JP2000339848A - Information recording method and information recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent illegal use and illegal copying by generating key information based on pattern information which is a combination of first pattern information and second pattern information caused by sticking a first substrate in which the first pattern information is recorded and a second substrate in which the second pattern information is recorded, and recording ciphered information. SOLUTION: A signal of combination pattern information on pattern information and 1 pattern information 2 is detected from a disk optical recording medium 20 by a two layer combination signal detecting section 21. The pulse interval of a detected signal is detected by a period detecting section 22. Detected time information is replaced by a quantized value by a cipher key generating section 23, and made a key information. In a cipher section 24, inputted contents information is ciphered by, for example, a cipher system such as DES and the like using key information. Ciphered contents information is converted into a format set in a recording medium by a format section 25, and recorded in the disk optical recording medium 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording method and an information recording apparatus which can be used for copyright protection of recorded information, for example, for preventing unauthorized use or unauthorized copying of video software recorded on an optical disk.

[0002]

2. Description of the Related Art In recent years, devices for digitally recording and reproducing information such as music and video have been rapidly increasing. Digitally recording and reproducing information has the characteristic that sound quality and image quality are not degraded even if copying is repeated.However, illegal use of software, illegal copying and piracy increase, and the rights of copyright holders are infringed. The problem is emerging. As a method of performing copy control in a conventional digital recording system, music information is SCMS (Serial Copy Mana).
gement System) and CGMS (CopyGenerat
ion Management System). All of these define flags for generation management, and depending on the state of the generation management flag, copy free, copy prohibited, 1
This is a method of performing control such as copying permission only once, and has a feature that it can be realized by a simple circuit.

[0003] Japanese Patent Application Laid-Open No. 9-134330 discloses an example of a technology in which security such as unauthorized use prevention and unauthorized copy prevention is further improved compared to SCMS and CGMS.
A system has been proposed in which a medium ID, a unique ID, and a terminal ID are checked, and when the result is OK, writing / reading of encrypted data is permitted.

[0004] It is preferable that the unique ID is provided with a serial number on a disk (medium) or information having a probability of occurrence of one and the same ID on one thousand sheets. There is a method called BCA (Burst Cutting Area) recording as a method of marking different data for each disk and using it as a disk identifier. In this method, burst data is recorded on the inner periphery of a disk by laser trimming or laser marking.

[0005]

However, the above-mentioned BCA recording requires a step of processing each recording medium with a laser so that each recording medium has a different unique ID one by one, and the manufacturing process is complicated. Had been transformed. Also,
Also in the BCA recording, the physical information of the unique ID can be obtained by inspecting and observing a legitimate disk. There is a risk of manufacturing, and there is room for improvement in the security of recorded information. SUMMARY OF THE INVENTION An object of the present invention is to provide an information recording method and an information recording apparatus capable of improving security such as prevention of unauthorized use of recorded information and unauthorized copy by a simpler method.

[0006]

In order to solve the above-mentioned problems, the present invention provides: (1) a disk-shaped optical recording having a first substrate and a second substrate bonded to the first substrate; An information recording method for recording encrypted information on a medium, wherein the first substrate on which first pattern information is recorded is bonded to the second substrate on which second pattern information is recorded. Arises,
Key information is generated based on combination pattern information of the first pattern information and the second pattern information, and encrypted information encrypted using the key information is recorded on the disc-shaped optical recording medium. An information recording method, characterized in that: (2) The information recording method according to (1), wherein the first pattern information and the second pattern information are recorded as a slit structure using light transmittance. (3) An information recording apparatus for recording encrypted information on a disc-shaped optical recording medium having a first substrate and a second substrate bonded to the first substrate, wherein the first pattern information is This is caused by bonding the recorded first substrate and the second substrate on which the second pattern information is recorded.
Key information generating means for generating key information based on combination pattern information of the first pattern information and the second pattern information; and encrypting information encrypted by using the key information. An information recording apparatus, comprising: recording means for recording on a recording medium. (4) The information recording apparatus according to (3), wherein the first pattern information and the second pattern information are recorded as a slit structure using light transmittance. Is provided.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the first substrate on which first pattern information is recorded and the second substrate on which second pattern information is recorded are bonded together.
Generating key information based on combination pattern information of the first pattern information and the second pattern information, and recording encrypted information encrypted using the key information on a disc-shaped optical recording medium It is. This makes it possible to improve security such as prevention of unauthorized use of recorded information and prevention of unauthorized copy by a simpler method.

