JP2004088540A - Method and system for recording and reproducing digital information signal, media drive, method for recording and reproducing the same, recording medium, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording and reproducing drive device used in computer environment and to provide system constitution optimal to preventing copying, etc. of a recording medium having information which needs protection of copyright recorded thereon even in a PC system which easily edits information. <P>SOLUTION: By using specific information EK used only in an ODD drive A20 as a key for double encryption of a contents encryption key Enc-TK, a double encrypted encryption key Enc2-TK encrypted by this is recorded in the ECC block of the recording medium. By embedding an encryption key Enc-EK obtained by encrypting the specific information EK into the double encrypted encryption key Enc2-TK by recording by digital watermark. Thus, decryption except by the CDD drive A20 is impossible. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording / reproducing method, a recording / reproducing system, a media drive, a recording / reproducing method of a media drive, a recording medium and a program of a digital information signal subjected to a content encryption process for copyright protection.
[0002]
[Prior art]
In recent years, as referred to as the digital revolution, a technology has been developed in which all information is digitized and can be distributed through a medium such as a transmission medium or a recording medium. As a result, many people can freely obtain digital information. In such an environment, digital signals such as digital audio signals, digital video signals, and other related data handled by a computer are recorded on a recording medium. In addition, information such as reproduction of an audio signal or a video signal from a recording medium, transfer of the signal to a read-only information medium, reproduction of the transferred information, transmission of the signal over a transmission line, and the like. Transmission and information storage are performed.
[0003]
In recent years, a DVD (Versatile Digital Disc) has been realized as a recording medium capable of recording a large amount of information of video and audio signals. Movie information of two hours or more is recorded on a DVD, and the DVD recording information is reproduced by a reproducing device. By playing it back, I can watch it freely at home.
[0004]
Furthermore, the transmission environment of digital signals has entered the era of broadband, and high-speed, large-capacity digital data transmission and mutual communication can be realized.
[0005]
DVDs include read-only (reproducible) DVD-ROMs, DVD-Rs that can be recorded once, DVD-RWs that can be freely recorded and reproduced, and DVD-RAMs.
[0006]
Among the application standards of DVD-ROM, there is DVD-video standard, which has a capacity to completely record, for example, movie information on one disc. The user can freely obtain digital information by playing such a DVD-video disc or using a digital broadcast signal in a broadcast system. In such an environment, if the obtained digital signal is copied to a recording medium such as a hard disk or the above-mentioned DVD-RAM, and encoded and recorded again by an encoder conforming to the DVD-video standard, the same digital signal as the original disk is obtained. You will be able to create another copied disc.
[0007]
For this reason, digital information recorded on DVD-video is encrypted. The copy protection method using the encryption technique effectively functions on a DVD-video disc or DVD-ROM disc on which information encrypted in advance is recorded.
[0008]
In such information transmission / storage processing, the handling of copyright protection has recently become important. In particular, when information requiring copyright protection is recorded on a normal recording medium, the copyright holder records the same information on a plurality of recording media, even though the copyright holder permits information recording on only one recording medium. The occurrence of such misconduct is conceivable, and prevention of such misconduct has become indispensable.
[0009]
The following describes a related art of a copyright protection system in a recording / reproducing apparatus which is considered as an advanced form based on a copyright protection system CSS (Content Scramble System) used in DVD-video.
[0010]
FIG. 4 is a block diagram of a signal processing step for a recording medium in the copyright protection system for DVD-video signals. Here, a signal recording system for recording a master disc of a DVD-video disc will be described.
[0011]
In FIG. 4, digital data contents such as video / audio data are first compressed by a data control unit a1 according to the MPEG method or the like, and are further formatted into a digital data stream to which a reproduction control signal or the like is added. The formatted digital data is data-sectorized into packet data in units of 2 Kbytes in a data sectoring unit a2, and an ID or the like as a sector number is added in an ID adding unit a3.
[0012]
Next, after the digital data to which the ID is added is encrypted (data scrambled) by the content encryption unit a4, an error detection code EDC is added to the encrypted data by the EDC encoding unit a5. After that, the data portion is scrambled based on a random signal generated by an initial value determined by the ID information for the purpose of stabilizing the servo system in the reproducing operation in the scramble processing section a6.
