JP4853294B2 - Data recording device - Google Patents

Description

  The present invention relates to an apparatus for encrypting and recording data on a portable recording medium.

  When recording data on a portable recording medium such as a CD or DVD, there is always a risk of data leakage due to loss or theft because the medium can be freely carried. Therefore, the key data is recorded on the portable recording medium, and it is determined whether or not it matches the key data set on the drive side for recording / reproducing data on the portable recording medium. A technique that enables recording and reproduction by the drive is known.

  In Patent Document 1 shown below, a password encrypted as an authentication key is stored in a recording device, and when using a portable information device, the recording device is connected to the portable device and connected to a password input by the user. It is disclosed that user authentication is performed by comparing with the authentication information of the stored storage device.

  Patent Document 2 discloses that encoded data is decoded and audio data is decoded based on an input security key.

  Further, in Patent Document 3, when recording encrypted data on a recording medium, key data necessary for decrypting the encrypted data is recorded on a medium different from the recording medium for recording the encrypted data. In addition, it is disclosed that the key data is deleted after data reproduction to ensure security.

  Further, Patent Document 4 discloses that a security key for performing encryption and decryption is detachably attached to a personal computer, and data operated by the personal computer is automatically encrypted or decrypted when the personal computer is attached. Further, it is disclosed that authentication is performed when a security key is attached to a personal computer.

Japanese Patent Laid-Open No. 11-272563 Japanese Patent Laid-Open No. 2001-197041 JP 2003-303136 A JP 2005-173197 A

  On the other hand, in addition to protecting data by encrypting data, a technique that can easily prevent copying of a portable recording medium is desired.

  An object of the present invention is to provide an apparatus that can easily prevent copying of a portable recording medium.

The present invention is a data recording apparatus for recording data on a portable recording medium, and has a security mode and a normal mode for encrypting and recording the data using key data as an operation mode, Holding means for holding key data; and in the case of the security mode, out of data to be recorded in the user data area, at least part of the file management information included in the data is other than the user data area of the portable recording medium A recording means for recording the file management information in the user data area in the normal mode, by recording dummy data in a portion from which at least a part of the file management information is extracted, and recording the file management information in the normal mode It is characterized by having.

  According to the present invention, copying of a portable recording medium can be easily and effectively prevented.

  Hereinafter, an embodiment of the present invention will be described with reference to an optical disc apparatus that records and reproduces data on an optical disc, taking an example of a recordable optical disc as a portable recording medium.

  FIG. 1 shows the overall configuration of the optical disc apparatus according to this embodiment. An optical disc 10 such as a CD, DVD, HD-DVD, or Blu-ray is driven by a spindle motor (SPM) 12. The spindle motor SPM 12 is driven by a driver 14, and the driver 14 is servo-controlled by a servo processor 30 so as to have a desired rotation speed.

  The optical pickup 16 includes a laser diode (LD) for irradiating the optical disk 10 with laser light and a photodetector (PD) that receives reflected light from the optical disk 10 and converts it into an electrical signal, and is disposed opposite to the optical disk 10. . The optical pickup 16 is driven in the radial direction of the optical disk 10 by a sled motor 18 constituted by a stepping motor, and the sled motor 18 is driven by a driver 20. The driver 20 is servo-controlled by the servo processor 30 similarly to the driver 14. The LD of the optical pickup 16 is driven by a driver 22, and the driver 22 is controlled by an auto power control circuit (APC) 24 so that the drive current becomes a desired value. The APC 24 and the driver 22 control the light emission amount of the LD according to a command from the system controller 32. In FIG. 1, the driver 22 is provided separately from the optical pickup 16, but the driver 22 may be mounted on the optical pickup 16.

