JP3709198B1 - Optical disc, optical disc recording apparatus and method, and optical disc reproducing apparatus and method - Google Patents

Abstract

A recording film of a recording optical disk is protected when a first area such as BCA is formed.
In an optical disk, a first region having a region that is formed in a stripe shape in the circumferential direction and that intermittently obtains a signal with a reduced amount of reflected light, and a second region are irradiated with a light beam. And a second area in which the user can record user data. The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the same as the first area and the first area. Data is also recorded between the areas, and the data in the second area is encrypted and recorded using the data recorded in the first area as a key.
[Selection] Figure 21

Description

  The present invention relates to illegality from an optical disk on which data such as copyrighted movie image data and music audio data such as AV data (Audio and Visual Data) is recorded to a recording medium such as another recordable optical disk. The present invention relates to an optical disc, an optical disc recording apparatus and method, and an optical disc playback apparatus and method that can prevent digital copying.

  Optical discs are superior in random accessibility as compared with conventional tape media, and are characterized by little deterioration due to repeated use because they can perform non-contact recording and reproduction using laser light. In addition, optical discs have the feature that they can be copied in large quantities at low cost by mastering by the disc manufacturer, and CD (Compact Disk) is generally used as a high-quality digital audio instead of conventional analog recording records. It has become. Furthermore, in recent years, DVDs (Digital Video Disks or Digital Versatile Disks) in which high-quality image data is digitally recorded are commercialized, and optical discs as digital recording media for AV data are expected to further develop in the future. .

  On the other hand, in addition to a read-only optical disc in which data is pre-recorded in a pre-pit format by a disc manufacturer, such as a music CD, CD-ROM, or DVD-ROM, users can record AV data at home in recent years. For example, recordable optical discs such as CD-R, CD-RW, MO, MD, and DVD-RAM have been developed and are spreading to the world.

  Also, in television broadcasting, a digital system capable of increasing the number of channels and various services has been introduced from the conventional analog system, and such a trend will further expand in the future. In particular, a recordable optical disc is used as a recording medium for contents distributed by digitized broadcasting or communication, for recording AV data mainly for the purpose of time-shift use for selecting and viewing a program after being stored at the time of distribution. Expected to be used.

  Conventionally, recording type optical discs that have been used mainly by computers are used for the purpose of storing data created by users themselves, and do not have a mechanism for restricting copying between recording type optical discs. It was. When a recordable optical disk is widely used, a general user illegally copies the recorded optical disk data to another recordable optical disk as it is, and the work that should be paid to the creator of the AV data. Without paying a fee, and because digital recording is possible, it is possible to obtain unauthorized copies without deterioration of sound quality and image quality, which has become a factor that hinders the spread of high-quality content. . In an MD for digitally recording music or the like, a mechanism for performing generation management for limiting the number of recordings is introduced, and recording is performed on an optical disc together with generation management data, and the number of copies is limited by the generation management data.

  Also, for example, in order to prevent unauthorized copying of a CD-ROM or DVD-ROM, a burst cutting area (hereinafter referred to as BCA), which is an additional recording area for overwriting a barcode on a pit portion of an optical disc. And a method of recording different IDs for each disc on the BCA at the time of manufacturing the optical disc is proposed in an international application of International Publication No. WO 97/14144. According to this method, since the password differs depending on the disc ID, only one disc can be decrypted with one password, and even if the content is copied illegally, the disc ID information is missing. The content will not be deciphered.

  FIG. 39 is a block diagram showing a configuration of a user data area of a conventional DVD-ROM and a configuration of an optical disc playback apparatus that decrypts encrypted content from the data in the user data area. In the DVD-ROM, as shown in FIG. 39, the content data recorded on the disc is encrypted.

  In FIG. 39, the user data area of the DVD-ROM is composed of a sector header area 3201, a main data area 3202, and an error detection code 3203. Here, in the sector header area 3201, a sector address 3204 indicating the position of a sector and copyright control information (for example, a scramble flag, copy control information, etc.) relating to data recorded in the main data area 3202 are recorded. The right control information 3205 and a decryption key 3206 for decrypting when the data in the main data area 3202 is encrypted are recorded. In the main data area 3202, AV data and the like mainly requiring copyright protection are encrypted and recorded.

  When reproducing such a user data area, first, a decryption key 3206 necessary for reproducing encrypted content is obtained from the sector header area 3201. The obtained decryption key 3206 is input to the key decryptor 3207, and the key decryptor 3207 decrypts the content decryption key using the predetermined decryption key 3206 using a predetermined disk key and outputs the decrypted content key to the decryptor 3208. Next, the decryptor 3208 decrypts the encrypted content in the main data area 3202 using the decrypted content decryption key according to the copyright control information 3205 stored in the sector header area 3201 corresponding to the main data area 3202. To obtain decrypted content that is reproducible data.

  In the optical disk having the configuration shown in FIG. 39, the main data area 3202 can be read from a drive device of a personal computer, but only the optical disk reproducing apparatus having a normal authentication function can read the area in which the decryption key 3206 is recorded. By configuring this, unauthorized duplication and creation of pirated versions can be prevented.

JP-A-10-2333019. Pamphlet of International Publication WO98-58368-A. UK Patent Application Publication GB-2332977-A. US Pat. No. 5,596,639. European Patent Application Publication EP-0 422 656-A. Specification of US Pat. No. 5,752,009. Pamphlet of International Publication WO00-21087-A. European Patent Application Publication No. EP-0984346-A. Specification of US Pat. No. 5,745,568. European Patent Application Publication EP-0802527-A. European Patent Application Publication EP-0951743-A. Japanese Patent Laid-Open No. 10-208386. Specification of US Pat. No. 5,646,993. JP 2000-113586 A. Japanese Patent Application Laid-Open No. 09-171619. Specification of US Pat. No. 5,513,169. Pamphlet of International Publication WO97-14144-A. Specification of US Pat. No. 6,516,064. Specification of US Pat. No. 5,761,301. Specification of US Pat. No. 5,289,102. Specification of US Pat. No. 6,546,490. Specification of US Pat. No. 6,587,948. Specification of US Pat. No. 6,081,785. Chinese Patent Application Publication CN 1166223.

  However, in the illegal copy prevention method using the generation management data, it is indispensable to change the generation management data at the time of copying (change of information from “copyable once” to “copy not possible”). There has been a problem that illegal copying cannot be sufficiently prevented by copying the data on the optical disc together with the generation management data without alteration, or by falsifying and recording the generation management data with a computer or the like. Furthermore, since the number of copies is limited by the generation management data recorded in advance with the content, even if a regular copyright fee is paid, the data that is “copy impossible” on the optical disc is completely allowed to be copied to another optical disc. However, the user had to wait for the supply from the content supplier. Tsu supplier is by not sufficiently manage the copy to the recording type optical disc performed by the user.

  In recent years, personal computers have been improved in performance and further connected to a network, whereby high-performance and high-speed decryption of a plurality of personal computers has been performed. In order to increase the encryption strength against such decryption, it is necessary to extend the key length of the key used for encryption. However, in a key management method for recording a decryption key in a sector header as proposed conventionally, only a decryption key having a predetermined length (decryption key area size) or less can be recorded, There was a problem that the key length could not be increased in order to increase the strength of the encryption in the future.

  Further, as described above, a method of providing a BCA and recording a different ID for each disc on the BCA at the time of manufacturing the optical disc has been proposed in an international application of International Publication No. WO 97/14144. This BCA trims the recording film on the concave and convex pits in the inner peripheral portion of the control data area, but the recording film constituting the recording type optical disk which is a rewritable or write-once type optical disk is a reflective film in a read-only optical disk. However, there is a problem that it is easily affected by heat.

  An object of the present invention is to solve the above problems and to protect a recording film of a recording optical disk when forming a first area such as a BCA, an optical disk, an optical disk recording apparatus and method, and an optical disk To provide a reproducing apparatus and method.

An optical disc according to a first aspect of the present invention is a first region having a region that is formed in a stripe shape in the circumferential direction and in which a signal with a reduced amount of reflected light is intermittently obtained;
An optical disc including a second area where a user can record user data by irradiating the second area with a light beam,
The first region is formed apart from the second region so as to have a predetermined radial distance,
Data recorded in the form of concave and convex pits in the first area is also recorded between the second area and the first area,
The data in the second area is encrypted and recorded using the data recorded in the first area as a key.

The optical disc includes a lead-in area formed inside the second area,
The lead-in area includes at least a part of the first area.

  In the optical disc, the second area is a rewritable area. Instead, in the optical disc, the second area is a writable area.

An optical disk recording apparatus according to a second aspect of the present invention includes a first region having a region that is formed in a stripe shape in the circumferential direction and in which a signal with a reduced amount of reflected light is intermittently obtained, and a second region,
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And an optical disk recording device for an optical disk recorded between the first area and the first area,
Recording means for recording user data by irradiating the second region with a light beam;
The data in the second area is encrypted and recorded using the data recorded in the first area as a key.

An optical disk recording method according to a third aspect of the present invention includes a first region having a region that is formed in a stripe shape in the circumferential direction and from which a signal with a reduced amount of reflected light is intermittently obtained, and a second region,
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And an optical disc recording method for an optical disc recorded also between the first area,
Recording user data by irradiating the second region with a light beam,
The data in the second area is encrypted and recorded using the data recorded in the first area as a key.

An optical disk reproducing device according to a fourth aspect of the present invention is a first region having a region that is formed in a stripe shape in the circumferential direction, and in which a signal with a reduced amount of reflected light is intermittently obtained, and a light beam as a second region A second area where the user can record user data by irradiating;
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And a reproducing apparatus for an optical disc recorded between the first area and the first area,
First reproducing means for reproducing the first area;
Second reproducing means for reproducing data recorded in the form of concave and convex pits between the second area and the first area;
Third reproducing means for reproducing user data recorded in the second area,
The data in the second area is encrypted and recorded using the data recorded in the first area as a key.

An optical disc reproducing method according to a fifth aspect of the present invention is a first region having a region that is formed in a stripe shape in the circumferential direction and that can intermittently obtain a signal with a reduced amount of reflected light, and a light beam in the second region. A second area where the user can record user data by irradiating;
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And a reproducing method for an optical disc recorded between the first area,
Playing back the first region;
Replaying data recorded in the form of concavo-convex pits between the second region and the first region;
Replaying user data recorded in the second area,
The data in the second area is encrypted and recorded using the data recorded in the first area as a key.

  In the optical disc recording apparatus, information is recorded on the optical disc.

  The optical disc playback apparatus plays back information from the optical disc.

  As described above in detail, according to the optical disc of the present invention, the first region including the region that is formed in a stripe shape in the circumferential direction and in which a signal with a reduced amount of reflected light is intermittently obtained, and the light beam An optical disc including a second area where a user can record user data by irradiating the second area, wherein the first area is a predetermined radial distance from the second area. Are formed apart to have Therefore, since the first area is formed away from the second area, when forming the first area such as BCA, the recording film of the recording optical disk is protected from the heat generated during the formation. Therefore, user data recorded on the optical disc can be protected easily and reliably.

  Embodiments according to the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is a plan view showing a data recording area of a recordable optical disc 100 according to the first embodiment of the present invention. The recordable optical disc 100 is a recording medium capable of recording digital data, and includes a write-once optical disc and a rewritable optical disc.

  In FIG. 1, 101 is a lead-in area in which management information of the optical disc 100 is recorded, 102 is content of AV data including at least one of image data (including still images and moving images) such as movies and audio data such as music. And a user data area in which digital data such as computer software requiring copyright protection is recorded, and a lead-out area 103 in which defect management information and the like are recorded. The lead-in area 101 includes a reproduction-only area 104 recorded in the form of prepits and a recording / reproduction area 105 which is a rewritable area having a guide groove. Here, in the read-only area 104, a control area describing the physical characteristics of the optical disc 100 is recorded in a pre-pit format by the manufacturer. In the lead-out area 103 and the rewritable area 105, data for a writing test by the optical disk recording apparatus, management information for managing defects on the optical disk 100, and the like are recorded by the optical disk recording apparatus. Further, on the inner circumference side of the read-only area 104 of the lead-in area 101, the BCA 106 is recorded as individual disk information by a known method as described below, after the optical disk 100 on which content is recorded is completed, It is added.

  2A is a block diagram and a longitudinal sectional view showing a device configuration when forming the BCA 106 of the optical disc 100 of FIG. 1, and FIG. 2B is an optical disc after the BCA 106 of the optical disc 100 of FIG. 1 is formed. It is a longitudinal cross-sectional view of 100, and the graph which shows the intensity | strength of the reflected light with respect to the horizontal direction. 2A and 2B show an example of a double-sided recording type optical disc 100. The optical disc 100 includes a recording layer 202, a reflective layer 203, and an adhesive layer between two substrates 201 and 207. FIG. 204, a reflective layer 205 and a recording layer 206 are inserted.

  When recording the BCA on the optical disc 100, as shown in FIG. 2A, for example, the reflection layer 205 of the optical disc 100 is irradiated in a pulsed manner through the focus lens 212 with the laser light from the high power laser light source 211, for example. Then, by removing a part of the reflective layer 205, stripe-shaped data subjected to phase encoding modulation is recorded on the pits. At the time of reproduction, as shown in FIG. 2B, a signal whose reflected light amount is reduced is intermittently reproduced at a portion where the reflection layer 205 is removed, and the reproduced signal is binarized and then phase-encoded. By demodulating (phase encoding demodulation), BCA data is reproduced. The BCA created by such a recording method has a feature that it can record a disc identifier, which is information unique to each optical disc 100, and cannot be further tampered with.

  FIG. 3 is a diagram showing a recording format of the BCA 106 of FIG. As shown in FIG. 3, a synchronization code 301, an error detection code 302, an error correction code 303, and the like are recorded in the BCA 106 in order to improve the reading rate of the BCA data 304. The disc identification information 305 is configured by concatenating the plurality of BCA data 304. The disc identification information 305 records the type of data that can be recorded in the user data area and the type of data that can be reproduced from the user data area. Since the data of the BCA 106 cannot be tampered with, the disk identification information recorded at the time of manufacturing the optical disk 100 can give a certain restriction to the user's use of the disk.

  FIG. 4 is a diagram showing a sector structure of sector data 401 in the user data area 102 of FIG. 4, the user data area 102 in FIG. 1 has a sector structure that can be accessed in a certain amount of units, and the sector data 401 includes a header 402, main data 403, and an error detection code 404. .

  Here, the main data 403 is an area in which AV data, computer data, and the like are recorded. In the header 402, a data ID (Data Identifier) 405, an ID error detection code 406, scramble control information 407, key information 408, and the like are recorded. The data ID 405 records a logical address for identifying a sector, and the ID error detection code 406 is a code for detecting an error in the data ID. The scramble control information 407 is a flag indicating whether or not the main data is scrambled, and the key information 408 records information about a key for descrambling the main data. As information about the key, the descrambling key itself (modified example of the first embodiment) or a key index (first embodiment) that is a pointer to the descrambling key recorded in another area on the optical disc 100 is recorded. Is done. The example of FIG. 4 shows a case where a key index for referring to the descrambling key recorded in the key management information area 107 of FIG.

  FIG. 5 is a diagram showing the configuration of the key management information area 107 in FIG. In FIG. 5, the key management information area 107 includes a key information area 501, a content information area 502, and a key index list area 503.

  In the key information area 501, the number of used descrambling key areas 504 is recorded, and the key information area 501 is an area for recording a descrambling key for unscrambling the AV data or the like. A descrambling key area 505 and a key status area 506 for recording the recording state of the descrambling key recorded in the descrambling key area 505 (indicating unused, area reserved, recorded, etc.). A plurality of descrambling keys are recorded in the descrambling key area 505, and a key index indicating a storage position in the descrambling key area 505 is recorded in the key index list area 503. The plurality of descrambling keys are stored in the key index. Can be referred to. In the key status area 506, status information indicating the recording state of the previous descrambling key is stored at a position that can be referred to by the key index.

  In the content information area 502, content that needs to be copyright-protected is registered among the content recorded on the optical disc 100, and information about keys used in the content is also registered. In the content information area 502, the number of contents 507 registered in the key index list area 503 and the content information 508 corresponding to the number of contents are recorded. Further, the content information 508 records a content ID for identifying the content, the number of descrambling keys used in the content, and a pointer to a key index list 509 that records the keys to be used. The key index list area 503 is an area for recording an index for referring to a key used in content in a list format in units of contents. In the key index list area 503, a key index referring to a recording area of all descrambling keys used in the content is recorded.