[0013]
The data scrambling here differs from the data scrambling for encryption described above in that data is scrambled with published contents. The purpose is that when the digital data is all "0", the recording data is a repetition of the same pattern.
[0014]
This is because in a disk system, there is a concern that a problem such as a failure to accurately detect a tracking servo error signal occurs due to crosstalk or the like of an adjacent track. Upon execution, the initial value of the M-sequence generator is determined by the ID value. Data scrambling is performed by multiplying the signal from the M-sequence generator with digital data.
[0015]
This prevents the data scrambled recording signal from repeating the same pattern. In this specification, data scrambling used for servo stabilization and the like will be described only as an example, and data scrambling described below indicates data scrambling used for encryption used for copyright protection of information.
[0016]
The digital data subjected to the above processing is subjected to error correction processing in a unit of 16 sectors (192 rows per frame × 172 bytes, 12 sectors per sector) by the ECC blocking unit a7, so that an error correction code (ECC) is generated. The block is divided into blocks, and the next error correction coding unit a8 generates error correction codes of an error correction inner code PI (10 bytes for each row) and an outer error correction code PO (16 bytes for each column).
[0017]
The error-correcting outer code PO is interleaved by the PO interleaving unit a9 to be distributed and arranged for each sector (13 rows per sector, 1 row per PO area) to form a recording sector. Then, the recording sector data is modulated by the modulation / synchronization adding section a10, and the modulated signal is driven by the optical pickup apparatus a12 via the driver section 11 which is a drive section of the optical pickup apparatus a12, and is transmitted to the disk master a13. Cutting records.
[0018]
The disk master a13 is provided to the market as a DVD-ROM disk on which a video signal is recorded by duplicating a large number of disks using an injection machine or the like, in which a disk manufacturing mold is created in a disk manufacturing process. You.
[0019]
FIG. 5 is a conceptual diagram showing an entire configuration of a copyright protection system CSS (Content Scramble System) for a DVD-video signal used in a read-only medium of the DVD standard.
[0020]
In FIG. 5, on the disc creator B10, after the digital content b1 is MPEG-encoded by the MPEG encoding unit b2, the content is encrypted by the CSS method in the content encryption unit b3 and recorded on the read-only medium b4.
[0021]
In the playback process for the playback-only medium b4, in a general AV (consumer equipment) environment, in the dedicated DVD player B20, the encrypted content is decoded by the content decoding unit b5, and the MPEG decoding unit b6 decodes the MPEG decoder. Etc., the compressed data is expanded. Then, the video signal and the audio signal are restored.
[0022]
On the other hand, in reproduction processing in a computer environment such as a personal computer, digital data from the medium b4 is reproduced by the DVD-ROM drive B30. The reproduced digital data is not transferred on the PC bus as it is, but first, a mutual authentication is performed by the bus authentication section b7 of the DVD-ROM drive B30 and the bus authentication section b8 of the MPEG decoder module B40.
[0023]
Then, the encrypted content is transferred only when it can be confirmed as a valid decoder module. Then, the data is transferred from the DVD-ROM drive B30 to the content decoding unit b9 via the bus authentication unit b8 of the MPEG decoder module B40, and is processed by the MPEG decoding unit b10.
[0024]
FIG. 6 is a diagram showing a CSS content encryption method.
[0025]
In this method, three encryption key data, that is, a master key MK (Master Key) held by a CSS management mechanism, a disk key DK and a title key TK determined by a copyright holder or the like are hierarchically combined, and video and audio data are combined. This is a method of encrypting the data.
[0026]
In the example of FIG. 6, the disk key DK is encrypted using the master key MK (block c1), and becomes a disk key ring DKB. Further, the title key TK is encrypted using the disk key DK (block c2), and becomes an encrypted title key Enc-TK. The content c3 of data such as video / audio data is subjected to data compression processing by an authoring company or the like (block c4), and this compressed data is used to generate scrambled audio / video (A / V) data using the title key TK, and to generate a disc. (Block c5).
[0027]
Here, the master key MS is encryption key data that differs for each maker of the decryption LSI and the software CSS module.
[0028]
The CSS management mechanism collectively holds master keys MK of many manufacturers. When the disk key DK is encrypted, it is basically created as a disk key ring DKB that can be decrypted by any master key MK, and this disk key ring DKB is stored on the disk. By doing so, damage when the information of the master key MK given to a certain manufacturer leaks out can be minimized.