First, the concept of the present invention will be described with reference to FIGS. As a typical example of a disc-shaped optical recording medium, a DVD (Dig
The ital Video Disc is generated by bonding two substrates (two layers) as a manufacturing process to both a two-layer recording disk having two recording surfaces and a one-layer recording disk having one recording surface. In the present invention, in a disc-shaped optical recording medium generated by bonding two substrates (layer 1 and layer 2) in this manner, the first pattern information that cannot be changed to the first substrate (layer 1) (Pattern information 1) is recorded, and unchangeable second pattern information (Pattern information 2) is recorded on the second substrate (Layer 2).

For example, as shown in FIG.
Separately, pattern information 1 having a slit structure using light transmittance is formed at an inner peripheral portion 12 at intervals of 90 degrees. This slit is an opaque high-reflectance aluminum reflective film, and can be easily detected by a predetermined optical reading device by detecting reflected light. This is referred to as layer 1. Also, as shown in FIG. 2, pattern information 2 having a slit structure is formed on the layer 2 at the same 90-degree intervals.

In the step of bonding the layers 1 and 2 to each other, the two layers are not bonded by positioning the layers 1 and 2 at a phase angle in the circumferential direction. Therefore, in the bonding step, a random bonding phase angle shift occurs in the two layers in the circumferential direction. FIG. 5 shows the layer 1 in the state of FIG.
2 shows a state in which the layer 2 in the state of FIG. 2 is bonded without a phase angle shift. FIG. 3 shows a state in which the layer 2 in the state of FIG. 2 is shifted by 45 degrees and the layer 1 in the state of FIG. 1 and the slit are completely overlapped with each other. FIG. 4 shows a state in which the sheets are bonded with an intermediate shift.

When the reflected light is detected by the aluminum reflecting film for the slits of the disk shown in FIGS.
The disc of FIG. 3 is as shown in FIG. 6, and the disc of FIG.
5 can detect the reflected light pulse as shown in FIG. This reflected light pulse is a signal of combination pattern information of pattern information 1 and pattern information 2. For example, the shorter time (frequency) of the interval between the reflected light pulses is detected, and the detected time is set to, for example, 1024 as the maximum width (the state of the pulse in FIG. 6).
The quantization value is replaced with a quantization value of 023, and that value is used as a unique ID of the disc.

[0012] Unlike the BCA, the unique ID has a smaller number of types than a serial number ID. However, for example, in consideration of a mode of encrypting the content information recorded on the optical disk by using the ID in the encryption information recording method described later, the encrypted data is copied to an appropriate optical disk. Therefore, the probability that the ID of the copied optical disk matches the ID of the copy source optical disk is statistically 1/1024. Unless the unique IDs match, it is impossible to reproduce on the copy destination optical disk. That is, since it is unlikely that one user purchases 1024 optical disks for one illegal copy, the accuracy of the unique ID of the present invention is practically sufficient.

[0013] The physical information of the unique ID can be obtained by a third party by observing a valid disc as in the case of the conventional unique ID by BCA recording. It is very difficult to realize the phase angle shift of the bonding of the two layers, and it is difficult to manufacture a disc with a unique ID. Therefore, the unique ID creation method according to the present method has higher security than the unique ID creation based on BCA recording.

Next, a case will be described in which pattern information 1 and 2 to be recorded on layers 1 and 2 are recorded depending on the presence or absence of a highly reflective film, a translucent film or a transparent film.

First, a typical manufacturing process will be described using a typical optical disk as an example. FIG. 9 is an explanatory diagram of a bonded optical disk (single-layer recording disk) having a single-layer recording surface. In the disc making process, first, layer 2 (second substrate)
Then, a metal such as aluminum or gold is sputtered to form a highly reflective film. In another step (pits are unnecessary in principle), a transparent substrate of layer 1 (first substrate) is prepared, and an adhesive layer of an ultraviolet curable resin is applied by spin coating. After laminating this layer 1 with the layer 2 having a highly reflective film, it is cured by irradiating ultraviolet rays from the outside, and the two sheets are firmly adhered. After that, the printing layer on which the title is printed on the layer 1 is printed by screen printing or offset printing. In this way, a normal bonded optical disk is produced. The disk is formed with a thickness of about 1200 μm, and the upper part is a printing surface. The pit surface to be recorded is about 600 μm, and the pit depth is about 0.1 μm.