  The normal recording / reproducing operation (normal operation mode) with respect to the optical disc 10 in the case of non-encryption is as follows. When data recorded on the optical disk 10 is reproduced, a laser beam of reproduction power is irradiated from the LD of the optical pickup 16, and the reflected light is converted into an electric signal by the PD and output. A reproduction signal from the optical pickup 16 is supplied to the RF circuit 26. The RF circuit 26 generates a focus error signal and a tracking error signal from the reproduction signal and supplies them to the servo processor 30. The servo processor 30 servo-controls the optical pickup 16 based on these error signals, and maintains the optical pickup 16 in an on-focus state and an on-track state. Further, the RF circuit 26 supplies an address signal included in the reproduction signal to the address decoding circuit 28. The address decoding circuit 28 demodulates the address data of the optical disk 10 from the address signal and supplies it to the servo processor 30 and the system controller 32.

  The address signal is a wobble signal. The wobble signal is extracted from the reproduction signal and decoded to obtain address data. Further, the RF circuit 26 supplies the reproduction RF signal to the binarization circuit 34. The binarization circuit 34 binarizes the reproduction signal and supplies the obtained signal to the encoding / decoding circuit 36. The encode / decode circuit 36 demodulates the binary signal and corrects errors to obtain reproduction data, and outputs the reproduction data to a host device such as a personal computer via the interface I / F 40. When the reproduction data is output to the host device, the encoding / decoding circuit 36 temporarily stores the reproduction data in the buffer memory 38 and outputs it.

  When recording data on the optical disk 10, data to be recorded from the host device is supplied to the encode / decode circuit 36 via the interface I / F 40. The encode / decode circuit 36 stores data to be recorded in the buffer memory 38, encodes the data to be recorded, and supplies the data to the write strategy circuit 42 as modulated data. The write strategy circuit 42 converts the modulation data into a multi-pulse (pulse train) according to a predetermined recording strategy, and supplies it to the driver 22 as recording data. Since the recording strategy affects recording quality, optimization is performed prior to data recording. The laser light whose power is modulated by the recording data is irradiated from the LD of the optical pickup 16 and the data is recorded on the optical disk 10. The recording power at the time of data recording is optimized by trial writing test data using a PCA (Power Calibration Area) formed on the inner circumference side of the optical disc 10 by OPC (Optical Power Control). . After recording the data, the optical pickup 16 reproduces the recorded data by irradiating a laser beam with a reproduction power, and supplies it to the RF circuit 26. The RF circuit 26 supplies the reproduction signal to the binarization circuit 34, and the binarized data is supplied to the encode / decode circuit 36. The encoding / decoding circuit 36 decodes the modulated data and collates it with the recording data stored in the buffer memory 38. The result of the verification is supplied to the system controller 32. The system controller 32 determines whether to continue recording data or execute a replacement process according to the result of verification. The system controller 32 controls the operation of the entire system, drives the sled motor 18 via the servo processor 30, and controls the position of the optical pickup 16. Further, the system controller 32 optimizes the recording power by controlling the OPC.

  On the other hand, the optical disc apparatus of the present embodiment has a security mode in addition to the normal operation mode. The security mode is a mode in which data is encrypted and recorded on the optical disc, and the encrypted data is decrypted and reproduced. In the present embodiment, an optical disc apparatus having a security mode is appropriately referred to as a “security drive”, and an optical disc on which data is recorded after being encrypted by the security drive is appropriately referred to as a “security disc”. The system controller 32 determines whether to operate the apparatus in the security mode or the normal operation mode. When the optical disk device is connected to a personal computer or the like, or built in the personal computer, the system controller 32 determines the operation mode of the device in accordance with a command from the personal computer OS (operating system) or application program. The user can use an application program to determine whether to operate the apparatus in the security mode or the normal mode. In response to the inquiry command from the personal computer side, the system controller 32 returns information indicating that it is a “security drive” capable of operating in the security mode to the personal computer side. The application program (security program) installed on the personal computer side recognizes that the connected or built-in optical disk device is a security drive based on information from the system controller 32, and receives a mode setting request from the user and The password is accepted and the optical disc apparatus is shifted to the security mode.

  FIG. 2 shows processing at the time of starting a personal computer in which the optical disk apparatus shown in FIG. 1 is connected or built in.

