JP4228863B2 - Recording apparatus, signal processing system, recording method program, and recording medium storing program - Google Patents

Description

The present invention relates to, for example, a recording apparatus and signal processing applied when a content connected to a disc medium such as a DVD (Digital Versatile Disc) standard disc is recorded by a drive connected to a personal computer and the content is reproduced from the disc medium. system, a recording medium storing the program as well as the program of record method.

  In a recently developed recording medium such as a DVD, it is possible to record a large amount of data for one movie as digital information on one medium. As described above, when a large amount of video information or the like can be recorded as digital information, it becomes more and more important to prevent unauthorized copying and protect the copyright holder.

  For example, DVD-Video employs a copyright protection technology called CSS (Content Scramble System). Non-patent document 1 and non-patent document 2 below are described regarding copyright protection methods for DVDs.

“Part 2 Intellectual Property Protection: Meditation to prevent unauthorized copying, the key to software decryption”, Nikkei Electronics 1997.8.18, p.110-119 Yamada, “Expanding copyright protection space from DVD”, Nikkei Electronics 2001.8.13, p.143-153

  FIG. 1 shows an overview of the CSS scheme described in these documents. In the case of this method, three encryption key data are used. The three encryption key data are a master key issued by the CSS key issuing center, a disc key and a title key determined by the copyright holder or the like. The master key is a secret key that has a fixed value that varies from manufacturer to manufacturer, and the disk key has a value that varies from disk to disk. A set of disc keys that can be decrypted by any master key is created and stored on the disc. When the disk key is stored on the disk, it is encrypted and is called a secured disk key.

MPEG (Moving) that compresses content data such as video data and audio data
For picture 1 (picture coding experts group) data 1, a title key 2 which is an encryption key assigned to the content is prepared. Further, a disk key 3 that is an encryption key assigned to each disk is prepared. Then, the key issuing center 4 that manages encryption uses the master key 5 managed by the center 4 to encrypt the disk key 3 with an encryption circuit (hereinafter referred to as an encryptor) 6. 3 is used to encrypt the title key 2 by the encryptor 7. Then, the MPEG data 1 is encrypted by the scrambler 8 using the title key 2.

  Encrypted content data (hereinafter referred to as scrambled MPEG data or scrambled content as appropriate) 9, encrypted disc key (hereinafter referred to as secure disc key as appropriate) 10, and encrypted title key ( 11) is recorded on the DVD-Video disc 12 when the DVD-Video disc is manufactured. The secured disc key is recorded in a predetermined position in the lead-in area of the disc 12, and the encrypted title key is recorded in each sector of the content data having the sector structure. These secured disk key and encrypted title key are key information for a copyright protection system, and both are collectively referred to as a CSS key.

As shown in FIG. 2, the DVD-Video disc 12 is reproduced by the DVD player, and the scrambled MPEG data 9, the secured disc key 10 and the encrypted title key 11 are reproduced and read into the DVD player 21. In the DVD player 21, the master key 22 is used to decrypt the disc key by an encryption decryption circuit (hereinafter referred to as a “decryptor” as appropriate) 23, the decrypted disc key is used to decrypt the title key by the decryptor 24, MPEG data is decrypted by the descrambler 25 using the decrypted title key. Audio / visual data 27 is decoded by the MPEG decoder 26.

  FIG. 3 shows the data structure of the lead-in area, which is the area that is first read by the player during disc playback. The lead-in area is used from a sector with a physical sector number of 0h (h is a symbol indicating that it is in hexadecimal notation: the same shall apply hereinafter) to 30000h. A reference code is arranged in this area, an area having all values of 0 is arranged again, and a control data area is provided thereafter. Thereafter, there is an area where all the values are 0, which becomes a main data area where content data is recorded from the sector number 30000h.

  In the control data area, physical format information is arranged in the first 1 sector (sector 0), disk manufacturing information is arranged in the next 1 sector (sector 1), and contents are supplied to the next 14 sectors (sectors 2 to 15). Information is placed. Information of 16 sectors from sector 0 to sector 15 is repeatedly arranged in the control data area. Then, a secure disk key specific to the disk is arranged in a section where content provider information (content supplier information) is arranged.

  The structure in which the title key is recorded will be described based on the sector structure example shown in FIG. 4. Each sector in which main data such as content data is recorded is composed of 2064 bytes. Of the 2064 bytes, the first 4 bytes are used as ID data indicating a sector number, and the subsequent 2 bytes are used as ID data error detection data. Further, the next 6 bytes are used as copy management data, and an encrypted title key is arranged in the copy management data. Then, 2048 (2K) bytes following the copy management data are used as a main data recording area in which content data and the like are recorded. Further, error detection data for the entire sector is arranged in the last 4 bytes.

In this way, a disk in which data is stored after being encrypted using a disk key and a title key is basically a reproduction-only disk, but some DVD standards include a recordable standard disk. Exists. For example, DVD-RW / -R standard discs and DVD + RW / + R standard discs are capable of recording data, and are digitally reproduced from other media called bit-by-bit copies. The data is recorded on another medium as it is, and the data read from the DVD-Video is recorded on the disc of these standards as it is, so that the content data such as the video data of the DVD-Video disc can be copied. Can be created illegally. However, by preparing the above-described disc key and title key, content data such as illegally copied video data cannot be decrypted.

The point that this illegally copied disk cannot be correctly decrypted from encryption will be described with reference to FIG. First, a DVD-Video disc Da in which a secured disc key and an encrypted title key are recorded in the above-described arrangement is prepared, and the user reproduces the disc Da. In the player, a secured disc key is obtained from the lead-in area at the innermost periphery of the disc, and an encrypted title key is obtained from the sector in which the content data is recorded. The secured disc key is decrypted with the master key, and the encrypted title key is decrypted with the disc key. The scrambled MPEG data is decoded by the title key, and audio / visual data is obtained.

The content data recorded on the DVD-Video disc Da is DVD-RW /-.
It is assumed that the user executes recording on the R standard disc Db by bit-by-bit copying. Here, in the disk Db, a part of the lead-in area is an area that has been written with pits at the time of manufacturing the disk, and a disk key assigned to the disk Db or an invalid key is previously written in the written area. is there.

Therefore, the DVD-Video disc Da is placed in the data recordable area of the disc Db.
When the user produces a DVD-R / RW standard disc Db ′ in which the content data read from is recorded as it is, the disc Db ′ has a disc key different from that of the original disc Da. Since the disc key is different from the original disc Da, even if the user tries to reproduce the copied disc Db ′, the player cannot correctly decrypt it, and as a result, illegal copying is prevented. .

FIG. 6 shows a method of taking out a disc key and a title key by a PC and a drive for reproducing a ROM disc, for example, a DVD-Video disc recorded by the CSS method, and a descrambling method of scramble data. In FIG. 6, reference numeral 31 denotes a DVD drive as a playback device for playing back a DVD-Video disc recorded in CSS. Reference numeral 51 indicates a PC as a data processing apparatus. DVD player application software is installed on the PC 41.

  The DVD drive 31 and the PC 41 are connected with a standard interface. The interfaces are ATAPI (AT Attachment with Packet Interface), SCSI (Small Computer System Interface), USB (Universal Serial Bus), IEEE (Institute of Electrical and Electronics Engineers) 1394, and the like.

  The DVD drive 31 connected to the PC 41 is provided with an authentication unit 32 and bus encryptors 33 and 34. The PC 41 includes an authentication unit 42 and bus encryptors 43 and 44. The authentication unit 32 and the authentication unit 42 perform mutual authentication and generate a different session key (also called a bus key) Ks for each authentication operation. Further, the PC 41 is provided with a master key 45, decryptors 46 and 47, and a descrambler 48, and MPEG data obtained from the descrambler 48 is decoded by an MPEG decoder 49 to obtain audio / visual data 50.

