HK1069475B - Recording medium reproduction method and reproduction apparatus, and recording medium recording method and recording apparatus - Google Patents

Description

Recording medium reproducing method and apparatus and recording medium recording method and apparatus

Technical Field

The present invention relates to a reproducing method and a reproducing apparatus for a recording medium and a recording method and a recording apparatus for a recording medium that allow security to be maintained using encryption.

Background

The contents of digital data of music information recorded on a CD (compact disc) that have been compressed according to MP3(MPEG1 audio layer III) are distributed on the internet. Data read from a CD is copied onto a CD-R (recordable CD) disc. In addition, a peer-to-peer music file exchange service provided by Napster (a united states company) has been widely used. As a result, in recent years, a problem of copyright protection (hereinafter sometimes referred to as security) has attracted attention. Therefore, in a new type of media that has been proposed in recent years, such as optical disks, memory cards, and the like corresponding to SACD (super audio CD) and DVD (digital versatile disk or digital video disk) audio standards, content data is encrypted to maintain the security of the content. For example, memory cards use flash memory and are attachable to and removable from devices. The apparatus and the memory card authenticate each other when attempting to record the encrypted music data in the memory card. The encrypted data can be recorded into the memory card only when they successfully authenticate each other.

To prevent illegal acquisition or copying of data recorded on a CD, a new type of media, which has the same physical structure as a conventional CD and uses a copy protection device, has been designed. In this new type of media, hidden key data incorporated in the media is recorded therein in order to prevent the data from being bitwise copied.

Only those devices that are capable of handling the new type of media can read the key data. Therefore, although the security (copyright protection) of data is sufficiently maintained, many conventional CD players cannot reproduce content data from new media because they cannot read key data. Therefore, in order to use such new media, the user must purchase a recorder/player that handles the new media. Therefore, a new burden including an economic burden is added to the user. This burden has hindered the widespread use of new media.

It is, therefore, an object of the present invention to provide a reproducing method and reproducing apparatus for a recording medium and a recording method and recording apparatus for a recording medium, which allow easy introduction of a new type of medium, a drive, etc., having a comprehensive security function using a key incorporated in the medium.

Disclosure of Invention

To achieve the above object, a playback method for a recording medium according to claim 1 of the present invention includes the steps of:

judging whether or not the content data that has been read from the recording medium is encrypted content data;

generating third key data (key locker key data) for decrypting the encrypted content key data that has been read from the recording medium, with at least the first key data (medium binding key data) and the second key data (medium key data) that has been read from the recording medium, when the content data that has been read from the recording medium is encrypted content data; and

the encrypted content data that has been read from the recording medium is decrypted with the content key data that has been decrypted by the third key data.

Technical means 9 of the present invention is a reproducing apparatus of a recording medium, comprising:

a header portion for reading data from a recording medium on which at least data and identification data identifying the data as encrypted data have been recorded;

a reproduction signal processing section for performing reproduction signal processing on the output data of the header section;

a judging section for judging whether or not the data that has been read from the recording medium is encrypted data based on the identification data;

a decryption processing section for receiving the output data of the reproduction signal processing section; generating third key data (key locker key data) for decrypting the encrypted content key data that has been read from the recording medium, with at least the first key data (media key block) and the second key data (media combination key data) that has been read from the recording medium; and decrypting the encrypted content data that has been read from the recording medium with the content key data that has been decrypted by the third key data.

Technical means 17 of the present invention is a recording method for a recording medium, including the steps of:

judging whether the provided content data is the content data which needs to be encrypted or not, and encrypting the provided content data through content key data when the judgment result shows that the provided content data is the content data which needs to be encrypted;

encrypting the content Key data with third Key data (KL _ Key) generated with at least the first Key data (MB _ Key) and the second Key data (MKB) recorded in the recording medium; and

the encrypted content data, the encrypted content key data, and identification data for identifying the content data as the encrypted content data are recorded.

Technical means 23 of the present invention is a recording apparatus for a recording medium, comprising:

a judgment section for judging whether the supplied content data is content data that needs to be encrypted;

an encryption processing section for encrypting the supplied content data with the content Key data and encrypting the content Key data with third Key data (KL _ Key) generated with at least the first Key data (MB _ Key) and the second Key data (MKB) recorded in the recording medium, when the judging section has judged that the supplied content data is the content data that needs to be encrypted; and

a recording section for performing signal processing on the encrypted content data, the encrypted content key data, and identification data for identifying the content data as the encrypted content data, which have been output from the encryption processing section, and recording the resultant signal on a recording medium.

Technical means 29 of the present invention is a method for reproducing a recording medium, comprising the steps of:

generating third key data (key locker key data) for decrypting the encrypted content key data read from the recording medium with at least the first key data (media combination key data) and the second key data (media key block) read from the recording medium; and

the encrypted content data that has been read from the recording medium is decrypted by the content key data that has been decrypted with the third key data.