  First, when a personal computer (PC) is activated (S101), a security program (security software) installed in the personal computer is activated (S102). The security program can be provided by the manufacturer of the optical disk device. The security program may be installed on a personal computer from a recording medium such as a CD-ROM or DVD-ROM, or may be installed via a network. The security program is stored in the RAM of the personal computer and is sequentially executed by the CPU of the personal computer. The security program has at least a function for causing a personal computer to determine whether the connected or built-in optical disc apparatus is a “security drive” having a security mode, and when it is a “security drive”, the security program operates in the security mode. And a function for inputting the key data necessary for transmission to the system controller 32 of the optical disc apparatus via the communication interface.

  When the security program is activated, the personal computer first determines whether the connected or built-in optical disk device is a “security drive” (S103). The CPU of the personal computer makes an inquiry to the optical disk device and determines whether or not it is a “security drive” based on the information received from the system controller 32 of the optical disk device. If it is not a “security drive”, it shifts to normal operation. If it is “security drive”, it is determined whether or not the security mode setting input is performed (S104), and if the user desires the setting input, the security mode ON / OFF is determined (S105). If the user selects the security mode ON from the menu displayed on the screen of the personal computer, for example, the password request as the unique key data is requested next (S106), and when the user enters the password, the CPU of the personal computer uses the password to the optical disk. This is supplied to the system controller 32 of the apparatus. The system controller 32 stores the password received from the personal computer side in a volatile memory such as a DRAM and makes settings for shifting to the security mode (S107). That is, an internal flag indicating that the operation mode is the security mode is set. The password may be stored in a non-volatile memory such as a flash memory. However, in order to ensure security, the password is preferably lost when the optical disk device is turned off. The password stored in the volatile memory of the optical disc apparatus is used as an encryption key for recording data and a decryption key for decrypting the data, but the password itself is not recorded on the optical disc, and the optical disc apparatus Only in volatile memory. Encryption is performed by converting the address of data to be recorded on the optical disc.

  When the user does not wish to enter the security mode, the user selects the security mode OFF. In this case, since the password is not input, it is not held in the volatile memory, and encryption is not executed.

  Through the above processing, the password necessary for execution in the security mode is stored in the volatile memory of the optical disc apparatus. In addition to inputting the password from the keyboard of the personal computer, the user may store it in advance in a USB memory or the like and connect it to the personal computer for input. When connecting a USB memory to a personal computer, it may be connected after authentication.

  FIG. 3 shows processing at the time of data recording. The system controller 32 determines whether a write command is received from the personal computer (S201). When a ride command is received from a personal computer, it is determined whether or not the optical disk 10 inserted into the apparatus is an optical disk 10 on which data is newly recorded, that is, whether or not the optical disk 10 has not yet been recorded with data. (S202).

  In the case of a new optical disc, the system controller 32 determines whether or not the operation mode of the apparatus is the security mode (S203). When the operation mode is the security mode, first, a security identification signal is sent to an area other than the user data area of the optical disc 10. (S204). The security identification signal is a signal indicating that data is recorded in the security mode by the “security drive” on the optical disc 10, and includes at least a drive ID of “security drive” and a flag indicating that the data has been encrypted. .