[0029]
Specifically, a disk key ring DKB created by removing the leaked master key MK from the next time a disk key set is created is created. Thus, decryption using the leaked master key MK cannot be performed.
[0030]
FIG. 7 is a diagram showing content decryption processing in a DVD player that plays back a disk on which the encrypted content created in FIG. 6 is recorded. The disk key processing unit d1 reads the encrypted disk key ring DKB encrypted from the disk, and decrypts the disk key DK using the master key MK.
[0031]
Next, the decryption unit d2 decrypts the title key TK from the encrypted encrypted title key Enc-TK read from the disk using the decrypted disk key DK. Then, the descrambling unit d3 descrambles the scrambled audio / video (A / V) data, which is the content, using the decrypted title key TK. The descrambled content is reproduced as a video signal and an audio signal by an A / V decoder unit d4 such as an MPEG decoder.
[0032]
The above is the outline of the copyright system adopting the reproduction-only CSS system. As described above, in order to protect the copyright, the content is encrypted by the scramble process. In the reproduction system, the copyright is protected by a mechanism in which the content cannot be decrypted without decrypting the encrypted key in order to decrypt the encrypted content.
[0033]
On the other hand, in a read-only DVD system, processing is performed by editing work during reproduction of the master disc, so that the recording side can easily manage copyright protection. However, in a DVD system capable of performing recording and reproduction, a recording processing unit exists in many devices. For this reason, it is conceivable to manufacture an unauthorized device capable of illegally copying content and to create a large number of illegally copied content recording media.
[0034]
Then, next, the configuration of the copyright protection system in the recording / reproducing apparatus will be shown, and this copyright protection system will be described.
[0035]
FIG. 8 is a diagram showing a configuration of a copyright protection system in the recording / reproducing device.
[0036]
In FIG. 8, a block e1 is a random number generator, a block e2 is an A / V encoder (MPEG), a block e3 is a scramble processing unit, a block e4 is an encryption unit, and a block e5 is a disk key processing unit. Block e10 is a disk key processing unit, block e11 is a decryption unit, block e12 is a descrambling processing unit, and block e13 is an A / V decoder unit (MPEG).
[0037]
The video / audio contents are MPEG-encoded by the A / V encoder e2 and input to the scramble processing unit e3. The scramble processing unit e3 encrypts the MPEG encoding using the title key TK generated by the random number generation device e1 as a key (Key), and stores it on a disk. On the other hand, the title key TK is input to the encrypting unit e4, which encrypts the title key TK using the disk key DK and records it on the disk as an encrypted title key Enc-TK. The disk key DK at this time is generated by the disk key processing unit e5 in the same manner as the disk key in the reproduction-only device, and decrypts the disk key bundle DKB and the master key MK read from the recording medium to obtain the disk key DK. A key DK is generated.
[0038]
Note that, as described above, a key bunch obtained by encrypting a disk key with many master keys MK is recorded on the recording medium in advance, so that the disk key processing unit e5 uses the master key MK to execute the disk key set DKB. Can be decrypted to generate a disk key DK.
[0039]
On the other hand, the disk key processing unit e10 on the reproducing side decrypts the disk key set DKB read from the recording medium using the master key MK to obtain the disk key DK.
[0040]
Next, the decryption unit e11 decrypts the encrypted title key Enc-TK read from the recording medium using the disk key DK to obtain the title key TK. Then, the descrambling processing unit e12 descrambles the encrypted content Enc-C read from the recording medium using the decrypted title key TK. The content thus decoded is decoded by the A / V decoder unit e13 and output as an audio signal and a video signal.
[0041]
FIG. 9 shows a recording / reproducing apparatus adopting the copy protection method as described in FIG. 8, including a drive. It is unlikely that illegal copying will occur with a dedicated recorder in a general consumer environment. However, in a PC (personal computer) environment, it is easy to copy data read by a drive to another recording medium. It is possible.
[0042]
In the PC environment, the recording medium is configured as a peripheral device, and the input / output of the drive in FIG. 9 generally performs a recording / reproducing operation irrespective of data contents. To this end, it is conceivable to illegally obtain data on the data transmission / reception bus. As a method for preventing such fraud, it is necessary to use a bus authentication system.
[0043]
FIG. 9 shows the A / V encoder module f101 and the drive f on the recording side.