Drawings

FIG. 1 is a schematic diagram schematically illustrating an encryption system according to the present invention;

fig. 2 is a block diagram illustrating an example of the structure of a recording apparatus according to an embodiment of the present invention;

FIG. 3 is a flow chart illustrating a process of a recording operation according to an embodiment of the present invention;

fig. 4 is a block diagram illustrating an example of the structure of a reproducing apparatus according to an embodiment of the present invention; and

fig. 5 is a flowchart illustrating a procedure of a reproducing operation according to an embodiment of the present invention.

Detailed Description

Next, an embodiment of the present invention is described. This embodiment is an example of the present invention for a new optical disc. Next, referring to fig. 1, a security (copyright protection) system of the optical disc D is briefly described. The optical disc is almost the same as a commercially available CD in terms of physical standards including size. Accordingly, the data recorded on the optical disk D can be optically read by a conventional reproducing apparatus such as a CD player. However, unlike the CD, the encrypted content data has already been recorded on the optical disc D. The encrypted content data is, for example, audio data that has been encrypted corresponding to, for example, a CD-ROM format or a CD-DA (digital audio) format or graphics. As a method of encryption, DES (data encryption standard) or the like can be used. Audio data as content data has been compressed and encoded as necessary according to ATRAC (adaptive transform acoustic coding), MP3(MPEG1 audio layer III), TwinVQ (transform domain weighted interlaced vector quantization), and the like.

In addition to the encrypted content data, content Key data, DRM (digital rights management) -related data, media combination Key data MB _ Key, and media Key block data MKB, have been recorded on the optical disk D. The data on DRM is management data that specifies how to handle content data, how many times the content data has been copied, whether to reproduce or copy the content data, and generation of copied content data. The contents key data and the data on DRM have been encrypted and recorded on the optical disc D.

The encrypted content data read from the optical disc D by the optical pickup (not shown) is decrypted by the decryptor 51 with the content Key data CON _ Key. The decrypted content data is output from the decryptor 51. Upon decryption of the encrypted content data by the decryptor 51, data regarding DRM is extracted. The decrypted contents data outputted from the decryptor 51 is controlled corresponding to the DRM-related data. As a result, reproduction and copying of the decrypted content data are restricted. The contents key data and DRM-related data read from the optical disc D by an optical pickup (not shown) are supplied to the decryptor 52. The decryptor 52 decrypts the content data and the data about DRM using the Key locker Key data KL _ Key and obtains the content Key data CON _ Key as output data.

The hash (hash) calculation section 53 generates Key locker Key data KL _ Key using the media combination Key data MB _ Key, the media Key block data MKB, and the device Key data DEV _ Key. The device Key data DEV _ Key is Key data unique to a recording and/or reproducing apparatus that records or reproduces content data to or from the optical disc D or unique to application software installed to a personal computer that reproduces content data from the optical disc D. The recording and/or reproducing apparatus that handles the optical disc D has device Key data DEV _ Key. The device Key data DEV _ Key is Key data that is output outside the apparatus and transmitted to another apparatus.

The media combination Key data MB _ Key is Key data that cannot be reproduced by a conventional CD player, a conventional CD drive, or conventional application software. The media combination Key data MB _ Key has a predetermined bit length. The media combination Key data MB _ Key means Key data recorded on the optical disk D in a manner combined therein. The media bind Key data MB _ Key has been embedded on the optical disk D so that the CD drive or the like cannot read the media bind Key data MB _ Key from the optical disk D when the CD drive or the like reproduces content data from the optical disk D. In contrast, the aforementioned recording and/or reproducing device or the like capable of recording content data to or reproducing content data from the optical disk D can read the media join Key data MB _ Key from the optical disk D. In practice, the Key data expressed in the deformation of pits formed on the optical disk D, the Key data expressed in the wobble of pits, or the Key data expressed in the combined bits (three bits) of EFM modulation are the media binding Key data MB _ Key.

The media combination Key data MB _ Key that has been read from the optical disk D by an optical pickup (not shown) is supplied to the hash calculation section 53. Likewise, the media key block data MKB that has been read from the optical disk D is supplied to the calculating section 54. Unlike the media Key block data MB _ Key, the media Key block data MKB can be read from the optical disk D by a conventional CD drive or the like. The device Key data DEV _ Key stored in the controller or the like of the apparatus is supplied to the calculation section 54. The calculation section 54 calculates the media Key block data MKB and the device Key data DEV _ Key and generates the Key data MKB _ Key. The same Key data MKB _ Key is generated by a different recording and/or reproducing apparatus that records content data to the optical disk D and reproduces the content data from the optical disk D. The hash calculation section 53 obtains a hash value of the media combination Key data MB _ Key and the Key data MKB _ Key as the Key locker Key data KL _ Key. The hash calculation section 53 supplies the Key locker Key data KL _ Key to the decryptor 52. Using the Key locker Key data KL _ Key, the decryptor 52 decrypts the content Key data and the data artifact regarding DRM and obtains the content Key data CON _ Key.