  The security identification signal merely indicates that the optical disk 10 is an encrypted “security disk”, and does not include key data used for encryption, that is, a password. Therefore, even if the optical disk 10 is lost or stolen, the key data does not flow out. The security identification signal is recorded not in the user data area but in an area other than the user data area. When copying the optical disk 10, the user data area is read and written to another optical disk, so that the security identification signal recorded outside the user data area is not copied, and the copy destination optical disk 10 has no security identification signal. Become. That is, the copy destination optical disk 10 is no longer recognized as a “security disk” having a security identification signal. Therefore, if it is confirmed that the optical disc 10 is a “security disc” and data reproduction is allowed, the copy destination optical disc 10 cannot be reproduced, and copying can be prevented. For the area other than the user data, for example, PCA for executing OPC can be used. In the case of a DVD-R, there are a recording information management area, a lead-in area, a user data area, and a lead-out area sequentially from the inner circumference to the outer circumference of the disc, and the recording information management area includes a PCA and a recording management information area. (RMA) exists. In OPC, test data is written on the PCA by trial while changing the recording power stepwise prior to data recording. The test data written by trial is reproduced and the reproduction signal quality such as β value, γ value and error rate is evaluated to determine the optimum recording power. The security identification signal is recorded at an arbitrary position of the PCA or a specific area of the PCA that is not used by the OPC. The security identification signal may be recorded on the PCA prior to the OPC, or may be recorded on the PCA after the OPC. In the case of a rewritable optical disc such as a DVD-RW, a security identification signal may be recorded so as to overwrite the test data after OPC. The security identification signal may have a header part and a data part, record information indicating that it is a security identification signal in the header part, and record a security drive ID and other information in the data part. In multi-session recording, when a session recorded by normal operation and a session recorded by encryption are mixed, information indicating the session recorded by encryption may be recorded.

  After the security identification signal is recorded in an area other than the user data area, the address of the recorded data is converted using the key data held in the volatile memory, that is, the password (S205). An address conversion method using a password is arbitrary. For example, when recording data supplied from a personal computer is stored in the buffer memory 38, the address is converted by scrambling the storage order using the password. Specifically, the buffer memory 38 is divided into a plurality of areas, for example, four areas, and management numbers are assigned in order from 1 to each area. If the capacity of the buffer memory 38 is 1 MB and there are 512 blocks, the buffer memory 38 is divided into four areas, a first area to a fourth area, and a management number of 1 to 128 is assigned to each area. That is, the first area has the first block to the 128th block, and the second area also has the first block to the 128th block. The same applies to the third and fourth regions. Then, the ASCII code of the first two characters of the password is converted by a certain mathematical formula to obtain a block number to be stored first. The second and subsequent numbers are determined so as not to overlap by using a certain mathematical formula from the first management number. Then, permutations in four areas are determined using the ASCII code of the third character of the password. For example, when the third character of the password is a certain character, it is stored in the order of the first region → the third region → the second region → the fourth region, and when the third character of the password is another character, the second character is stored. For example, the area, the fourth area, the third area, and the first area are stored in this order. Thus, in the case of a certain password “ABCDEFG”, the first data block of the data to be recorded is stored in the 68th block of the first area, the next data block is stored in the third block of the third area, Further, the next data block is stored in the 120th block of the second area. In the case of another password “STUVWX”, the first data block of the data to be recorded is stored in the first block of the fourth area. The next data block is stored in the 89th block in the first area, and the next data block is stored in the 56th block in the second area. As described above, the address is converted by converting the order of storage in the buffer memory 38, and the data is recorded (S206).

  FIG. 4 schematically shows the address conversion process of the present embodiment. The system controller 32 receives the data to be recorded from the personal computer and stores it in the buffer memory 38. The system controller 32 reads the password held in the volatile memory and converts the position stored in the buffer memory 38 using the characters of the password. To do. In the normal operation mode, data to be recorded is stored in order from the top of the buffer memory 38. In the security mode, the storage position of the buffer memory 38 is converted according to the password. In the figure, the first data block is stored in the 110th block of the first area 38a of the buffer memory 38, the next data block is stored in the 50th block of the third area 38c, and the next data block is the fourth area 38d. The next data block is stored in the 70th block of the second area 38b. The data stored in the buffer memory 38 in this way is read from the beginning and recorded in the user data on the optical disc 10. Since data is recorded from the inner circumference to the outer circumference in the order of reading, the data is recorded at an address different from the normal mode, and the original data cannot be reproduced even if read as it is. become.