  In the recordable optical disc 100 configured as described above, an area identifier, a data category identifier, a disc identifier, and the like are recorded at the time of manufacture as information indicating the use condition of the disc in disc identification information that is difficult to rewrite. This information is detected by the recording / reproducing apparatus, and the recording operation and the reproducing operation can be controlled in accordance with the copyright protection level and usage level of the content. In addition, since it is recorded by a method that is difficult to rewrite and cannot be changed by the user, the user data area can be copied even when the copyright-protected content is copied to another optical disc. The identification information cannot be copied. Accordingly, by recording the data scrambled using the disc identification information on the optical disc, there is a user data area that cannot be descrambled on an optical disc having different disc identification information, and correct reproduction cannot be performed.

  FIG. 15A is a diagram showing whether or not content can be copied and reproduced in the same region and in different regions when the region identifier is recorded at the time of content recording in the first embodiment. FIG. 15B shows that, in the first embodiment, when the region identifier is recorded in advance at the time of shipment of the optical disc, the content can be copied and reproduced in the same region and in different regions. It is a figure which shows whether or not.

  For example, as shown in FIG. 15A, when the area identification code is not recorded at the time of shipment of the optical disc and the area identifier representing the area where the content can be used is recorded in the recording and playback area. The use in other areas can be prevented. However, content can be recorded on a disc to be used in another region (for region RC2 in FIG. 15A), and the content can be reproduced correctly. A recording medium capable of digitally copying content is provided with a levy system in order to protect the interests of the copyright holder, and is collected by adding to the fee when the optical disc is sold. However, since the added levy varies from country to country, if a recording medium to be used in other countries is used illegally, there is a possibility that it will not be properly distributed to the copyright holders who should be profited.

  Also, as shown in FIG. 15B, the region identifier is recorded in advance by a method that cannot be tampered with at the time of shipment of the optical disc, thereby preventing the content from being copied or reproduced on the optical disc to be used in other regions. be able to. Similarly, when a data category identifier is recorded as disc identification information, content copying to and reproduction from a disc on which data can be recorded and reproduced can be restricted by comparing with the category identifier included in the data to be recorded. When a disc identifier unique to each optical disc is recorded as disc identification information, the data to be recorded can be used only on that optical disc, for example, by encrypting the data to be recorded with the disc identifier.

  In this embodiment, the data scrambled by the disc identification information may be AV data or computer data that requires copyright protection, or may be a descrambling key for unscrambling the AV data or computer data. .

  FIG. 13 is a block diagram illustrating a method for determining whether or not the encrypted descrambling key is a regular descrambling key according to a modification of the first embodiment. As shown in FIG. 13, the encrypted descrambling key calculated by scrambling the data with the error detection code for detecting the descrambling key error added to the descrambling key using the disc identification information is recorded on the optical disc. May be recorded. In the optical disc playback apparatus, the encrypted descrambling key is decrypted into a descrambling key and an error detection code, and the decrypted descrambling key is verified by performing error detection based on a parity check or the like in the decrypted error detection code. It is determined whether it is a thing. For example, when descrambling with different disc identification information, an incorrect descrambling key is generated, and by checking the error detection code, it can be determined that it is not a legitimate descrambling key. it can.

  As another method for recording disc identification information, by preparing a stamper in which a plurality of types of disc identification information are created by pre-pits and creating an optical disc from each of them, different usage restrictions are imposed on optical discs produced from different stampers. You may do it. Furthermore, the disc identification information is scrambled using a secret key, and the disc identification information scrambled is recorded on the optical disc, thereby making it impossible for the user to know the copyright protection level described in the disc identification information. As a result, copyright protection is further strengthened.

  When the descrambling key itself is recorded as information about the key described in FIG. 4 (variation of the first embodiment), and a key index that is a pointer to the descrambling key recorded in another area on the disk is recorded. The case (first embodiment) will be described with reference to FIGS. 6 (a) and 6 (b). Here, FIG. 6A is a block diagram showing a recording method for recording a descrambling key and AV data in the sector data 401 of FIG. 1 according to a modification of the first embodiment, and FIG. FIG. 4 is a block diagram showing a recording method for recording a key index to a descrambling key and AV data in the sector data 401 of FIG. 1 according to the first embodiment.

  In the case of FIG. 6A, main data 403 and a descrambling key which is key information 408a necessary for descrambling the main data 403 are recorded in the same sector data 401. For this reason, when recording AV data, it is necessary to obtain a descrambling key necessary for descrambling. In other words, it is indispensable to obtain and purchase the key itself when recording AV data.

  On the other hand, in the case of FIG. 6B, the key data 408 refers to a main data 403 and a descrambling key area in which information necessary for descrambling the main data 403 is recorded in the same sector data 401. The key index is recorded, and the descrambling key is recorded in the area specified by the key index. When recording AV data, a key ID indicating which key can be descrambled among keys used in the content to be recorded is obtained, and a key index corresponding to the key ID is obtained from a key index list included in the content information. Key information 408 is acquired and recorded together with the main data 403. The descrambling key is recorded when the descrambling key is obtained, and is recorded in the descrambling key area indicated by the key index corresponding to the key ID. As a result, recording of AV data and the corresponding descrambling key can be performed independently. In other words, recording of AV data and acquisition or purchase of a key can be performed independently, and acquisition or purchase of a key is not necessarily required when recording AV data. The user can record the contents, and obtain a key when actually reproducing the contents.

  FIG. 14 is a diagram illustrating a configuration of a descrambling area management table according to a modification of the first embodiment. In the above embodiment, a case has been described in which a key index for referring to a descrambling key is recorded in the same sector data 401 in order to associate an encrypted content with a descrambling key for decrypting the encrypted content. Alternatively, the descrambling area management table of FIG. 14 for managing the correspondence between the address range of the sector where the encrypted content is recorded and the descrambling key may be used. In this descrambling area management table, the address range of the sector where the encrypted content is recorded is represented by a start address and an end address, and when data of those sectors is reproduced, the descrambling key is referred to and the encryption is performed. Descrambled content.

  In order to acquire the content to be recorded and the descrambling key used there, a content ID that makes the content identifiable is used. As shown in FIG. 5, the content information recorded in the content management list in the content information area 502 recorded on the optical disc is recorded as a list of content IDs and descrambling keys used in the content. By adopting a list structure in which a plurality of descrambling keys can be used for one content, a service in which a part of content or software is sold and sold is possible.

  Further, in the modification described above with reference to FIG. 13, the data scrambled with the disc identification information of the descrambling key to which an error detection code such as a checksum or cyclic redundancy check code is added is illegally copied to another disc. In this case, an error is detected by descrambling with different disc identification information. In such a case, it is possible to obtain a disc that can be correctly reproduced by obtaining a descramble key obtained by scrambling the descramble key with disc identification information recorded on the optical disc and replacing it.

  The key management information area 107 in FIG. 1 is recorded in a rewritable lead-in area 101. Usually, the user data area 102 is composed of a user area accessible from a drive device of a personal computer and a spare area for a defective sector on the optical disk. In a normal read command or write command, only the user area is a logical continuous area. As accessible. By placing the key management information in the lead-in area 101, it is possible to prevent direct access from a drive device of a personal computer and to obtain a key for unscrambling the AV data from the personal computer. It can be.

<Second Embodiment>
FIG. 7 is a block diagram showing a configuration of an optical disc recording / reproducing apparatus according to the second embodiment of the present invention. This optical disc recording / reproducing apparatus is an apparatus for recording contents of AV data such as image data and music data requiring copyright protection on the optical disc 100 according to the first embodiment.

  In FIG. 7, 701 is the optical disk of the first embodiment, 702 is an optical head that is an optical pickup composed of a semiconductor laser and an optical element, and 703 is a recording / reproducing unit that controls the operation of the semiconductor laser and binarizes a reproduction signal. A control circuit 704 is a modulation / demodulation circuit that digitally modulates digital data to be recorded and digitally demodulates a binarized reproduction signal. 705 is an error detection and correction process for errors caused by scratches, dust, etc. on the optical disk 701. An error detection and correction circuit for generating an error correction code necessary for error detection and correction processing; 706, a buffer memory which is a RAM used as a working memory and data buffer memory of the error detection and correction circuit 705; and 707, scrambled Descramble to descramble recorded AV data Path 708, an MPEG decoding circuit that decompresses compressed and recorded moving image data, 709, an output circuit that generates and outputs a video signal and an audio signal by D / A converting the decompressed image data, and 710 A control CPU that controls the operation of the entire optical disc recording / playback apparatus, 711 is a communication circuit that acquires a descrambling key for decrypting the encryption applied to the content, and 712 is image data, music data, etc. from a communication terminal device such as a set-top box A data receiving circuit for receiving digital data of encrypted content.

  A data recording operation in the optical disc recording / reproducing apparatus of FIG. 7 configured as described above will be described. Digital data of encrypted content such as image data and music data transmitted from a communication terminal device such as a set-top box or an MPEG encoder is received by the data receiving circuit 712 and then temporarily stored in the buffer memory 706. Is done. The error detection and correction circuit 705 generates error detection and correction codes necessary for error detection and correction processing due to scratches, dust, etc. on the optical disc 701 in the stored content digital data, and reconstructs the recorded data To do. For the error detection and correction code, a code such as a known Reed-Solomon code is used. Here, the reconstructed recording data includes digital data of contents and error detection and correction codes. The modulation / demodulation circuit 704 digitally modulates recording data using a modulation method such as an 8/16 modulation method during recording. The recording / reproducing control circuit 703 modulates the intensity of the laser beam output from the optical head 702 in accordance with the digitally modulated recording data, and irradiates the optical disc 701 with the laser, thereby recording the recording data on the optical disc 701. Record above.

  FIG. 8 is a flowchart showing AV data recording processing executed by the control CPU 710 of the optical disc recording / reproducing apparatus of FIG.

  In FIG. 8, first, in step S801, the disc identification information in the lead-in area 101 is reproduced prior to the recording of AV data from the optical disc 701. Next, in step S802, the user data recorded in the disc identification information is reproduced. It is determined from the type of data that can be recorded in the area 102 whether or not the digital data of the content to be recorded can be recorded. If YES in step S802, the process proceeds to step S803. If NO, the recording operation is stopped in step S810, and the AV data recording process is terminated.

  In step S803, the data of the sector in which the key management information is recorded in the lead-in area 101 is reproduced. In step S804, whether or not an area for key information necessary for content recording has been allocated to the reproduced key management information. Determine whether. If NO in step S804, an area for recording key information is allocated to the key management information area 107, and the process advances to step S806. On the other hand, if “YES” in the step S804, the process proceeds to a step S806 as it is.

  When recording content, the control CPU 710 of the optical disc recording / playback apparatus sends the data of the encrypted content to be recorded and the information related to the descrambling key for decrypting the data reception circuit 712 from the communication terminal device. Receive via. Here, the key-related information is a key ID indicating the key itself used in the content or the number corresponding to the key used in the entire content. When the key ID is received, in step S806, the received key ID is converted into a key index that is a pointer indicating an area in which the descrambling key corresponding to the key ID is recorded, and the converted descrambling key is converted. Are arranged in the header area of the sector in which the data of the content decrypted with the descrambling key is recorded. In step S 807, the control CPU 710 controls the recording / reproduction control circuit 703, the modulation / demodulation circuit 704, and the error detection / correction circuit 705 to execute the following recording data processing. In this process, error detection and correction codes are added to the sector data to be recorded, and the sector data to which these codes are added is digitally modulated using a modulation method such as a known 8/16 modulation method. The optical head 702 is controlled to a predetermined recording position, and the intensity of the laser beam is modulated according to the digitally modulated recording data. As a result, the recording data is recorded on the optical disc 701. Further, in step S808, it is determined whether or not the content recording is finished. If NO, the process returns to step S806, and the above processing is repeated. If “YES” in the step S808, the updated key management information is recorded in the key management information area 107 on the optical disc 701 in the step S809, and the AV data recording process is ended.

  FIG. 9 is a flowchart showing key management information area allocation processing executed by the control CPU 710 of the optical disc recording / reproducing apparatus of FIG. This process is a process for allocating an area for recording a descrambling key prior to recording of content data.

  In FIG. 9, first, in step S901, information about the key of the content to be recorded (including the number of descrambling keys to be used, etc.) is obtained from, for example, an electronic program guide, and then recorded on the optical disc 701 in step S902. The key management information in the key management information area 107 is reproduced, and in step S903, the free area of the descrambling key area 505 is checked from the key status area 506, and the descrambling key used in the content to be recorded is recorded. Determine if you can. If NO in step S903, the recording operation is stopped in step S907 and the allocation process is terminated. On the other hand, if YES in step S903, the content to be recorded is registered in the content list in the content information area 502 in step S904, and is necessary for recording the descrambling key in the descrambling key area 505 in step S905. In order to reserve an area, a recording area is allocated by setting an area reserved flag in the corresponding key status area. In step S906, a key index indicating an area allocated for recording the descrambling key is created as a key list, a pointer as content information is allocated, and the allocation process is terminated.

  FIG. 10 is a flowchart showing a descrambling key recording process executed by the control CPU 710 of the optical disc recording / reproducing apparatus of FIG. This recording process is a process for acquiring a descrambling key from the key management center and recording it on the optical disc 701.

  In FIG. 10, first, after reproducing the disc identification information of the lead-in area 101 of the optical disc 701 in step S1001, in step S1002, in order to obtain the descramble key from the key management center, A key ID for identifying a key required for content descrambling is transmitted to the key management center via the communication circuit 711. At the key management center, a descrambling key necessary for descrambling the content is selected from the given key ID, and the descrambling key is encrypted and returned with information such as the disc identification information sent thereto.

  In step S1003, after the descrambling key corresponding to the key ID is obtained from the key management center via the communication circuit 711, the data in the key management information area 107 is reproduced in step S1004, and the reproduced key management information area A key index indicating an area for recording the descrambling key is acquired from the key index list indicated by the key ID among the data in 107. In step S1005, the acquired descrambling key is placed in the descrambling key area indicated by the key index, and an acquired flag indicating that the key has been acquired is set in the corresponding key status area 506. In step S1006, it is determined whether or not all keys have been acquired. If NO, the process returns to step S1003 and the above processing is repeated. On the other hand, if YES in step S1006, the updated key management information is recorded in the key management information area 107 in step S1007, and the descrambling key recording process is terminated.

  Next, the data reproduction operation of the optical disk recording / reproducing apparatus of this embodiment will be described with reference to FIG. Digital data recorded on the optical disk 701 is reproduced as follows. Laser light from the semiconductor laser of the optical head 702 is irradiated onto the optical disk 701, and reflected light reflected by the optical disk 701 at that time enters the recording / reproduction control circuit 703 via the optical head 702. The recording / reproduction control circuit 703 photoelectrically converts incident reflected light, and then performs amplification and binarization processing to generate a digitized reproduction signal and output it to the modulation / demodulation circuit 704. The modulation / demodulation circuit 704 digitally demodulates a signal digitally modulated using a known modulation method such as an 8/16 modulation method at the time of recording, and outputs the digital signal to the error detection and correction circuit 705. Next, the error detection and correction circuit 705 performs error detection and correction processing due to scratches or dust on the optical disc 701 using the buffer memory 706 as a working memory. This error detection and correction processing is executed by decoding, for example, a known Reed-Solomon code.

  The reproduced data that has been subjected to error detection and correction processing is output to a descrambling circuit 707 for descrambling. The descrambling circuit 707 performs descrambling processing on the reproduction data using the descrambling key in the key management information area 107 reproduced in advance prior to data reproduction, and then outputs the data to the MPEG decoding circuit 708. Next, the MPEG decoding circuit 708 decompresses the compressed moving image data and music data, and then outputs the decompressed data to the output circuit 709. Further, the output circuit 709 D / A converts the input decompressed data into a video signal and an audio signal, and outputs them to a higher-level device such as a television device or an audio device.

  FIG. 11 is a flowchart showing AV data playback processing executed by the control CPU 710 of the optical disk recording / playback apparatus of FIG. In FIG. 11, first, in step S1101, the disc identification information in the lead-in area 101 is reproduced prior to recording of AV data from the optical disc 701. In step S1102, reproducible data recorded in the disc identification information. It is determined from the type of whether or not the content to be reproduced can be reproduced. If NO in step S1102, the reproduction operation is stopped in step S1112 and the reproduction process of the AV data is ended. On the other hand, if “YES” in the step S1102, the data of the sector in which the key management information is recorded in the key management information area 107 of the lead-in area 101 is reproduced in the step S1103, and the key management information reproduced in the step S1104 is reproduced. Then, it is determined whether or not key information necessary for content reproduction has been recorded. If YES in step S1104, the process directly proceeds to step S1106. If NO, in step S1105, a descrambling key is obtained from the key management center that manages the key via the communication circuit 711, and the optical disc 701 is recorded. The information is recorded in the key management information area 107, and the process proceeds to step S1106.

