a processing flow when reproducing backup data from the optical disk 6 when the encryption key and the unique data unique to the optical disk apparatus 7 are used in pairs. First, in step S21, the encrypted data from the error correction coding / decoding circuit 19 is decrypted by the decryption circuit 30 using the recording / playback encryption key stored in the nonvolatile storage means in the optical disk device 7. At this time, the CPU 25 sets the recording / reproducing encryption key in the non-volatile storage means in the optical disc apparatus 7 in the register 32, and the decryption circuit 30 uses the recording / reproducing encryption key from the register 32 to perform error correction coding / decoding. The read data of the optical disk 6 from the converting circuit 19 is decoded, and the CPU 25 detects data unique to the optical disk device 7 from the decoded data and stores it in the register 38.

  Next, in step S22, the CPU 25 compares the unique data held in the register 38 with the unique data stored in the non-volatile storage means in the optical disc device 7 to determine whether or not they match. If they match, the data is reproduced from the optical disk 6 to the optical disk device 7 in step S23 and output from the decoding circuit 30 via the bus interface circuit 17 so that the data is input to the hard disk device 5. Record on the hard disk and finish the process. If they do not match, the CPU 25 determines whether or not the reproduction-only encryption key is stored in the nonvolatile storage means in the optical disk device 7 in step S24, and the reproduction-only encryption key is stored in the optical disk device 7. If not stored in the non-volatile storage means, a warning such as “Data cannot be reproduced” is displayed on the liquid crystal display device of the operation unit 8 in step S28, and the process is terminated.

  If the reproduction-only encryption key is stored in the non-volatile storage means in the optical disk device 7, the CPU 25 returns to step S25, sets the reproduction-only encryption key in the register 32, and again returns to the error correction coding / decoding circuit. The encrypted data from 19 (data reproduced from the optical disc 6) is decrypted by the decryption circuit 30, and the unique data is detected from the decrypted data. In step S26, the CPU 25 determines whether or not the decrypted unique data matches the unique data corresponding to the reproduction-only encryption key stored in the non-volatile storage means in the optical disc device 7. If they match, the process proceeds to step S23 where the optical disk device 7 reproduces the data from the optical disk 6 and outputs the data from the decoding circuit 30 via the bus interface circuit 17 so that the data is input to the hard disk device 5 and the hard disk And finish the process.

  Further, if they do not match, the CPU 25 determines whether or not another reproduction-only encryption key is stored in the nonvolatile storage means of the optical disc apparatus 7 in step S27, and the nonvolatile storage in the optical disc apparatus 7 is determined. If another reproduction-only encryption key is stored in the means, the process returns to step S25, the reproduction-only encryption key is set in the register 32, and the encrypted data from the error correction coding / decoding circuit 19 is again stored. Decryption is performed by the decryption circuit 30.

  If the two further do not match in step S26, the CPU 25 repeatedly determines whether or not another reproduction-only encryption key is stored in the nonvolatile storage means in the optical disk device 7 in step S27. As long as there is a read-only encryption key stored in the non-volatile storage means, the process returns from step S27 to step S25 until the two match in step S26, and the read-only encryption key is set in the register 32 and an error occurs again. The encrypted data from the correction encoding / decoding circuit 19 is decoded by the decoding circuit 30. If the CPU 25 does not have an encryption key that can normally decrypt the data in the non-volatile storage means in the optical disk device 7, a warning such as “Data cannot be reproduced” is displayed on the liquid crystal display device of the operation unit 8 in step S28. Display and finish the process.

  By doing so, even if the encryption is decrypted, the confidentiality of the backup data recorded on the optical disk 6 when the data recorded on the hard disk in the hard disk device 5 built in the image forming apparatus is backed up to the optical disk 6 can be protected. . In addition, the recording / playback encryption key of another optical disk device is stored in the nonvolatile storage means as a playback-only encryption key, and the serial number of the optical disk device is also stored, so that the optical disk data recorded by the other optical disk device is also played back. It is also possible to replace the image forming apparatus or the optical disk apparatus.