Examples of the optical disk D are a read-only (ROM) type, a write-once type, and a rewritable type optical disk D. In fig. 1, the optical disk D is a multi-session (multi-session) type optical disk. The recording area of the optical disc D is divided into two parts in the radial direction of the optical disc D. The inner peripheral side of these two portions is the first session P1 in which one of unencrypted content data (i.e., plain content data) and encrypted data can be recorded. The outer periphery side of these two portions is a second session P2 in which unencrypted content data (clear content data) or encrypted data that is not recorded in the first session P2 can be recorded. Each session is composed of a lead-in area, a program area, and a lead-out area. In the lead-in area, management data of content data recorded in the program area, identifier data identifying the type of the optical disc D, and the like are recorded. Content data is recorded in the program area. The lead-out area is provided on the outer peripheral side of the program area.

Fig. 2 shows an example of a recording apparatus according to the invention. The recording apparatus shown in fig. 2 is not limited to dedicated hardware. Alternatively, the recording apparatus may be implemented by a personal computer that has been installed with dedicated software. In fig. 2, a block enclosed by a dotted line is constituted by hardware, which is an optical disc drive for a conventional CD-R optical disc recording and reproducing apparatus or a conventional CD-R/W optical disc recording and reproducing apparatus. The rest is implemented by software executed by a controller such as a CPU. The software may contain device Key data DEV _ Key and media Key block data MKB.

In fig. 2, reference numeral 1 denotes a recordable optical disc such as a CD-RW or CD-R optical disc. Content data that has been reproduced from a conventional recording medium such as a CD-DA or a CD-ROM or content data that has been reproduced from an optical disk D (which is the aforementioned new type of medium) is recorded into the optical disk 1. In other words, the recording device shown in fig. 2 may be used to form a copy of data that has been read from a conventional recording medium such as a CD or the aforementioned optical disc D.

The recording apparatus shown in fig. 2 can record data that has been read from the optical disc D into a recording and reproducing apparatus for a conventional optical disc, i.e., an optical disc drive. In other words, the recording device capable of handling the new optical disk D or the drive constituted by the application software and capable of handling the optical disk D records the media bind Key data MB _ Key on the optical disk D so that the media bind Key data MB _ Key is bound therein. In contrast, the conventional recording apparatus or the conventional drive cannot record the media bind Key data MB _ Key on the optical disk D so that the media bind Key data MB _ Key is bound therein. Therefore, as described later, a conventional recording apparatus or a conventional drive receives the media combination Key data MB _ Key through a network.

The spindle motor 2 rotates and drives the optical disc 1 at a constant linear velocity or a constant angular velocity. To record and read data to and from the optical disc 1, an optical pickup 3 is provided. The optical pickup 3 is advanced in the radial direction of the optical disc 1 by an advancing mechanism using a feed motor (not shown).

According to the present embodiment, the optical disc 1 is a phase-change type optical disc, data is recorded by irradiating laser light having a recordable output level to the optical disc 1 and data is reproduced by detecting a change in the amount of light of the laser light reflected from the optical disc 1. A recording film made of a phase-change type recording material is coated on a substrate made of polycarbonate. The track guide grooves have been formed on the substrate by injection molded polycarbonate. The track guiding grooves are also called pregrooves because they have been formed in advance. The portion formed between the grooves is called a land. Typically, the nearby side is a land and the distant side is a groove, as viewed from the incident side of the read laser on the substrate. The grooves are formed continuously and spirally from the inner periphery to the outer periphery. As long as the optical disc 1 is a recordable optical disc, the present invention can be applied to a magneto-optical disc or a write-once optical disc using such coloring material as a recording material, in addition to the phase-change type optical disc.

The groove wobbles in the radial direction of the optical disc to control the rotation of the optical disc 1 and obtain a reference signal for recording data. Data is recorded in the grooves and lands. Further, the groove is wobbled in accordance with wobble information in a radial direction of the optical disc corresponding to absolute time information as address information to continuously record data. In the CD-R disc and the CD-RW disc, a desired writing position is found on the optical disc 1 with reference to absolute time information as address information obtained from the wobble information of the groove. The optical pickup 3 travels to a desired writing position and radiates laser light from the optical pickup 3 to the optical disc 1. As a result, data is written to the optical disc.

An optical disc having a wobbling groove is produced in the following manner. In the mastering apparatus, laser light is irradiated onto a photoresist film coated on a disk-shaped glass substrate. Furthermore, the laser is deflected or wobbled in the radial direction. In other words, laser light is displayed. As a result, a groove (i.e., a wobbling groove) wobbling in the radial direction of the optical disc is formed. The photoresist film that has been irradiated with the laser light is developed. As a result, a master is formed. Electroforming the developed master disc. Thereby, a template is formed. Using the template, an injection molding process is performed. Thereby forming a disk substrate having a wobbling groove. The phase-change recording material is coated on the disk substrate by a sputtering method or the like. Thereby forming an optical disc.

Referring to fig. 2, content data Din such as audio and/or video data to be recorded is supplied from an input terminal 4 to a content judgment section 5. The content data Din is content data that requires encryption or content data that does not require encryption. The content data that needs to be encrypted is, for example, content data that has been reproduced from the aforementioned optical disc D. The content data that does not need to be encrypted is, for example, content data that has been reproduced from a conventional CD. The content judgment section 5 judges whether the content data Din is content data that does not require encryption or content data that requires encryption to format, for example, information contained in the input content data. The content judging section 5 outputs an identifier signal Sid representing the result of the identification, the content data SCD1 which does not need to be encrypted, and the content data SCD2 which needs to be encrypted.