  In step S1106, the control CPU 710 moves the optical head 702 to the user data area of the optical disc 701, and controls the recording / reproduction control circuit 703, modulation / demodulation circuit 704, and error detection / correction circuit 705 to reproduce AV data. In step S1107, a descrambling key necessary for descrambling the sector data is acquired from the descrambling key area 505 indicated by the key index included in the reproduced sector header. In step S1108, the descrambling key is acquired. On the other hand, the scrambled data is decoded by descrambling with the disc identification information. In step S1108, the error detection code assigned to the descrambling key is checked to determine whether the descrambling key has an error. If “YES” in the step S1108, it is regarded as illegally obtained content (or illegally copied content), the reproduction operation is stopped in the step S1112, and the reproduction process of the AV data is ended.

  On the other hand, if NO in step S1108, the content data is descrambled by the descrambling key in step S1109, and the descrambled AV data is output to the MPEG decoding circuit 708 in step S1110. Then, the control CPU 710 controls the MPEG decoding circuit 708 and the output circuit 709 so that the descrambled AV data is MPEG-decompressed and then D / A-converted into a video signal and an audio signal so as to be a television apparatus or audio device. Output to a higher-level device such as Next, in step S1111, it is determined whether or not the reproduction of the content is finished. If NO, the process returns to step S1106 to repeat the above process. On the other hand, when YES is determined in the step S1111, the AV data reproduction process is ended.

  If an error is detected in step S1109, the content is regarded as illegally obtained content. For example, the content is regarded as illegally copied content, and the reproduction operation is stopped. However, as in the case where the key is not recorded, By executing the processing of step S1105, the key information may be acquired from the key management center that manages the key via the communication circuit 711 and recorded in the key management information area 107 of the optical disc 701. Thereby, even the copied AV data can be made reproducible by properly obtaining the key.

  FIG. 12 is a flowchart showing a descrambling key acquisition process executed by the control CPU 710 of the optical disc recording / reproducing apparatus of FIG. This process is a process of reproducing the descrambling key from the reproduced key index, and is executed prior to the AV data reproduction process shown in FIG.

  In FIG. 12, first, in step S1201, it is determined from the scramble control information whether or not the reproduced sector area data is scrambled. If NO, the process proceeds to step S1206. If YES, step S1206 is performed. In step S1202, a key index is obtained by reproducing key information recorded in the same sector area as the sector area. Next, in step S1203, a descrambling key indicated by the key index is obtained from the descrambling key area 505. After the acquisition, in step S1204, the acquired descrambling key is descrambled using the disc identification information, and it is determined whether or not the descrambling key has an error by examining the error detection code. If YES in step S1204, the reproduction operation is stopped in step S1205 and the descrambling key acquisition process is terminated. On the other hand, if NO at step S1204, the process proceeds to step S1206. If the reproduced sector is not scrambled or if there is no error in the result of descrambling the descrambling key with the disc identification information, the reproduction operation is permitted in step S1206, and the reproduced sector data is output. Then, the descrambling key acquisition process ends.

  As described above, in the optical disc and the optical disc recording / playback apparatus according to the embodiment of the present invention, the recording and playback operations by the user can be controlled using the playback-specific disc identification information created at the disc manufacturing stage. Further, by scrambling a part of the data using the above-described disc identification information, it is possible to prevent normal reproduction with respect to the disc on which the user data area has been physically copied. In addition, by disposing a descrambling key necessary for data descrambling in a separate area from the data, it is possible to record the content and the descrambling key independently. For this reason, it is possible to make the content reproducible by recording the content and acquiring the descrambling key when necessary, for example, when reproducing the content data. At this time, it is apparent that unauthorized use by physical copying can be prevented by scrambling the descrambling key with the disc identification information as in the case described above. In addition, even if the disc has been copied illegally, the descramble key scrambled with the disc identification information of the optical disc is formally obtained from the key management center and recorded on the optical disc, so that the disc can be reproduced correctly. You can also.

  The content data input to the optical disc recording / playback apparatus has already been encrypted. However, by providing a circuit for encrypting the content in the optical disc recording / playback apparatus, the input content data is encrypted. The same effect can be obtained by recording on the optical disk.

  In the present embodiment, only the descrambling key necessary for decrypting the encrypted content is encrypted using the disc identification information, thereby preventing copying between discs having different disc identification information. However, if the content itself is encrypted using the disc identification information, the copy can be similarly prevented. Further, by encrypting the disc identification information using a secret key, it is possible to make it more difficult to illegally decrypt the content recorded on the disc.

<Effects of the first and second embodiments>
In the optical disc of the embodiment according to the present invention, the disc identification information for performing the recording operation and the reproducing operation in the user data area for each optical disc is recorded in the non-rewritable read-only area, so that the user can write onto the optical disc. Content recording and playback operations can be controlled using information recorded during manufacture of the optical disc.

  The optical disk according to the embodiment of the present invention records the encrypted data using the read-only disk identification information that cannot be rewritten as a key in the user data area on the optical disk, so that the user data area by the user can be recorded. Even if it is copied to a recordable optical disc, disc identification information cannot be copied, and correct decoding and reproduction of data cannot be performed.

  In the optical disc according to the embodiment of the present invention, encrypted data and decryption descrambling keys are recorded in different sector areas, thereby acquiring and encrypting data such as movies and music that require copyright protection. It is possible to acquire a descrambling key for solving the problem independently. Furthermore, by encrypting and recording the descrambling key using the disc identification information as a key, the disc identification information cannot be copied even if it is copied to another recording type optical disc by the user in the user data area. Therefore, the correct decryption and reproduction of the data can be performed by acquiring and recording the descramble key encrypted using the disc identification information of the copy destination optical disc as a key.

<Third Embodiment>
Next, an encrypted content recording and playback method according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 16 is a plan view showing a data recording area of an optical disc 1101 according to the third embodiment of the present invention.

  In FIG. 16, reference numeral 1101 denotes a recording medium capable of recording digital data, and a recording type optical disk which is a rewritable or write-once optical disk, and 1102 is a control in which disk information is recorded in the form of minute concave and convex pits. A user data area 1103 is a user data area in which a user records data by irradiating an optical disk with a laser beam. 1104 is a BCA in which a disk ID is recorded. In the BCA 1104, the recording film on the minute concave and convex pits in the inner peripheral portion of the control user data area 1102 is a part of the recording film so that a plurality of trimming areas 1105 are formed in a long shape in the radial direction. Trimming is performed by emitting laser light from a pulse laser such as a YAG laser, and thereby a disc ID which is descrambling identification information is recorded.

  FIG. 17 is a waveform diagram showing signal waveforms of the reproduction signal 1201 and the reproduction binarized signal 1207 in the BCA reproduction circuit 1401 according to the third embodiment, and FIG. 18 is a BCA reproduction circuit according to the third embodiment. 1 is a block diagram showing the configuration of 1401. FIG. FIG. 17 shows a reproduction signal 1201 when data of BCA 1104 is reproduced. In FIG. 18, 1301 is an optical pickup, 1302 is a preamplifier, 1303 is a low-pass filter (LPF), 1304 is a binarization circuit, and 1305 is a demodulation circuit.

  In FIG. 18, the laser light output from the optical pickup 1301 irradiates the BCA 1104 of the optical disk 1101, and the reflected light is photoelectrically converted by the optical pickup 1301, and the electric signal after the photoelectric conversion is amplified by the preamplifier 1302. A reproduction signal 1201 is obtained. Here, the reproduction signal 1201 in FIG. 17 is a signal having a level corresponding to the concavo-convex pits in the control user data area 1102. In this reproduction signal 1201, 1202, 1203 and 1204 are removed from the recording film by a trimming process using a pulse laser. This is a trimming portion where a signal due to uneven pits is missing. This trimming process is performed by the optical disc manufacturer.

  Returning to FIG. 18, the reproduction signal 1201 is input to the low-pass filter 1303, and the modulation signal due to the uneven pits is removed, and then input to the binarization circuit 1304. The reproduction signal input to the binarization circuit 1304 uses not a normal slice level 1205 for binarizing the signal in the control user data area 1102, but a slice level 1206 which is a level sufficiently lower than the slice level 1205. By binarization, a reproduction binary signal 1207 is obtained. A reproduced binary signal 1207 output from the binarization circuit 1304 is demodulated by a demodulation circuit 1305 to obtain a disk ID signal 1306.

  As described above, by adding disc identification information for identifying an optical disc, management of the optical disc can be easily realized. Further, since the BCA 1104 is recorded on the concave and convex pits, it is possible to prevent information for identifying the optical disk in the BCA 1104 from being easily tampered with. Further, since the control user data area 1102 and the BCA 1104 in FIG. 16 are adjacent to each other, when the data in the control user data area 1102 is reproduced, the data in the BCA 1104 can be reproduced continuously, or the data in the BCA 1104 can be reproduced. When reproducing, the data in the control user data area 1102 can be reproduced continuously. For example, when the optical disk is activated, the CPU obtains the information of the BCA 1104 for quickly identifying the optical disk and is encrypted. It is possible to speed up the process for recording the content.

  The BCA 1104 of this embodiment is formed by trimming the recording film on the concavo-convex pits in the inner peripheral portion of the control user data area 1102, but constitutes a recording type optical disc that is a rewritable or write once type optical disc. The recording film to be subjected is easily affected by heat with respect to the reflective film in the read-only optical disk. By trimming the inner peripheral portion of the control user data area 1102, the user data area 1103 can be protected from heat generated during trimming as compared with the case of trimming the outer peripheral portion. The reason why the BCA 1104 is formed on the inner peripheral side of the control user data area 1102 is that a margin in the case where the spot diameter of the laser light beam changes due to the instability of the focus servo circuit is taken into consideration.

  Note that data recorded in the BCA 1104 before trimming may be recorded in the control user data area 1102. Since the data recorded in the BCA 1104 is also recorded in the control user data area 1102, the data in the control user data area 1102 can be protected even when trimming is performed. Further, when the data recorded in the BCA 1104 is continuously and repeatedly recorded from the BCA 1104 to the control user data area 1102, the position of the BCA 1104 is predicted by finding the data in the control user data area 1102. can do.

  Next, a procedure for recording content encrypted with the disc ID on the optical disc 1101 having the BCA 1104 via a network will be described. In the third to fifth embodiments, the network refers to a communication network such as the Internet, a public telephone line, or a dedicated line. FIG. 19 is a block diagram showing a configuration of an optical disc recording / playback system according to the third embodiment, and a device configuration for recording encrypted content on a recordable optical disc 1101 that is a rewritable or write once optical disc having the BCA 1104. Indicates.

  In FIG. 19, the optical disc recording / reproducing system includes an optical disc recording / reproducing device 1410 and an encryption unit 1406 that are connected to each other via a network 1405 such as the Internet. The optical disc recording / reproducing apparatus 1410 includes an optical pickup 1301, a BCA reproducing circuit 1401, the Internet 403, a recording circuit 1411, a data reproducing unit 1412, and an encryption decoder 1413. The encryption unit 1406 includes an interface 1404, a content memory 1407, and an encryption encoder 1408.

  First, the laser light output from the optical pickup 1301 irradiates, for example, the BCA 1104 of the RAM type optical disk 1101, and the reflected light is photoelectrically converted by the optical pickup 1301, and then the photoelectrically converted reproduction signal is input to the BCA reproduction circuit 1401. Entered. The BCA reproduction circuit 1401 reproduces the disc ID signal 1402 in the BCA based on the inputted reproduction signal, outputs the reproduced disc ID signal 1402 to the encryption decoder 1413, and via the interfaces 1403 and 1404 and the network 1405. And sent to the encryption encoder 1408 of the encryption unit 1406. The encryption encoder 1408 encrypts the content data so that the disc ID signal 1402 of the optical disc 1101 on which the content data in the content memory 1407 is recorded becomes a decryption key for decryption, or scrambles for video and audio I do.

  Note that in this embodiment, the encryption process has the same meaning even if the content 1407 is expressed as being encrypted using the disc ID signal 1402 as an encryption key. In the present embodiment, encryption and decryption are considered in the relationship between a lock and a key, and closing the lock with the key is encryption, and opening the lock with the key is decryption. Therefore, although the actual calculation differs between encryption and decryption, it is assumed that the key for encryption and the key for decryption are the same. Note that the content 1407 is C, the disc ID signal 1402 is BCAS, the encrypted content 1409 is C [BCAS], and the computation of the encryption process is represented by *, which is expressed as the following equation.

[Equation 1]
C * BCAS = C [BCAS]

  The content 1409 encrypted by the encryption unit 1406 is sent to the recording circuit 1411 of the recording / reproducing apparatus 1410 via the interfaces 1403 and 1404 and the network 1405. The recording circuit 1411 digitally modulates input content data, modulates the intensity of the laser light from the optical pickup 1301 according to the digitally modulated data, and irradiates the optical disc 1101 with the content data. Recording on the optical disk 1101.

  Next, when reproducing the content recorded encrypted on the optical disc 1101, the laser beam output from the optical pickup 1301 irradiates the area where the encrypted content in the user data area 1103 is recorded, After the reflected light is photoelectrically converted by the optical pickup 1301, the photoelectrically converted reproduction signal is input to the data reproduction unit 1412. The data reproduction unit 1412 A / D converts the input reproduction signal into digital data and outputs the digital data to the encryption decoder 1413. On the other hand, the laser light from the optical pickup 1301 irradiates the BCA 1104 of the optical disc 1101, and the reflected light is photoelectrically converted by the optical pickup 1301, and then the photoelectrically converted reproduction signal is input to the BCA reproduction circuit 1401. The BCA playback circuit 1401 A / D converts the input playback signal to generate a disk ID signal 1402 and outputs the disk ID signal to the encryption decoder 1413.

  The encryption decoder 1413 decrypts the encrypted content data using the input disc ID signal 1402 as a key. At this time, if the content is properly recorded on the optical disc 1101, the key for decrypting the encrypted content recorded on the optical disc 1101 is the disc ID signal 1402 of the optical disc 1101. A disc ID signal 1402 output from 1401 is also a disc ID signal (BCAS) of the optical disc 1101. Accordingly, the decrypted or descrambled content is output from the encryption decoder 1413 as an output signal 1414. In addition, when the calculation of the decoding process is #, the following expression is used.

[Equation 2]
C [BCAS] # BCAS = C

  Here, when the content data is image data, for example, MPEG signal data is expanded to obtain image signal data.

  As described above, the encryption in the present embodiment uses the disk ID as a key, and since there is only one disk ID corresponding to one optical disk, the same encryption is applied only to that one optical disk. There is an effect that the recorded content cannot be recorded. That is, when the content 1407 is copied from a regular optical disk having a disk ID of ID1, for example, to another optical disk having another disk ID of ID2, and reproduced, the BCA reproduction circuit 401 generates a disk ID signal 1402 as the disk ID signal 1402. ID2 is output. However, since the encrypted content is encrypted with the disk ID signal of ID1, the encrypted decoder 1413 cannot decrypt the encrypted content.

  Note that the encryption encoder 1408 may be in the form of an IC card or the like on the recording / playback apparatus side with respect to the network, not the content supply source, and mounted with the encryption encoder. Further, since the optical disk 1101 is encrypted only by the disk ID, it can be reproduced by any optical disk recording / reproducing apparatus having the BCA reproduction circuit 1401 and the encryption decoder 1413.

<Fourth Embodiment>
Next, an encrypted content recording method according to a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 20 is a block diagram showing a configuration of an optical disc recording / playback system according to the fourth embodiment of the present invention, and records encrypted content on a recordable optical disc that is a rewritable or write once optical disc having BCA. An apparatus structure is shown. Note that in the description of the fourth embodiment, the description of the parts common to the third embodiment is simplified.

  In FIG. 20, the optical disc recording / reproducing system according to the fourth embodiment includes a CATV company device 1501, a key issuing center device 1507, a CATV decoder 1506, an optical disc recording / reproducing device 1514, and a television device 1530. Composed. Here, the CATV company apparatus 1501 includes a content memory 1502 for storing content data such as movie software, a first encryption key memory 1503 for storing a first encryption key, and a first encryption encoder 1504. The key issuing center device 1507 includes a control unit 1507a that controls the operation of the device 1507, a time limit information memory 1510 that stores time limit information, and a recording permission code memory 1511 that stores a recording permission code. The CATV decoder 1506 further includes a system ID memory 1508 that stores the system ID of the CATV decoder 1506, a first encryption decoder 1513, a second encryption encoder 1516, and a company identification signal memory 1523 in the IC card 1522. . Furthermore, the optical disc recording / reproducing apparatus 1514 includes a recording circuit 1518, a data reproducing unit 1519, a BCA reproducing circuit 1521, a second encryption decoder 1520, and a company identification signal memory 1526 in the IC card 1524.