  Further, when data is reproduced from the optical disk, the unique data read from the optical disk is compared with the unique data of the optical disk apparatus that is performing the reproduction, and the data is output only when they match. Even if a third party steals an optical disc, obtains another optical disc device of the same model, and decrypts the encryption key, the recorded data of the stolen optical disc cannot be reproduced.

  In the above embodiment, either the serial number of the optical disk device or the unique data is used. However, if both the serial number of the optical disk device and the unique data are combined, the security maintenance of the backup data recorded on the optical disk is further performed. Safety can be improved. In the following, a case will be described in which the serial number and unique data of the optical disk device are used in combination in this embodiment.

  First, the operation of inserting the unique data of the optical disk device into the data and encrypting and recording the data and the manufacturing number of the optical disk device will be described. As shown in FIG. 3, the CPU 25 sets the manufacturing number of the optical disk device 7 in the register 33 and sets unique data of the optical disk device 7 in the register 34. Further, the CPU 25 sets data selector control data for the data selector 31 to select the manufacturing number of the optical disk device 7 in the register 35, and sets the manufacturing number of the optical disk device 7 set in the register 33 via the data selector 31. The data is recorded on the optical disc 6 by being encrypted by the encryption circuit 29 and outputted to the error correction coding / decoding circuit 19. Next, the CPU 25 stores the data selector control data in the register 35 so that the unique data is inserted into the data input from the hard disk device 5 via the system bus 28 and the bus interface circuit 17 at regular intervals. Set. Therefore, the data selector 31 inserts the specific data of the optical disk device set in the register 34 at regular intervals with respect to the data input from the hard disk device 5 via the system bus 28 and the bus interface circuit 17. The output of the data selector 31 is encrypted with the encryption key set in the register 32 by the encryption circuit 29 and output to the error correction encoding / decoding circuit 19, thereby being recorded on the optical disk 6.

  Further, as shown in FIG. 4, when the CPU 25 adds the recording / reproducing encryption key 2 of the image forming apparatus 40b to the non-volatile storage means of the optical disc apparatus 7a as the reproduction-only encryption key 1 of the image forming apparatus 40a, the image formation is performed. The serial number and unique data of the optical disk device 7b of the device 40b are also stored in addition to the nonvolatile storage means of the optical disk device 7a. In this way, the encryption key, serial number, and unique data unique to the optical disc apparatus are used as a set.

  FIG. 8 shows a processing flow when reproducing backup data from an optical disc when using a set of an encryption key, a serial number and unique data unique to the optical disc apparatus. First, in step S31, the encrypted data from the error correction coding / decoding circuit 19 (reproduced from the optical disk 6) is decrypted by the decryption circuit 30 using the recording / playback encryption key stored in the non-volatile storage means in the optical disk device 7. Data) is decrypted. At this time, the CPU 25 sets the recording / reproducing encryption key in the nonvolatile storage means of the optical disc apparatus 7 in the register 32, and the decryption circuit 30 uses the recording / reproducing encryption key from the register 32 to perform error correction encoding. The serial number of the optical disc device reproduced from the optical disc 6 input from the decryption circuit 19 is decrypted, and the CPU 25 causes the register 37 to hold the decrypted serial number of the optical disc device. Further, the decryption circuit 30 decrypts the read data of the optical disc 6 from the error correction coding / decryption circuit 19 using the recording / playback encryption key from the register 32, and the CPU 25 is specific to the optical disc apparatus from the decrypted data. Is detected and held in the register 38.

  Next, in step S32, the CPU 25 compares the serial number of the optical disc device 7 held in the register 37 with the serial number of the optical disc device 7 stored in the nonvolatile storage means of the optical disc device 7, and the two match. And the unique data held in the register 38 is compared with the unique data stored in the non-volatile storage means of the optical disk device 7 to determine whether or not the two match. If both of the manufacturing number and the unique data match, the data is reproduced from the optical disk 6 to the optical disk device 7 and output from the decoding circuit 30 via the bus interface circuit 17 in step S33. The data is input to the hard disk device 5 and recorded on the hard disk, and the process is terminated. If the CPU 25 does not agree with either or both of the manufacturing number and unique data of the optical disk device, is the reproduction-only encryption key stored in the non-volatile storage means in the optical disk device 7 in step S34? If the reproduction-only encryption key is not stored in the non-volatile storage means in the optical disk device 7, a warning such as “Data cannot be reproduced” is displayed on the liquid crystal display device of the operation unit 8 in step S38. Then, the process ends.

