JP2000339699A - Method and device for digital recording of information using disk shaped optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording system of a disk shaped optical recording medium in which a recorded disk shaped optical recording medium is made as a parent, duplicates of the parent are successively made and grandchildren copies are made into totally nonsensical duplicates. SOLUTION: The digital recording device of information uses a disk shaped optical recording medium 14 having a read-only region and a programmable region. In the device, the positional relationship between a mark 24b, which is provided at least at one place on the medium 14, and the read-only signals from a read-only region 24, is made into key information to cipher input information and the ciphered information is recorded in the programmable region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method for a disk-shaped optical recording medium in which the recorded disk-shaped optical recording medium is copied one after another as a parent, and the so-called "grandchild copy" is a meaningless copy. I will provide a.

[0002]

2. Description of the Related Art In recent years, devices for recording and reproducing information such as voice, music, and video in digital form have been rapidly spreading. When information is recorded and reproduced in digital format, the sound quality and image quality do not deteriorate even if copying is repeated many times, but the problem that the copyright holder's rights have been violated by unauthorized copying has emerged. I have. The present invention provides a system in which the recorded disc-shaped optical recording medium is copied one after another as a parent, and a so-called "grandchild copy" is converted to a meaningless copy. Leads to prevention.

As a first method of performing copy control in a system for recording information in digital form, a serial copy management system (SCMS) is used for music information.
CGMS (Copy
Generation Management System), which has been adopted for some time.

[0004] As a first method, each of them defines a flag for generation management, and controls a free copy, a copy prohibition, a one-time copy permission, and the like according to the state of the generation management flag. It has the feature that it can be realized with a simple circuit configuration. As a second method, the input information is not recorded as it is, but is temporarily encrypted and then recorded, so that even if the copy itself is possible, the original information cannot be restored without the key used for the encryption. Such a method.

FIGS. 4 and 5 show a block configuration of a system for performing copy control using a generation management flag, which is a first conventional method. In FIG. 4, the signal read from the disk optical recording medium 41 of the copy source is a decoder block 4.
After processing such as error correction is performed in 2, information recorded on the disc-shaped optical recording medium 41 is sent to the output terminal 44.

[0006] From the decoder block 42, a signal of the generation management flag is supplied to a generation management judgment block 43.
The state of generation management regarding information recorded on the disc-shaped optical recording medium 41 is determined. Here, if the result determined in the generation management determination block 43 indicates that copying is prohibited,
In order to prevent illegal copying, a mechanism in which the decoder block 42 does not send information to the output terminal 44 is considered.

However, in this case, for example, when a connection is made to an amplifier or a television with a digital input in order to reproduce information recorded on the disc-shaped optical recording medium 41 instead of copying, nothing is reproduced. Such a problem occurs. Therefore, the digital output terminal 44 merely adds a generation management flag to the information recorded on the disc-shaped optical recording medium 41.

FIG. 5 is a block diagram of a recording apparatus for recording input information in a digital form on a disc-shaped optical recording medium. In FIG. 5, for example, the above-mentioned information and a generation management flag are integrally supplied to an input terminal 51, and the information is subjected to predetermined processing in an encoder block 52, and is recordable on a disc-shaped optical recording medium. Recorded at 54.

On the other hand, a generation management flag detection / judgment block 53 detects a generation management flag added to the input information, judges the state indicated by the flag, and controls the encoder block 52 in accordance with the state. I do.

For example, 1) if copying is indicated, the recording on the disk-shaped optical recording medium 54 is permitted without changing the current flag. 2) If only one copy is permitted, the generation management flag is rewritten to a copy prohibited state, and then recording on the disc-shaped optical recording medium 54 is permitted. 3) If copy inhibition is indicated, the encoder block 52
To stop the recording on the disc-shaped optical recording medium 54.

The above is the outline of the management method for copying information which has been adopted before. Naturally, for example, by ignoring the input generation management flag in the generation management flag detection determination block 53 shown in FIG. 5, or by rewriting the generation management flag from the signal supplied to the input terminal 51, However, unauthorized copying can be easily performed.

In particular, a recording / reproducing apparatus for a personal computer, which has been spreading rapidly recently, has a problem that such a flag can hardly be detected because there is almost no mechanism for detecting such a flag.

Next, a brief description will be given of a second method for preventing unauthorized copying. In FIG. 6, information from an input terminal 61 is encrypted by an encryption block 62 and then recorded on a writable disc-shaped optical recording medium 64 via an encoder block 63.