102, a drive f103 and an A / V decoder module f104 on the reproduction side. Parts corresponding to those in FIG. 8 are denoted by the same reference numerals. Further, in the A / V encoder module f101, the encryption control unit f11 corresponds to the random number generator e1, the disk key processing unit e5, the encryption unit e4, and the like in FIG.
[0044]
On the recording side, the title key TK, which is an encryption key, is encrypted with the disk key DK to form an encryption key Enc-TK. When transferring this encryption key Enc-TK to the recording drive f102, It is necessary to transfer via the authentication unit f12. Other processes are substantially the same as the processes in the CSS.
[0045]
In the drive f102, the encrypted content is ECC-encoded by the ECC encoder f13, and then subjected to modulation processing by the modulator f14. The output signal of the modulation unit f14 is written to a recording medium by the writing control unit f15.
[0046]
On the reproduction side, the read control unit f16 of the drive f103 reads the signal of the recording medium, and the read signal is demodulated by the demodulation unit f17. The demodulated signal is decoded by the ECC decoding unit f18.
[0047]
Also at the time of reproduction, mutual authentication by the bus authentication unit f19 is performed between the drive f103 and the A / V decoder module f104. When the mutual authentication is confirmed, the title key TK is decrypted by the decryption control unit f20, and is input to the descramble processing unit e12 to descramble the encrypted content. Thus, the output of the ECC decoding unit f18 is descrambled by the descrambling processing unit e12, then decoded by the A / V decoder e13, and output as an audio signal and a video signal. The decryption control unit f20 corresponds to the disk key processing unit e10 and the decryption unit e11. .
[0048]
As described above, in the copyright protection system CSS, the content is encrypted, and the encryption key obtained by encrypting the content is recorded on the recording medium. However, in this system, the encrypted content and the encryption key are public digital signals on the transmission, reception, recording, and reproduction paths.
[0049]
The copy protection method using the above-described encryption technique effectively functions on a DVD-Video disc or a DVD-ROM disc on which information encrypted in advance is recorded. However, in the case of a DVD-RAM or the like in which a user can newly record information, the following problem occurs.
[0050]
(1) It is difficult for a recording device used by a general user to introduce a strong and inexpensive encryption device. (2) It is difficult to manage an encryption key during encryption. (3) When encryption and decryption are performed on the information recording device side, there is a high possibility that information to be copy-protected is easily copied. (4) If the entire encrypted content or encryption key is copied, a violating disc that can be reproduced by a normal device can be obtained. (If there is no hidden area). (5) When handling an audio signal, it is handled in units of a large number of files (songs), and it is difficult to maintain the copyright protection capability in response to a request for management in units of files.
[0051]
As described above, it is difficult for the copy protection of the digital information signal to effectively use the conventional encryption technique as it is. When reproducing the encrypted record information, a decryption process is performed in the reproduction process, but depending on the handling of the digital signal after decryption, the possibility of illegal copying remains. In particular, there is a possibility that a large amount of duplicate recording media can be created by copying the entire encrypted information or encryption key.
[0052]
When various media such as a DVD-ROM for reproduction only and a DVD-R / RW / RAM for recording and reproduction are available, such as a DVD, the digital signal recorded on the recording medium is an original original signal or illegally copied. It is difficult to determine whether the digital signal is a digital signal.
[0053]
This problem similarly occurs in other recording media. For this reason, from the viewpoint of copyright protection, in addition to the configuration in which only the correct system can be decrypted by encrypting the information signal, the input digital signal is converted to the original digital signal at the entrance on the playback side. By confirming whether the signal is a signal or an illegally copied signal, by incorporating a part of the protection system in an area that cannot be processed by ordinary users, it is expected that the capability can be greatly improved.
[0054]
FIG. 10 is a conceptual diagram illustrating a path of an illegal copy with respect to a whole copy.
[0055]
Since the purpose of a recording / reproducing drive generally used in a computer environment is to record / reproduce information in accordance with an instruction from a PC, the contents (contents of information and control codes for the information, etc.) recorded on a recording medium are determined. Since the data is not read, the read data becomes open. In FIG. 10, if all data read by the reproduction drive are recorded in the order read by the recording drive, a plurality of the same recorded recording media can be created.
[0056]
That is, even if the content is subjected to encryption processing, illegal copying can be realized if the entire copy including the encryption key information is performed.