  The authentication operation is always performed when a disk is detected after the power is turned on and when a disk is replaced. Further, the authentication operation may be performed when the recording operation is performed by pressing the recording button and when the reproducing operation is performed by pressing the reproduction button. As an example, authentication is performed when a record button or a playback button is pressed.

The scrambled MPEG data 9 obtained from the DVD-Video disc, the secured disc key 10, and the encrypted title key 11 are read into the DVD drive 31. An encrypted title key is obtained from the sector in which the content data is recorded. The secured disc key is decrypted with the master key, and the encrypted title key is decrypted with the disc key. The scrambled MPEG data is decoded by the title key, and audio / visual data is obtained.

FIG. 7 shows a procedure for exchanging signals between the DVD drive 31 and the PC 41 in the current system shown in FIG. The PC 41 sends a command to the DVD drive 31, and the DVD drive 31 performs an operation in response to the command. The sequence starts when a DVD-Video disc is inserted, and the authentication sequence AKE (Authentication and Key Exchange) (
Step S1) is performed. When mutual authentication is established, the session key Ks is shared by the DVD drive 31 and the PC 41. If the authentication is not successful, the process is interrupted.

Next, the content data area on the DVD-Video disc 12 is sought and read in response to a request from the PC 41 (step S2). In the next step S3, the PC 41 requests a secured disk key from the drive 31, and the drive 31 reads the secured disk key from the DVD-Video disk 12 (steps S4 and S5). The secured disk key is encrypted by the bus encryptor 33 using the session key Ks. The secured disk key encrypted with Ks is returned from the drive 31 to the PC 41 (step S6).

Next, the PC 41 requests the drive 31 for the encrypted title key and copy generation management information CGMS (Copy Generation Manager System) (step S7).
1 reads the encrypted title key and CGMS from the DVD-Video disc 12 (steps S8 and S9). The encrypted title key and CGMS are encrypted by the bus encryptor 34 using the session key Ks. The encrypted title key and CGMS encrypted with Ks are returned from the drive 31 to the PC 41 (step S10).

Next, the PC 41 requests the drive 31 for scrambled content (which has the same meaning as the scrambled MPEG data) (step S11), and the drive 31 reads the scrambled content from the DVD-Video disc 12 (step S12). , S1
3). The scrambled content is returned from the drive 31 to the PC 41 (step S14).

The above-described CSS system is only approved for use with DVD-ROM media, and the CSS system is prohibited by a CSS contract for recording DVDs such as DVD-R, DVD-RW, DVD + R, and DVD + RW. Therefore, the entire contents of a DVD-Video that is copyright-protected by the CSS method can be copied to a recordable DVD (bit-by-bit copy).
To do is not an accepted act under the CSS contract.

However, there was a situation where the CSS encryption method was broken. "DeC" that enables the content of DVD-Video to be copied to the hard disk easily by removing CSS encryption
Software called “SS” was distributed on the Internet. The background of the appearance of “DeCSS” was that the reproduction software designed without tamper-proofing the key data for CSS decryption that should have been tamper-proof was reverse engineered and the key data was decrypted As a result, the entire CSS algorithm has been decoded in a chain.

  After CSS, CPPM (Content Protection for Pre-Recorded Media), which is a copyright protection technology for DVD-ROM such as DVD-Audio, and CPRM (Content Protection for Recordable Media) for recordable DVD and memory cards Has been proposed. These systems have the feature that the system can be updated when a problem occurs in content encryption, management information storage, etc., and reproduction can be restricted even if the entire data is copied. That is, CPRM pre-records an area for recording key information of the lead-in area in order to prohibit bit-by-bit copying. CPRM is described in the following document (Non-Patent Document 3) distributed by license manager 4C Entity, LLC.

"Content Protection for Recordable Media Specification DVD Book", Internet <URL: http://www.4Centity.com/>

  For easy understanding of the present invention, the architecture of the CPRM for DVD will be described with reference to FIG. In FIG. 8, reference numeral 601 indicates a writable disc DVD medium such as DVD-R / RW, DVD-RAM, or the like that complies with the CPRM standard, reference numeral 602 indicates a recorder that complies with the CPRM standard, for example, and reference numeral 603 Indicates a player compliant with the CPRM standard, for example. The recorder 602 and the player 603 are devices or application software.

In an unrecorded disc state, a media ID 611 is recorded in an area called BCA (Burst Cutting Area) or NBCA (Narrow Burst Cutting Area) in the lead-in area on the innermost circumference side of the CPRM compatible DVD medium 601. ing. As shown in FIG.
In the control data area, which is an embossed or pre-recorded data area of the lead-in area, a media key block (hereinafter abbreviated as MKB as appropriate) 612 is recorded in advance. The same MKB is repeatedly recorded 12 times. The MKB is composed of 16 ECC blocks. One ECC block includes physical format information (2048 bytes = 2 Kbytes), disk manufacturing information (2 Kbytes), an undefined area (4 Kbytes), and an MKB pack (12 × 2 Kbytes). A more detailed description of the data format shown in FIG. 9 is described in Non-Patent Document 3 described above.

  The media ID 611 is a number different for each media unit, for example, one disc, and is composed of a media manufacturer code and a serial number. The media ID 611 is necessary when the media key is converted into a media unique key different for each media. The media key block MKB is a key bundle for realizing media key derivation and device revocation (invalidation). These media ID and media key block MKB are information that can only be reproduced. In other words, it is information that cannot be copied and cannot be falsified.

  The encrypted content 613 encrypted with the content key is recorded in a data area of the disc 601 that can be rewritten or additionally written. C2 (Cryptomeria Ciphering) is used as an encryption method.

  An encrypted title key 614 and a CCI (Copy Control Information) 615 are recorded on the DVD medium 601. The encrypted title key 614 is encrypted title key information, and the title key information is key information added for each title. The CCI is copy control information such as copy no more (copy prohibited), copy once (one copy is possible), and copy free (copy is possible). The CCI is sent from the content side at the time of recording, is used as a parameter for calculating a content key for encrypting the content, and is recorded together with the encrypted content.

The recorder 602 includes a device key 621, a process MKB 622, and C2. G623, random number generator 624, C2 E625, C2 G626 and C2 It has the components of ECBC627. The player 603 includes a device key 631, a process MKB 632, and C2. G633, C2 D635, C2 G636 and C2 It has the components of DCBC637. C2 G623 and 633 are blocks for calculating a media unique key from the media ID and the media key, respectively. C2 G626 and 636 are blocks for calculating a content key from the CCI and the title key, respectively.

  The device keys 621 and 631 are identification numbers issued by a license management company for each device manufacturer or application software vendor. The device key is information unique to the electronic device or application software that is given only to the legitimate electronic device or application software by the license management company. By calculating the MKB 612 and the device key 621 reproduced from the DVD medium 601 in the process MKB 622, it is possible to determine whether or not the revocation has been performed. As in the recorder 602, in the player 603, the MKB 612 and the device key 631 are calculated in the process MKB 632 to determine whether or not the revocation has been performed.

Further, in each of the processes MKB 622 and 632, a media key is calculated from the MKB 612 and the device keys 621 and 631. If the device key of the recorder 602 or the player 603 is not included in the MKB 612 and the calculated result matches a predetermined value, for example, zero, the recorder 602 or the player 603 having the device key is valid. It is judged that it is not something. That is, such a recorder 602 or player 603 is revoked. C2 G623 and 633 are processes for calculating a media key and a media ID, respectively, and deriving a media unique key. The CPRM method uses the device key as described above, and is different from the CSS method using only the media identification information, and is a stronger method in terms of security.