A block 65 is an encryption key generation block for generating a key for encryption, and selects one from a predetermined number of key bundles or generates a key by generating a random number. Generate. Then, the key information is sent to the encryption block 65, and is recorded on the disk-shaped optical recording medium 64 for decryption. At this time, the key information is recorded in a special area, so that it is not usually output to the outside.

If the information is recorded after being encrypted in this way, even if the information is copied, if the code is not decrypted, it becomes completely meaningless. As a result, illegal copying is prevented. It is.

[0016]

As a matter of course,
For example, illegal generation can be easily performed by ignoring the input generation management flag in the generation management flag detection determination block 53 shown in FIG. 5 or by rewriting the generation management flag from the signal supplied to the input terminal 51. Would.

In particular, a recording / reproducing apparatus for a personal computer, which has been rapidly spreading recently, has a problem that such a flag can be easily copied because there is almost no mechanism for detecting such a flag. Also, as shown in FIG. 6, since the key information is recorded on the disc-shaped optical recording medium 64 even though it is a special area, the entire area including the area where the key information is recorded is copied. For example, there is a problem that the encryption can be broken.

[0018]

According to a first aspect of the present invention, there is provided a method for digitally recording information using a disc-shaped optical recording medium having a read-only area and a writable area. The input information is encrypted using the positional relationship between the positional information of the mark provided on the disc-shaped optical recording medium and the positional information of the reference point signal in the read-only area as key information, and is recorded in the writable area. A digital recording method of information using a disc-shaped optical recording medium is provided, and the invention according to claim 2 is directed to a disc-shaped recording medium using a disc-shaped optical recording medium having a writable area. In the digital information recording method, the input information is encrypted using the positional relationship between the positional information of the mark provided on the disk-shaped recording medium and the positional information of the reference point in the writable area as key information. However, the provide digital recording method of information using the disc-shaped optical recording medium characterized by recording a writable area, the invention of claim 3,
3. A method for digitally recording information using a disc-shaped optical recording medium according to claim 1 or 2, wherein a special pattern is printed on a mark provided on the disc-shaped optical recording medium. A digital recording method for information using a disc-shaped optical recording medium is provided. The invention according to claim 4 is directed to a digital recording apparatus for information using a disc-shaped optical recording medium having a read-only area and a writable area. A mark detection unit that detects position information of a mark provided in at least one place on the disk-shaped optical recording medium, a reference point detection unit that detects position information of a reference point signal in the read-only area, and the disk An encryption key generation unit that generates encryption key information from a positional relationship between the position information of the mark provided on the optical recording medium and the position information area of the reference point signal in the read-only area; An encryption unit is provided with an output signal of the key generation unit and encrypts input information, and an encoder unit that encodes an output signal of the encryption unit and generates a signal to be recorded in the writable area. Provided is a digital recording device for information using a disc-shaped optical recording medium characterized by the fact that the invention of claim 5 is a digital recording device for information using a disc-shaped optical recording medium having a writable area, A mark detection unit that detects position information of a mark provided in at least one place on the disc-shaped optical recording medium, a reference point detection unit that detects position information of a reference point signal in the writable area, and the disc An encryption key generation unit configured to generate encryption key information from a positional relationship between position information of the mark provided on the optical disk recording medium and position information of a reference point in the writable area; An output unit that supplies an output signal of the unit and encrypts input information; and an encoder that encodes an output signal of the encryption unit and generates a signal to be recorded in the writable area. A digital recording device for information using a disc-shaped optical recording medium is provided.
6. A digital recording apparatus for information using a disc-shaped optical recording medium according to claim 5, wherein a special pattern is printed on a mark provided on the disc-shaped optical recording medium. Provided is a digital recording device for information using an optical recording medium.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a method of managing a key used when recording information once without encrypting the information as it is is significantly different from the conventional method. In order to understand the basic concept of encryption key management according to the present invention, a description will be given with reference to FIG. In FIG. 1A, reference numeral 14 denotes a writable disc-shaped optical recording medium. A read-only area 14A is provided on a part of the inner circumference and a writable area 14B is provided on the outer circumference. The region may be on the outer periphery. A specific location in the read-only area 14A is indicated by 14a in the figure.

The reference point 14a is located in the read-only area 1
A signal indicating a specified location in 4A is recorded, and is not particularly directly visible from the outside. On the other hand, 14b in the figure is a mark (mark) provided on the surface of the disc-shaped optical recording medium 14, and is formed by printing or engraving. In the present invention, key information for encryption is generated from the positional relationship between the reference point 14a and the mark 14b, and the input information is encrypted using the key information.