The content data SCD1 that does not require encryption is output from the content judgment section 5 and supplied to the error correction code encoder 6. The error correction code encoder 6 performs error correction code encoding on the content data SCD 1. The output data of the error correction code encoder 6 is supplied to a modulation section 7. The modulation section 7 performs a modulation process such as an EFM modulation process. The output data of the modulation section 7 is supplied to a recording circuit 8. Furthermore, the identifier signal Sid is supplied to the recording circuit 8. The recording circuit 8 performs a process of adding a frame synchronization signal, address data, and the like to output data from the modulation section 7. The laser drive circuit portion of the recording circuit 8 generates a drive signal for causing the semiconductor laser device to output laser light having a predetermined level to cause recording data to be recorded in the optical disc 1. A drive signal of the laser drive circuit section is supplied to a semiconductor laser device as a light source of the optical pickup 3. Laser light modulated corresponding to a drive signal supplied from the semiconductor laser device is radiated to the optical disc 1. As a result, data is recorded in the optical disc 1.

The identifier signal Sid identifying the content recorded on the optical disc 1 is supplied to the recording circuit 8 as plain content/content data that does not need to be encrypted or content/content data that needs to be encrypted and has been encrypted. The recording circuit 8 outputs the identifier signal Sid to the optical pickup 3 to record the identifier signal Sid as TOC data in a predetermined position such as a lead-in area of the optical disc 1.

When the content data Din is content data that needs to be encrypted, the content data SCD2 is output from the content judgment section 5. The encryptor 11 encrypts the content data SCD2 with the content Key data CON _ Key. The encrypted data is supplied to the selector 12. The output data of the encryptor 13, the media Key block data MKB and the media Key combination Key data MB _ Key are supplied to the selector 12 in addition to the output data of the encryptor 11. The encryptor 13 encrypts the content Key data CON _ Key with the Key locker Key data KL _ Key. The encrypted content key data is supplied to the selector 12. Data regarding DRM is added to the content Key data CON _ Key.

The Key locker Key data KL _ Key is data calculated by the hash calculation section 14. Both the media Key block data MKB and the device Key data DEV _ Key are calculated by the calculating section 15. The output of the calculation section 15 is supplied to the hash calculation section 14. The media combination Key data MB _ Key in the storage section 16 is supplied to the hash calculation section 14. The hash calculation section 14 generates a hash value of the media combination Key data MB _ Key and the Key data MKB _ Key (i.e., the Key locker Key data KL _ Key). The aforementioned Key data required for encryption except for the media combination Key data MB _ Key is contained in the reproduction data of the optical disk D and extracted from the reproduction data by the application software. The media combination Key data MB _ Key is hidden but not contained in the reproduction output data of the optical disk D.

Key data equivalent to the media combination Key data MB _ Key is downloaded from a WEB (WEB site) 19 to the storage section 16 through the switch 17 and the network 18. Since the downloaded Key data has not been incorporated into the recording medium, the Key data is strictly different from the media-incorporated Key data MB _ Key of the optical disk D. However, since they are identical in their functions, the downloaded Key data is also referred to as media combination Key data MB _ Key. When the structures other than the optical disk drive are implemented by application software of a personal computer, the media combination Key data MB _ Key is implemented through the network 18 using the communication function of the personal computer. The switch 17 operates between an on state and an off state corresponding to the identifier signal Sid. The switch 17 operates in the on state only when content data that needs to be encrypted is recorded on the optical disc 1.

To obtain the media combination Key data MB _ Key through the network 18, both the server 19 and the recording device as shown in fig. 2 should successfully authenticate each other. When the recording apparatus shown in fig. 2 is constituted by, for example, application software, a personal computer, and a drive, the personal computer inputs user ID data, a software unique number, a password, and the like to the server 19. The media combination Key data MB _ Key can be obtained from the server 19 only if these input contents are correct. The network 18 is, for example, the internet. For security reasons, after one recording operation has been performed on the optical disc 1, the media Key data MB _ Key that has been downloaded to the storage section 16 is erased. Alternatively, the media combination Key data MB _ Key may be erased within a predetermined time after it has been downloaded.

The selector 12 outputs the content data encrypted with the content Key data CON _ Key, the content Key data CON _ Key encrypted with the Key locker Key data KL _ Key, the media Key block data MKB, and the media combination Key data MB _ Key to the error correction code encoder 6 enclosed by a dotted line in the optical disc drive at a predetermined timing. The encrypted content data is processed as main data by the optical disc drive. The optical disc drive processes the content Key data CON _ Key, the media Key block data MKB, and the media join Key data MB _ Key so that they coexist in the master data. These data are recorded as files different from the files of the main data, for example. Alternatively, the content Key data CON _ Key, the media Key block data MKB, and the media Key combination Key data MB _ Key may be all processed or recorded as sub-code data in the lead-in area. The output data of the error correction code encoder 6 is modulated by a modulation section 7. The modulated data is supplied to the optical pickup 3 through the recording circuit 8. The optical pickup 3 records the modulated data on the optical disc 1. The identifier signal Sid is recorded in a predetermined position, for example, in the lead-in area of the optical disc 1.