A random number generator (RNG) 624 is used to generate a title key. The title key from the random number generator 624 is C2. In E625, the title key is encrypted with the media unique key. An encrypted title key 614 is recorded on the DVD medium 601.

In the player 603, the encrypted title key 614 reproduced from the DVD medium 601 and the media unique key are stored in C2. The encrypted title key is decrypted with the media unique key, and the title key is obtained.

In the recorder 602, the CCI and title key are C2 Supplied to G626 and the content key is derived. Content key is C2 The content is supplied to the ECBC 627 and the content is encrypted using the content key as a key. Encrypted content 613 is recorded on the DVD medium 601.

In the player 603, the CCI and title key are C2 Supplied to G636 and the content key is derived. Content key is C2 The encrypted content 613 supplied to the ECBC 637 and reproduced from the DVD medium 601 is decrypted using the content key as a key.

  In the configuration of FIG. 8, a recording procedure by the recorder 602 will be described. The recorder 602 reads the MKB 612 from the DVD medium 601, calculates the device key 621 and the MKB 612 by the process MKB 622, and calculates the media key. If the calculation result shows a predetermined value, it is determined that the device key 621 (the device or application of the recorder 2) has been revoked by the MKB, and the recorder 602 interrupts the subsequent processing and records on the DVD medium 601. Is prohibited. If the media key value is other than a predetermined value, the processing is continued.

Next, the recorder 602 reads the media ID 611 from the DVD medium 601 and sets the media ID together with the media key to C2. A media unique key that is input to G623 and is different for each media is calculated. The title key generated by the random number generator 624 is C2. It is encrypted at E625 and recorded on the DVD medium 601 as an encrypted title key 614. The title key and the CCI information of the content are C2 The content key is derived by calculation in G626. Content with the content key C2 It is encrypted by ECBC 627 and recorded together with CCI 615 as encrypted content 613 on DVD media 601.

A playback procedure by the player 603 will be described. First, the MKB 612 is read from the DVD medium 601, the device key 631 and the MKB 612 are calculated, and revocation is confirmed. When the device key 631, that is, the device or application of the player 603 is not revoked, a media unique key is calculated using the media ID, and a title key is calculated from the read encrypted title key 614 and the media unique key. Is done. Title key and CCI615 are C2 Input to G636 and the content key is derived. Content key is C2 The encrypted content 613 input from the DCBC 637 and reproduced from the DVD medium 601 using the content key as a key is C2 The calculation of DCBC 637 is performed. As a result, the encrypted content 613 is decrypted.

  As described above, in order to obtain a content key necessary for decrypting the content, a different media ID is required for each DVD media, so even if the encrypted content on the media is faithfully copied to other media. However, since the media ID of other media is different from the original media ID, the copied content cannot be decrypted, and the copyright of the content can be protected.

  The configuration of FIG. 8 described above is configured as a recording / reproducing device. Further, FIG. 10 shows the division of roles between the PC and the drive when the content protection processing for the DVD medium 601 is handled in the PC environment. In FIG. 10, reference numeral 604 indicates a DVD drive as a recording / reproducing apparatus for recording and reproducing the DVD medium 601 compliant with the CPRM standard described above.

  Reference numeral 605 indicates a host, for example, a PC as a data processing apparatus. The PC 605 is a device (hardware) or application software that can be recorded on the DVD medium 601, can handle content reproducible from the DVD medium 601, and can be exchanged with the DVD drive 604. For example, the PC 605 is configured by installing application software on the PC.

The DVD drive 604 and the PC 605 are connected by an interface 604a. The interface 604a is ATAPI (AT Attachment with Packet Interface)
, SCSI (Small Computer System Interface), USB (Universal Serial Bus), IE
EE (Institute of Electrical and Electronics Engineers) 1394. DVD
When the drive 604 and the PC 605 are connected, it is necessary to add an authentication function that is unnecessary for the recording / reproducing device described above.

In the DVD medium 601, a media ID 611, a media key block 612, and an ACC (Authentication Control Code) are recorded in advance. The ACC is data recorded in advance on the DVD medium 601 so that authentication between the DVD drive 604 and the PC 605 differs depending on the DVD medium 601.

The DVD drive 604 reads the ACC 616 from the DVD medium 601. The ACC 616 read from the DVD medium 601 is input to an AKE (Authentication and Key Exchange) 641 of the DVD drive 604 and transferred to the PC 605. PC
In step 605, the received ACC is input to the AKE 651. The AKEs 641 and 651 exchange random number data, and generate a common session key having a different value for each authentication operation from the exchanged random number and the ACC value.

Session key is MAC (Message Authentication Code) calculation block 642 and 6
52 respectively. The MAC calculation blocks 642 and 652 are processes for calculating the media ID and the MAC of the media key block 612 using the session keys obtained by the AKEs 641 and 651 as parameters, respectively. Used by the PC 605 to confirm the integrity of the MKB and media ID.

  The MACs respectively calculated by the MACs 642 and 652 are compared in the comparison 653 of the PC 605, and it is determined whether or not both values match. If these MAC values match, the integrity of the MKB and the media ID is confirmed. The switch SW1 is controlled by the comparison output.

  The switch SW1 is shown as turning on / off the signal path between the recording or playback path of the DVD medium 601 of the DVD drive 604 and the encryption / decryption module 654 of the PC 605. Note that the switch SW1 is shown to turn the signal path ON / OFF, but more actually, the processing of the PC 605 continues when the signal is ON, and the processing of the PC 605 stops when it is OFF. Represents. The encryption / decryption module 54 calculates a content key from the media unique key, the encrypted title key, and the CCI, encrypts the content into the encrypted content 613 using the content key as a key, or encrypts the content using the content key as a key. This is an operation block for decoding 613.

  The media unique key calculation block 655 is a calculation block for calculating a media unique key from the MKB 612, the media ID, and the device key 656. That is, as in the recorder or player shown in FIG. 8, a media key is calculated from the device key and the MKB 612, and a media unique key is calculated from the media key and the media ID 611. When the media key reaches a predetermined value, it is determined that the electronic device or application software is not valid, and it is revoked. Therefore, the media unique key calculation block 655 also has a function as a revocation processing unit that performs revocation.

  When the integrity is confirmed by the comparison 653 at the time of recording, the switch SW1 is turned on, and the encrypted content 613, the encrypted title key 614 and the CCI 615 are transferred from the encryption / decryption module 654 to the drive 604 through the switch SW1. Are recorded on the DVD medium 601. When the integrity is confirmed by the comparison 653 at the time of reproduction, the switch SW1 is turned on, and the encrypted content 613, the encrypted title key 614 and the CCI 615 respectively reproduced from the DVD medium 601 are encrypted by the PC 605 through the switch SW1. / Decryption module 654 is supplied to decrypt the encrypted content.

  FIG. 11 shows a procedure for exchanging signals among the DVD medium 601, the DVD drive 604, and the PC 605 in the system using the DVD medium under the current PC environment shown in FIG. The PC 605 sends a command to the DVD drive 604, and the DVD drive 604 performs an operation in response to the command.

First, the ACC on the DVD medium 601 is sought and read in response to a request from the PC 605 (step S71). In the next step S72, the read ACC is input to the AKE 641 and transferred to the PC 605. In the PC 605, the received ACC is input to the AKE 651. The AKEs 641 and 651 exchange random number data, generate a session key having a different value for each authentication operation from the exchanged random number and the value of the ACC 616, and the DVD drive 604 and the PC 605 share the session key. If mutual authentication is not established, the process is interrupted. CPRM employs the same session key generation method as CSS, which is a DVD-Video copyright protection technology.