  On the other hand, as described above, the security identification signal is recorded in an area other than the user data area, for example, the PCA. However, not only the security identification signal but also a part of data to be recorded is recorded in an area other than the user data area. A part of the data to be recorded is recorded in an area other than the user data area. When the address of the data to be recorded is converted, the converted address is not limited to the user data area but the other area. It means expanding. By recording a part of data to be recorded on an area other than the user data area, for example, the PCA in the same manner as the security identification signal, the data recorded on the PCA disappears without being copied when the optical disk 10 is copied. Therefore, the copy destination optical disk 10 is an incomplete disk with missing data. Of the data to be recorded, data to be recorded outside the user data area is arbitrary, but it is preferable to record file management data (system information) in the PCA. In the ISO9660 format used for the CD, the PVD (Primary Volume Descriptor) exists in the first sector of the first track of the final session, and the volume attribute, root directory position, and path table position necessary for file access in the PDV Is described. Further, in the UDF format used for DVDs and next-generation discs, AVDP (Ancor Volume Descriptor Pointer) exists at the 257th position of the last border. Therefore, it is preferable to record PVD or AVDP on the PCA, so that there is no PVD or AVDP on the copy destination optical disk, and copying can be prevented. When file management data such as PVD and AVDP is recorded in the PCA, the file management data portion to be recorded in the user data area is blank, but in this portion, meaningless dummy data is recorded instead. deep. FIG. 4 shows that a security identification signal and system information are recorded in the PCA, and other data is recorded in the user data area. All of the file management data may be recorded on the PCA, or only a part of the file management data may be recorded on the PCA.

  Of course, the method of address translation is not limited to the above. Without dividing the buffer memory 38, an arbitrary number of 1 to 512 is assigned to the data block using a password, and the data block is assigned to the block position indicated by the assigned number among the first block to the 512 block of the buffer memory 38. It may be stored. Alternatively, the buffer memory 38 may be divided into two areas and data stored alternately. The password held in the volatile memory can be said to be key data that defines the storage order of data to be recorded in the buffer memory 38.

  Data is recorded as described above, and is repeatedly executed until the session is closed (S207). When the session is closed, an end process is performed (S208), and the data recording process is completed.

  On the other hand, if it is not a new optical disk 10, that is, if it is an optical disk 10 on which data has already been recorded, it is next determined whether or not a security identification signal exists (S209). In the case of a “security disk”, as described above, the security identification signal is recorded in a specific area other than the user data area, for example, the PCA. Therefore, the optical pickup 16 seeks to the PCA and reads the security identification signal. If there is a security identification signal in the PCA, since it is a “security disk”, the system controller 32 prohibits data addition (S210). Thereby, falsification of data is prevented. In this case, the system controller 32 notifies the personal computer that it is a security disk. In accordance with the notification from the system controller 32, the CPU of the personal computer displays a message indicating that no additional writing is possible. If there is no security identification signal, it is not a “security disc” and data recording in the normal operation mode is permitted (S206). That is, the data to be recorded as it is without address conversion is recorded in the user data area. Even in the case of the new optical disc 10, even when the optical disc apparatus is not set to the security mode, the data to be recorded is recorded in the user data area without performing address conversion. Accordingly, file management data is also recorded in the user data area.

  In summary, when a new optical disk 10 is inserted, the system controller 32 of the optical disk apparatus records the security identification signal in the PCA and converts the address in the security mode and records the user data in the user data area. A part of user data, for example, file management data is recorded in the PCA. When the recorded optical disk 10 is inserted, the system controller 32 of the optical disk apparatus prohibits additional writing if there is a security identification signal regardless of the security mode or normal operation mode, and adds writing if there is no security identification signal. Is acceptable. When there is no security identification signal, in the security mode, the security identification signal is recorded in the PCA with respect to the additional recording portion, the address is converted, and user data is recorded in the user data area. Also, a part of the user data, for example, file management At least a part of the data may be recorded on the PCA. In this case, the encrypted data portion and the unencrypted data portion are mixed on the optical disc 10.

  The security identification signal may be recorded on the PCA prior to data recording, or may be recorded on the PCA after the data recording is completed. Further, when a security identification signal is present in the case of an already recorded disc, it is determined whether or not the security drive ID included in the security identification signal matches the drive ID that the user has, and additional writing is permitted when the IDs match. However, additional writing may be prohibited when the IDs do not match.