[0057]
In order to solve such a problem, a method has been proposed in which an individual unique ID is assigned to a recording medium or the like, and the unique ID is used as a function in the encryption process at the time of recording. With this method, illegal copying can be prevented because the unique ID of the copied medium is different even if the whole is copied.
[0058]
However, this method can also limit the rights of the user. That is, when data errors increase in contents recorded on a certain recording medium due to scratches or the like, it is the greatest feature of the digital system that the contents can be reproduced as new by copying.
[0059]
In this case, it is assumed that the encryption key portion is read out in advance, stored in another buffer memory, and then the content in the recording medium is copied to another medium by a proper method. Since this is a regular method, the content of the original recording medium is erased at the same time when the copy is completed.
[0060]
However, in practice, it is not possible to spend a lot of time for erasing due to the merchantability, so as a result, only the encryption key part is erased, and it is assumed that the contents of the original recording medium have been erased Is taken. In such a method, the content data is recorded on the original recording medium, and the encryption key, which has been read out before the copy processing is first performed by the regular method, is written on the original recording medium (returning the encryption key). ), And a recording medium on which reproducible content is recorded is created.
[0061]
As a result, it is difficult to increase the prevention of illegal copying in a system capable of copying as shown in FIG. As a countermeasure, in a normal recording / reproducing or data transfer by a transmission reception route, a confidential area is provided in a partial area, and a configuration for recording / reproducing specific information such as a part of encryption key information is provided. It is possible to respond.
[0062]
In order to provide confidentiality, it is optimal to use a method that can be detected only in the first stage area of the reproduction process and that the specific information disappears in the normal data area.
[0063]
One example of a technique relating to encryption is disclosed in Japanese Patent Application Laid-Open No. 9-128890. The technology disclosed herein replaces a part of a correction code of information to which an error correction code is added with specific information, and records a specific code recorded in a partial area of the correction code before error correction processing at the time of recording or reproduction. This method extracts information and performs control to prevent unauthorized copying, etc., and utilizes the fact that specific information embedded by error correction processing disappears.
[0064]
However, even with the above method, even if the whole copy shown in FIG. 10 can be prevented, there is a possibility that a signal area at the preceding stage where error correction processing is not performed may be copied, and it is difficult to prevent illegal copying.
[0065]
FIG. 11 is a diagram illustrating a path of an illegal copy with respect to a whole copy of a signal area at a stage before the error correction processing is performed. As shown in FIG. 11, there is a problem that an illegal copy route in which demodulated data before error correction processing is sent to a recording side, and an error correction code is not generated and directly sent to a modulation unit for recording.
[0066]
[Problems to be solved by the invention]
As described above, in the related art, although various measures for protecting the copyright have been taken, complete copy protection cannot be constructed. In particular, there has been a problem that an illegal copy route in which demodulated data before error correction processing is sent to a recording side and directly sent to a modulation unit to be recorded cannot be prevented.
[0067]
Therefore, the present invention has been made in view of the above problems, and even in a system using a recording / reproducing drive used in a computer environment and a PC that can easily edit information, information that requires copyright protection is recorded. It is an object of the present invention to provide a digital information signal recording / reproducing method, a recording / reproducing system, a media drive, a media drive recording / reproducing method, and a recording medium and a program which can prevent duplication of a recording medium.
[0068]
[Means for Solving the Problems]
In order to achieve the above object, a digital information signal recording / reproducing method according to the present invention performs an encryption process on a digital information signal in a predetermined block unit, generates an error correction code for the block, and A digital information signal recording and reproducing method for recording and reproducing the digital information signal block and its error correction code block on a recording medium, wherein an encoding section encrypts a first encryption key used in the encryption processing. In the drive of the recording medium, the encrypted first encryption key is double-encrypted using a second encryption key, and the double-encryption first encryption key is replaced with the error of the recording medium. Recording in a correction code block, encrypting the second encryption key using a third encryption key, and encrypting the encrypted second encryption key. Recording the double-encryption first encryption key recorded in the error-correction code block at a predetermined position by a digital watermark, reading the error-correction code block on the recording medium, Extracting and decrypting the encrypted second encryption key recorded by a digital watermark at a predetermined position of the encryption key, and using the decrypted second encryption key to correct the error of the recording medium. Decoding the double-encryption first encryption key recorded in the correction code block and outputting the decrypted first encryption key as an encryption first encryption key; and decoding the encryption first encryption key in a decoder unit. And decrypting the encrypted digital information signal block read from the recording medium using the decrypted first encryption key. And it features.
