JPH04149864A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To make it impossible to use a normal optical disk driving device and to improve the secrecy of data by recording false information in an ISO defined area, and only when a secret flag is set up in an ISO undefined area, reproducing the false information. CONSTITUTION:An optical information recording medium forming an ISO defined area and an ISO undefined area is formed in a control track and a secret flag is set up in the ISO defined area of the control track. On the other hand, false information is recorded in the ISO defined area of the control track by a recording system different from an ISO recording system. Whether the secret flag has been set up in the ISO undefined area or not is decided, and at the time of deciding the existence of the secret flag, the false information is reproduced, so that the using range of a driving device is restricted and the secrecy of data is furthermore improved.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an optical information recording medium.

Conventional technology Conventionally, ISO (International O
organization for S standardi
zation)-compliant optical discs generally have a format as shown in FIG. That is, within one sector, a data area 2 for recording data and a preformat area 3 for control (hereinafter referred to as control track 3) are formed between each guide groove 1.

Information bits 2a are formed in the data area 2, and bits 3a such as track addresses, sector numbers, and synchronization marks are formed in the control track 3.

In such a format, compatibility between various media is maintained by having a "control track 3" on the optical disk. That is, as shown in Fig. 5, the drive device reads the contents of the control track of the inserted medium and sets the conditions for erasure, recording, playback, etc. recorded therein, thereby controlling various media. Compatible.

Problems to be Solved by the Invention Currently, there is a movement to use ISO-compliant optical discs to store various types of personal information. However, in such a case where personal information is stored, it is not preferable that ``compatibility exists for all users.'' The reason is,
If such compatibility existed for all users, an unspecified number of people would be able to access optical discs containing personal information, which would create problems in terms of data confidentiality. .

A specific example is the idea of storing personal medical data on, for example, a 5-inch ISO compliant rewritable optical disc. In this case, unless a drive that can access such confidential data is specified, problems may occur such as a third party reading the data or changing its contents without permission.

Means for Solving the Problems Therefore, in order to solve such problems, the present invention provides an optical information recording medium having an ISO format in which an ISO defined area and an ISO undefined area are formed in a control track. a security flag setting means for setting a security flag in the ISO undefined area of the control track;
A false information recording means is provided for recording false information in the defined area using a recording method different from the ISO recording method, and a security flag determining means is provided for determining whether or not a security flag is set in the ISO undefined area. False information reproducing means is provided for reproducing false information recorded in the ISO defined area when it is determined by the secrecy flag determining means that a secrecy flag exists in the ISO undefined area.

In this way, by recording false information in the ISO defined area by the false information recording means and reproducing the false information by the false information reproducing means only when the confidentiality flag is set in the ISO undefined area, the ISO compatible normal This makes it impossible to accurately access recording, playback, etc. using an optical disk drive device, and this makes it possible to limit the range of use of the drive device that can be assessed, thereby reducing the confidentiality of recorded data. It can be improved further.

Example An embodiment of the present invention will be described based on FIG.

First, an outline of the overall configuration of the optical information recording medium used in this example will be described. In an optical disc as an optical information recording medium having an ISO format, an ISO defined area and an ISO undefined area are formed within its control track. For example, when using a 5-inch rewritable optical disc, there are two types of control tracks: PEP with a length of 18 bytes and SFP with a length of 512 or 1024 bytes. The first 18 bytes of SFP have the same content as PEP).

Also, here, a confidentiality flag setting means (not shown),
A false information recording means, a confidentiality flag determining means, and a false information reproducing means are provided.

The security flag setting means sets a security flag in the ISO undefined area of the control track. Further, the false information recording means records false information in the ISO defined area of the control track using a recording method different from the ISO recording method. Further, the security flag determining means determines whether a security flag is set in the ISO undefined area. Furthermore, the false information reproducing means reproduces the false information recorded in the ISO defined area when the confidentiality flag determining means determines that a confidentiality flag exists in the ISO undefined area.

In such a configuration, the four means described above (secrecy flag setting means, false information recording means, confidentiality flag determining means,
An outline of the operation procedure of the false information reproducing means) will be explained based on FIG. First, a case will be described in which various conditions are recorded in a control track of an optical disc. When the secrecy flag setting means sets a ``secrecy flag'' in the ISO undefined area in the control track, the false information recording means records ``false information'' in the ISO defined area in the control track. In this case, the fake information sets various conditions such as erasing, recording, and reproducing so that the drive device can reproduce by a method other than the ISO standard. Also, if you do not set a confidentiality flag on the IS○ undefined area, the ISO
Record false information in the defined area.

Next, the case of reproducing various conditions from the control track of an optical disc will be described. The contents of the control track are read out, and a confidentiality flag determining means determines whether or not a confidentiality flag is set in an undefined area in the control track. In this case, if the confidentiality flag is set, the drive device uses the false information reproducing means to check the false information recorded in the ISO defined area by a method other than the ISO standard, that is, the conditions for erasing, recording, reproducing, etc. Reproduce. Furthermore, if the confidentiality flag is not set, the false information recorded in the ■S○ definition area is reproduced using the normal ISO-specified method.