  FIG. 5 shows data reproduction processing in the security mode. First, when the optical disk 10 is inserted (S301), the system controller 32 determines whether or not a security identification signal exists (S302). If there is a security identification signal, a read command is received from the personal computer (S303), and file management data recorded in an area other than the user data area, for example, PCA is reproduced (S304). In addition, data is sequentially read from the user data area and stored in the buffer memory 38, but the address is reversely converted by converting the position stored in the buffer memory 38 using the password held in the volatile memory (S305). That is, since the address conversion is performed using the password at the time of data recording, the address of the data read using the same password is reversely converted to restore the original sequentially. If the password at the time of data recording is different from the password at the time of data reproduction, for example, if the optical disk device that recorded the data is different from the optical disk device that reproduces the data, the address reverse conversion is not correct and the data cannot be restored. Can not. As described above, the address is inversely converted using the password to reproduce the data (S306), and the reproduced data is supplied to the personal computer. The CPU of the personal computer determines the state of the reproduction data on the OS (S307), and if the reproduction data is normal, the process is terminated (S308). On the other hand, if the reproduction data is abnormal, the abnormality is displayed on the display (S309).

  On the other hand, when there is no security identification signal in the inserted optical disk 10, the system controller 32 performs a normal reproduction operation (S310). Therefore, a normal disk that is not a security disk can be played back by a normal playback operation. Further, in the case of the optical disc 10 copied with the security disc, the data cannot be reproduced because the data is scrambled in a normal reproducing operation.

  When the optical disk device is set to the normal operation mode, the normal reproduction operation is always performed regardless of the presence or absence of the security identification signal (without determining whether or not the security identification signal exists). Therefore, in the case of a security disc, data cannot be reproduced normally, and an optical disc copied from the security disc cannot be reproduced normally, and data can be reproduced normally only in the case of a non-security disc.

  As described above, the optical disc apparatus according to the present embodiment has a security mode and a normal operation mode. When data is recorded in the security mode, a security identification signal and file management data are recorded in an area other than the user data area. In addition, encryption is performed by converting the address of the user data and recording it in the user data area. Address conversion is performed using a password, and the password is not recorded on the optical disc 10 itself, but is stored in the volatile memory of the optical disc apparatus, and is lost when the optical disc apparatus is turned off. When reproducing data in the security mode, the presence or absence of a security identification signal is determined, and if there is a security identification signal, the address of the data read using the password held in the volatile memory is inversely converted to obtain the data. Reproduce. By such processing, data recorded on the optical disc can be protected and copying of the optical disc can be prevented.

  In the present embodiment, the optical disk is exemplified as the portable recording medium, but the present invention is not limited to this, and can be applied to other memories such as an SD memory.

  In this embodiment, the password is used as key data for address conversion. However, after address conversion, data to be recorded may be further encrypted using the password.

1 is an overall configuration diagram of an optical disc device. It is a processing flowchart at the time of personal computer starting. It is a process flowchart at the time of data recording. It is an address conversion process explanatory drawing. It is a processing flowchart at the time of data reproduction.

Explanation of symbols

  10 optical disk, 16 optical pickup, 32 system controller, 38 buffer memory.

Claims (3)

A data recording apparatus for recording data on a portable recording medium,
A security mode and a normal mode for encrypting and recording the data using key data as an operation mode;
Holding means for holding the key data;
Among the data to be recorded in the user data area in the case of the security mode, at least a part of the file management information included in the data is recorded in a recording information management area other than the user data area of the portable recording medium, A data recording apparatus comprising: recording means for recording dummy data in a portion obtained by extracting at least a part of the file management information, and recording the file management information in the user data area in the normal mode . The apparatus of claim 1.
The recording means records at least a part of the file management information in the security mode and identification information indicating that it has been encrypted and recorded in the recording information management area of the portable recording medium. In the mode, the file management information is recorded in the user data area. The apparatus according to claim 1,
The portable recording medium is an optical disc;
The data recording apparatus, wherein the recording unit records at least a part of the file management information in a power calibration area existing in the recording information management area.

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