[0069]
Further, the digital information signal recording / reproducing system of the present invention performs an encryption process on a digital information signal in a predetermined block unit, generates an error correction code for the block, and generates the encrypted digital information signal block and the encrypted digital information signal block. In a recording / reproducing system that records and reproduces an error correction code block on a recording medium, an encoding unit encrypts a first encryption key used for the encryption processing in an encoding unit; First encrypting the encrypted first encryption key using a second encryption key and recording the double-encrypted first encryption key in the error correction code block of the recording medium; Recording means for encrypting the second encryption key using a third encryption key, and recording the encrypted second encryption key in the error correction code block; A second recording means for recording the digital code at a predetermined position of the obtained double encrypted first encryption key, and reading the error correction code block of the recording medium, and A first decryption unit for extracting and decrypting the encrypted second encryption key recorded by a digital watermark at a predetermined position of the key, and using the decrypted second encryption key, A second decryption means for decrypting the double encrypted first encryption key recorded in the error correction code block and outputting the decrypted first encryption key as an encrypted first encryption key; Third decryption means for decrypting an encryption key, and fourth decryption means for decrypting the encrypted digital information signal block read from the recording medium using the decrypted first encryption key. Have And wherein the door.
[0070]
Further, the media drive of the present invention performs an encryption process on a digital information signal in a predetermined block unit, generates an error correction code for the block, and generates the encrypted digital information signal block and its error correction code block. In a media drive for recording and reading data on and from a recording medium, the first encryption key used for the encryption processing is encrypted and the first encryption key is received, and double encryption is performed using the second encryption key. First encryption means for generating an encrypted first encryption key; first recording means for recording the double-encryption first encryption key in the error correction code block of the recording medium; Second encryption means for encrypting an encryption key using a third encryption key to generate an encrypted second encryption key, and the double-encryption first encryption key recorded in the error correction code block of A second recording unit for recording the encrypted second encryption key at a predetermined position by an electronic watermark, and reading the error correction code block of the recording medium, and reading a predetermined code of the double encrypted first encryption key. First decryption means for extracting and decrypting the encrypted second encryption key recorded at a position by an electronic watermark, and using the decrypted second encryption key, the error correction code of the recording medium. And a second decryption means for decrypting the double-encrypted first encryption key recorded in the block and outputting the decrypted first encryption key to a decoder unit.
[0071]
Further, the recording / reproducing method of the media drive of the present invention performs an encryption process on a digital information signal in a predetermined block unit, generates an error correction code for the block, and generates the encrypted digital information signal block and its error. In a recording / reproducing method of a media drive for recording and reading a correction code block on a recording medium, a second encryption key obtained by encrypting a first encryption key used for the encryption processing is received, and a second encryption key is received. Generating a double encrypted first encryption key using an encryption key; recording the double encrypted first encryption key in the error correction code block of the recording medium; Generating an encrypted second encryption key by encrypting the encryption key using a third encryption key; and generating the encrypted second encryption key recorded in the error correction code block. Recording the encrypted second encryption key by a digital watermark at a predetermined position of the encryption key, reading the error correction code block of the recording medium, and determining the predetermined position of the double-encryption first encryption key Extracting and decrypting the encrypted second encryption key recorded by a digital watermark in the error correction code block of the recording medium using the decrypted second encryption key. Decrypting the double-encrypted first encryption key and outputting the decrypted first encryption key to a decoder unit.
[0072]
Further, the computer readable recording medium of the present invention performs an encryption process on a digital information signal in a predetermined block unit, generates an error correction code for the block, and generates the encrypted digital information signal block and its error. In the recording medium on which the correction code block is recorded, the first encryption key used in the encryption processing is encrypted using the second encryption key and the second encryption key is used to perform double encryption. A first encrypted key is generated and supplied, the double encrypted first encryption key is recorded in the error correction code block of the recording medium, and the second encryption key is replaced with a third encryption key. An encrypted second encryption key is generated and supplied, and the encrypted second encryption key is a predetermined encryption key of the double-encryption first encryption key recorded in the error correction code block. Electron in position Characterized in that it is recorded by the lend.