  First, the first encryption encoder 1504 of the CATV company apparatus 1501 encrypts the content data in the content memory 1502 such as movie software by using the first encryption key 1503, so that the first encrypted content 1505 is stored. The generated first encrypted content 1505 is transmitted to the first encrypted decoder 1513 of the CATV decoder 1506 of each user via the network. Here, when the data in the content memory 1502 is C, the first encryption key 1503 is FK, and the first encrypted content 1505 is C [FK], the following expression is used.

[Equation 3]
C * FK = C [FK]

  The CATV decoder 1506 is given in advance to the system ID of the CATV decoder 1506 in the system ID memory 1508 and the content to be viewed or recorded on the RAM type optical disc 1101, for example, a keyboard (not shown) of the CATV decoder 1506. The title code 1509 input using the.) Is transmitted to the key issuing center device 1507 via the network. Here, the title code 1509 may be input by being selected according to a TV screen, may be input directly from a keyboard, or may be input from a remote controller or the like. Therefore, the title code 1509 may be obtained by the user independently, may be sent to the CATV decoder 1506 together with the first encrypted content 1505, or may be sent to the first encrypted content 1505 in the form of a program guide or the like. May be sent in advance at another time.

  Based on the system ID of the CATV decoder 1506 and the title code 1509 of the content, the control unit 1507a of the key issuing center device 1507, the time restriction information in the time restriction information memory 1510, and the recording permission in the recording permission code memory 1511 Referring to the code, the key (K) 1512 corresponding to the code is transmitted to the first encryption decoder 1513 of the CATV decoder 1506 via the network together with the recording permission code and the time limit code. Note that it is possible to distinguish the case where the same content is broadcast a plurality of times at different times based on the time restriction information. Here, when the first decryption key is FK, the system ID of the CATV decoder 1506 is DID, the time limit information is TIME, the recording permission code is COPY, and the content title code 1509 is T, the key (K) is The relationship of the following formula is satisfied.

[Equation 4]
FK = K * T * DID * TIME * COPY

  Note that the recording permission code in the recording permission code memory 1511 allows the CATV company apparatus 1501 to determine whether the content to be broadcast is a new work or an old work, and permits only viewing or both viewing and recording. To decide.

  The first encryption decoder 1513 of the CATV decoder 1506 includes the first decryption key (FK), the key (K) 1512, the content title code 1509, the system ID, the recording permission code, and the time restriction information as described above. If the relationship is satisfied and the current time information output from the clock circuit 1527 satisfies the condition of the time limit information, the first encrypted content 1505 is decrypted. When the encrypted content is an image signal, the descrambled image signal is output from the first encryption decoder 1513 to the television device 1530 and can be viewed. Here, the decryption process of the first encryption decoder 1513 is expressed by the following equation.

[Equation 5]
C [FK] # (K * T * DID * TIME * COPY)
= C [FK] #FK
= C

  Note that, when the recording permission code permits only viewing, recording cannot be performed on the optical disc 1101, but when both viewing and recording are permitted, recording is possible. Therefore, this method will be described below.

  The BCA playback circuit 1521 of the optical disc recording / playback device 1514 plays back the data of the BCA 1104 of the optical disc 1101 to obtain the disc ID signal 1515 and outputs the disc ID signal to the second encryption encoder 1516 of the CATV decoder 1506. The second encryption encoder 1516 of the CATV decoder 1506 encrypts the content data output from the first encryption decoder 1513 by using the disc ID signal 1515 as the second encryption key, so that the second encrypted content 1517 is obtained. Is transmitted to the recording circuit 1518 of the optical disc recording / reproducing apparatus 1514. Note that the encryption of the second encryption decoder 1516 is limited to the time during which the first encrypted content is decrypted and output from the first encryption decoder 1513. Here, when the content that is the output signal of the first encryption decoder 1513 is C, the disc ID signal 1515 that is the second encryption key is BCAS, and the second encrypted content 1517 is C [BCAS], the following equation is obtained. It is written in.

[Equation 6]
C * BCAS = C [BCAS]

  The second encrypted content 1517 sent to the recording circuit 1518 of the optical disc recording / reproducing apparatus 1514 is modulated by the recording circuit 1518 by, for example, a known 8/16 modulation method, and the optical disc 1101 by an optical pickup (not shown). Are recorded in the user data area 1103. When the content recorded encrypted on the optical disc 1101 is reproduced, the laser beam output from the optical pickup irradiates the area on the optical disc 1101 where the encrypted content is recorded, and the reflected light is emitted. Incident on the optical pickup. The optical pickup photoelectrically converts incident reflected light and outputs the photoelectrically converted reproduction signal to the data reproduction unit 1519. The data reproduction unit 1519 performs A / D conversion of the input reproduction signal into a digital reproduction signal. The data is output to the second encryption decoder 1520.

  On the other hand, the laser beam output from the optical pickup irradiates the BCA 1104 of the optical disc 1101 and the reflected light enters the optical pickup. The optical pickup photoelectrically converts incident reflected light, and outputs the photoelectrically converted reproduction signal to the BCA reproduction circuit 1521. The BCA playback circuit 1521 generates a disk ID signal 1515 based on the input playback signal and outputs it to the second encryption decoder 1520. In response to this, the second encryption decoder 1520 decrypts the reproduced encrypted content output from the data reproducing unit 1519 using the input disc ID signal 1515 as a key. At this time, if the content is properly recorded on the optical disc 1101, the key for decrypting the encrypted content recorded on the optical disc 1101 is the disc ID of the optical disc 1101, and is output from the BCA playback circuit 1521. Since the disc ID signal is also the disc ID signal (BCAS) of the optical disc 1101, the second encryption decoder 1520 can normally execute the decryption process. Accordingly, the decrypted or descrambled content data is output as the output signal 1525 from the second encryption decoder 1520. Here, the decryption process of the second encryption decoder 1520 can be expressed by the following expression. When the content is an image signal, the second encryption decoder 1520 decompresses the MPEG signal, for example, and reproduces the original image signal. And output.

[Equation 7]
C [BCAS] # BCAS = C

  Further, since the optical disk 1101 is encrypted only with the disk ID signal (BCAS) 1515, it can be reproduced by any optical disk recording / reproducing apparatus having the BCA reproducing circuit 1521 and the second encryption decoder 1520. Note that the encryption by the encryption encoders 1504 and 1516 and the decryption by the encryption decoders 1513 and 1520 have been described. However, the encryption algorithm and the program executed by the CPU that is the control unit in each of the devices 1501, 1506, and 1514 can be added. A decryption algorithm program may be provided to perform encryption or decryption.

  In the present embodiment, the second encryption encoder 1516 of the CATV decoder 1506 encrypts the content using the disc ID signal 1515 as the second encryption key. However, the content may be encrypted as follows. For example, an IC card 1522 prepared for each CATV company device 1501 is attached to the CATV decoder 1506, and the company identification signal recorded in the company identification signal memory 1523 of the IC card 1522 and the BCA reproduction circuit 1521 are reproduced. The content may be encrypted by the second encryption encoder 1516 using a combination of the disc ID signal (BCAS) as the second encryption key. Here, the content that is the output signal of the first encryption decoder 1513 is C, the disk ID signal 1515 that is the first second encryption key is BCAS, and the company identification signal 1523 that is the second second encryption key is CK. Assuming that the second encrypted content 1517 is C [BCAS, CK], the encryption processing of the second encryption encoder 1516 is expressed by the following equation.

[Equation 8]
C * BCAS * CK = C [BCAS, CK]

  Next, when reproducing the content encrypted and recorded on the optical disc 1101, the laser beam output from the optical pickup irradiates the area where the encrypted content of the optical disc 1101 is recorded, and the reflection is performed. Light enters the optical pickup. The optical pickup photoelectrically converts incident reflected light into a reproduction signal and outputs it to the data reproduction unit 1519. The data reproduction unit 1519 A / D converts the input reproduction signal into a digital reproduction signal and outputs the digital reproduction signal to the second encryption decoder 1520. On the other hand, the laser beam output from the optical pickup irradiates the BCA 1104 of the optical disc 1101 and the reflected light enters the optical pickup. The optical pickup photoelectrically converts incident reflected light into a reproduction signal and outputs it to the BCA reproduction circuit 1521. The BCA reproduction circuit 1521 reproduces the disc ID signal 1515 based on the inputted reproduction signal, and outputs the disc ID signal 1515 to the second encryption encoder 1516 and the second encryption decoder 1520.

  Further, the company identification signal in the company identification signal memory 1526 of the IC card 1524 attached to the optical disc recording / reproducing apparatus 1514 is input to the second encryption decoder 1520. The company identification signal may not be recorded in the company identification signal memory 1526 of the IC card 1524. For example, when the recording program of the optical disc recording / reproducing device 1514 is installed, the company identification signal is displayed on the optical disc recording / reproducing device. It may be recorded in a memory (not shown) connected to a CPU 1515 as a control unit. Instead, the company identification signal may be input using a keyboard (not shown) of the optical disc recording / reproducing apparatus 1514.

  The second encryption decoder 1520 decrypts the encrypted content using the input disc ID signal 1515 and the company identification signal as a decryption key. At this time, if the user of the CATV decoder 1506 forms a contract with a specific CATV company having the CATV company device 1502 and the content 1502 is properly recorded on the optical disk 1101, it is encrypted and recorded on the optical disk 1101. The first decryption key of the encrypted content is the disc ID signal (BCAS) of the optical disc 1101 to be reproduced, and the second decryption key is the company of the IC card 1524 provided by the contracted CATV company. It is a company identification signal (CK) in the identification signal memory 1526. Accordingly, the output signal 1525 of the decrypted or descrambled content is output from the second encryption decoder 1520. Here, the decryption processing of the second encryption decoder 1520 is expressed as the following expression. When the content is an image signal, for example, the MPEG signal is expanded by the second encryption decoder 1520, and the output signal 1525 of the image signal is Is output.

[Equation 9]
C [BCAS, CK] # (BCAS * CK) = C

  Further, since the content of the optical disc 1101 is encrypted with the disc ID signal 1515 and the company identification signal, if a contract is made with the CATV company that provides the content, the BCA playback circuit 1521 and the second encryption The data can be reproduced by any optical disk recording / reproducing apparatus having the decoder 1520. On the other hand, if the contract is not made with the CATV company, the company identification signal cannot be obtained, so the content cannot be reproduced, and differentiation from the contracted user is enabled.

  Further, in this embodiment, each user sends a disc ID signal from the optical disc recording / reproducing device 1514 to the CATV decoder 1506 at home and encrypts image data and the like, so that the CATV company device 1501 transmits encrypted content to each user. It is not necessary to change the content individually, the broadcasting system can be simplified, and the same content can be provided to a large number of viewers at low cost. Furthermore, according to the present embodiment, it is possible to permit recording on only one RAM type optical disk for each user having the CATV decoder 1506.

  In the present embodiment, the case where content is broadcast from the head end of a cable television has been described, but the same applies to broadcasting using radio waves.

<Fifth Embodiment>
Furthermore, an encrypted content recording and reproduction method according to the fifth embodiment of the present invention will be described with reference to the drawings. FIG. 21 is a plan view showing a data recording area of an optical disc 1601 according to the fifth embodiment of the present invention, and FIG. 22 is a block diagram showing a configuration of an optical disc recording / reproducing system according to the fifth embodiment. is there. In the fifth embodiment, the description of the parts common to the third and fourth embodiments is simplified.

  In FIG. 21, 1601 is a recordable optical disk which is a rewritable or write-once optical disk, 1602 is a control user data area in which disk information is recorded in the form of concave and convex pits, and 1603 is obtained by irradiating the optical disk with a laser beam. A user data area for recording data by the user, 1604 is a BCA in which a disc ID is recorded.

  In the BCA 1604, the recording film on the concave and convex pits in the inner peripheral portion of the control user data area 1602 is partially trimmed with a pulse laser such as a YAG laser, so that a plurality of trimming areas 1606 are formed in a long shape in the radial direction. It is formed. Trimming is performed by the disc manufacturer. Further, by adding a disk ID to data recorded in the BCA 1604, management of the optical disk can be easily realized. Furthermore, since the data of BCA 1604 is recorded on the concave and convex pits, it is possible to prevent the information identifying the optical disc recorded in BCA 1604 from being easily falsified.

  Further, since the control user data area 1602 and the BCA 1604 are adjacent to each other, when the data of the control user data area 1602 is reproduced, the data of the BCA 1604 can be reproduced continuously or when the data of the BCA 1604 is reproduced. In addition, since the data in the control user data area 1602 can be continuously reproduced, for example, when the optical disk is activated, the CPU quickly obtains information of the BCA 1604 for identifying the disk and records the encrypted content. This makes it possible to speed up the process.

  The BCA 1604 of this embodiment is formed by trimming the recording film on the concavo-convex pits in the inner peripheral portion of the control user data area 1602, but constitutes a recording type optical disc that is a rewritable or write once type optical disc. The recording film is easily affected by heat with respect to the reflective film in the read-only optical disk. By trimming the inner peripheral portion of the control user data area 602, the recorded data in the user data area 1603 can be protected from heat generated during trimming as compared with the case of trimming the outer peripheral portion. The reason why the BCA 1604 is formed on the inner circumference side of the control user data area 1602 is that a margin when the diameter of the laser beam spot diameter changes due to the instability of the focus servo circuit is taken into consideration. Note that data recorded in the BCA 1604 before trimming may be recorded in the control user data area 1602. Since the data recorded in the BCA 1604 is also recorded in the control user data area 1602, the data in the control user data area 1602 can be protected even when trimming is performed.

  Furthermore, when the data is repeatedly recorded continuously from the BCA 1604 to the control user data area 1602, the position of the BCA 1604 can be predicted by finding the data in the control user data area 1602. The data in the key information recording area 1605 is recorded by irradiating the light beam in the same manner as the user data area 1603.

  Since the control user data area 1602 and the key information recording area 1605 are adjacent to each other as in the present embodiment, the data in the key information recording area 1605 is continuously reproduced when the data in the control user data area 1602 is reproduced. When the data in the key information recording area 1605 can be reproduced, the data in the control user data area 1602 can be reproduced continuously. For example, when starting the optical disk, the CPU quickly identifies the disk. Thus, it is possible to speed up the processing for obtaining the information of the BCA 1604 for playing back the encrypted content.

  In FIG. 22, the optical disk recording / reproducing system according to the fifth embodiment includes a CATV company apparatus 1701, a key issuing center apparatus 1707, a CATV decoder 1706, an optical disk recording / reproducing apparatus 1714, and a television apparatus 1730. Composed. Here, the CATV company apparatus 1701 includes a content memory 1702 that stores content such as movie software, a first encryption key memory 1703 that stores a first encryption key, and a first encryption encoder 1704. The CATV decoder 1706 includes a system ID memory 1708, a first encryption decoder 1713, and a clock circuit 1725 that outputs current time information. The key issuing center device 1707 further includes a control unit 1707a that controls the operation of the device 1707, and a time limit information memory 1710 that stores time limit information. Furthermore, the optical disc recording / reproducing apparatus 1714 includes a recording circuit 1717, a key information recording circuit 1719, a BCA reproducing circuit 1720, a data reproducing unit 1721, a second encryption decoder 1722, and a key information reproducing unit 1723.

  First, the first encryption encoder 1704 of the CATV company apparatus 1701 encrypts content data such as movie software in the content memory 1702 using the first encryption key 1703, thereby obtaining the first encrypted content 1705. It is generated and transmitted to the first encryption decoder 1713 of the CATV decoder 1706 of each user via the network. Here, when the content in the content memory 1702 is C, the first encryption key in the first encryption key memory 1703 is FK, and the first encrypted content 1705 is C [FK], the following expression is expressed. The

[Equation 10]
C * FK = C [FK]

  The CATV decoder 1706 receives the system ID in the system ID memory 1708 of the CATV decoder 1706 and the title code 1709 of the content to be viewed, which is input using, for example, a keyboard (not shown), via the network. The data is transmitted to the control unit 1707a of the device 1707. The title code may be input by selecting according to the screen of the television device 1730, may be input directly from a keyboard, or may be input from a remote controller or the like. Accordingly, the title code may be obtained by the user independently, may be sent to the CATV decoder 1706 together with the first encrypted content, or may be different from the first encrypted content in the form of a program guide or the like. It may be sent in advance at the time.