FIG. 10 is an explanatory diagram of a bonded optical disk (double-layer recording disk) having two recording surfaces. FIG. 9 shows the case of a bonded disc having a single recording surface in which a highly reflective film is formed only on one layer (only the second substrate), whereas FIG. This shows the case of a two-layer recording disk in which a film is formed on both layers. Although both are basically processed in the same process, the main differences will be briefly described.

First, when the recording surface is a single-layer disc,
The high-reflection film is a polycarbonate substrate and is an aluminum film having a high reflectance of about 70% or more as a value considering surface reflection and the like.
The reflection film formed on the layer 2 (second substrate) on the reading optical pickup side is made of a semi-transmissive gold (Au) half having a reflectivity of about 30% as a value considering similar surface reflection. Layer 1 (first substrate) on the printing layer side, which is a transparent reflective film
Is a high reflection film which is the same as that of a disk having a single recording layer. In the case of a disc having a two-layer recording surface, an adhesive layer in the middle of an optical path such as an optically transparent layer and a uniform thickness, compared to a disk having a single layer. Optical precision is required.

According to the present invention, pattern information is recorded on such a disk in the layer 1 and the layer 2 before the lamination, depending on the presence or absence of a highly reflective film, a translucent film or a transparent film. FIG. 11 shows an example in which the present invention is applied to a bonded optical disk having a single recording surface. As is apparent from the difference from FIG. 9, a high-reflection film layer is also formed by a high-reflection film on the layer 1 not originally used. As in the case of the highly reflective film slit described in FIGS.
In the case of recording one mark, a mark pattern (pattern information 1) is created in a portion having a high reflection film and a portion not having the high reflection film. Also, the data may be recorded with some modulation. In the layer 2, a high reflection film layer is formed by a high reflection film by a conventional method. Then, the mark pattern (pattern information 2) is recorded by removing the high reflection film of the layer 2. The removal method is to remove the aluminum reflection film, which is a high reflection film, with a laser or, if the mark pattern is large enough to be formed by physical cutting, remove the high reflection film with a cutter. The portion without the high reflection film becomes the transparent substrate surface and can be regarded as a transparent film.

When the information of the mark pattern is read, the focus of the pickup is read with respect to the layer 2 so that the layer 1 has a large beam spot diameter of light. Therefore, the mark pattern of layer 1 may be made larger than layer 2 in consideration of ease of detection. FIG. 12 shows an example in which the present invention is applied to a bonded optical disk having two recording surfaces. In the layer 1, a mark pattern (pattern information 1) is recorded by using the presence or absence of the highly reflective film, and in the layer 2, the mark pattern (pattern information 2) is recorded by the presence or absence of the semi-transmissive reflective film. The method for removing the high-reflection film and the semi-transparent reflection film is similar to that of a single-layered optical disc in which the recording layer is removed by laser or when the mark pattern is large enough to be formed by physical cutting. , Remove by cutting machine. The recorded mark pattern (pattern information 1, 2) cannot be changed by a normal user.

The mark pattern is not limited to the slit information in the circumferential direction. For example, as shown in FIG. 14, a circular pattern is recorded on the layer 1 and the layer 2 with the center axis thereof shifted (circular pattern). May be a pattern of a plurality of rows), and a shift between two circular patterns generated by bonding may be used for generating a unique ID. In the above description, the shorter time (frequency) of the pulse interval is detected. However, when the number of layers to be bonded is three or more, the types of generated patterns are increased.
D.

Further, the disc-shaped optical recording medium of interest is C
D-ROM, CD-R, DVD-R, DVD-RW, D
Any type can be used as long as two or more layers are bonded, such as a VD-RAM.

Next, as described above, the pattern information 1,
2 shows an embodiment of an information recording apparatus for encrypting content information using combination pattern information of pattern information 1 and pattern information 2 of a disc-shaped optical recording medium on which disc 2 is recorded and recording the content information on the disc-shaped optical recording medium. 13 will be described.

From the disc-shaped optical recording medium 20, a signal of combination pattern information of pattern information 1 and pattern information 2 is detected by a two-layer combination signal detection section 21. In the detected signal, for example, the shorter time (frequency) of the pulse interval is detected by the cycle detection unit 22. The detected time (frequency) information is converted to key information in the encryption key generation unit 23 by setting the maximum width (the state of the pulse in FIG. 6) to 1024 and replacing this time width with a quantization value from 0 to 1023. This key information is the unique ID described above. The key information may be the unique ID itself, or may be created in combination with another parameter (for example, a personal ID).