  If the authentication is successful, the PC 605 next requests the DVD drive 604 to read the MKB (media key block) pack # 0 from the DVD medium 601 in step S73. In the MKB, as described with reference to FIG. 9, 16 sectors of pack 0 to pack 15 are repeatedly recorded 12 times in the lead-in area.

  The DVD drive 604 reads the MKB pack # 0 in step S4, and the pack # 0 is read in step S75. The DVD drive 604 returns the modified MKB to the PC 605 (step S76). That is, when reading the MKB, the MAC value is calculated using the session key as a parameter, the MAC value is added to the MKB, and the data is transferred to the PC 605. For example, pack # 15 is read and transferred to the PC 605 until the remaining MKB pack requests other than pack # 0, the read operation of the DVD drive 604, and the transfer operation of the modified MKB pack are completed. Up to step S77 and S78.

  Next, in step S79, the PC 605 requests the DVD drive 604 for a media ID. The DVD drive 604 reads the media ID recorded on the DVD medium 601 (step S80), and the media ID is read in step S81. When reading the media ID, the DVD drive 604 calculates the MAC value using the session key as a parameter, adds the MAC value m1 to the read media ID, and transfers the data to the PC 605 in step S82. .

  The PC 605 calculates the MAC value again using the session key as a parameter from the MKB 612 and the media ID 611 received from the DVD drive 604, compares the calculated MAC value with the MAC value received from the DVD drive 604 in the comparison 653, and the two match. If so, it is determined that the correct MKB and media ID have been received, the switch SW1 is set to ON, and the process proceeds. Conversely, if the two do not match, it is determined that the MKB and the media ID have been tampered with, and the process is interrupted by setting the switch SW1 to OFF.

  In step S83, the PC 605 requests encrypted content from the DVD drive 604. In step S84, the DVD drive 604 reads the encrypted content. In step S83, the read encrypted content is transferred to the PC 605. In the media unique key calculation block 655 of the PC 605, a media unique key is calculated from the device key 656, the MKB 612, and the media ID 611. Then, the media unique key is supplied to the encryption / decryption module 654, the content key is obtained from the encrypted title key 614 and the CCI 615, and the encrypted content read from the DVD medium 601 is decrypted using the content key as a key. In addition, the content recorded on the DVD medium 601 is encrypted.

  In the flowchart of FIG. 12, step ST1 is a step of comparing the MAC calculated value obtained using the session key as a parameter in the MAC operation block 642 and the MAC calculated value obtained using the session key as a parameter in the MAC operation block 653. is there. If they match, the switch SW1 is turned on in step ST2, and if they do not match, the switch SW1 is turned off in step ST3, and the process stops.

  Now that BS digital broadcasting and terrestrial digital broadcasting have been put into practical use, there is an increasing need for encrypted recording of broadcasts in order to protect the copyright of digital broadcast content. At present, it is expected that copy-free broadcast contents will be subject to scrambled broadcasting and encryption recording will be required in the future. Therefore, it is expected that a recorder that uses a disc such as a writable DVD needs to have a performance capable of recording by encryption.

  At present, the CSS method and the CPRM method described above exist as encryption recording methods. Unlike the CSS method, the CPRM method increases the data length of the encryption key from 40 bits to 56 bits of the CSS method, uses a device key unique to the device, and further updates the system or uses the key illegally. Supports data abolition. Accordingly, there is no free software that breaks the CSS system such as “DeCSS”, which is more powerful than the CSS system in terms of copyright protection.

  Updating the system is to redistribute key data and encryption programs to make them new. In an apparatus capable of downloading software such as a digital broadcast receiver, the system can be updated. Further, a large amount of key data MKB is recorded on the recording medium, and the device side includes some of the key data, and the key data matches between the device and the medium, and the content can be reproduced. In a medium in which an unauthorized device appears, only the key data included in the unauthorized device is deleted from the key data MKB. This is the abolition of key data, and as a result, it is possible to prevent the device from decrypting the encrypted content. This technique can be applied to both broadcasting and media.

However, DVD players that have already been supplied to the market in large quantities do not support the CPRM system that was standardized later, and DVD players manufactured after the CPRM standard was formulated also for cost reasons. Most of them do not support the CPRM system. Therefore, the CPRM method is disadvantageous compared to the CSS method in terms of compatibility with existing DVD-Video players.

  Even in the presence of “DeCSS” software that breaks CSS encryption, the recorded content is scrambled with CSS approved by a legitimate licensing organization. It makes sense to specify that the content is protected.

Accordingly, an object of the present invention is to record content information by using an encryption recording method having compatibility that can be played back by an existing player, and to improve security through a revoke mechanism using a device key unique to a device. recording apparatus capable, signal processing systems, is to provide a recording medium which stores a program and a program of record method.

In order to solve the above-described problem, the present invention provides a recording apparatus that records encrypted content information in a data area of a data recording medium.
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
When a recording area is set near the first encryption key in the management area, no data is recorded in the recording area before the first recording, and content information is recorded by the CPRM method. , The first encryption key is copied to the recording area,
An authenticating means for authenticating the recording device or the disc in accordance with the CPRM method by using the reproduced first encryption key and the device-specific second encryption key;
Holding means for holding a third encryption key;
First encryption key generation means for generating a fourth encryption key;
In order to record content information by a method different from the CPRM method, the fourth encryption key encrypted with the third encryption key is stored in the recording area in the management area only when authenticated by the authentication means. First key encryption means for recording;
Second encryption key generation means for generating a fifth encryption key,
Content encryption means for encrypting content information recorded with the fifth encryption key according to a method different from the CPRM method;
Second key encryption means for encrypting the fifth encryption key with the fourth encryption key;
It is a recording device having an encrypted fifth encryption key and means for recording the encrypted content information in the data area.

The present invention comprises a recording / reproducing apparatus that reads information from a data recording medium and records information on the data recording medium, and an information processing apparatus to which the recording / reproducing apparatus is connected via a transmission means, and a data area of the data recording medium Is a signal processing system for recording encrypted content information.
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
When a recording area is set near the first encryption key in the management area, no data is recorded in the recording area before the first recording, and content information is recorded by the CPRM method. , The first encryption key is copied to the recording area,
Information processing device
An authenticating means for authenticating the recording device or the disc in accordance with the CPRM method by using the reproduced first encryption key and the device-specific second encryption key;
Holding means for holding a third encryption key;
First encryption key generation means for generating a fourth encryption key;
A first key encryption unit that encrypts the fourth encryption key with the third encryption key only when authenticated by the authentication unit in order to record the content information in a method different from the CPRM method;
Second encryption key generation means for generating a fifth encryption key;
Content encryption means for encrypting content information recorded with the fifth encryption key according to a method different from the CPRM method;
Second key encryption means for encrypting the fifth encryption key with the fourth encryption key;
An authentication means for performing authentication with the recording / reproducing apparatus and generating a session key when the authentication is established;
First bus encryption means for bus-encrypting the encrypted fourth encryption key with a session key and sending it to the recording / reproducing apparatus;
Second bus encryption means for encrypting the encrypted fifth encryption key with a session key and sending it to the recording / reproducing apparatus,
The recording / playback device
Authentication means for performing authentication with the information processing apparatus and generating a session key when authentication is established;
First bus decrypting means for performing bus decryption on the fourth encryption key and recording the fourth encryption key encrypted with the third encryption key in a recording area in the management area;
Second bus decryption means for performing bus decryption on the fifth encryption key encrypted with the fourth encryption key and recording the same in the data area;
And a means for recording encrypted content information in a data area.