  Based on the system ID of the CATV decoder 1706 and the title code of the content, the control unit 1707a of the key issuing center device 1707 refers to the corresponding time restriction information in the time restriction information memory 1710 and corresponds to the corresponding key (K ) 1712 is generated and transmitted to the first encryption decoder 1713 of the CATV decoder 1706 via the network. Note that it is possible to distinguish the case where the same content is broadcast a plurality of times at different times based on the time restriction information. Here, when the first decryption key is FK, the system ID of the CATV decoder 1706 is DID, the time limit information is TIME, and the content title code is T, the key (K) 1712 satisfies the relationship of the following equation: ing.

[Equation 11]
FK = K * T * DID * TIME

  The first encryption decoder 1713 includes the first decryption key (FK), the key (K) 1712 transmitted from the key issuing center apparatus 1707, the title code of the content, the system ID, and the time restriction information. And the time restriction information satisfies the condition of the current time information from the clock circuit 1725, the first encrypted content 1705 can be decrypted. Here, when the first encrypted content 1705 is an image signal, the descrambled image signal is output from the first encryption decoder 1713 to the television device 1730, and the user can view the content on the television device 1730. Here, the decryption process of the first encryption decoder 1713 is expressed as the following equation.

[Equation 12]
C [FK] # (K * T * DID * TIME)
= C [FK] #FK
= C

  Next, a method for recording the content on the optical disc 1601 will be described. When recording content on the optical disc 1601, the first encrypted content 1705 that has not been decrypted by the CATV decoder 1706 is transferred from the first encryption encoder 1704 of the CATV company device 1701 to the recording circuit of the optical disc recording / reproducing device 1714. 1717. The recording circuit 1717 digitally modulates the received data of the first encrypted content 1705 using a modulation method such as a known 8/16 modulation method, and the modulated digital data is received by an optical pickup (not shown). .) Is recorded on the optical disc 1601. Therefore, the first encrypted content 1705 needs to be decrypted in order to reproduce the content that is encrypted and recorded on the optical disc 1601.

  The optical disc recording / reproducing apparatus 1714 receives the disc ID signal 1715 of the optical disc 1601 reproduced by the BCA reproducing circuit 1720 and the title code 1716 of the content to be reproduced, which is input using, for example, a keyboard (not shown). The data is transmitted to the control unit 1707a of the key issuing center device 1707 via the network. The timing for sending the disc ID may be sent when accessing the key issuing center device 1707, or may be sent together with the title code when viewing.

  Further, as a method for transmitting the disk ID, a method for reproducing the BCA 1604 of the optical disk 1601 and transmitting the output signal of the BCA reproduction circuit 1720 directly to the key issuing center device 1707 as shown in FIG. The present invention is not limited to this, and the following method may be used. For example, before access to the key issuing center device 1707, such as when the disc is activated, the data of the BCA 1604 is reproduced and stored in the memory (not shown) of the optical disc recording / reproducing device 1714 or CATV decoder 1706. May be transmitted to the control unit 1707a of the key issuing center device 1707. Further, when the disc ID can be visually recognized in the form of a label or the like, it may be input from a keyboard, or may be read from a bar code reader when the label is a bar code.

  The control unit 1707a of the key issuing center device 1707 generates a key (DK) 1718 corresponding to the disc ID signal 1715 of the optical disc 1601 and the title code 1716 of the content, and transmits it to the key information recording circuit 1719 of the optical disc recording / reproducing device 1714. . Here, when the first decryption key is FK, the disc ID signal 1715 of the optical disc 1601 is BCAS, and the content title code 1716 is T, the key (DK) satisfies the relationship of the following equation.

[Equation 13]
FK = DK * BCA * T

  The key (DK) input to the key information recording circuit 1719 of the optical disc recording / reproducing device 1714 is digitally modulated using a modulation method such as a known 8/16 modulation method, and the modulated digital data is optically picked up (FIG. Is recorded in the key information recording area 1605 of the optical disc 1601. Note that a plurality of identical keys may be recorded in the key information recording area 1605 as keys (DK). By recording a plurality of identical keys, the key (DK) can be protected when the recording film in the key information recording area 1605 deteriorates or the optical disk 1601 is damaged. If the key (DK) data can be reproduced, the content can be decrypted.

  In this embodiment, the key information recording area 1605 is provided on the inner peripheral side of the user data area 1603. However, the key information recording area 1605 may be provided on the outer peripheral side of the user data area 1603. It may be provided. By providing on the outer peripheral side, more keys (DK) can be recorded. Also, by providing a plurality of key information recording areas in a distributed manner, even when one key information recording area cannot be reproduced, the key (DK) can be protected by another key information recording area.

  On the other hand, the laser beam output from the optical pickup irradiates the area where the content of the optical disk 1601 is recorded, and the reflected light enters the optical pickup. The optical pickup photoelectrically converts incident reflected light and outputs a photoelectrically converted reproduction signal to the data reproduction unit 1721. In response to this, the data reproduction unit 1721 A / D converts the input reproduction signal into encrypted digital data and outputs the encrypted digital data to the second encryption decoder 1722. Further, the laser beam output from the optical pickup irradiates the BCA 604 of the optical disc 1601 and the reflected light enters the optical pickup. The optical pickup photoelectrically converts incident reflected light and outputs the photoelectrically converted reproduction signal to the BCA reproduction circuit 1720. In response to this, the BCA reproduction circuit 1720 reproduces the disc ID signal 1715 based on the inputted reproduction signal and outputs it to the encryption decoder 1722. Further, the laser light output from the optical pickup irradiates the key information recording area 1605 of the optical disk 1601, and the reflected light enters the optical pickup. The optical pickup photoelectrically converts incident reflected light and outputs a reproduction signal to the key information reproduction unit 1723. In response to this, the key information reproduction unit 1723 determines the key (DK) based on the input reproduction signal. Data is generated and output to the second encryption decoder 1722.

  When content is played back immediately after accessing the key issuing center device 1707, the key information recording circuit 1719 directly records the second encryption before recording the key (DK) in the key information recording area 1605. The data may be input to the decoder 1722. By doing so, it is possible to shorten the time until the reproduction is started. The encryption decoder 1722 decrypts the encrypted content using the input disc ID signal 1715, a key (DK), and a decryption key composed of the content title code 1716. The decryption process of the second encryption decoder 1722 is expressed by the following equation. When the content is an image signal, for example, the MPEG signal is expanded and the output signal 1724 of the image signal is output from the second encryption decoder 1722.

[Formula 14]
C [FK] # (DK * BCA * T)
= C [FK] #FK
= C

  In this embodiment, if the user is charged when receiving a key signal from the control unit 1707a of the key issuing center device 1707, the user is charged separately when viewing and when the content recorded on the optical disc 1601 is played for the first time. You are not charged only by recording on the optical disc 1601. Therefore, in the case of charging for both viewing and recording on the optical disc 1601, a user who wants to watch but does not need to record on the optical disc 1601, or wants to record on the optical disc 1601, is broadcast. For users who do not need to watch, the amount charged can be reduced. Further, since the user is not charged only by recording on the optical disk 1601, the user can determine whether or not to receive a key for reproducing the optical disk 1601 for viewing again after viewing. In the above embodiment, a method of receiving the key (DK) from the control unit 1707a of the key issuing center device 1707 via the network is used. However, the present invention is not limited to this, and the content title and disc ID number are used. May be received verbally by telephone or the like and input from the keyboard.

  Next, a case where the optical disc 1601 in which the key (DK) is recorded in the key information recording area 1605 is reproduced after the access with the key issuing center device 1707 is completed will be described. First, the laser beam output from the optical pickup irradiates the area of the optical disc 1601 where the content is recorded, and the reflected light is input to the data reproducing unit 1721 via the optical pickup that performs photoelectric conversion. In response to this, the data reproducing unit 1721 outputs the encrypted content data to the second encryption decoder 1722. On the other hand, the laser beam output from the optical pickup irradiates the BCA 1604 of the optical disc 1601 and the reflected light is input to the BCA reproducing circuit 1720 via the optical pickup that performs photoelectric conversion. In response to this, the BCA playback circuit 1720 generates a disk ID signal 1715 based on the input playback signal and outputs it to the second encryption decoder 1722.

  Further, the laser light output from the optical pickup irradiates the key information recording area 1605 of the optical disc 1601 and the reflected light is input to the key information reproducing unit 1723 via the optical pickup that performs photoelectric conversion. In response to this, the key information playback unit 1723 generates key (DK) data based on the input playback signal and outputs the key (DK) data to the second encryption decoder 1722. The second encryption decoder 1722 uses the decryption key composed of the input disc ID signal 1715, the key (DK), and the title code 1716 of the content, and the encrypted content output from the data reproduction unit 1721. Decrypt. The decryption process of the second encryption decoder 1722 is expressed by the following equation. When the content is an image signal, for example, the MPEG signal is expanded and the image signal is output from the second encryption decoder 1722.

[Equation 15]
C [FK] # (DK * BCA * T)
= C [FK] #FK
= C

  By recording the key (DK) data once in the key information recording area 1605, the encrypted content can always be reproduced without accessing the key issuing center device 1707. Since all the decryption keys necessary for the decryption processing are recorded on the optical disc 1601, the optical disc 1601 is an arbitrary optical disc having a BCA reproduction circuit 1720, a key information reproduction unit 1723, and a second encryption decoder 1722. It can be played back by a recording / playback apparatus.

  Further, when the encrypted content is copied to the optical disc 1601 having a different disc ID and is played back, a disc ID signal different from that of the optical disc 1601 is output from the BCA playback circuit 1720. Cannot be decrypted, and the content is not reproduced even if it is copied. However, also in this case, the decryption key may be received after accounting by transmitting the content title and disc ID to the key issuing center via the network or verbally. As described above, even if the encrypted content is copied to another optical disk 1601, it is not reproduced illegally, and there is always a charge when reproducing the optical disk 1601 copied with the encrypted content. Can protect the copyright.

  FIG. 23 is a table showing the configuration of an ID assignment table according to the fifth embodiment. The key (K) input to the first encryption decoder 1713 and the key information recording circuit when the system ID and the disk ID are different. The keys (DK) input to 1719 are organized and shown. In FIG. 23, T1, T2, and T3 are title codes of different contents, and FK1, FK2, and FK3 are decryption keys for decrypting encrypted contents having title codes of T1, T2, and T3, respectively. DID1, DID2, and DID3 are system IDs of different CATV decoders 1706, and BCAS1, BCAS2, and BCAS3 are disk IDs of different optical disks 1601, respectively. At this time, the key (Kmn) input to the CATV decoder 1706 is determined so as to satisfy the following equation.

[Equation 16]
FKn = Kmn * Tn * DID * TIMEn

  The key (DKmn) input to the optical disc recording / reproducing device 1714 is determined so as to satisfy the following equation.

[Equation 17]
FKn = DKmn * BCAm * Tn

  As shown in FIG. 23, the key information obtained from the key issuing center apparatus 1707 is different for each content even when the contents are the same. Protection of copyrights over a wide range. Similarly, even if the content is the same, if the system ID, the disc ID, and the time information are different, the key information is different. Therefore, the CATV company apparatus 1701 does not need to change the encrypted content for each user, and 1 for one content. One encrypted content should be prepared. As a result, the broadcasting system can be simplified, and content can be provided to a large number of viewers at low cost.

  In this embodiment, the case of broadcasting content from a cable television head end has been described, but the same applies to broadcasting by radio waves.

<Effects of the third to fifth embodiments>
The optical disc according to the present embodiment includes a first information area in which first disc information is recorded, a second information region in which second disc information for identifying individual discs is recorded, It has a user data area where information can be recorded by irradiating a light beam. Therefore, management of the optical disk can be easily realized by adding information for identifying the optical disk to the conventional optical disk. Here, the second information area is preferably recorded in the first information area, and can be reproduced by an optical pickup that reproduces the first information area. The second information area is recorded by partially removing the recording film in the first information area so that a plurality of trimming areas are formed in a long shape in the radial direction. Therefore, it is possible to prevent the second disc information from being easily falsified.

  Also, according to the encrypted content recording method of the present embodiment, the first information area in which the first disc information is recorded and the second disc information for identifying each disc are recorded. When recording content data in the user data area of an optical disk having a second information area and a user data area where information can be recorded by irradiating a light beam, at least the second disk information The content data is encrypted and recorded so that the content data can be decrypted and reproduced by an operation using. Therefore, by encrypting the content using the identification information of the optical disc that exists only on one specific optical disc, it is possible to prevent unauthorized copying of the content and to protect the copyright. is there.

  Furthermore, the optical disc according to the present embodiment has a key information recording area for recording key information for decrypting encrypted and recorded content in the user data area. Therefore, in a system that requires key information when decrypting encrypted and recorded content, the key information is once recorded in the key information recording area, so that it is not necessary to input the key information every time it is played back. There is a unique effect.

  Still further, according to the encrypted content recording method of the present embodiment, the first information area in which the first disc information is recorded and the second disc information for identifying each disc are recorded. A second data area, a user data area in which information can be recorded by irradiating a light beam, and a key for decrypting the content data encrypted and recorded in the user data area When content is recorded in the user data area of the optical disc having a key information recording area for recording information, the content data is decrypted and reproduced by an operation using at least the second disc information and the key information. The content data is encrypted and recorded so that it can be recorded. Therefore, even if the encrypted content data is copied to another optical disk, it will not be played back illegally, and there will always be a charge when playing back an optical disk copied with the encrypted content data. Can protect the copyright.

  Here, the first disc information is preferably composed of minute uneven pits, and second disc information for identifying the optical disc is recorded on the uneven pits. Therefore, it is possible to prevent the second disk information from being easily falsified. Further, preferably, the first disk information and the second disk information are adjacent to each other. As a result, when the first disc information is reproduced, the second disc information can be reproduced continuously, or when the second disc information is reproduced, the first disc information is reproduced continuously. Therefore, for example, when the optical disk is activated, the CPU can quickly obtain the second disk information for identifying the disk and speed up the process for recording the encrypted content. .

  Also, according to the encrypted data recording method according to the present embodiment, the CATV company apparatus 701 encrypts for each user because the key information is different if the system ID, disk ID, and time information are different even if the content is the same. There is no need to change the content, and it is only necessary to prepare one encrypted content for one content. This makes it possible to simplify the broadcasting system and to provide the content to a large number of viewers at low cost. become.

<Modification of the third and fifth embodiments>
In the third and fifth embodiments described above, as shown in FIGS. 16 and 21, the trimming areas 1105 and 1606 are respectively stored in the BCAs 1104 and 1604 located in the inner periphery of the control user data areas 1102 and 1602. However, the present invention is not limited to this, and as shown in FIGS. 24 and 25 showing the data recording areas of the optical disks 1101a and 1601a according to the modifications of the third and fifth embodiments, respectively, the control user The trimming areas 1105a and 1606a may be formed by trimming the recording film so as to protrude from the data areas 1102 and 1602 to the inner peripheral side of the optical disk. That is, the BCAs 1104a and 1604a are not included in the control user data areas 1102 and 1602, respectively, and are arranged so as to protrude from the inner periphery of the control user data areas 1102 and 1602 to the inside of the control user data areas 1102 and 1602. Is done. In this modification, the BCAs 1104a and 1604a are formed in this way because a margin when the diameter of the laser beam spot diameter changes due to the instability of the focus servo circuit is taken into consideration. Also in this modified example, since user data areas 1103 and 1603 exist outside the controller user data areas 1102 and 1602, in order to protect the data recorded in these user data areas 1103 and 1602 from being destroyed. In addition, trimming regions 1105a and 1606a are arranged and formed.

<Sixth Embodiment>
FIG. 26 is a block diagram showing the configuration of the user data area in the optical disc and the configuration of the optical disc playback apparatus for decrypting the encrypted content from the data in the user data area according to the sixth embodiment of the present invention. In the present embodiment, the optical disk is a recordable optical disk such as a DVD-RAM.

  As shown in FIG. 26, the user data area 2150 includes a sector header area 2101, a main data area 2102, and an error detection code 2103. In the sector header area 2101, a sector address 2104 indicating the position of the sector and copyright control information (including a scramble flag, copy control information, etc.) relating to data recorded in the main data area 2102 are recorded. Information 2105 is recorded, and the sector head area 2101 includes a decryption key area 2106 for decrypting data in the main data area 2102 when the data is encrypted. The main data area 2102 is divided into an area where the non-encrypted content 2107 is recorded and an area where the encrypted content 2108 is recorded. The non-encrypted content 2107 includes an MPEG synchronization pattern and various control information. Including control information of subsequent data such as. Furthermore, the encrypted content 2108 mainly includes content data obtained by encrypting AV data or the like that requires copyright protection.