Since the mark 14b is provided on the surface of the disk-shaped optical recording medium by printing or engraving, the positional relationship with the reference point 4a differs for each medium. When mass-produced, it becomes impossible to keep the positional relationship between the reference point 14a and the mark 14b constant.

This means that the key information of the encryption is different for each medium. Even if the encrypted information is copied to another medium as it is, the key information is different. Therefore, it cannot be decrypted. The above is the basic method of key management according to the present invention.

An embodiment of a digital information recording apparatus using a disc-shaped optical recording medium incorporating a key management method according to the present invention and a method thereof will be described below with reference to FIG. FIG.
An embodiment of a digital recording device incorporating a key management method according to the present invention includes a disc-shaped optical recording medium 14, an encryption block 22 to which input information is supplied, and a disc-shaped optical recording medium 1.
4 includes an encoder block 23 that generates a recording signal for the C.4, an encryption key generation block 25, a reference point detection block 26, a mark detection block 27, and a phase difference detection unit 28.

The reference point detection block 26 is a reference point detection block for detecting the position information of the above-described reference point 14a from the read-only area 14A of the disc-shaped optical recording medium 14 by the pickup 14ap. The mark detection block 27 is a mark detection block that reads the position information of the mark 14b provided in the writable area 14B on the surface of the disc-shaped optical recording medium 14 by the pickup 14bp.

Since the rotation speed of the reference point 14a and the rotation speed of the printed mark 14b are the same, the position information of the reference point 14a and the position information of the mark 14b are obtained from the detection results of the two blocks 26 and 27. Phase difference detection block 28
Can determine the mutual positional relationship (phase difference). The encryption key generation block 25 generates a key using the value of the positional relationship (phase difference) from the phase difference detection block 28 and supplies the key to the encryption block 22.

Although the description has been given of the case where there is one mark, the present invention is not limited to this. For example, marks 14b1 and 14b2 (not shown) are provided at two places, and a first value of a positional relationship (phase difference) between the reference point 14a and the mark 14b1 and a positional relationship (phase difference) between the reference point 14a and the mark 14b2 are provided. ) Is determined, a cryptographic key is generated from a value indicating the mutual relationship between the first value and the second value, and the cryptographic key is supplied to the cryptographic block 22 so as to further improve the cryptographic accuracy. It may be.

An input information signal is supplied from an input terminal 21, and an output signal encrypted by an encryption block 22 is supplied to an encoder block 23 and encoded to generate a recording signal to be supplied to the disc-shaped optical recording medium 14. .

As a matter of course, the key generation for the encryption is required before the data is written to the disk-shaped optical recording medium 14, so that it is necessary to generate the key prior to the information writing operation. . Also, when reading the encrypted information and returning it to the original information, an encryption key can be generated in a similar procedure. The above is the outline of the operation of the device adopting the key management method according to the present invention.

Another embodiment of the information digital recording method and recording apparatus of the present invention will be described below with reference to FIG. In the case shown in FIG. 1A, the reference point is set in the read-only area of the disc-shaped recording medium 14,
As shown in FIG. 1B, the writable area 14
The reference point 14c can be provided even within B. Generally, read-only information, for example, address information is often recorded on the writable medium 14 in advance, so that a specific address can be set as the reference point 14c.

Alternatively, even if the information is not the read-only information but the information written by itself, if the information always exists at a fixed position, such as a volume descriptor of a file system, the information is used as the reference point 14c. I can do it. On the other hand, 14b is a mark provided on the surface of the disc-shaped recording medium 14, and its setting method is the same as in the case of FIG. In the present invention, the reference point 14c and the mark 14
key information for encryption is generated from the positional relationship with b,
The key information is used to encrypt the input information.

Since the mark 14b is provided on the surface of the disk-shaped recording medium 14 by printing, the positional relationship with the reference point 14c differs for each medium. Conversely, such a disk-shaped recording medium was mass-produced. At this time, it is impossible to keep the positional relationship between the reference point 14c and the mark 14b constant.

This means that the encryption key information differs for each medium. Even if the encrypted information is copied to another medium as it is, the key information differs. Therefore, it cannot be decrypted.

Next, the marks printed on the surface of the disk-shaped optical recording medium will be described below. The shape of the mark is desirably a special pattern to some extent in order to avoid erroneous detection due to scratches or attached dust, rather than a simple pattern simply required to determine the position.

FIG. 3 shows an embodiment of a special pattern. FIG. 3A shows a pattern printed on the surface of a disc-shaped optical recording medium, and FIG. 3B shows an envelope of a reproduction signal when such a pattern is provided. In particular, FIG. 3A shows an embodiment in which the first fine pattern is made translucent, followed by an opaque pattern.