This invention is a program which is adapted to record the encrypted content information to the data area of the data recording medium,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
When a recording area is set near the first encryption key in the management area, no data is recorded in the recording area before the first recording, and content information is recorded by the CPRM method. , The first encryption key is copied to the recording area,
An authentication step of authenticating the recording device or disc according to the CPRM method with the reproduced first encryption key and device-specific second encryption key;
A first encryption key generation step of generating a fourth encryption key;
In order to record the content information in a method different from the CPRM method, the fourth encryption key encrypted with the third encryption key that is held is stored in the management area only when authenticated by the authentication step. A first key encryption step for recording in the recording area of
A second encryption key generation step of generating a fifth encryption key;
A content encryption step of encrypting content information to be recorded with the fifth encryption key according to a method different from the CPRM method;
A second key encryption step of encrypting a fifth encryption key with a fourth encryption key;
A fifth encryption key that is encrypted, a Help program to execute the steps on a computer for recording the encrypted content information to the data area. The present invention also provides a recording medium storing a program.

The present invention comprises a recording / reproducing apparatus that reads information from a data recording medium and records information on the data recording medium, and an information processing apparatus to which the recording / reproducing apparatus is connected via a transmission means, and a data area of the data recording medium a program which is adapted to record the encrypted content information to the,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
When a recording area is set near the first encryption key in the management area, no data is recorded in the recording area before the first recording, and content information is recorded by the CPRM method. , The first encryption key is copied to the recording area,
In the information processing device,
An authentication step of authenticating the recording device or disc according to the CPRM method with the reproduced first encryption key and device-specific second encryption key;
A first encryption key generation step of generating a fourth encryption key;
In order to record content information by a method different from the CPRM method, the first key encryption that encrypts the fourth encryption key with the third encryption key only when authenticated by the authentication step Step,
A second encryption key generation step of generating a fifth encryption key;
A content encryption step of encrypting content information to be recorded with the fifth encryption key according to a method different from the CPRM method;
A second key encryption step of encrypting a fifth encryption key with a fourth encryption key;
An authentication step of performing authentication with the recording / reproducing device and generating a session key when authentication is established;
A first bus encryption step of bus-encrypting the encrypted fourth encryption key with a session key and sending it to the recording / reproducing apparatus;
And a second bus encryption step of performing a bus encryption of the encrypted fifth encryption key with the session key and sending it to the recording / reproducing apparatus,
In the recording and playback device,
An authentication step of performing authentication with the information processing device and generating a session key when authentication is established;
A first bus decryption step of performing bus decryption on the fourth encryption key and recording the fourth encryption key encrypted with the third encryption key in a recording area in the management area;
A second bus decryption step of performing bus decryption on the fifth encryption key encrypted with the fourth encryption key and recording it in the data area;
A Help program to execute the steps of recording the content information being encrypted in the data area. The present invention also provides a recording medium storing a program.

  In the present invention, the data recording medium can be used for two types of encryption recording methods. It becomes possible to record content by any one of the encryption recording methods by formatting.

  According to the present invention, content information can be encrypted and recorded while maintaining compatibility that can be reproduced by an existing player, and it is clear that the recorded content information is copyright-protected. That is, if the recorded content information is copied or reproduced in an illegal manner without receiving a legitimate license, it can be claimed that the copyright has been infringed.

  In the present invention, for example, a revocation mechanism using a device key, which is used in the CPRM system, is introduced, and content information can be encrypted and recorded only when revocation is not performed. You can reduce the risk of encrypted recording by devices or software that is not installed.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, recording on DVD media will be mainly described. The correspondence between terms used in the claims of the present specification and terms used in the embodiments will be described below.

  Recording medium: Media such as a DVD rewritable disc, recording device: recorder, recording / reproducing device: drive, information processing device: personal computer, transmission means: interface, signal processing system: drive for recording / reproducing media and personal computer interface It is a system connected through

  Content information: Information to be recorded on the medium, for example, audio / visual data is used as content information. First encryption key: MKB, second encryption key: device key, revocation means: process MKB, third encryption key: master key. Fourth encryption key: a disc key, which is generated by a random number generator 58 and recorded on the disc as a secured disc key encrypted with a master key. Fifth encryption key: a title key, which is generated by the random number generator 54, encrypted on the disc with the disc key, and recorded as an encrypted title key. Authentication means: authentication units 62 and 72.

  FIG. 13 shows a first embodiment of the present invention. In the first embodiment, the DVD recorder 51 writes content on a recordable DVD medium (hereinafter referred to as a writable disc or a recordable disc as appropriate) 13 by the CSS method. Here, the writable disc 13 is a CPRM compatible medium. That is, a media key block MKB 612 is recorded in the lead-in area of the writable disc 13 so that only reproduction is possible, and a media ID (not shown) is recorded in the BCA or NBCA. However, in the present invention, as will be described later, the configuration of the lead-in area is changed with respect to the existing CPRM-compatible medium.

  The DVD recorder 51 performs recording similar to the CSS system. Audio / visual data 60 is compressed and encoded by the MPEG encoder 52 of the DVD recorder 51, scrambled by the scrambler 53, and scrambled MPEG data 9 is recorded in the data area of the writable disc 13. The audio / visual data 60 is content information received by digital broadcasting, for example.

  Although omitted in FIG. 13, copyright management information (for example, CGMS) accompanying the content information to be recorded is also recorded on the writable disc 13. For example, CGMS data is 2-bit data based on copyright management information included in video data to be recorded, and is 2-bit information defined as follows.

(0, 0): Copy free (0, 1): EPN (Encryption Plus Non-assertion) (
Content management information in digital broadcasting) (1, 0): Allow only one copy (1, 1): Copy prohibited

  A title key is generated by a random number generator 54 inside the DVD recorder 51. The title key is generated each time recording is performed, and is also generated when the CGMS status changes. The scrambler 53 scrambles the MPEG data using the title key. The title key is encrypted with the disc key by the encryptor 55, and the encrypted title key 11 is recorded on the writable disc 13.

  The random number generator 58 generates a disc key. The disc key is encrypted by the encryptor 56 and recorded on the writable disc 13 as the secured disc key 10. Since the secured disc key 10 may be recorded once on the writable disc 13, it is recorded on the disc at the time of formatting or the first recording. The encryptor 55 for encrypting the title key is supplied with a disc key from the random number generation record 58 or a disc key obtained by decrypting the secured disc key read from the disc. When decrypting the secured disk key 10, it is a necessary condition that revocation processing is performed and revocation is not performed. In the encryptor 56, the disk key is encrypted by the master key 57, but can be encrypted and recorded only when the switch SW2 is on.

  The switch SW2 is turned on and off according to the result of the revoke process in the CPRM method. The switch SW2 is shown as turning on / off the supply path to the encryptor 56 of the master key 57. More practically, however, the encryptor 56 is the result of encryption processing and encryption when turned on. This indicates that the process for recording the secured disk key is performed, and the encryptor 56 does not perform the encryption and recording process when OFF.

  Whether or not revocation has been performed is determined by calculating in the process MKB 622 the MKB 612 read from the writable disc 13 and the device key 621 unique to the recorder 51. As described above, when the calculation result of the process MKB 622 matches a predetermined value, for example, zero, the recorder having the device key is revoked as not valid. In this case, the switch SW2 is turned off. If it is determined that the recorder is not revoked and is a valid recorder, SW2 is turned ON.