  In the decryption key area 2106, a decryption key for reproducing the subsequent main data area 2102 is divided and recorded into a plurality of divided decryption keys (hereinafter referred to as divided decryption keys) having a predetermined size. For example, when the decryption key is 8 bytes for one decryption key area of 4 bytes, the decryption key of two sectors that are logically continuous by dividing the decryption key of 8 bytes into 4 decryption keys of each Two divided decryption keys are recorded in areas 2106 and 2109, respectively. When reproducing such a user data area, a plurality of divided decryption keys that are logically continuous (however, sectors that cannot be used due to defects or the like are skipped) are divided from the decryption key areas 2106 and 2109 of a plurality of sectors. And the necessary number of divided decryption keys obtained are concatenated by the data concatenation unit 2111 to obtain an encryption / decryption key (8 bytes) necessary for reproduction. The data recorded in the main data area 2102 of the sector where the encryption / decryption key (8 bytes) can be obtained is decrypted using the decryptor 2114 according to the contents of the copyright control information 2105. To do.

  Furthermore, in order to further increase the strength of encryption, it is possible to encrypt the decryption key, and the decryption key conversion data that is information in the data is used as a key so that the result of the encryption is not constant. In addition, even with the same encryption key, it is possible to provide different encryption results. Specifically, as shown in FIG. 26, the encryption / decryption key output from the data concatenator 2111 is input to the key decoder 2112. The key decoder 2112 converts the input encryption / decryption key into a predetermined value. Using the disk key, the padding data (1 byte) and the decryption key (7 bytes), which are dummy data, are decrypted and output to the key converter 2113. Here, the disc key is obtained by decrypting an encrypted disc key recorded on the optical disc, for example, with a disc key decryptor (not shown) using a secret key that is a predetermined master key. . Next, the key converter 2113 uses the decryption key output from the key decryptor 2112 for the decryption key conversion data 2110 read from the main data area 2102, for example, multiplication or division, and calculation using a predetermined weight coefficient. A content decryption key (7 bytes) is generated by data conversion by a predetermined conversion operation such as, and is output to the decoder 2114. The decryptor 2114 decrypts the content data read from the main data area 2102 using the content decryption key (7 bytes) output from the key converter 2113, thereby decrypting the content data. Is generated and output. As the decryption key conversion data 2110, it is preferable to use data that can immediately detect unauthorized use of data by tampering with copy generation management information, an analog macrovision control flag, or the like. .

  FIG. 27 is a block diagram showing the arrangement of the copyright control information and the decryption key in the user data area and the arrangement of the encrypted content in the main data area in the optical disc according to the sixth embodiment. In the example of the user data area 2150 illustrated in FIG. 27, the decryption key area includes a first decryption key area 2201 having a 4-byte split decryption key and a second decryption key having a 4-byte split decryption key. The area 2202 is divided and arranged. For this reason, a plurality of sectors (two sectors in FIG. 27) are used regardless of the size of the encrypted content recorded in these two sectors. In this case, dummy data is recorded as complementary data in the unused area. In the example of FIG. 27, when there is only encrypted content 2204 for one sector, complementary data 2203 for one sector is recorded.

  FIG. 28 is a block diagram showing an arrangement when an error correction unit extends over a plurality of sectors in the optical disc according to the sixth embodiment. For example, when the optical disk is a DVD, error correction capability is enhanced by using a unit block (hereinafter referred to as ECC block) of an error correction code of 16 sectors. For this reason, when recording or reproducing data, it is necessary to record in units of ECC blocks. If recording is performed by dividing the decryption key into a plurality of arbitrary divided decryption keys, one decryption key may be recorded across a plurality of error correction blocks. At the time of reproduction, since it is necessary to reproduce all of the divided divided decryption keys, not only the sector in which the encrypted content data is recorded, but also the ECC block immediately before the decryption key is recorded is reproduced. There is a need. The example of FIG. 28 is characterized in that the number of divisions when the decryption key is divided is set to a divisor of the number of sectors of the ECC block. Thereby, a plurality of divided divided decryption keys are not recorded across the ECC block. Furthermore, when only one type of decryption key is used as the decryption key used in one ECC block, and AV data to be recorded is less than the ECC block, reproduction is performed by arranging complementary data and complementary sectors. Sometimes it is possible to prevent reading of unnecessary sector data from the optical disc.

<Seventh Embodiment>
FIG. 29 shows the configuration of the lead-in area 2401 and user data area 2402 in the optical disk according to the seventh embodiment of the present invention, and the optical disk that decrypts the encrypted content from the data in the lead-in area 2401 and user data area 2402. It is a block diagram which shows the structure of a reproducing | regenerating apparatus.

  29, as in the sixth embodiment of FIG. 26, the lead-in area 2401 and the user data area 2402 are each composed of sectors having a sector header area 2101, a main data area 2102, and an error detection code 2103. Is done. In the sector header area 2101, a sector address 2104 indicating the position of the sector and copyright control information (including a scramble flag, copy control information, etc.) relating to data recorded in the main data area 2102 are recorded. The information 2105 is recorded, and the sector header area 2101 stores a decryption key recording position (referred to as a decryption key for decrypting when data in the main data area 2102 is encrypted). A key index area 2403 for recording a key index indicating a recording position or a storage position in the decryption key table 2404 in the main data area 2102. The decryption key for decrypting the encrypted content recorded in the user data area 2402 is recorded in the format of the decryption key table 2404 in the lead-in area 2401 rewritable in the table format. The decryption key recorded in the lead-in area 2401 is referred to by the key index recorded in the key index area 2403. Similarly to the sixth embodiment shown in FIG. 26, the decryption key referred to above is decrypted into padding data and a decryption key (or title key) by a key decryptor 2112 using a predetermined disc key. The decrypted decryption key (or title key) is converted into a content decryption key by the key converter 2113 using the decryption key conversion data and output to the decryptor 2114. The decryptor 2114 generates and outputs decrypted content data by decrypting the encrypted content data using the content decryption key.

  In the optical disc and the optical disc reproducing apparatus according to the seventh embodiment configured as described above, the reference key index is recorded in the key index region 2403 in the sector header region 2101, so that the key index region 2403 The decryption key size of the decryption key table 2404 can be assigned independently of the size. Further, even after the size of the decryption key table 2404 is allocated, by using a plurality of decryption keys in succession from the decryption key table 2404 indicated by the key index in the key index area 2403, a decryption key having a free size can be obtained. Can be used.

  FIG. 30A is a block diagram showing a data structure when an unrecorded state is displayed with the initial value of the decryption key in the main data area 2102 of the lead-in area 2401 in the optical disc according to the seventh embodiment. In FIG. 30A, unrecorded state data 2501, which is a known fixed value (for example, data such as all 0) that is not used as a key, is recorded as an initial value of a decryption key that is recorded when an optical disk is formatted. This indicates the unrecorded state of the decryption key.

FIG. 30B is a block diagram showing a data structure when the recording state is displayed in the decryption key state table in the main data area 2102 of the lead-in area 2401 in the optical disc according to the seventh embodiment. In FIG. 30B, similarly to the decryption key shown in FIG. 30A, a decryption key state table 2502 in a table format that can be referred to by an index is arranged in the lead-in area 2401, and the recording state of the decryption key Is described as recording state data 2503 as follows.
(1) 0x00: unused,
(2) 0x01: area reservation,
(3) 0x03: Key recorded,
(4) Other: Reserved.
Here, 0x indicates hexadecimal notation for the following character.

  FIG. 31 is a block diagram showing the arrangement of decryption keys in the optical disc according to the seventh embodiment. In the example of FIG. 31, the arrangement of the decryption key area on the disk is devised in order to increase the reliability of the decryption key. Normally, defect management is performed in the user data area 2602. Therefore, when a writing failure occurs, a replacement process is performed on an alternative area or the like. However, the defect management as described above is not performed in the lead-in area 2601. For this reason, when a write failure or read failure occurs, a decryption key necessary for reproducing AV data may become unusable, and the optical disc itself may become unusable. Therefore, it is desirable to record a total of a plurality of decryption keys over a plurality of different ECC blocks. In addition, when a plurality of decryption keys are recorded in an adjacent area, all of the plurality of recorded keys may be unreadable due to scratches or dust. Therefore, as shown in FIG. 31, in the lead-in area 2601 and the lead-out area 2603, it is more preferable to record each decryption key at a position distant from the layout such as the inner circumference side and the outer circumference side of the optical disc. preferable.

  In the embodiment of FIG. 29, the decryption key areas are arranged in the lead-in areas 2401 and 2601. This is because the user data area 2602 is an area that can be accessed by a normal read command or write command, and the safety when accessing from a drive device of a personal computer or the like is increased. Therefore, even if these are arranged in the user data area 2602, the same effect can be obtained.

<Eighth Embodiment>
FIG. 32 is a block diagram showing a data structure when data on an optical disc according to the eighth embodiment of the present invention is managed by a file management system. In the example of FIG. 32, the sector address where a desired file is stored is managed based on the structure of the file system.

  In the structure of a file system defined by ISO 13346 by the International Organization for Standardization, the recording position of a file is managed using information called a file entry in order to support a rewritable optical disc. As shown in FIG. 32, for example, the recording position data of file (1) 2703 is stored as file entry (1) 2701 in file management information area 2751, and the recording position data of file (2) 2704 is file. It is stored as entry (2) 2702. Each file is composed of extents 2705 and 2706 for managing a plurality of consecutive sector areas on the optical disc. On the optical disc, the encrypted content shown in the seventh embodiment is recorded in the main data area 2102 indicated by the file entry, and the decryption key is recorded in the decryption key table 2707 in the lead-in area 2601. In the sector header area 2101 in the user data area 2602 in which the encrypted content is recorded, a pointer indicating a recording position for referring to a decryption key necessary for decryption is recorded in the key index area 2708. In this embodiment, the decryption key is managed and recorded in file units and extent units. However, the present invention is not limited to this, and the decryption key is managed in at least one of file units and extent units. May be recorded.

  With reference to FIG. 33, a recording operation of content that requires copyright protection on the optical disk managed by the file system as described above will be described. FIG. 33 shows a recording process of content requiring copyright protection, which is executed by the file management system according to the eighth embodiment.

  When recording the encrypted content, first, in step S2801, the decryption key state table 2502 shown in FIG. 30B is read and the free area of the decryption key table 2707 is checked. Next, in step S2802, it is determined whether or not there is an empty area in the decryption key table 2707. If NO, since the decryption key for the encrypted content cannot be recorded, the recording operation is stopped in step S2807 and the content is deleted. The recording process is terminated. On the other hand, when YES is determined in the step S2802, the acquired decryption key (or title key) is recorded, and when the decryption key is not acquired, the decryption key area is reserved. Next, in step S2804, copyright control information of the content to be recorded (including information on whether or not to perform encryption, information on the type indicating the type of encryption, and the like), and a key to be recorded in the key index area 2708 After setting the index, in step S2805, the content is encrypted and recorded on the optical disc in the file format in units of extents. At this time, the same copyright control information and key index may be used in units of files, or they may be switched in units of extents. That is, in steps S2804 and S2805, the unit to be processed is at least one of a file unit and an extent unit. Finally, in step S2806, the file management information for managing the recorded data is updated based on the information related to the recorded content, and then the content recording process is terminated.

  FIG. 34 is a flowchart showing content reproduction processing executed by the file management system according to the eighth embodiment. FIG. 34 shows a process of reproducing content recorded in a file format by the method shown in FIG. 33 from the optical disc.

  When performing the file reproduction operation, a key index for the area indicated by the file entry in the file management information area 2751 is acquired in order to know the area of the decryption key table used by the file to be reproduced. Specifically, after obtaining the file entry of the file to be reproduced from the file management information 2751 in step S2901, the file index is obtained from the sector header area 2102 in the area indicated by the file entry in step S2902. Is obtained by reading and playing the value of. When different encryption is performed for each extent, the key index area in the sector header is read in each extent. Next, in step S2903, the decryption key is obtained by reading out and reproducing the decryption key from the decryption key area of the decryption key table 2707 indicated by the obtained key index. Further, in step S2904, the content data in the file is read from the area indicated by the file entry and reproduced, and the reproduced content data is decoded. Here, when the reproduction and decoding of the content file are completed, the content reproduction processing is terminated.

  FIG. 35 is a flowchart showing content deletion processing executed by the file management system according to the eighth embodiment. In FIG. 35, content data in the file format recorded by the method shown in FIG. 33 is deleted. The operation will be described.

  When performing the file deletion operation, in order to know the area of the decryption key table 2707 used by the file to be deleted, the key index for the area indicated by the file entry is acquired. Specifically, in step S3001, after obtaining the file entry of the file to be deleted from the file management information in the file management information area 2751, the value of the key index area is obtained from the sector header of the area indicated by the file entry in step S3002. get. Here, when different encryption is performed for each extent, the key index area in the sector header is read in each extent. Next, in step S3003, the decryption key is released from the decryption key area of the decryption key table 2707 indicated by the acquired key index (here, the release of the decryption key means that the decryption key is deleted from the table). .) Thereafter, in step S3004, the file entry indicating the write position of the file to be deleted is deleted from the file management information, and the content deletion process is terminated. In the conventional file system, when deleting a file, only the file entry is deleted. However, since the decryption key and the recording sector of the encrypted content are recorded in different areas, they are recorded in different areas. Unable to delete the decryption key. In the above-described embodiment, the decryption key on the optical disc is managed by deleting the decryption key indicated by the key index in the sector header area from the decryption key table 2707 prior to the deletion of the file entry.

<Ninth Embodiment>
FIG. 36 is a block diagram showing the configuration of an optical disc system according to the ninth embodiment of the present invention. This optical disc system records and reproduces content requiring copyright protection on the optical disc 3100. It is. The optical disc system includes an encoding device 3101, an optical disc device 3102, a decoding device 3103, and a personal computer 3104.

  The encoding device 3101 includes a content memory 3131 for storing content data, an encoding circuit 3132 for encoding the content data in the format of MPEG format, an encryption key memory 3133 for storing an encryption key, An encryption circuit 3134 for encrypting content data using an encryption key, generating a decryption key and storing it in the decryption key memory 3111, a decryption key memory 3111 for storing the decryption key, and a bus for encrypting the decryption key with a bus An encryption circuit 3112 and an interface 3124 for transmitting encrypted content data and a decryption key connected to the interface 3122 of the personal computer 3104 via the PCI bus 3151 are provided. Further, the optical disc apparatus 3102 records data on the optical disc 3100 and reads and reproduces data from the optical disc 3100 while recording data on the optical disc 3100, a decryption key table memory 3113 for storing a plurality of decryption keys, The circuit 3119 includes an interface 3120 that is connected to the interface 3121 of the personal computer 3104 via the SCSI bus 3152 and performs processing such as transmission and reception of data and signals, signal conversion, and protocol conversion. SCSI bus 3152 may be an ATAPI bus. Here, the bus encryption and the bus decryption refer to an encryption process and a decryption process used to encrypt and transmit an encryption key and a decryption key on the PCI bus 3151 and the SCSI bus 3152, respectively.

  Further, the personal computer 3104 includes a control unit 3130 for controlling the operation, a bus encryption / decryption key table memory 3115 for storing a plurality of bus encryption / decryption keys, and a plurality of bus encryption / decryption keys corresponding to the plurality of bus encryption / decryption keys. A decryption key status table memory 3116 for storing data of a decryption key status (indicating a recording state of the decryption key, specifically indicating unused, area reservation, key recording, reserved, etc.), and an optical disc apparatus 3102 The interface 3120 is connected to the interface 3120 via the SCSI bus 3152 and executes processing such as transmission and reception of data and signals, signal conversion and protocol conversion, an interface 3123 of the decoding device 3103, an interface 3124 of the encoding device 3101 and the PCI. Via bus 3151 Transmission of the connected data or signals and reception and signal conversion Te, and a interface 3122 to execute the processing such as the protocol conversion. Still further, the decoding device 3103 is connected to the interface 3122 of the personal computer 3104 and performs an operation such as data and signal transmission and reception, signal conversion and protocol conversion, and an encryption / decryption key received by the interface 3123. A decryption key memory 3118 for storing the decryption key, decryption data of the encrypted content received by the interface 3123 using the decryption key of the decryption key memory 3118, and MPEG format And a decoding circuit 3141 that generates an image signal and an audio signal and outputs them to the display device 3105.