As mentioned above, by recording false information in the IS○ definition area,
By playing the false information only when the confidentiality flag is set in the SO undefined area, the ISO
It becomes impossible to perform accurate access such as recording and playback using a compatible ordinary optical disk drive device, and this limits the scope of use of the drive device that supports AXF, thereby reducing the confidentiality of data. It becomes possible to improve the performance.

Next, specific conditions of this embodiment will be explained based on FIGS. 2 to 4. 2 to 4 show the contents of data recorded on the control track. Figure 2 shows an example of an ISO undefined area, and Figure 3 shows an example of an ISO undefined area.
The figure shows an example of the contents of bytes 0 to 7 of the PEP and SFP, and FIG. 4 shows an example of the contents of bytes 18 and after of the SFP.

First, as the first specific condition, a confidentiality flag is set in all or part of bytes 14 to 17 of PEP and SFP in the ISO undefined area and bytes 448 to 511 of SFP. For example, a special pattern indicating a confidentiality flag is recorded in bytes 14 to 17 of PEP and SFP.

Next, as the second specific condition, it is possible to select from ■ to ■ as the false information to be recorded in the ISO definition section. In other words, ■ Change the method of recording information (bit reversal, position swapping, etc.).

■ L and / Groove recording (PEP, S
FP byte 4, bit 7) is inverted from the actual value.

Reproducing power Pr Recording power Pw Erasing power Pe Recording pulse Tp Erasing pulse Ep (SFP byte 2 (SFP byte 2 (SFP byte 3 (SFP byte 3 (SFP byte 4 1st grade) 2nd grade) 5th grade) 2nd grade) 5th whistle) Change these ■～■ from the regular values. As an example,
If these values are extremely low, normal drive devices may not be able to erase, record, or play back, or
If r is made large, data may be destroyed during playback.

Next, as the third specific condition, various conditions for the medium (optical disk) on which the confidentiality flag is set can be obtained by various methods as shown below.

■ ■ ■ Have a list for optical disks in advance in the drive device and copy it.

Change how to read the ISO definition area of SFP (bit inversion, Pr←→Pw replacement, etc.).

SFP ISO undefined area (bytes 448 to 511.6
4 bytes), a list of correct conditions for the media (content that should originally be in bytes 0 to 47 of the SFP)
Record this and read this part.

■ False information is recorded in bytes O to 511 of PEP and SFP using the method shown in ■, and byte 51 of SFP is
Correct information is recorded in 2 to 1023.

■ For media with confidential flags, SF
The information in bytes 512 to 1023 of P is read and used as erasure, recording, and reproduction conditions.

By setting various conditions as described above, it is possible to create the desired media.

According to ISO, bytes 512 to 1023 are FFh.
However, it is thought that there is actually no drive device that checks whether this area is FFh. In addition, in this example, a 5-inch rewritable type media was used, but control tracks are defined for other ISO optical discs to maintain compatibility, and the same method as described above is used for other ISO optical discs. The method allows the confidentiality of recorded data to be maintained.

Effects of the Invention The present invention provides an optical information recording medium having an IS○ format in which an ISO defined area and an ISO undefined area are formed in a control track, and sets a security flag in the IS○ undefined area of the control track. a security flag setting means for setting a confidentiality flag; a false information recording means for recording false information in the ISO defined area of the control track by a recording method different from the ISO recording method;
A security flag determination means is provided for determining whether or not a security flag is set in the ISO undefined area, and when the security flag determination means determines that the security flag exists in the ISO undefined area, the ISO defined area is Since we have provided a false information reproducing means to reproduce the false information recorded in IS,
Record false information in the O defined area by the false information recording means,
By reproducing false information using the false information reproducing means only when the confidentiality flag is set in the SO undefined area,
It becomes impossible to perform accurate access for recording, playback, etc. using an ordinary ISO-compliant optical disk drive device, and as a result, it becomes possible to limit the range of use of the drive device that can be assessed. It is possible to further improve the confidentiality of the information.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a method of reading information in a control track according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an example of data recorded in an ISO undefined area in a control track, and FIG. The figure is an explanatory diagram showing an example of data from bytes O to 17 of PEP and SFP in the control track, FIG. 4 is an explanatory diagram showing an example of data after byte 18 of SFP in the control track, and FIG. 5 is a conventional diagram. FIG. 6 is an explanatory diagram showing the state of an optical information recording medium conforming to the ISO format. Applicant Ricoh Co., Ltd. Contents of Nikon SFP (Byte Taut)

Claims (1)

[Claims] An optical information recording medium having an ISO format in which an ISO defined area and an ISO undefined area are formed in a control track is provided;
A confidentiality flag setting means is provided for setting a confidentiality flag in the SO undefined area, a false information recording means is provided for recording false information in the ISO defined area of the control track by a recording method different from the ISO recording method, and A confidentiality flag determination means is provided for determining whether or not a confidentiality flag is set in the defined area, and when the confidentiality flag determination means determines that the confidentiality flag exists in the ISO undefined area, recording is performed in the ISO defined area. An optical information recording medium characterized in that it is provided with a false information reproducing means for reproducing the false information that has been generated.