  As described above, the recorder according to the first embodiment uses the CPRM revoke mechanism, and can perform recording by the CSS method only when it is determined to be a valid recorder by the device key. Although not shown, the encrypted content information is reproduced at the time of reproduction in the same manner as the CSS method. However, the secured disk key is also used only when the revocation process using the MKB and the device key is performed and the revocation is not performed. Can be decrypted with the master key.

  FIG. 14 shows a second embodiment of the present invention in which the function of writing video content scrambled by the CSS method to a writable disc is realized by a combination of a PC and a drive. In FIG. 14, reference numeral 61 denotes a DVD drive as a recording / reproducing apparatus for recording and reproducing data on the writable disc 13. Reference numeral 71 indicates a PC as a data processing apparatus (host), application software is installed in the PC 71, and the PC 71 functions as a DVD video encoder. However, the present invention is not limited to software processing, and may be a hardware configuration (substrate configuration) as a DVD video encoder. For example, a hardware video encoder board may be incorporated in a television tuner board.

  The DVD drive 61 and the PC 71 are connected by an interface. The interfaces are ATAPI (AT Attachment with Packet Interface), SCSI (Small Computer System Interface), USB (Universal Serial Bus), IEEE (Institute of Electrical and Electronics Engineers) 1394, and the like.

  The DVD drive 61 includes an authentication unit 62 and bus decryptors 64, 65, and 66. The PC 71 includes an authentication unit 72 and bus encryptors 74, 75, and 76. The PC 71 includes an MPEG encoder 52, a scrambler 53, a random number generator 54, an encrypter 55, a random number generator 58, an encryptor 59, and a master key 57. Further, a process MKB 622 for calculating the MKB 612 read from the writable disc 13 and the device key 621 and a switch SW2 that is turned on / off according to the result of the revoke process are provided for the revoke process.

  The audio / visual data 60 is compression-encoded by the MPEG encoder 52 and converted into stream data in the DVD format. The scrambler 53 scrambles with the title key, the bus encryptor 76 encrypts the bus with the session key Ks, and supplies it to the DVD drive 61 via the interface. In the DVD drive 61, the bus decryptor 66 performs bus decoding with the session key Ks, and the scrambled MPEG data 9 is recorded on the writable disc 13. Since the content information between the DVD drive 61 and the PC 71 is also bus-encrypted, it is possible to reduce the risk of the content information being intercepted.

  A title key is generated by a random number generator 54 inside the PC 71. The scrambler 53 scrambles the MPEG data using the title key. The title key is reproduced by the encryptor 55 from the disc key from the random number generator 58 or the writable disc 13 and encrypted with the disc key decrypted with the master key. When decrypting the secured disk key 10, it is a necessary condition that revocation processing is performed and revocation is not performed. The encrypted title key is encrypted by the bus encrypter 74 with the session key generated when the authentication is established. The output data of the bus encrypter 74 is supplied to the bus decryptor 64 of the DVD drive 61, and the encrypted title key is decrypted with the session key by the bus decryptor 64. The encrypted title key 11 is recorded on the writable disc 13.

  A disc key is generated by a random number generator 58. The disk key is encrypted by the master key 57 in the encryptor 59, and the secured disk key is bus encrypted by the session key Ks in the bus encryptor 75. The output of the bus encryptor 75 is transmitted to the DVD drive 61 via the interface, and decrypted by the session key Ks in the bus decrypter 65. Then, the secured disc key 10 is recorded on the writable disc 13.

  Further, the disk key is encrypted by the master key 57 in the encryptor 59, but the encryption is possible only when the switch SW2 is on. As in the first embodiment, the switch SW2 is turned on and off according to the result of the revoke process in the CPRM method. Whether the PC 71 (which means application software or hardware such as a board) has been revoked is determined by calculating in the process MKB 622 the MKB 612 read from the writable disk 13 and the device key 621 unique to the application software. Is done. When the PC 71 is revoked, the switch SW2 is turned off. If it is determined that the PC 71 is valid without being revoked, the SW 2 is turned on, and the encryptor 59 encrypts the disc key with the master key.

  As described above, in the system under the PC environment according to the second embodiment, recording by the CSS method can be performed only when it is determined that the application software is valid by the device key by using the mechanism of the revocation of the CPRM method. Yes. Although not shown, the encrypted content information is reproduced at the time of reproduction in the same manner as the CSS method. However, the secured disk key is also used only when the revocation process using the MKB and the device key is performed and the revocation is not performed. Can be decrypted with the master key.

  FIG. 15 shows a procedure for exchanging signals between the DVD drive 61 and the PC 71 during CSS recording when the PC 71 is not revoked in the system shown in FIG. The PC 71 sends a command to the DVD drive 61, and the DVD drive 61 performs an operation in response to the command. The sequence is started by inserting a writable disc or the like, and an authentication sequence AKE (step S21) is first performed. When the authentication is established, the DVD drive 61 and the PC 71 share the session key Ks. If the authentication is not successful, the process is interrupted.

  Next, in response to a request from the PC 71, the DVD drive 61 seeks the control data area on the writable disc 13 and reads the control data (step S22). In the next step S <b> 23, the PC 71 sends the secured disk key bus-encrypted with the session key Ks to the DVD drive 61. The DVD drive 61 performs bus decryption and writes the secured disc key 10 onto the writable disc 13 (step S24).

  Next, in step S25, the PC 71 sends the encrypted title key and CGMS encrypted with the session key Ks to the DVD drive 61. In step S 26, the scrambled MPEG data encrypted with the session key Ks is sent to the DVD drive 61. The DVD drive 61 records the encrypted title key 11 and the scrambled MPEG data 9 decrypted by the bus decryptors 64 and 66 on the writable disc 13 (step S27).

  In the first and second embodiments of the present invention described above, the writable disk 13 is a CPRM compatible disk, and is a disk capable of recording a secured disk key. FIG. 16 schematically shows the disc format of the writable disc 13.

  If a PSN (Physical Sector Number), which is a physical address on the disk, is less than 030000h (h means a hexadecimal number), it is defined as a lead-in area. 02F200h to 02FDFFh in the lead-in area are defined as the control data area. As described with reference to FIG. 9, in the existing CPRM compatible disc, the MKB is repeatedly recorded 12 times in the entire control data area. In the writable disc 13 according to the embodiment of the present invention, the MKB data is repeatedly recorded six times in advance in the latter half of the control data area as embossed, that is, only for reproduction. The first half is a recording area where data can be recorded. However, in a blank disc, it is set as an unrecorded (blank) area. Note that the area where the MKB is recorded and the unrecorded area need not have the same length. Further, these two types of areas may be further subdivided and exist alternately.

  FIG. 17A shows a writable disc having a control data area similar to FIG. When recording on a writable disc by the CPRM method, formatting is performed on the disc, and as shown in FIG. 17B, the MKB recorded in the second half is copied to the blank area in the first half. On the other hand, when recording is performed by the CSS method as in the present invention described above, the secured disc key is written to the blank area in the first half, as shown in FIG. 17C. The pre-recorded MKB is used for revoke processing as described above.

  In the first and second embodiments described above, similarly to a CPRM compatible disc, recording is performed by the CSS method using a writable disc on which an MKB is recorded in advance and a secure disc key can be recorded. Is to do. Further, it may have a function of recording by the CPRM method. As a result, the content information can be recorded by either the CSS method or the CPRM method.

  As described above, when two encryption recording methods are possible, the content can be encrypted and recorded by one method selected by the user. For example, when importance is attached to compatibility that can be reproduced by an existing player, the CSS method is selected. On the other hand, when it is desired to increase security, the CPRM method is selected.