[0073]
Further, the program of the present invention encrypts a digital information signal in a predetermined block unit, generates an error correction code for the block, and records the encrypted digital information signal block and its error correction code block. In a program for controlling a media drive for recording and reading data on and from a medium, the first encryption key used for the encryption processing is encrypted, the first encryption key is received, and a second encryption key is used. A function of generating a double encryption first encryption key, a function of recording the double encryption first encryption key in the error correction code block of the recording medium, and a function of storing the second encryption key in a third And a function of generating an encrypted second encryption key by using the encryption key of the second encryption key, and an electronic key at a predetermined position of the double encryption first encryption key recorded in the error correction code block. A function of recording the encrypted second encryption key by caulking, and reading the error correction code block of the recording medium, and recording the error-corrected code block at a predetermined position of the double-encryption first encryption key by a digital watermark. The function of extracting and decrypting the encrypted second encryption key, and using the decrypted second encryption key, the double encrypted first encryption key recorded in the error correction code block of the recording medium. And a function of decrypting the encryption key and outputting it to the decoder unit.
[0074]
According to the present invention, the specific information used only in the media drive is used as a key for double encryption of the content encryption key (title key), and the double encrypted title key encrypted by this is used as the ECC of the recording medium. By recording the information in the block and embedding the encryption key obtained by encrypting the specific information into the double-encrypted title key by recording with an electronic watermark, it becomes impossible to decipher the information by a device other than the media drive, and the copyright is recorded on the media. You can protect things completely.
[0075]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0076]
FIG. 1 shows the configuration of a digital information signal recording / reproducing system to which content encryption key encryption according to the present invention is applied. In particular, FIG. 1 shows the arrangement relationship between a content encryption key and the specific information encryption key provided by the present invention. It is a block diagram shown.
[0077]
In FIG. 1, the digital information signal recording / reproducing system of the present invention includes an A / V encoder board A10, an ODD drive A20, and an A / V decoder board A30.
[0078]
The A / V encoder board A10 includes a random number generator 10, an A / V encoder unit (MPEG) 11, a scramble processing unit 12, a master key unit 13, a disk key processing unit 14, an encryption unit 15, and the like.
[0079]
The ODD drive A 20 includes a random number generator 16, a first encryption unit 17, a public key 18, a second encryption unit 19, a recording medium (disk) 100, a public key unit 20, a first decryption unit 21, It comprises a second decoding unit 22 and the like.
[0080]
Further, the A / V decoding board A30 includes a master key unit 23, a disk key processing unit 24, a decoding unit 25, a scramble processing unit 26, an A / V decoder 27, and the like.
[0081]
Since the function of each component is partially described in FIG. 8 and the like, the function of each component will be described below while describing the operation of the present invention.
[0082]
First, audio signals and video signals input to the A / V encoder unit 11 of the A / V encoder board A10 are subjected to signal processing according to the procedure shown in FIG. 4 and recorded on the recording medium 100. Now, the description will be simplified, and the description will focus on the content encryption processing. That is, the content in block units from the A / V encoder unit 11 and the content encryption key (title key) TK generated by the random number generator 10 are input to the scramble processing unit 12, and the scramble processing unit 12 The content is encrypted (scrambled) using the encryption key TK, and the encrypted content Enc-C is generated and recorded on the recording medium 100 of the ODD drive A 20 in block units.
[0083]
Then, in order to encrypt the content encryption key (title key) TK, the content encryption key TK from the random number generation device 10 is input to the encryption unit 15. The disk key DK is input from the disk key processing unit 14 to the encryption unit 15. The disk key DK is generated based on the master key MK issued from the master key unit 13 and the disk key block DKB read from the recording medium 100. Then, the encryption unit 15 encrypts the content encryption key TK using the generated disk key DK, generates an encrypted title key Enc-TK, and outputs the generated title key Enc-TK to the first encryption unit 17 of the ODD drive A20. .
[0084]
On the other hand, when the first encryption unit 17 of the ODD drive A20 receives the encrypted title key Enc-TK, the first encryption unit 17 generates a new encryption key (specific information) EK generated from the random number generation device 16 in the ODD drive A20. To generate a double-encrypted title key Enc2-TK. The double-encrypted title key Enc2-TK is recorded in a specific ECC block of the recording medium 100, which will be described later.