  If the reproduction-only encryption key is stored in the non-volatile storage means in the optical disk device 7, the CPU 25 sets the reproduction-only encryption key in the register 32 in step S35, and again from the error correction coding / decoding circuit 19 The encrypted data (data reproduced from the optical disc 6) is decrypted by the decryption circuit 30, and the serial number and unique data of the optical disc apparatus 7 are detected from the decrypted data. In step S36, the CPU 25 compares the decrypted serial number of the optical disc device 7 with the serial number of the optical disc device stored in the non-volatile storage means in the optical disc device 7 to determine whether or not they match. And comparing the decrypted unique data with the unique data corresponding to the reproduction-only encryption key stored in the non-volatile storage means in the optical disc apparatus 7 to determine whether or not they match. If both the manufacturing number and unique data of the optical disk device match, the process proceeds to step S33, where the optical disk device 7 reproduces data from the optical disk 6 and outputs it from the decoding circuit 30 via the bus interface circuit 17. As a result, the data is input to the hard disk device 5 and recorded on the hard disk, and the process is terminated.

  Further, if neither the above-mentioned manufacturing number or unique data or both of the optical disc device 7 match, the CPU 25 stores another reproduction-only encryption key in the non-volatile storage means of the optical disc device 7 in step S37. And if another read-only encryption key is stored in the non-volatile storage means in the optical disc apparatus 7, the process returns to step S35 to set the read-only encryption key in the register 32. The encrypted data (data reproduced from the optical disk 6) from the error correction coding / decoding circuit 19 is decrypted by the decoding circuit 30 again.

  In step S36, if either or both of the serial number and unique data of the optical disk device do not match, the CPU 25 further stores other reproduction-only data in the non-volatile storage means in the optical disk device 7 in step S37. The determination whether or not the encryption key is stored is repeated, and as long as there is a reproduction-only encryption key stored in the non-volatile storage means in the optical disk device 7, both the manufacturing number and the unique data of the optical disk device are further stored in step S36. Until both the above match, the process returns from step S37 to step S35, the reproduction-only encryption key is set in the register 32, and the encrypted data (reproduced from the optical disc 6) from the error correction encoding / decoding circuit 19 is again set. Data) is decrypted by the decryption circuit 30. If the CPU 25 does not have an encryption key capable of normally decrypting data in the nonvolatile storage means in the optical disc device 7, a warning such as “Data cannot be reproduced” is displayed on the liquid crystal display device of the operation unit 8 in step S38. Display and finish the process.

  By doing this, even if the encryption key is decrypted, the backup data is double protected by the serial number of the optical disk device and the unique data. Therefore, the data in the hard disk of the hard disk device 5 built in the image forming apparatus is stored. Thus, the confidentiality of the backup data recorded on the optical disk 6 when backed up to the optical disk 6 can be protected. Also, the recording / reproducing encryption key of another optical disk device is stored as a reproduction-only encryption key, and the manufacturing number and unique data of the other optical disk device are also stored, so that the recording data of the optical disk recorded by the other optical disk device is also stored. It can be played back and can be used when replacing an image forming apparatus or an optical disk apparatus.

  Further, when the recorded data of the optical disk is reproduced, the manufacturing number and unique data read from the optical disk are compared with the manufacturing number and unique data of the optical disk apparatus performing the reproduction, respectively, and only when they match each other, the optical disk apparatus. Even if a malicious third party steals the optical disc, obtains another optical disc device of the same model, and decrypts the encryption key, the recorded data on the stolen optical disc is stored. This has the effect of preventing playback.