  Furthermore, it is possible to automatically select one of the two recording methods corresponding to the copyright related information accompanying the content. For example, when the copyright-related information indicates copy free, recording is performed by the CSS method, and when this indicates that copying is possible once, recording is performed by the CPRM method. The copyright-related information to be recorded is usually changed to copy prohibition. By providing such a mechanism, copyright protection can be further enhanced.

  In the above-described second embodiment of the present invention, the recording data transmitted from the PC to the DVD drive is encrypted by the bus encryptor, and the DVD drive is decrypted by the bus decryptor. In FIG. 18, reference numeral 501 indicates a bus encryptor, and reference numeral 511 indicates a bus encryptor.

  Data is transmitted from the PC to the DVD drive in a pack composed of 2 KB (kilobytes) of sector data. The type of pack is specified by the pack header. The AV pack detection unit 502 detects an audio pack, a bidet pack, and a sub-picture pack, and outputs a control signal according to the detection result.

  The selector 503 is controlled by a control signal from the AV pack detection unit 502. When the input data is an audio pack, a bidet pack, and a sub-picture pack, the input data is guided to the AV data encryptor 504 and encrypted by the session key. However, the pack header is not encrypted. In cases other than these packs, the input data is not encrypted and transmitted to the DVD drive via the interface.

  The AV pack detection unit 512 of the bus decrypter 511 detects the received pack type from the pack header. The selector 513 is controlled by a control signal from the AV pack detection unit 512. If the pack is an audio pack, a bidet pack or a sub-picture pack, the received data is guided to the AV data decryptor 514 and decoded by the session key.

  Since what is to be protected in the CSS system is audio / visual data, it is not necessary to encrypt other general data such as computer file data. Therefore, only the AV pack is encrypted.

  FIG. 19 shows a flow of bus encryption / decryption processing. In step ST31, it is determined whether or not it is a video pack from the detection result of the pack header detection unit. If it is a video pack, the data is encrypted / decrypted in step ST32. If it is not a video pack, the process moves to the step of determining whether or not it is an audio pack in step ST33.

  If it is determined in step ST33 that it is an audio pack, the data is encrypted / decrypted in step ST32. If not, the process moves to a step for determining whether or not it is a sub-picture pack in step ST34. If it is determined in step ST34 that it is a sub-picture pack, the data is encrypted / decrypted in step ST32. If not, the data is not encrypted / decrypted (step ST35). Then, the bus encryption / decryption process ends.

  FIG. 20 shows the configuration of an audio pack, video pack or sub-picture pack of DVD video data. A pack header in which pack control information is arranged is arranged at the head, followed by a packet header, and then audio data (AC3 data), video data (MPEG program stream) or sub-picture data (text data such as subtitles). ) Is arranged. Since the pack header and the packet header are variable-length data, for example, 128 bytes including the pack header and the packet header are excluded from bus encryption / decryption in consideration of the longest data length. Of 1920 bytes are subject to bus encryption / decryption. A total of 2K (2048) bytes is used as main data for one sector.

  The present invention is not limited to the above-described embodiment of the present invention, and various modifications and applications can be made without departing from the gist of the present invention. For example, the encryption method is not limited to the CSS method and the CPRM method. Any encryption method other than the CPRM method may be used as long as it is an encryption method that performs revocation using the encryption key on the recording medium and the device-specific key. The present invention can also be applied to a case where information is recorded on a medium such as an optical card or a memory card in addition to the disk.

It is a block diagram which shows the relationship of the key information at the time of recording on a ROM disk by a CSS system. It is a block diagram which shows the method of reproducing | regenerating the key information and scramble data in the DVD player which reproduces | regenerates the ROM disc recorded by the CSS system. It is a basic diagram which shows the data structure of the lead-in area of a ROM disc. It is a basic diagram which shows the structure of a sector. It is a basic diagram for demonstrating the copy protection function by a CSS system. It is a block diagram which shows the method of reproducing | regenerating the key information and scramble data by PC and a drive which reproduce | regenerate the ROM disc recorded by the CSS system. FIG. 7 is a schematic diagram illustrating a data flow between a drive and a disk in the system of FIG. 6. It is a block diagram which shows an example of the recording method at the time of writing data on a recordable DVD medium by the CPRM system. It is a basic diagram used for description of the disk format of a CPRM compatible disk. 1 is a block diagram for explaining a PC-based DVD media recording / reproducing system. FIG. FIG. 11 is a schematic diagram for explaining processing procedures of a DVD drive and a PC in the system of FIG. 10. It is a flowchart for demonstrating authentication operation | movement. 1 is a block diagram showing a first embodiment of the present invention. It is a block diagram which shows 2nd Embodiment of this invention. FIG. 15 is a schematic diagram illustrating a data flow between a drive and a disk in the configuration of FIG. 14. It is a basic diagram used for description of the disk format of the writable disk used for embodiment of this invention. It is a basic diagram used for description of the disk format of the writable disk used for embodiment of this invention. It is a block diagram which shows an example of a process of bus encryption / decryption. It is a flowchart which shows the flow of the process of FIG. It is a basic diagram for demonstrating the structure of AV pack, and the target range of bus encryption.

Explanation of symbols

9 Scrambled MPEG data 10 Secured disc key 11 Encrypted title key 13 Writable disc 52 MPEG encoder 53 Scrambler 54, 58 Random number generator 55, 59 Encryptor 57 Master key 60 Audio / visual data 61 Drive 62, 72 Authentication unit 64 , 65, 66 Bus decryptor 71 PC
74, 75, 76 Bus encryptor

Claims (17)