In this way, the media is downloaded from the server 19 over the network 18 in combination with the Key data MB _ Key. Therefore, the same environment as a recording and/or reproducing apparatus that records and reproduces content data onto and from the optical disc D can be realized by a conventional optical disc or the like. As a result, a conventional optical disc or the like can record the encrypted content data into the optical disc 1 similar to the optical disc D.

Fig. 3 shows a process of application software to record content data. In step S1, content data that needs to be encrypted is input. In step S2, the optical disc drive determines whether the media bind Key data MB _ Key has been written to the media so that the media bind Key data MB _ Key is bound thereto. The optical disc D recording and reproducing device can write the media bind Key data MB _ Key to the media to bind the media bind Key data MB _ Key therein, and the flow proceeds to step S3. In step S3, the media joining Key data MB _ Key is recorded to the optical disc 1 so that only the recording and/or reproducing device of the optical disc D can read the media joining Key data MB _ Key (i.e., the media joining Key data MB _ Key is joined to the media).

Since the conventional optical disc drive or the like according to the present embodiment cannot write the media bind Key data MB _ Key into the media to bind the media bind Key data MB _ Key thereto, the result of the determination in step S2 is no. In step S4, it is determined whether or not the optical disk drive is connected to the server 19. When the server 19 and the optical disc drive as a recording device have successfully authenticated each other, the optical disc drive connects to the server 19. When the judged result at step S4 indicates that the optical disk drive and the server 19 have not been connected, the flow advances to step S5. In step S5, a prompt message such as "connect optical disk drive to Web Server! "is displayed on the display portion of the optical disc drive. A time-out error is generated and error processing (not shown) is performed when the optical disc drive has not been connected to the server 19 for a predetermined period of time.

When the judged result in step S4 denotes that the optical disc drive has been connected to the server 19 (i.e., the optical disc drive and the server 19 have successfully authenticated each other and the media combination Key data MB _ Key has been downloaded from the server 19), the flow proceeds to step S6. In step S6, the optical disc drive records the media joining Key data MB _ Key to the optical disc 1 so that a conventional optical disc drive can read the media joining Key data MB _ Key. To improve the security of the media in conjunction with the Key data MB _ Key, it may not be recorded on the optical disc 1. In this case, the media combination Key data MB _ Key can be obtained through the network as with the reproducing apparatus described below. The encrypted content data can be reproduced by the media in conjunction with the Key data MB _ Key.

Fig. 4 shows an example of a reproduction apparatus which is a conventional optical disc drive or the like and which is capable of reproducing content data that needs to be encrypted and has been encrypted. The reproduction apparatus is constituted by a drive of hardware, a CD-ROM optical disk reproduction apparatus, a CD-R optical disk recording and reproduction apparatus, a CD-RW optical disk recording and reproduction apparatus, and the like, as enclosed by a dotted line shown in fig. 4, and application software. Of course the reproduction device may be constituted by hardware only. The optical disc 1 shown in fig. 4 is an optical disc on which plain or encrypted content data has been recorded by the aforementioned apparatus. The plain or encrypted content data is a copy of the data that has been read from the CD or the aforementioned optical disc D. However, the optical disc 1 is not limited to these. Alternatively, the optical disc 1 may be a disc on which content data that has been distributed by, for example, an EMD (electronic music distribution device) has been recorded. Alternatively, the optical disc 1 may be a read-only optical disc on which encrypted content data has been recorded.

The optical pickup 3 irradiates laser light required for reproducing content data onto the optical disc 1. The four-division photodetector provided on the optical pickup 3 detects the laser light reflected by the optical disc 1. The signal detected by the photodetector is supplied to the RF processing block 21. In the RF processing block 21, a matrix amplifier calculates a detection signal of the photodetector and generates a Reproduction (RF) signal, a tracking error signal, and a focus error signal. When the clock signal and the address data have been recorded as information of the wobble groove on the optical disc 1, a wobble detection signal is output from the RF processing block 21. The RF signal is supplied to the demodulation section 22. The demodulation section 22 performs, for example, EFM demodulation. The output data of the demodulation section 22 is supplied to an error correction circuit 23. The error correction circuit 23 performs error correction processing. The output data of the error correction circuit 23 is supplied to a switch 24.

The tracking error signal and the focus error signal are supplied from the RF processing block 21 to a servo circuit (not shown) to control the rotation of the spindle motor 2 and the tracking and focusing of the laser light radiated from the optical pickup 3. The servo circuit performs tracking servo and focus servo for the optical pickup 3 and spindle servo and screw servo for the spindle motor 2.