  In the encoding apparatus 3101 of this optical disc system, the encoding circuit 3132 encodes content data such as AV data stored in or input to the content memory 3131 in the format of MPEG format, and the encryption circuit 3134 includes a personal computer. The encoded content data is encrypted using the encryption key in the encryption key memory 3133 generated to avoid unauthorized use of the content on the 3104, and the encrypted content data is transferred to the interface 3124 and personal The data is transmitted to the optical disc apparatus 3102 via the computer 3104. Here, the encrypted content data is transmitted from the interface 3124 of the encoding apparatus 3101 to the recording / reproducing circuit 3119 via the PCI bus 3151, the interface 3122 and interface 3121 of the personal computer 3104, and the interface 3120 of the optical disk apparatus 3102. Is done. The encrypted content data is recorded on the optical disc 3100 by the recording / reproducing circuit 3119 of the optical disc apparatus 3102. The recording / reproducing circuit 3119 of the optical disc apparatus 3102 reproduces the encrypted content data recorded on the optical disc 3100, and the reproduced encrypted content data is sent to the interface 3120, the interface 3121 of the personal computer 3104, and The data is transmitted to the decoding circuit 3141 via the interface 3122 and the interface 3123 of the decoding device 3103. The decryption circuit 3141 of the decoding device 3103 decrypts the encryption of the encrypted content data and performs the MPEG format decryption processing, and the image signal and the audio signal of the decrypted content are respectively displayed on the display device 3105 and the speaker device ( (Not shown).

  The encryption circuit 3134 of the encoding apparatus 3101 encrypts the content data encoded in the MPEG format using the encryption key in the encryption key memory 3133, and at the same time obtains a decryption key necessary for reproduction. Generated and stored in the decryption key memory 3111. It is necessary to record the encoded content data and the decryption key on the optical disc 3100. When the decryption key is handled in plain text on the personal computer 3104, the decryption key is read from the optical disc 3100 to be encrypted. There is a possibility that it will be easy to decipher the content data. In order to avoid this, mutual authentication is performed between the encoding apparatus 3101 and the optical disk apparatus 3102 and bus encryption is performed using a mutually shared bus key.

  Specifically, after the decryption key in the decryption key memory 3111 is encrypted by the bus encryption circuit 3112 of the encoding device 3101, the encryption / decryption key is sent to the interface 3124, the PCI bus 3151, and the interface 3122. Is stored in the bus encryption / decryption key table memory 3115 of the personal computer 3104. On the other hand, in the bus encryption / decryption circuit 3114 of the optical disc apparatus 3102, the decryption key decrypted after the decryption of the encryption / decryption key reproduced from the optical disc 3100 by the recording / reproduction circuit 3119 is performed in the decryption key table. Stored in the memory 3113. Further, the bus encryption / decryption circuit 3114 receives, for example, an updated bus-encrypted decryption key from the bus encryption / decryption key table memory 3115 via the interface 3121, the SCSI bus 3152, and the interface 3120 to decrypt the bus. After being stored in the decryption key table memory 3113, it is recorded on the optical disc 3100 via the recording / reproducing circuit 3119.

  The decryption key state table is reproduced from the optical disk 3100 by the recording / reproducing circuit 3119 and then transferred to and stored in the decryption key state table memory 3116 via the interface 3120, the SCSI bus 3152, and the interface 3121. Further, the decryption key state table updated by the personal computer 3104 is read from the decryption key state table memory 3116, transferred to the recording / reproducing circuit 3119 via the interface 3121, the SCSI bus 3152 and the interface 3120, and then recorded. The reproduction circuit 3119 records the received decryption key state table on the optical disc 3100. Therefore, on the personal computer 3104 located in the middle, only the encrypted decryption key is handled using the bus encryption / decryption key table 3115 and the decryption key state table memory 3116 for storing a plurality of bus encryption / decryption keys. As a result, further safety is ensured.

  By performing the bus encryption of the decryption key in the same manner between the optical disk device 3102 and the decoding device 3103, further safety is ensured. That is, the bus decryption circuit 3117 of the decoding device 3103 decrypts the encrypted decryption key received from the personal computer 3104 via the interface 3123 and stores it in the decryption key memory 3118. The decryption circuit 3141 decrypts the content data encrypted using the decryption key in the decryption key memory 3118.

  As shown in the seventh embodiment, when the decryption key for decrypting the encrypted content data is recorded in the table format on the optical disc 3100, it is reproduced on the optical disc apparatus 3102. After the decryption key table is bus encrypted by the bus encryption and decryption circuit 3114, the decrypted key table data encrypted by the bus is transferred to the bus encryption decryption key table memory 3115 of the personal computer 3104 via the interface 3120 and stored. To do. When recording content data, the personal computer 3104 checks the empty area of the decryption key table from the decryption key state table recorded on the optical disc 3100 in plain text, and the bus encrypted from the encoding device 3101 is encrypted. Assign the decryption key to the free space. At this time, if a cipher that completes in decryption key unit (for example, block cipher in decryption key length unit) is used as the bus cipher, there is no need to decrypt and re-encrypt the decryption key when assigning to the decryption key block. .

  Note that each of the decryption key table and the decryption key state table transferred and stored between the optical disc apparatus 3100, the optical disc apparatus 3102, and the personal computer 3104 is a block of block data, and therefore is called block data. Can do.

  Also in the case of content reproduction, only the decryption key necessary for decrypting the content to be reproduced from the decryption key block reproduced from the optical disc apparatus 3102 is retrieved from the bus encryption / decryption key table memory 3115 and extracted. The data is transferred and stored in the decryption key memory 3118 via the bus decryption circuit 3117 of the computer 3104 and the decoding device 3103. The decryption circuit 3141 receives the encrypted AV data reproduced from the optical disc 3100 by the recording / reproduction circuit 3119 of the optical disc apparatus 3102 via the personal computer 3104 and the interface 3123, and receives the received encrypted data. The AV data is decrypted into an image signal or an audio signal using the decryption key in the decryption key memory 3118 and output. Also in this case, as in the case of recording the content described above, if a cipher that completes in decryption key units (for example, block cipher in decryption key length units) is used as the bus cipher, the decryption key from the decryption key block is used. When extracting, there is no need to decrypt and re-encrypt the decryption key. Furthermore, when the size of the decryption key is increased, the decryption key area such as allocation of a plurality of decryption keys can be easily and safely performed on the personal computer 3104 without changing the configuration of the optical disc apparatus 3102. it can.

<Tenth Embodiment>
FIG. 37 shows the configuration of the user data area in the optical disc according to the tenth embodiment of the present invention, the configuration of the optical disc recording apparatus that encrypts the content and records it in the user data area, and the encryption from the data in the user data area. FIG. 2 is a block diagram showing a configuration of an optical disc playback apparatus that decrypts encrypted content. The tenth embodiment is characterized in that the configuration of the optical disk recording apparatus is added to the sixth embodiment, and this configuration will be described in detail.

  In the optical disk recording device, in order to increase the strength of encryption so that the result of encryption is not constant, the input encryption key is converted by the key converter 2119 using the decryption key conversion data which is information in the content, for example, After obtaining a content decryption key by performing a predetermined key conversion operation such as multiplication, division, or a calculation using a predetermined weighting coefficient, the content data is encrypted using the content decryption key.

  That is, when recording content, the content data and the encryption key for encrypting the content data are input to the optical disc recording apparatus. Here, the content data is input to the key converter 2119 and the encryptor 2120, and the encryption key is input to the key encryptor 2118 and the key converter 2119. The key converter 2119 performs a predetermined key conversion operation on the input encryption key using the first and second decryption key conversion data 2115 and 2116 which are partial information in the content. Thus, a content decryption key is generated and output to the encryptor 2120. Next, the encryptor 2120 encrypts the input content data using the content decryption key, and records the encrypted content in the AV data recording sector 2152 in the user data area 2150 of the optical disc.

  Here, the decryption key conversion data used in the optical disc playback device is included in the second decryption key conversion data 2116 which is information in the AV data which is substantially different for each sector, and in the sector in which the control information is recorded. The first decryption key conversion data 2115, which is copy control information including copy generation management information and an analog macrovision control flag, is used. By using the former second decryption key conversion data, the content decryption key for encrypting the content data is restored for each sector by the key converter 2113 according to the contents of the second decryption key conversion data. It becomes possible to do. Further, since the latter first decryption key conversion data is data that can easily detect unauthorized use of the data at the time of falsification, the content data is decrypted when the first decryption key conversion data is falsified. The effect that it is easy to make it impossible to do is obtained. Specifically, the encryption key is converted into a decryption key by a predetermined conversion operation using the data in the playback control recording sector in which the playback control information used for playback control of AV data is recorded as the first decryption key conversion data. This is used as a content decryption key in the encryptor 2120. Furthermore, it includes first decryption key conversion data that is data of the reproduction control recording sector, and second decryption key conversion data that is a part of the unencrypted content of the sector in which the encrypted content is recorded. Another content decryption key may be calculated by performing a predetermined conversion operation on the encryption key using the two decryption key conversion data, and this another content decryption key may be used as a content decryption key in the encryptor 2120. .

  On the other hand, the key encryptor 2118 generates an encryption / decryption key by encrypting the input encryption key using the input disk key in the same manner as the optical disk playback apparatus. Since the decryption key areas 2106 and 2109 in the sector header area are smaller than the size of the encryption / decryption key, the data divider 2121 divides the encryption / decryption key into a plurality of division / decryption keys and The key is recorded in different decryption key areas 2106 and 2109. In the example of FIG. 37, the encryption / decryption key is divided into two encryption division / decryption keys, and recorded in the decryption key areas 2106 and 2109 of two consecutive sectors, respectively. Here, since the decryption key that is the encryption key is encrypted by the key encryptor 2118, the strength of encryption for the encryption key can be increased.

  When reproducing the content, the key converter 2113 uses the information of the first decryption key conversion data 2115 and the second decryption key conversion data 2116 described above to convert the decryption key from the key decryptor 2112 into a predetermined key conversion. By performing the calculation, a content decryption key is generated and output to the decryptor 2114. Next, the decryptor 2114 obtains the decrypted content by decrypting the data of the encrypted content using the content decryption key. Here, the key converter 2113 may perform a predetermined key conversion operation on the decryption key from the key decryptor 2112 using only the information of the first decryption key conversion data 2115.

<Eleventh embodiment>
FIG. 38 shows the configuration of the user data area in the optical disc according to the eleventh embodiment of the present invention, the configuration of the optical disc recording apparatus that encrypts the content and records it in the user data area, and the encryption from the data in the user data area. FIG. 2 is a block diagram showing a configuration of an optical disc playback apparatus that decrypts encrypted content. The eleventh embodiment is characterized in that the configuration of the optical disk recording apparatus is added to the seventh embodiment, and this configuration will be described in detail.

  In FIG. 38, the optical disk recording apparatus is similar to the tenth embodiment of FIG. 37, and includes a key encryptor 2118 that encrypts an encryption key using a predetermined disk key, and first and second contents in the content. A key converter 2119 for calculating a content decryption key by performing a predetermined key conversion operation on the encryption key using the decryption key conversion data 2115 and 2116, and an encryptor for encrypting the content using the content decryption key 2120. Here, the decryption key output from the key encryptor 2118 is recorded in the main data area 2102 in the lead-in area 2401. On the other hand, the optical disk reproducing apparatus includes a key decryptor 2112, a key converter 2113, and a decryptor 2114, as in the seventh embodiment of FIG. Here, the decryption key recorded in the main data area 2102 in the lead-in area 2401 is read out and input to the key decryptor 2112. The key decryptor 2112 decrypts the decryption key using a predetermined disk key. To the key converter 2113. The key converter 2113 calculates a content decryption key by performing a predetermined key conversion operation on the decryption key from the key decryptor 2112 using the first and second decryption key conversion data 2115 and 2116. And output to the decoder 2114.

<Effects of the sixth to ninth embodiments>
As described in detail above, the recordable optical disc according to the present embodiment records the decryption key by dividing it into decryption key areas of a predetermined size arranged in the sector header area, or records the variable length decryption key in the sector header area. A recording type in which a decryption key having a free length can be used without being constrained by a decryption key area of a size defined in advance in the sector header area by recording in the decryption key area indicated by the key index area arranged in An optical disc can be provided. Thus, encryption using an arbitrary key length can be used according to the copyright protection level for the content to be recorded.

<Preferred modification>
In the above embodiment, the disc identification information is preferably composed of pre-pits that cannot be rewritten, and the disc identification information preferably has an area identifier representing an area where the disc is used. The disc identification information preferably includes a data category identifier indicating the type of content that can be recorded and reproduced on the optical disc. Further, the disc identification information is preferably encrypted using a secret key and recorded in the disc identification information area at the time of manufacture. Still further, the disc identification information preferably includes data indicating the type of data that can be recorded in the data recording / reproducing area or the type of data that can be reproduced from the data recording / reproducing area.

  In the embodiment described above, preferably, a descrambling area management table for managing a correspondence relationship between a sector area in which content data is recorded and a descrambling key is provided. The key management information area preferably includes key information having a descrambling key area for recording a descrambling key encrypted using the disc identification information as a key, and a descrambling key status area indicating a recording state of the descrambling key. An area, a content information area for recording key information used when reproducing the content recorded on the disc, and a key index area for recording a pointer for referring to a descramble key necessary for reproducing the content . Further, in the sector in which the content data is recorded, a pointer indicating an area in which the descrambling key is recorded is preferably recorded together with the content data.

  In the above embodiment, the disc identification information reproducing circuit of the optical disc recording / reproducing apparatus preferably includes a circuit for decrypting the disc identification information encrypted using the secret key. In the optical disc recording / reproducing apparatus, the data encrypted using the disc identification information as a key is preferably content data such as image data and music data. Further, the disc identification information preferably indicates the type of data that can be recorded in the data recording / reproducing area, and the disc identification information reproducing circuit determines whether or not the content data is recordable according to the data type. To do. Furthermore, the data decrypted using the disc identification information as a key is preferably content data such as image data or music data. Also, the disc identification information preferably represents the type of data that can be reproduced from the data recording / reproduction area, and the disc identification information reproduction circuit determines whether or not the content data can be reproduced according to the data type. To do.

  In the above embodiment, the content recording circuit preferably has the content data such as encrypted image data and music data and the descrambling key for decrypting the encryption applied to the content data in the same sector. Record. The content reproduction circuit preferably reproduces the content data such as encrypted image data and music data and the descrambling key for decrypting the encryption applied to the content data from the same sector.

  In the above embodiment, the key area allocation circuit or method preferably relates to a key used in reproducing content data by arranging an area reserved flag in a descrambling key status area indicating a recording state of a descrambling key. Information is recorded, and a key index representing a recording area of a descrambling key assigned to content data is recorded. Also, the descrambling key arrangement circuit or method preferably reproduces the descrambling key area index used by the content from the content information area and indicates the descrambling key indicated by the key index corresponding to the descrambling key to be recorded. A descrambling key is arranged in the area, and a recorded flag is arranged in the descrambling key status area indicated by the key index corresponding to the descrambling key to be recorded.

  In the above embodiment, the optical disc playback apparatus preferably plays back disc identification information, checks whether the content can be played back, plays back key management information, and stores content data such as image data and music data. Is reproduced, and a descrambling key is obtained from the reproduced sector. Further, preferably, the reproduced content data is descrambled by a descrambling key and output.

  In the above embodiment, the method for recording the content data preferably includes the recording of the first information area in which the first disc information is recorded and the second disc information for identifying each disc. At least when the content is recorded in the user data area of the optical disk having the second information area and the user data area where information can be recorded by irradiating a light beam. It is encrypted and recorded so that it can be decrypted and played back by an operation using. Here, preferably, the user data area has a key information recording area for recording key information for decrypting the encrypted and recorded data.

  In the above embodiment, the method for recording the content data preferably includes the recording of the first information area in which the first disc information is recorded and the second disc information for identifying each disc. Second information area, a user data area where information can be recorded by irradiating a light beam, and key information for decrypting the content recorded in the user data area When a content is recorded in the user data area of an optical disk having a key information recording area for recording the information, it can be decrypted and reproduced by an operation using at least the second disk information and the key information. As such, it is encrypted and recorded.

  In the above embodiment, in a sector of an optical disc having a decryption key area for recording a plurality of divided decryption keys divided into a plurality of consecutive sectors, the size of data including AV data is preferably (main data size) Dummy data is recorded in the main data area less than x (number of decryption key divisions). In the ECC block, preferably, a sector having a decryption key area in which a divided decryption key divided into a plurality of consecutive sectors is recorded (ECC block unit) / (number of decryption key divisions) times. Dummy data is recorded in a main data area in which the size of data including AV data is less than (main data size) × (ECC block unit).