In a recording apparatus for recording encrypted content information in a data area of a data recording medium,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
In the management area, a recording area is set near the first encryption key, and before the first recording, no data is recorded in the recording area, and content information is recorded by the CPRM method. In this case, the first encryption key is copied to the recording area,
An authentication means for authenticating the recording device or the disc in accordance with the CPRM method by using the reproduced first encryption key and the device-specific second encryption key;
Holding means for holding a third encryption key;
First encryption key generation means for generating a fourth encryption key;
In order to record content information by a method different from the CPRM method, the fourth encryption key encrypted with the third encryption key is stored in the management area only when authenticated by the authentication means. First key encryption means for recording in the recording area of
Second encryption key generation means for generating a fifth encryption key,
Content encryption means for encrypting content information recorded by the fifth encryption key according to a scheme different from the CPRM scheme;
Second key encryption means for encrypting the fifth encryption key with the fourth encryption key;
A recording apparatus comprising: the encrypted fifth encryption key; and means for recording the encrypted content information in a data area. In claim 1,
The content encryption unit is a recording device that encrypts content information by a CSS method. In claim 1,
In the second key encryption unit, the fifth encryption key is encrypted by the fourth encryption key generated by the first encryption key generation unit. In claim 1,
In the second key encryption means, a recording device in which the fifth encryption key is encrypted with the fourth encryption key reproduced from the recording area and decrypted with the third encryption key . A recording / reproducing apparatus for reading information from a data recording medium and recording the information on the data recording medium, and an information processing apparatus to which the recording / reproducing apparatus is connected via a transmission means, to a data area of the data recording medium A signal processing system for recording encrypted content information,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
In the management area, a recording area is set near the first encryption key, and before the first recording, no data is recorded in the recording area, and content information is recorded by the CPRM method. In this case, the first encryption key is copied to the recording area,
The information processing apparatus
An authentication means for authenticating the recording device or the disc in accordance with the CPRM method by using the reproduced first encryption key and the device-specific second encryption key;
Holding means for holding a third encryption key;
First encryption key generation means for generating a fourth encryption key;
In order to record content information by a method different from the CPRM method, a first key encryption that encrypts the fourth encryption key with the third encryption key only when authenticated by the authentication means. And
Second encryption key generation means for generating a fifth encryption key;
Content encryption means for encrypting content information recorded by the fifth encryption key according to a scheme different from the CPRM scheme;
Second key encryption means for encrypting the fifth encryption key with the fourth encryption key;
Authentication means for performing authentication with the recording / reproducing apparatus and generating a session key when authentication is established;
First bus encryption means for bus-encrypting the encrypted fourth encryption key with the session key and sending it to the recording / reproducing apparatus;
Second bus encryption means for encrypting the encrypted fifth encryption key with the session key and sending it to the recording / reproducing apparatus,
The recording / reproducing apparatus comprises:
Authentication means for performing authentication with the information processing apparatus and generating a session key when authentication is established;
First bus decrypting means for performing bus decryption on the fourth encryption key and recording the fourth encryption key encrypted with the third encryption key in the recording area in the management area When,
Second bus decrypting means for bus-decrypting the fifth encryption key encrypted with the fourth encryption key and recording it in the data area;
Means for recording the encrypted content information in the data area. In claim 5,
The content encryption unit is a signal processing system that encrypts content information by a CSS method. In claim 5,
A signal processing system further comprising third bus encryption means for bus-encrypting encrypted content information sent from the information processing apparatus to the recording / reproduction. In claim 5,
In the second key encryption unit, the fifth encryption key is encrypted with the fourth encryption key generated by the first encryption key generation unit. In claim 5,
Signal processing in which the fifth encryption key is encrypted with the fourth encryption key reproduced from the recording area and decrypted with the third encryption key in the second key encryption means system. In program which is adapted to record the encrypted content information to the data area of the data recording medium,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
In the management area, a recording area is set near the first encryption key, and before the first recording, no data is recorded in the recording area, and content information is recorded by the CPRM method. In this case, the first encryption key is copied to the recording area,
An authentication step of authenticating the recording device or disc according to the CPRM method with the reproduced first encryption key and device-specific second encryption key;
A first encryption key generation step of generating a fourth encryption key;
In order to record the content information in a method different from the CPRM method, the fourth encryption key encrypted with the third encryption key held only when the authentication is performed in the authentication step. A first key encryption step for recording in the recording area in the management area;
A second encryption key generation step of generating a fifth encryption key;
A content encryption step for encrypting content information recorded by the fifth encryption key according to a scheme different from the CPRM scheme;
A second key encryption step of encrypting the fifth encryption key with the fourth encryption key;
Said encrypted said a fifth encryption key, Help program to execute a step of recording the encrypted content information to the data area to the computer. In claim 10,
The content encryption step is a program for encrypting content information by a CSS method. A recording / reproducing apparatus for reading information from a data recording medium and recording the information on the data recording medium, and an information processing apparatus to which the recording / reproducing apparatus is connected via a transmission means, to a data area of the data recording medium a program which is adapted to record the encrypted content information,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
In the management area, a recording area is set near the first encryption key, and before the first recording, no data is recorded in the recording area, and content information is recorded by the CPRM method. In this case, the first encryption key is copied to the recording area,
In the information processing apparatus,
An authentication step of authenticating the recording device or disc according to the CPRM method with the reproduced first encryption key and device-specific second encryption key;
A first encryption key generation step of generating a fourth encryption key;
In order to record content information by a method different from the CPRM method, the first encryption key is encrypted with the third encryption key held only when authenticated by the authentication step. The key encryption step of
A second encryption key generation step of generating a fifth encryption key;
A content encryption step for encrypting content information recorded by the fifth encryption key according to a scheme different from the CPRM scheme;
A second key encryption step of encrypting the fifth encryption key with the fourth encryption key;
An authentication step for performing authentication with the recording / reproducing device and generating a session key when authentication is established;
A first bus encryption step of bus-encrypting the encrypted fourth encryption key with the session key and sending it to the recording / reproducing apparatus;
Executing the second bus encryption step of performing the bus encryption of the encrypted fifth encryption key with the session key and sending it to the recording / reproducing apparatus,
In the recording / reproducing apparatus,
An authentication step of performing authentication with the information processing device and generating a session key when authentication is established;
A first bus decryption step of recording the fourth encryption key encrypted with the third encryption key in the recording area in the management area by decrypting the fourth encryption key with the bus When,
A second bus decryption step of bus decrypting the fifth encryption key encrypted with the fourth encryption key and recording it in the data area;
Help program to execute the steps of recording the content information being the encrypted in the data area. In claim 12,
The content encryption step is a program for encrypting content information by a CSS method. A recording medium which stores a program which is adapted to record the encrypted content information to the data area of the data recording medium,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
In the management area, a recording area is set near the first encryption key, and before the first recording, no data is recorded in the recording area, and content information is recorded by the CPRM method. In this case, the first encryption key is copied to the recording area,
An authentication step of authenticating the recording device or disc according to the CPRM method with the reproduced first encryption key and device-specific second encryption key;
A first encryption key generation step of generating a fourth encryption key;
In order to record the content information in a method different from the CPRM method, the fourth encryption key encrypted with the third encryption key held only when the authentication is performed in the authentication step. A first key encryption step for recording in the recording area in the management area;
A second encryption key generation step of generating a fifth encryption key;
A content encryption step for encrypting content information recorded by the fifth encryption key according to a scheme different from the CPRM scheme;
A second key encryption step of encrypting the fifth encryption key with the fourth encryption key;
Recording medium storing the encryption key of the encrypted the fifth, the Help program to execute the steps on a computer for recording the encrypted content information to the data area. In claim 14,
The content encryption step is a recording medium for encrypting content information by a CSS method. A recording / reproducing apparatus for reading information from a data recording medium and recording the information on the data recording medium, and an information processing apparatus to which the recording / reproducing apparatus is connected via a transmission means, to a data area of the data recording medium a recording medium storing a program which is adapted to record the encrypted content information,
The first encryption key according to the CPRM method is recorded in advance in the management area of the data recording medium so that only the reproduction is possible,
In the management area, a recording area is set near the first encryption key, and before the first recording, no data is recorded in the recording area, and content information is recorded by the CPRM method. In this case, the first encryption key is copied to the recording area,
In the information processing apparatus,
An authentication step of authenticating the recording device or disc according to the CPRM method with the reproduced first encryption key and device-specific second encryption key;
A first encryption key generation step of generating a fourth encryption key;
In order to record content information by a method different from the CPRM method, the first encryption key is encrypted with the third encryption key held only when authenticated by the authentication step. The key encryption step of
A second encryption key generation step of generating a fifth encryption key;
A content encryption step for encrypting content information recorded by the fifth encryption key according to a scheme different from the CPRM scheme;
A second key encryption step of encrypting the fifth encryption key with the fourth encryption key;
An authentication step for performing authentication with the recording / reproducing device and generating a session key when authentication is established;
A first bus encryption step of bus-encrypting the encrypted fourth encryption key with the session key and sending it to the recording / reproducing apparatus;
Executing the second bus encryption step of performing the bus encryption of the encrypted fifth encryption key with the session key and sending it to the recording / reproducing apparatus,
In the recording / reproducing apparatus,
An authentication step of performing authentication with the information processing device and generating a session key when authentication is established;
A first bus decryption step of recording the fourth encryption key encrypted with the third encryption key in the recording area in the management area by decrypting the fourth encryption key with the bus When,
A second bus decryption step of bus decrypting the fifth encryption key encrypted with the fourth encryption key and recording it in the data area;
Recording medium content information is the encrypted stores Help program to execute the steps of recording in the data area. In claim 16,
The content encryption step is a recording medium for encrypting content information by a CSS method.

Images