The demodulation section 22 outputs the reproduced sub code data. The sub-code data is supplied to the sub-code demodulation section 25. The sub-code demodulation section 25 demodulates time data (the time data is address data corresponding to a position on the disc) contained in the sub-code data. Using this time data, the servo circuit operates. The time data is fed to a system controller (not shown). Using this time data, the position of the optical pickup 3 is controlled to read desired data from the optical disc 1. In an initial state when the optical disc 1 is loaded in the optical disc drive shown in fig. 4, the optical pickup 3 reads a lead-in area in the optical disc 1. The optical pickup 3 reads TOC data recorded in the lead-in area of the optical disc 1. The TOC data is supplied to the TOC reading section 26.

The data output from the TOC reading section 26 contains an identifier signal Sid. The judgment section 27 performs a judgment operation based on the identifier signal Sid extracted from the output data of the TOC reading section 26. The switch 24 is controlled according to the recognition result of the judgment section 27. In other words, when the data that has been read from the optical disc 1 is clear content data that has not been encrypted, the switch 24 operates to cause the output data of the error correction circuit 23 to be supplied to the output terminal 28. In contrast, when the data that has been read from the optical disc 1 is content data that has been encrypted, the switch 24 operates to cause the output data of the error correction circuit 23 to be supplied to the branching means 29.

The demultiplexing device 29 separates the content Key data encrypted with the content Key data CON _ Key, the content Key data CON _ Key encrypted with the Key locker Key data KL _ Key, and the media Key block data MKB. The encrypted content data is supplied to the decryptor 30. The decryptor 30 decrypts the content data encrypted with the content Key data CON _ Key and outputs the decrypted data to the output terminal 31. The decryptor 32 outputs the content Key data CON _ Key.

The media key block data MKB output from the demultiplexing means 29 is supplied to the calculating section 33. The device Key data DEV _ Key unique to the reproducing apparatus or the application software is supplied to the calculation section 33. The calculation section 33 generates Key data MKB _ Key. The Key data MKB _ Key and the media combination Key data MB _ Key delivered from the storage section 35 are delivered to the hash calculation section 34. The hash calculation section 34 calculates a hash value of the media combination Key data MB _ Key and the Key data MKB _ Key and obtains the Key locker Key data KL _ Key and transfers the obtained data to the decryptor 32. The decryptor 32 decrypts the content Key data and the data about DRM that have been encrypted and obtains content Key data CON _ Key.

Media which cannot be read by a conventional optical disk drive or the like is downloaded from a WEB (WEB site) 38 to the storage section 35 via the switch 36 and the network 37 in conjunction with the Key data MB _ Key. When the structures other than the drive enclosed by the dotted line shown in fig. 4 are implemented by application software of the personal computer, the media join Key data MB _ Key is implemented using the communication function of the personal computer. The switch 36 is controlled according to the result of the recognition. The switch 36 is turned on only when the encrypted content data is reproduced.

To obtain the media combination Key data MB _ Key through the network 37, the reproduction apparatus and the WEB server 38 as shown in fig. 4 should successfully authenticate each other. When the reproduction apparatus is constituted by application software, a personal computer, and a drive, the personal computer inputs ID data about a user, a software unique number, a password, and the like. Only when both the input content and the input data are correct, the reproducing apparatus (i.e., the optical disk drive) can obtain the media binding Key data MB _ Key from the WEB server 38. The network 37 is, for example, the internet. For security reasons, after the data or content data of the optical disc has been reproduced once, the media combination Key data MB _ Key that has been downloaded to the storage section 35 is erased. Alternatively, the media combination Key data MB _ Key may be erased within a predetermined time after it has been downloaded. The method of obtaining the media combination Key data MB _ Key from the WEB server 38 is the same as that used for the aforementioned recording apparatus.

Since the media combination Key data MB _ Key is downloaded from the WEB server 38 via the network 37, the same environment as that of the recording and/or reproducing apparatus for the optical disk D can be realized by a conventional optical disk drive or the like. As a result, a conventional optical disc drive or the like can read and reproduce the encrypted content data from the optical disc D.

When the media combination Key data MB _ Key is transmitted to the optical disk drive or the like through the network, the reproduction apparatus (reproduction application software) side or the server side can manage the data on DRM (digital rights management) such as the limit on the number of copies of the content data. When the server side manages the number of copies of the content data, the reproduction device, the drive, and the application software each manage the download history of the media Key data MB _ Key. In this case, when downloading of key data is requested, the identifier information of the optical disc or the content data is also transmitted to the WEB server 38. The WEB server 38 monitors the number of times key data for each disc or each content data has been downloaded. As a result, the WEB server 38 can hold the number of copies or reproductions of the disc or the content data. As a result, the WEB server 38 can restrict copying or reproduction of the disc or content data.

Fig. 5 shows a process of application software for reproducing content data from the optical disc D. In step S11, encrypted content data that has been read and reproduced by a drive of the reproduction apparatus is input. In step S12, it is determined whether the drive has read the media combination Key data MB _ Key. When the drive is the aforementioned reproduction device or the like capable of reproducing the content data from the optical disk D, since the drive can read the media join Key data MB _ Key, the flow proceeds to step S13. In step S13, a decryption process of decrypting the encrypted content data that has been read from the optical disc 1 is performed.