  In the above embodiment, the decryption key for decrypting the encryption applied to the data including the AV data is preferably divided into a plurality of divided decryption keys having a predetermined size, and the plurality of divided divided decryption keys Are recorded in a plurality of continuous decryption key areas of the decryption key table. The decryption key table is preferably recorded in the main data area in the rewritable lead-in area. Furthermore, the information indicating the recording state of the decryption key table is preferably recorded as a fixed value in each decryption key area of the decryption key table. Furthermore, the decryption key table is recorded only a plurality of times in different ECC blocks arranged on the inner and outer circumferences of the optical disc.

  In the above embodiment, the encoding device 3101 as the data encryption device and the optical disc device 3102 as the optical disc recording / reproducing device preferably share the bus key by a mutual authentication method. Also, the decoding device 3103 that is a data decoding device and the optical disk device 3102 that is an optical disk recording / reproducing device preferably share a bus key by a mutual authentication method.

  In the above embodiment, a recordable optical disc capable of recording data that is a rewritable or write once type optical disc including a RAM type has been described. However, the present invention is not limited to this, and prerecorded data is recorded. Can be read and reproduced, but can be applied to a read-only optical disc that cannot be newly recorded. In the case of a read-only optical disc, the data recording / reproducing area is replaced with a data reproducing area for reading and reproducing data, and content data and other various control information data are recorded in advance at the time of manufacture. Here, the recordable optical disk includes CD-R, CD-RW, MO, MD, DVD-RAM, and the like. The reproduction-only optical disk includes a music CD, a CD-ROM, a DVD-ROM, and the like.

  As described above in detail, according to the optical disc of the present invention, the first region including the region that is formed in a stripe shape in the circumferential direction and in which a signal with a reduced amount of reflected light is intermittently obtained, and the light beam An optical disc including a second area where a user can record user data by irradiating the second area, wherein the first area is a predetermined radial distance from the second area. Are formed apart to have Therefore, since the first area is formed away from the second area, when forming the first area such as BCA, the recording film of the recording optical disk is protected from the heat generated during the formation. Therefore, user data recorded on the optical disc can be protected easily and reliably.

1 is a plan view showing a data recording area of a recordable optical disc 100 according to a first embodiment of the present invention. (A) is a block diagram and a longitudinal sectional view showing a device configuration when forming the BCA 106 of the optical disc 100 of FIG. 1, and (b) is a longitudinal section of the optical disc 100 after forming the BCA 106 of the optical disc 100 of FIG. It is a graph which shows the intensity | strength of the reflected light with respect to a figure and its horizontal direction. It is a figure which shows the recording format of BCA106 of FIG. It is a figure which shows the sector structure of the sector data 401 in the user data area | region 102 of FIG. It is a figure which shows the structure of the key management information area | region 107 of FIG. (A) is a block diagram showing a recording method for recording a descrambling key and AV data in the sector data 401 of FIG. 1 according to a modification of the first embodiment, and (b) is a block diagram showing the first embodiment. It is a block diagram which shows the recording method which records the key index and AV data to a descrambling key in the sector data 401 of FIG. It is a block diagram which shows the structure of the optical disk recording / reproducing apparatus which is 2nd Embodiment based on this invention. It is a flowchart which shows the recording process of AV data performed by control CPU710 of the optical disk recording / reproducing apparatus of FIG. It is a flowchart which shows the allocation process of the key management information area | region performed by control CPU710 of the optical disk recording / reproducing apparatus of FIG. It is a flowchart which shows the recording process of the descrambling key performed by control CPU710 of the optical disk recording / reproducing apparatus of FIG. It is a flowchart which shows the reproduction | regeneration processing of AV data performed by control CPU710 of the optical disk recording / reproducing apparatus of FIG. It is a flowchart which shows the acquisition process of the descrambling key performed by control CPU710 of the optical disk recording / reproducing apparatus of FIG. It is a block diagram which shows the method for determining whether it is a regular descrambling key from the encryption descrambling key based on the modification of 1st Embodiment. It is a figure which shows the structure of the descrambling area | region management table based on the modification of 1st Embodiment. (A) is a figure which shows whether the copy and reproduction | regeneration of a content are possible in the same area and a different area, when recording an area identifier at the time of recording of a content in 1st Embodiment. (B) shows whether the content can be copied or reproduced in the same region as well as in a different region when the region identifier is recorded in advance in the first embodiment when the optical disc is shipped. FIG. It is a top view which shows the data recording area | region of the optical disk 1101 which is the 3rd Embodiment concerning this invention. FIG. 10 is a waveform diagram showing signal waveforms of a reproduction signal 1201 and a reproduction binarized signal 1207 in a BCA reproduction circuit 1401 according to a third embodiment. It is a block diagram which shows the structure of the BCA reproduction circuit 1401 which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the optical disk recording / reproducing system which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the optical disk recording / reproducing system which is 4th Embodiment based on this invention. It is a top view which shows the data recording area of the optical disk 1601 which is the 5th Embodiment which concerns on this invention. It is a block diagram which shows the structure of the optical disk recording / reproducing system which concerns on 5th Embodiment. It is a table | surface which shows the structure of the ID provision table which concerns on 5th Embodiment. It is a top view which shows the data recording area of the optical disk 1101a which concerns on the modification of 3rd Embodiment. It is a top view which shows the data recording area of the optical disk 1601a which concerns on the modification of 5th Embodiment. It is a block diagram which shows the structure of the user data area | region in the optical disk which is the 6th Embodiment concerning this invention, and the structure of the optical disk reproducing | regenerating apparatus which decodes encrypted content from the data of a user data area | region. FIG. 20 is a block diagram showing the arrangement of copyright control information and a decryption key in a user data area and the arrangement of encrypted content in a main data area in an optical disc according to a sixth embodiment. It is a block diagram which shows arrangement | positioning when the unit of error correction spans a some sector in the optical disk which concerns on 6th Embodiment. Configuration of lead-in area 2401 and user data area 2402 in an optical disc according to the seventh embodiment of the present invention, and configuration of an optical disc playback apparatus that decrypts encrypted content from data in lead-in area 2401 and user data area 2402 FIG. (A) is a block diagram showing a data structure in a case where an unrecorded state is displayed with an initial value of a decryption key in a main data area of a lead-in area in an optical disc according to a seventh embodiment, It is a block diagram which shows the data structure in the case of displaying a recording state with a decoding key state table in the main data area of the lead-in area | region in the optical disk which concerns on 7th Embodiment. It is a block diagram which shows arrangement | positioning of a decryption key in the optical disk which concerns on 7th Embodiment. It is a block diagram which shows a data structure when managing the data of the optical disk which is the 8th Embodiment which concerns on this invention with a file management system. It is a flowchart which shows the recording process of the content which requires the copyright protection performed by the file management system which concerns on 8th Embodiment. It is a flowchart which shows the reproduction | regeneration process of a content performed by the file management system which concerns on 8th Embodiment. It is a flowchart which shows the deletion process of a content performed by the file management system which concerns on 8th Embodiment. It is a block diagram which shows the structure of the optical disk system which is the 9th Embodiment concerning this invention. The configuration of the user data area in the optical disc according to the tenth embodiment of the present invention, the configuration of an optical disc recording apparatus that encrypts and records the content in the user data area, and decrypts the encrypted content from the data in the user data area It is a block diagram which shows the structure of the optical disk reproducing | regenerating apparatus which performs. The configuration of the user data area in the optical disc according to the eleventh embodiment of the present invention, the configuration of an optical disc recording apparatus for encrypting and recording the content in the user data area, and decrypting the encrypted content from the data in the user data area It is a block diagram which shows the structure of the optical disk reproducing | regenerating apparatus which performs. It is a block diagram which shows the structure of the user data area | region of DVD-ROM of a prior art, and the structure of the optical disk reproducing | regenerating apparatus which decodes encrypted content from the data of a user data area | region.

Explanation of symbols

100 ... optical disc,
101 ... Lead-in area,
102: User data area,
103 ... lead-out area,
104 ... playback-only area,
105. Recording / reproduction area,
106: Burst cutting area (BCA),
107 ... key management information area,
201 ... substrate,
202 ... recording layer,
203 ... reflective layer,
204 ... adhesive layer,
205 ... reflective layer,
206 ... recording layer,
207 ... a substrate,
211 ... High power laser light source,
212 ... Focus lens,
301 ... synchronization code,
302 ... error detection code,
303 ... error correction code,
304 ... BCA data,
305: Disc identification information,
401 ... sector data,
402 ... header,
403 ... main data,
404 ... error detection code,
405 ... Data ID,
406 ... ID error detection code,
407 ... scramble control information,
408, 408a ... key information,
501: Key information area,
502 ... content information area,
503: Key index list area,
504 ... Number of recorded keys,
505 ... descramble key area,
506 ... Key status area,
507 ... number of contents,
508 ... content information,
509 ... Key index,
701 ... recordable optical disc,
702 ... an optical head,
703. Recording / reproduction control circuit,
704 ... modulation / demodulation circuit,
705 ... Error detection and correction circuit,
706: Buffer memory,
707 ... descrambling circuit,
708 ... MPEG decoding circuit,
709 ... an output circuit,
710: Control CPU,
711 ... a communication circuit,
712. Data receiving circuit,
801: Encryption descrambling key,
802 ... descramble key,
803 ... error detection code,
1101, 1101a ... optical disc,
1102 ... control user data area,
1103 ... User data area,
1104, 1104a ... BCA,
1105, 1105a ... Trimming region,
1201... Reproduction signal,
1202 to 1204 ... trimming part,
1205, 1206 ... slice level,
1207: reproduction binarized signal,
1301 ... Optical pickup,
1302 ... Preamplifier,
1303 ... Low pass filter (LPF),
1304... Binarization circuit,
1305 Demodulation circuit,
1306: Disc ID signal,
1401 ... BCA reproduction circuit 1402 ... Disc ID signal,
1403, 1404 ... interface,
1405 ... the network,
1406: Encryption unit,
1407: Content memory,
1408: Encryption encoder,
1409 ... encrypted content,
1410 ... Optical disc recording / reproducing apparatus,
1411 ... Recording circuit,
1412: Data reproduction unit,
1413 ... cryptographic decoder,
1414 ... Output signal,
1501 ... CATV company equipment,
1502 ... content memory,
1503 ... 1st encryption key memory,
1504 ... first encryption encoder,
1505 ... first encrypted content,
1506 ... CATV decoder,
1507: Key issuing center device,
1507a: control unit,
1508: System ID memory,
1509 ... Input title code,
1510: Time limit information memory,
1511 ... Recording permission code memory,
1512 ... Key (K),
1513: first cryptographic decoder,
1514 ... Optical disc recording / reproducing apparatus,
1515: Disc ID signal,
1516 ... Second encryption encoder,
1517 ... Second encrypted content,
1518 ... Recording circuit,
1519: Data reproduction unit,
1520 ... Second cryptographic decoder,
1521 ... BCA regeneration circuit,
1522 ... IC card,
1523 ... Company identification signal memory,
1524 ... IC card,
1525 ... Output signal,
1526: Company identification signal memory,
1527 ... Clock circuit,
1530 ... Television apparatus,
1601, 1601a ... optical disc,
1602 ... control user data area,
1603 ... User data area,
1604, 1604a ... BCA,
1605: Key information recording area,
1606, 1606a ... trimming area,
1701 ... CATV company equipment,
1702 ... Content memory,
1703: first encryption key,
1704: first encryption encoder,
1705 ... key (K),
1706: CATV decoder,
1707: Key issuing center device,
1707a: control unit,
1708 ... System ID memory,
1709 ... Input title code,
1710: Time limit information memory,
1712: Key (K),
1713 ... first encryption decoder,
1714 ... Optical disc recording / reproducing apparatus,
1715: Disc ID,
1716 ... Input title code,
1717 ... Recording circuit,
1718: Key (DK),
1719: Key information recording circuit,
1720 ... BCA regeneration circuit,
1721 ... Data reproduction unit,
1722 ... second cryptographic decoder,
1723: Key information reproduction unit,
1724 ... Output signal,
1725 ... Clock circuit,
1730 ... Television apparatus,
2101 ... sector header area,
2102 ... main data area,
2103: Error detection code,
2104 ... sector address,
2105: Copyright control information,
2106: Decryption key area,
2107 ... unencrypted content,
2108 ... encrypted content,
2109: Decryption key area,
2110 ... Decryption key conversion data,
2111 ... Data connector,
2112 ... Key decryptor,
2113: Key converter,
2114 ... decoder
2115: First decryption key conversion data,
2116 ... second decryption key conversion data,
2117 ... Unencrypted control information,
2118 Key encryption device
2119 ... Key converter,
2120 ... encryptor,
2121 ... Data divider,
2150 User data area,
2151 ... Control information recording sector,
2152 ... AV data recording sector,
2201... First decryption key area,
2202 ... second decryption key area,
2203 ... complementary data,
2204 ... encrypted content,
2401 ... lead-in area,
2402 ... User data area,
2403 ... Key index area,
2404 ... Decryption key table,
2451 ... control information recording sector,
2452 ... AV data recording sector,
2501 ... unrecorded state data,
2502 ... Decryption key state table,
2503 ... recording state data,
2601: Lead-in area,
2602: User data area,
2603 ... lead-out area,
2701 ... File entry (1),
2702 ... File entry (2),
2703 ... file (1),
2704 ... file (2),
2705 ... extent (1) of file (1),
2706 ... extent (1) of file (2),
2707: Decryption key table,
2708: Key index area,
2751 ... File management information area,
3101 ... Encoding device,
3102: Optical disc device,
3103: Decoding device,
3104: Personal computer,
3111: Decryption key memory,
3112: Bus encryption circuit,
3113: Decryption key table memory,
3114 ... bus encryption and decryption circuit,
3115: Bus encryption / decryption key table memory,
3116: Decryption key state table memory,
3117: Bus decoding circuit,
3118: Decryption key memory,
3119: Recording / reproducing circuit,
3120, 3121, 3123, 3124 ... interface,
3130: control unit,
3131: Content memory,
3132: Encoding circuit,
3133: Encryption key memory,
3134: cryptographic circuit,
3141: Decoding circuit,
3151: PCI bus,
3152: SCSI bus.

Claims (10)

A first region having a region that is formed in a stripe shape in the circumferential direction and in which a signal with a reduced amount of reflected light is intermittently obtained;
An optical disc including a second area where a user can record user data by irradiating the second area with a light beam,
The first region is formed apart from the second region so as to have a predetermined radial distance,
Data recorded in the form of concave and convex pits in the first area is also recorded between the second area and the first area,
An optical disc, wherein the data in the second area is encrypted and recorded using the data recorded in the first area as a key. A lead-in area formed inside the second area;
2. The optical disc according to claim 1, wherein the lead-in area includes at least a part of the first area.   3. The optical disc according to claim 1, wherein the second area is a rewritable area.   3. The optical disk according to claim 1, wherein the second area is a writable area. A first region having a region formed in a stripe shape in the circumferential direction and intermittently obtaining a signal with a reduced amount of reflected light; and a second region,
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And an optical disk recording device for an optical disk recorded between the first area and the first area,
Recording means for recording user data by irradiating the second region with a light beam;
An optical disc recording apparatus, wherein the data in the second area is encrypted and recorded using the data recorded in the first area as a key. A first region having a region formed in a stripe shape in the circumferential direction and intermittently obtaining a signal with a reduced amount of reflected light; and a second region,
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And an optical disc recording method for an optical disc recorded also between the first area,
Recording user data by irradiating the second region with a light beam,
An optical disk recording method, wherein the data in the second area is encrypted and recorded using the data recorded in the first area as a key. The user can record user data by irradiating the second area with the first area and the second area, which are formed in a stripe shape in the circumferential direction and can intermittently obtain a signal with a reduced amount of reflected light A second region,
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And a reproducing apparatus for an optical disc recorded between the first area and the first area,
First reproducing means for reproducing the first area;
Second reproducing means for reproducing data recorded in the form of concave and convex pits between the second area and the first area;
Third reproducing means for reproducing user data recorded in the second area,
An optical disc reproducing apparatus, wherein the data in the second area is encrypted and recorded using the data recorded in the first area as a key. The user can record user data by irradiating the second area with the first area and the second area, which are formed in a stripe shape in the circumferential direction and can intermittently obtain a signal with a reduced amount of reflected light A second region,
The first area is formed so as to have a predetermined radial distance from the second area, and data recorded in the form of concave and convex pits in the first area is the second area. And a reproducing method for an optical disc recorded between the first area,
Playing back the first region;
Replaying data recorded in the form of concavo-convex pits between the second region and the first region;
Replaying user data recorded in the second area,
An optical disc reproducing method, wherein the data in the second area is encrypted and recorded using the data recorded in the first area as a key.   An optical disc recording apparatus for recording information on the optical disc according to any one of claims 1 to 4. An optical disc reproducing apparatus for reproducing information from the optical disc according to any one of claims 1 to 4.

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