  According to the present embodiment, the optical disc apparatus 7 as an information recording / reproducing apparatus for recording / reproducing data in the hard disk on a detachable recording medium decrypts the data with the encryption circuit 29 as means for encrypting the data. A recorded information recording / reproducing apparatus comprising: a decryption circuit 30 serving as a means for performing encryption; and a non-volatile storage means serving as a means for storing an encryption key unique to the information recording / reproducing apparatus 7 used for encryption and decryption Since the data can only be reproduced, the image forming apparatus capable of maintaining the confidentiality of the backup data recorded on the recording medium can be provided.

  According to the present embodiment, the information recording / reproducing apparatus 7 further includes a non-volatile storage unit as a means for storing an encryption key unique to another information recording / reproducing apparatus. An image forming apparatus capable of reproducing the data recorded on the recording medium by the another information recording / reproducing apparatus by the information recording / reproducing apparatus 7 when the apparatus is damaged can be provided.

  According to this embodiment, the information recording / reproducing apparatus 7 further has a non-volatile storage means as means for storing the manufacturing number of the information recording / reproducing apparatus, and encrypts the manufacturing number of the information recording / reproducing apparatus. Since the data is recorded on the recording medium, it is possible to provide an image forming apparatus capable of maintaining the confidentiality of backup data by preventing data from being output from the information recording / reproducing apparatus if the serial numbers do not match even if the encryption is decrypted.

  According to the present embodiment, the information recording / reproducing apparatus 7 further includes a non-volatile storage means as means for storing the manufacturing number of the other information recording / reproducing apparatus. When the data of the recording medium recorded by the above-mentioned information recording / reproducing apparatus is reproduced by the information recording / reproducing apparatus, the information recording is performed if the decrypted manufacturing number does not match the manufacturing number of the other information recording / reproducing apparatus. It is possible to provide an image forming apparatus capable of maintaining the confidentiality of backup data by preventing data output from the reproduction apparatus.

  According to the present embodiment, the information recording / reproducing apparatus 7 further has a non-volatile storage means as means for storing data unique to the information recording / reproducing apparatus, and encrypts the unique data and records the data. Since the data is recorded on the medium, it is possible to provide an image forming apparatus capable of maintaining the confidentiality of the backup data by preventing the data from being output from the information recording / reproducing apparatus if the unique data does not match even if the encryption is decrypted.

  According to the present embodiment, the information recording / reproducing apparatus 7 further includes a non-volatile storage means as means for storing data unique to the other information recording / reproducing apparatus. When the data of the recording medium recorded by the apparatus is reproduced by the information recording / reproducing apparatus, even if the cipher is decrypted, the unique data after the decryption does not match the unique data of the other information recording / reproducing apparatus It is possible to provide an image forming apparatus capable of maintaining the confidentiality of backup data by preventing data from being output from the information recording / reproducing apparatus.

  According to this embodiment, the information recording / reproducing apparatus 7 further stores nonvolatile data as means for storing the production number of the information recording / reproducing apparatus 7, and means for storing data unique to the information recording / reproducing apparatus. Non-volatile storage means, and the production number of the information recording / reproducing apparatus and the unique data are encrypted and recorded on the recording medium. Therefore, even if the encryption is decrypted, the production number and the unique data are If they do not match, it is possible to provide an image forming apparatus capable of maintaining the confidentiality of backup data by preventing data output from the information recording / reproducing apparatus.

  According to this embodiment, the information recording / reproducing apparatus 7 further stores non-volatile storage means as means for storing the manufacturing number of the other information recording / reproducing apparatus, and data unique to the other information recording / reproducing apparatus. Non-volatile storage means as storage means, so that when the data of the recording medium recorded by the other information recording / reproducing apparatus is reproduced by the information recording / reproducing apparatus, the encryption is decrypted. If the serial number and the unique data after decryption do not match the serial number and unique data of the other information recording / reproducing device, the data cannot be output from the information recording / reproducing device, and the confidentiality of the backup data is maintained. An image forming apparatus that can be provided can be provided.

  According to the present embodiment, the encrypted manufacturing number recorded on the recording medium is further decrypted and stored in the decrypted manufacturing number and the storage device (register 37) of the information recording / reproducing device 7. Since the data obtained by decrypting the data on the recording medium is input to the storage device when the production number matches, the decrypted production number is stored in the non-volatile state of the information recording / reproducing device even if the encryption is decrypted. Thus, it is possible to provide an image forming apparatus capable of maintaining the confidentiality of backup data by preventing data from being output from the information recording / reproducing apparatus unless it matches the manufacturing number stored in the storage device.