Since the conventional optical disc drive or the like cannot read the media bind Key data MB _ Key, the result of the judgment in step S12 is no. Thereafter, the flow advances to step S14. In step S14, it is determined whether or not the drive has been connected to the WEB server 38. When the WEB server 38 and the reproduction apparatus have successfully authenticated each other, the apparatus connects to the WEB server 38. When the judgment result at step S14 shows that the apparatus has not been connected to the WEB server 38, the flow advances to step S15. In step S15, a prompt message such as "connect device to Web Server! | A "is displayed on a display section (not shown) of the reproduction apparatus. When the device has not been connected to the WEB server 38 for a predetermined period of time, a timeout error is generated and the process shown in fig. 5 is terminated.

When the judgment result in step S14 indicates that the apparatus has been connected to the WEB server 38, the WEB server 38 and the recording apparatus have successfully authenticated each other. Therefore, to download the media in combination with the Key data MB _ Key, the flow proceeds to step S16. In step S16, the media combination Key data MB _ Key is downloaded from the WEB server 38 and stored in the storage section 35. The encrypted content data is decrypted by applying the obtained media combination Key data MB _ Key (in step S13).

While the invention has been shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes, omissions and additions to the detail of the foregoing embodiment may be made therein without departing from the spirit and scope of the invention. For example, the aforementioned application software may be installed to a network home electronic device such as a set-top box in addition to a personal computer. The recording apparatus in fig. 2 may be applied to a mastering apparatus when the recording method according to the present invention is applied to a read-only optical disc. Furthermore, the present invention can also be applied to other data recording media such as memory cards other than optical disks.

The present invention provides compatibility with a comprehensive security function in a stage where a new type of drive or the like, which implements the comprehensive security function using a media combination key combined with media, has not been popularized yet. When the safety function is realized, a new type of driver or the like can be smoothly introduced. Illegal copying can be prevented when a key combined with media is introduced. To obtain a key equivalent to the key associated with the media, the drive and WEB server should successfully authenticate each other using a conventional drive that cannot handle the key associated with the media. Therefore, safety can be ensured.

Claims (32)

1. A reproducing method of a recording medium, comprising the steps of:

judging whether or not the content data that has been read from the recording medium is encrypted content data;

generating third key data, i.e., key locker key data, for decrypting the encrypted content key data read from the recording medium, with at least first key data, i.e., media combination key data, and second key data, i.e., media key data, read from the recording medium, when the content data read from the recording medium is encrypted content data; and

the encrypted content data that has been read from the recording medium is decrypted with the content key data that has been decrypted by the third key data.

2. A reproduction method of the recording medium according to claim 1,

wherein the third key generating step is performed by the steps of:

generating further Key data (MKB _ Key) with the second Key data and the device-unique Key data, i.e., the device Key data, of the reproduction device; and

a calculation process is performed on the generated further key data and the first key data.

3. A reproduction method of the recording medium according to claim 2,

wherein the first key data is key data that can be read from the recording medium by a conventional reproducing apparatus.

4. A reproduction method of the recording medium according to claim 2,

wherein the first key data is key data that cannot be read by a conventional reproducing apparatus.

5. A reproduction method of the recording medium according to claim 1, further comprising the steps of:

the first key data is obtained from the outside through the network when the first key data has not been read from the recording medium by the reproducing apparatus.

6. A reproduction method of the recording medium according to claim 1,

wherein identification data identifying the content data as encrypted content data has been recorded on the recording medium, and

wherein the method further comprises the steps of;

it is determined whether or not the content data that has been read from the recording medium is encrypted data, based on the identification data that has been read from the recording medium.

7. A reproduction method of the recording medium according to claim 1, further comprising the steps of:

the output of the decrypted content data is controlled based on the copyright management data.

8. A reproduction method of the recording medium according to claim 1, further comprising the steps of:

reproduction signal processing is performed on the data that has been read from the recording medium and a resultant signal is output when the content data that has been read from the recording medium is unencrypted content data.

9. A reproducing apparatus of a recording medium, comprising:

a header portion for reading data from a recording medium on which at least data and identification data identifying the data as encrypted data have been recorded;

a reproduction signal processing section for performing reproduction signal processing on the output data of the header section;

a judging section for judging whether or not the data that has been read from the recording medium is encrypted data based on the identification data;

a decryption processing section for receiving the output data of the reproduction signal processing section; generating third key data, i.e., key locker key data, for decrypting the encrypted content key data, which has been read from the recording medium, with at least the first key data, i.e., the media key block, and the second key data, i.e., the media combination key data, which has been read from the recording medium; and decrypting the encrypted content data that has been read from the recording medium with the content key data that has been decrypted by the third key data.

10. The reproduction apparatus of the recording medium according to claim 9,

wherein the decryption processing section is configured to generate further Key data (MKB _ Key) with the second Key data and the Key data unique to the reproduction device, i.e., the device Key data, and perform calculation processing on the generated further Key data and the first Key data to generate third Key data.

11. The reproduction apparatus of the recording medium according to claim 9,

wherein the first key data is key data that can be read from the recording medium by a conventional reproducing apparatus.

12. The reproduction apparatus of the recording medium according to claim 9,

wherein the first key data is key data that cannot be read by a conventional reproducing apparatus.