If the shape of the mark is made a special shape to some extent, it is possible to reliably discriminate between the change in the envelope of the reproduced signal due to dust and flaws and the change in the envelope of the reproduced signal due to the mark printed on the surface of the medium. Becomes possible.

[0036]

As described above, the encryption is performed based on the positional relationship between the mark (mark) provided on the surface of the disk-shaped optical recording medium and the signal read from a specific position in the disk-shaped optical recording medium. Since the key information is generated, the code cannot be decrypted simply by copying the information in the disc-shaped optical recording medium, and as a result, it is useful to prevent unauthorized copying.

Further, providing a mark of a specific shape on a disc-shaped optical recording medium has a feature that it can be easily realized by a printing method and is suitable for mass production.

Since only one kind of pickup is required for detecting a mark provided on the surface of the disc-shaped optical recording medium and a signal read from a specific position in the disc-shaped optical recording medium,
The playback device can be configured without significantly increasing the cost.

[Brief description of the drawings]

FIG. 1 shows a basic conceptual diagram of an unauthorized copy prevention system according to the present invention.

FIG. 2 shows an embodiment of a recording device incorporating prevention of unauthorized copying according to the present invention.

FIG. 3 shows an embodiment of a mark provided on the surface of a disc-shaped optical recording medium according to the present invention.

FIG. 4 shows a configuration example on the reproducing side in a conventional recording / reproducing apparatus using a generation management flag.

FIG. 5 shows a configuration example on the recording side in a conventional recording / reproducing apparatus using a generation management flag.

FIG. 6 shows a configuration example of a conventional recording apparatus for encrypting information for the purpose of preventing unauthorized copying.

[Explanation of symbols]

 Reference Signs List 14 disc-shaped optical recording medium 14A read-only area 14B writable area 14a reference point 14ap, 14bp pickup 14b mark (mark) 14rh recording head 22 encryption section (encryption block) 23 encoder section (encoder block) 25 encryption key generation Section (encryption key generation block) 26 reference point detection section (reference point detection block) 27 mark detection section (mark detection block) 28 phase difference detection section (phase difference detection block)

Claims (6)

[Claims] 1. A method for digitally recording information using a disc-shaped optical recording medium having a read-only area and a writable area, wherein: position information of a mark provided on the disc-shaped optical recording medium; A digital recording method of information using a disc-shaped optical recording medium, wherein input information is encrypted using a positional relationship between positional information of a reference point signal and key information as key information and recorded in the writable area. 2. A method for digitally recording information on a disc-shaped recording medium using a disc-shaped optical recording medium having a writable area, wherein the position information of a mark provided on the disc-shaped recording medium and the writable information are recorded. A digital recording method of information using a disc-shaped optical recording medium, wherein input information is encrypted using a positional relationship with reference position information of a reference point in an area as key information and recorded in the writable area. 3. A method for digitally recording information using a disc-shaped optical recording medium according to claim 1, wherein a special pattern is printed on a mark provided on the disc-shaped optical recording medium. A digital recording method of information using a disc-shaped optical recording medium. 4. A digital recording apparatus for information using a disc-shaped optical recording medium having a read-only area and a writable area, wherein position information of a mark provided in at least one place on the disc-shaped optical recording medium is stored. A mark detection unit for detecting, a reference point detection unit for detecting position information of a reference point signal in the read-only area, and a position information of the mark provided on the disc-shaped optical recording medium and the position information of the mark in the read-only area. An encryption key generation unit that generates encryption key information from a positional relationship between a reference point signal and a position information area; an encryption unit that is supplied with an output signal of the encryption key generation unit and encrypts input information; And an encoder for encoding an output signal of the unit and generating a signal to be recorded in the writable area. Apparatus. 5. A digital recording apparatus for information using a disc-shaped optical recording medium having a writable area, wherein a mark detecting section for detecting position information of a mark provided at least at one position on the disc-shaped optical recording medium. A reference point detection unit that detects position information of a reference point signal in the writable area; and a position information of the mark provided on the disc-shaped optical recording medium and a reference point in the writable area. An encryption key generation unit that generates encryption key information from a positional relationship with the position information; an encryption unit to which an output signal of the encryption key generation unit is supplied to encrypt input information; and an output signal of the encryption unit. A digital recording device for information using a disc-shaped optical recording medium, comprising: an encoder unit for generating a signal to be encoded and recorded in the writable area. 6. A digital recording apparatus for information using a disc-shaped optical recording medium according to claim 4, wherein a special pattern is printed on a mark provided on the disc-shaped optical recording medium. A digital recording device for information using a disc-shaped optical recording medium.