The key information output from the encryption key generation unit 23 is transmitted to the encryption unit 24. The encryption unit 24 converts the input content information into, for example, the DE using the key information.
Encrypt with an encryption method such as S. The encrypted content information is converted into the format set in the recording medium by the format section 25 and recorded on the disc-shaped optical recording medium 20.

At the time of reproduction, the encrypted content information recorded as described above has a unique ID of the disc-shaped optical recording medium 20.
Decryption is performed based on Therefore, when the encrypted content information is illegally copied to another medium and reproduced, the unique ID of the copy destination medium is changed to the copy source medium 20.
Of course, the encrypted content information cannot be reproduced, and high security is ensured.

As described above, since it is difficult to manufacture a disk with the same unique ID as the medium 20 improperly, the unique ID based on the combined pattern information of the pattern information 1 and the pattern information 2 is used. Recording encrypted content information as key information is effective for improving security. In the above embodiment, the key information is stored in a unique I
Although D is used, any key information generated based on combination pattern information of pattern information 1 and pattern information 2 may be used.

[0027]

As described above, according to the information recording method and the information recording apparatus of the present invention, the first substrate on which the first pattern information is recorded and the second substrate on which the second pattern information is recorded are provided.
Key information is generated based on the combination pattern information of the first pattern information and the second pattern information generated by the bonding with the substrate, and the encrypted information is recorded using the key information. As a result, security such as prevention of unauthorized use of recorded information and prevention of unauthorized copying can be improved by a simpler method.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a layer 1 of an embodiment of a disc-shaped optical recording medium.

FIG. 2 is an explanatory diagram showing a layer 2 of an example of a disc-shaped optical recording medium.

FIG. 3 is an explanatory diagram of a first example of bonding a layer 1 and a layer 2;

FIG. 4 is an explanatory diagram of a bonding example 2 of a layer 1 and a layer 2;

FIG. 5 is an explanatory diagram of a third example of bonding the layers 1 and 2;

FIG. 6 is a conceptual diagram of a detection pulse in the bonding example 1.

FIG. 7 is a conceptual diagram of a detection pulse in a bonding example 2;

FIG. 8 is a conceptual diagram of a detection pulse in a bonding example 3;

FIG. 9 is a diagram showing a structure of an optical disk medium having a single recording surface.

FIG. 10 is a diagram showing a structure of an optical disk medium having two recording surfaces.

FIG. 11 is a diagram showing a structure of an embodiment of a disc-shaped optical recording medium having a single recording surface.

FIG. 12 is a diagram showing a structure of an embodiment of a disc-shaped optical recording medium having two recording surfaces.

FIG. 13 is a block diagram of one embodiment of an information recording device.

FIG. 14 is a conceptual diagram of another embodiment of a disc-shaped optical recording medium.

[Explanation of symbols]

 Reference Signs List 20 disc-shaped optical recording medium 21 two-layer combination signal detection unit 22 cycle detection unit 23 encryption key generation unit 24 encryption unit 25 format unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B017 AA06 BA07 BB03 CA09 CA16 5B085 AE13 AE29 5D044 AB05 AB07 BC06 CC04 DE49 GK12 GK17 5D119 AA31 BA01 BB03 DA01 EA10

Claims (4)

[Claims] 1. An information recording method for recording encrypted information on a disk-shaped optical recording medium having a first substrate and a second substrate bonded to the first substrate, comprising: Combination pattern of the first pattern information and the second pattern information generated by bonding the first substrate on which information is recorded and the second substrate on which second pattern information is recorded An information recording method, wherein key information is generated based on information, and encrypted information encrypted using the key information is recorded on the disc-shaped optical recording medium. 2. The information recording method according to claim 1, wherein the first pattern information and the second pattern information are recorded as a slit structure using light transmittance. 3. An information recording apparatus for recording encrypted information on a disc-shaped optical recording medium having a first substrate and a second substrate bonded to the first substrate, comprising: Combination pattern of the first pattern information and the second pattern information generated by bonding the first substrate on which information is recorded and the second substrate on which second pattern information is recorded Key information generating means for generating key information based on the information; and recording means for recording, on the disc-shaped optical recording medium, encrypted information encrypted using the key information. Recording device. 4. An information recording apparatus according to claim 3, wherein said first pattern information and said second pattern information are recorded as a slit structure utilizing light transmittance.