13. The reproduction apparatus of the recording medium according to claim 9,

wherein the first key data is obtained from the outside through the network when the first key data has not been read from the recording medium by the reproducing apparatus.

14. The reproduction apparatus of the recording medium according to claim 9,

wherein the decryption processing section is configured to control output of the decrypted content data based on the copyright management data.

15. The recording medium reproducing apparatus of claim 9, further comprising:

at the output end of the optical fiber,

wherein when the judging section has judged that the content data that has been read from the recording medium is the unencrypted content data, the output data of the reproduction signal processing section is supplied to the output terminal.

16. The recording medium reproducing apparatus of claim 9, further comprising:

an output terminal, and

a switching circuit controlled according to a judgment result of the judging section,

wherein when the judging section has judged that the content data which has been read from the recording medium is the encrypted content data, the switching circuit is operated so that the output data of the reproduction signal processing section is supplied to the decryption processing section, and

wherein the switching circuit is operated to cause the output data of the reproduction signal processing section to be supplied to the output terminal when the judging section has judged that the content data which has been read from the recording medium is the unencrypted content data.

17. A recording method of a recording medium, comprising the steps of:

judging whether the provided content data is content data which needs to be encrypted, and encrypting the provided content data through content key data when the judgment result shows that the provided content data is the content data which needs to be encrypted;

encrypting the content Key data with third Key data (KL _ Key) generated with at least the first Key data (MB _ Key) and the second Key data (MKB) recorded in the recording medium; and

the encrypted content data, the encrypted content key data, and identification data for identifying the content data as the encrypted content data are recorded.

18. The recording method of a recording medium according to claim 17, further comprising the steps of:

further Key data (MKB _ Key) is generated with the second Key data and device Key data that is unique to the reproducing device of the recording medium, and calculation processing is performed on the further Key data and the first Key data to generate third Key data.

19. The recording medium recording method as claimed in claim 17,

wherein the first key data is key data that can be read from the recording medium by a conventional recording medium reproducing apparatus.

20. The recording medium recording method as claimed in claim 17,

wherein the first key data is key data that cannot be read from the recording medium by a conventional recording medium reproducing apparatus.

21. The recording method of a recording medium according to claim 17, further comprising the steps of:

the first key data is obtained from the outside through a network.

22. The recording method of a recording medium according to claim 17, further comprising the steps of:

signal processing is performed on identification data for identifying the content data recorded on the recording medium as non-encrypted data and the supplied content data, and a resultant signal is recorded on the recording medium when the determination result indicates that the supplied content data is content data that does not require encryption.

23. A recording apparatus of a recording medium, comprising:

a judgment section for judging whether the supplied content data is content data that needs to be encrypted;

an encryption processing section for encrypting the supplied content data with the content Key data and encrypting the content Key data with third Key data (KL _ Key) generated with at least the first Key data (MB _ Key) and the second Key data (MKB) recorded in the recording medium, when the judging section has judged that the supplied content data is the content data that needs to be encrypted; and

a recording section for performing signal processing on the encrypted content data, the encrypted content key data, and identification data for identifying the content data as the encrypted content data, which have been output from the encryption processing section, and recording the resultant signal on a recording medium.

24. The recording apparatus of the recording medium according to claim 23,

wherein the encryption processing section is configured to generate further Key data (MKB _ Key) with the second Key data and Key data unique to the reproducing apparatus of the recording medium, that is, apparatus Key data, and perform calculation processing on the generated further Key data and the first Key data to generate third Key data.

25. The recording apparatus of the recording medium according to claim 23,

wherein the first key data is key data that can be read from the recording medium by a conventional reproducing apparatus.

26. The recording apparatus of the recording medium according to claim 23,

wherein the first key data is key data that cannot be read by a conventional reproducing apparatus.

27. The recording apparatus of the recording medium according to claim 23,

wherein the encryption processing section is configured to obtain the first key data from outside through the network.

28. The recording apparatus of the recording medium according to claim 23,

wherein the recording section is configured to perform signal processing on the identification data for identifying the content data recorded on the recording medium as the non-encrypted content data and the supplied content data and record the resultant signal on the recording medium, when the judging section has judged that the supplied content data is the content data that does not require encryption.

29. A reproducing method of a recording medium, comprising the steps of:

generating third key data, i.e., key locker key data, for decrypting the encrypted content key data, which has been read from the recording medium, with at least the first key data, i.e., the medium binding key data, and the second key data, i.e., the medium key block, which has been read from the recording medium; and

the encrypted content data that has been read from the recording medium is decrypted by the content key data that has been decrypted with the third key data.

30. A reproduction method of the recording medium according to claim 29,

wherein further Key data (MKB _ Key) is generated with the second Key data and the Key data unique to the reproduction device, i.e., the device Key data, and calculation processing is performed on the generated further Key data and the first Key data to generate third Key data.

31. A reproduction method of the recording medium according to claim 30,

wherein the first key data is key data that can be read from the recording medium by a conventional reproducing apparatus.

32. A reproduction method of the recording medium according to claim 30,

wherein the first key data is key data that cannot be read by a conventional reproducing apparatus.