  According to the present embodiment, the encrypted unique data recorded on the recording medium is further decrypted, and the decrypted unique data and the storage device (register 38) of the information recording / reproducing device 7 are stored. When the stored unique data matches, the decrypted data of the recording medium is input to the storage device, so even if the cipher is decrypted, the decrypted unique data remains in the information recording It is possible to provide an image forming apparatus capable of maintaining the confidentiality of backup data by preventing data from being output from the information recording / reproducing apparatus unless it matches the unique data stored in the reproducing apparatus.

  According to the present embodiment, the encrypted manufacturing number and unique data recorded on the recording medium are decrypted, and the decrypted manufacturing number and the storage device (register 37) of the information recording / reproducing apparatus 7 are stored. When the stored production number matches and the decrypted unique data matches the unique data stored in the storage device (register 38) of the information recording / reproducing device 7, the data of the recording medium Since the decrypted data is input to the storage device, the decrypted manufacturing number and unique data do not match the serial number and unique data stored in the storage device of the information recording / reproducing device even if the encryption is decrypted. In addition, it is possible to provide an image forming apparatus capable of maintaining the confidentiality of backup data by preventing data output from the information recording / reproducing apparatus.

It is a block diagram which shows one Embodiment of this invention. It is a block diagram which shows the optical disk apparatus of the embodiment. 2 is a block diagram showing an internal configuration of an encryption / decryption circuit of the optical disc apparatus. FIG. FIG. 4 is a diagram for explaining a method of using an encryption key for protecting the confidentiality of backup data recorded on an optical disc when data from the hard disk device of the embodiment is recorded on the optical disc for backup. 4 is a flowchart showing a processing flow when data is reproduced from an optical disk on which data encrypted by a recording / reproducing encryption key is recorded when the manufacturing number and unique data of the optical disk device in the embodiment are not used. 6 is a flowchart showing a processing flow when reproducing backup data from an optical disc when using a pair of an encryption key and a production number unique to the optical disc apparatus in the embodiment. 4 is a flowchart showing a processing flow when reproducing backup data from an optical disc when using an encryption key and unique data unique to the optical disc apparatus in the embodiment in pairs. 4 is a flowchart showing a processing flow when reproducing backup data from an optical disc when a set of an encryption key, a serial number and unique data unique to the optical disc apparatus in the embodiment is used.

Explanation of symbols

7 Optical disk device 18 Encryption / decryption circuit 25 CPU
27 ROM
29 Encryption circuit 30 Decryption circuit 31 Data selector 32 to 38 Register

Claims (1)

A storage device for storing input data;
An image forming apparatus having an information recording / reproducing device for recording / reproducing data in the storage device on a recording medium,
The information recording / reproducing apparatus comprises:
Encryption means for encrypting data to be recorded on the recording medium when data is recorded on the recording medium;
Decoding means for decoding data reproduced from the recording medium when reproducing data from the recording medium;
Means for storing an encryption key unique to the information recording / reproducing apparatus used for the encryption and the decryption;
The information recording / reproducing apparatus is
Storage means for storing an encryption key unique to another damaged information recording / reproducing apparatus,
Using an encryption key unique to the other information recording / reproducing apparatus for decrypting the data,
Means for storing the serial number of the information recording / reproducing apparatus;
Means for storing data unique to the information recording / reproducing apparatus,
The production number of the information recording / reproducing apparatus and the unique data are encrypted and recorded on the recording medium,
Decrypt the encrypted serial number and unique data recorded on the recording medium,
The decrypted manufacturing number and the manufacturing number stored in the information recording / reproducing apparatus match, and the decrypted unique data and the unique data stored in the information recording / reproducing apparatus match. The data reproduced from the recording medium is decrypted and input to the storage device ,
A unique encryption key of the damaged another information recording / reproducing apparatus is additionally stored in the storage means, and the storage means additionally stores a plurality of the unique encryption keys. An image forming apparatus.

Images