[0085]
Furthermore, the ECC block in which the double-encrypted title key Enc2-TK is recorded has a feature that an encrypted version of the specific information EK provided by the present invention is embedded and recorded. .
[0086]
That is, the specific information EK generated from the random number generation device 16 is input to the second encryption unit 19, and the encryption unit 19 generates the public key from the public key unit 18 newly provided in the ODD drive A20. The encrypted title key Enc-EK is generated using GS. This encrypted title key Enc-EK is stored in the ECC block of the recording medium 100 where the encrypted title key Enc2-TK is recorded by a digital watermark recording method described later, using the data of the double-encrypted title key Enc2-TK. It is recorded on the recording medium 100 after being replaced with a part. At this time, the ODD drive A20 manages where in the double encrypted title key Enc2-TK the encrypted title key Enc-EK is to be embedded.
[0087]
In addition, instead of the public key GS from the public key unit 18, the disk key DK is generated using the master key MK and the disk key block DKB in the ODD drive A20, and the specific information EK is encrypted with the disk key DK. Then, the encrypted title key Enc-EK may be created.
[0088]
In this manner, at a predetermined position of the EEC block where the double encrypted title key Enc2-TK is recorded, the encrypted title key Enc- Enc-TK of the specific information EK when the double-encrypted title key Enc2-TK is generated. Even if the recording medium 100 itself is copied by recording the EK, the double encryption key cannot be decrypted unless the ODD drive A 20 is used. Copyrighted works are protected.
[0089]
Further, since the recording of the encrypted title key Enc-EK uses a recording method based on an electronic watermark, it is impossible to decipher where the encrypted title key Enc-EK is embedded in the ECC block, and the key can be found. The copyrighted work is completely protected from its absence.
[0090]
Next, in the reproduction processing, first, the above-described ECC block is read from the recording medium 100 of the ODD drive A20, the encrypted title key Enc-EK embedded by the recording method using the digital watermark is extracted, and the first decryption is performed. Input to the unit 21. In this extraction, the encrypted title key Enc-EK recorded by the digital watermark can be extracted by the error correction processing of the ECC block. The first decryption unit 21 decrypts the encrypted title key Enc-EK using the public key GS output from the same public key unit 20 as the public key unit 18 to generate the specific information EK. Then, the specific information EK is input to the second decryption unit 22, and the decryption unit 22 uses the specific information EK to decrypt the double-encrypted title key Enc2-TK read from the recording medium 100. Then, it generates an encrypted title key Enc-TK and outputs it to the decryption unit 25 of the A / V decoder board unit A30.
[0091]
On the other hand, in the A / V decoder board A30, the disk key block DKB read from the recording medium 100 is input to the disk key processing unit 24. The disk key processing unit 24 generates a disk key DK based on the master key MK issued from the master key unit 23 and the disk key block DKB, and inputs the disk key DK to the decryption unit 25. The decryption unit 25 decrypts the encrypted title key Enc-TK output from the second decryption unit 22 of the ODD drive A20 using the disk key DK, and generates the content encryption key TK.
[0092]
The content Enc-C that has been encrypted and recorded on the recording medium 100 is read from the recording medium 100 and sent to the descrambling unit 26 of the A / V decoder board unit A30. The descrambling unit 26 decrypts the content Enc-C using the content encryption key TK from the decrypting unit 25, and outputs the decrypted content to the A / V decoder 27. As a result, audio signals and video signals are output from the A / V decoder unit 27.
[0093]
2 and 3 are configuration diagrams of a physical sector in which specific information EK encrypted according to the present invention is embedded in an ECC block of the recording medium 100.
[0094]
In FIG. 2, the double encrypted title key Enc2-TK from the first encryption unit 17 is recorded in an ECC block (32 Kbytes) generated after the recording information (Main Data) of the encrypted content Enc-C. Further, the encrypted title key Enc-EK from the second encrypting unit 19 is recorded at a predetermined position in the area where the double-encrypted title key Enc2-TK is recorded by a recording method using an electronic watermark. It shows the situation.
[0095]
FIG. 3 shows a detailed physical sector configuration of the ECC block. Each of the two frames is composed of a 32-bit synchronization bit and a 1456-bit data block. In this example, the encrypted title key Enc-EK of the specific information EK is recorded in the third line SY2 and the eighth line SY3 of the left frame by a recording method using an electronic watermark. Further, the encrypted title key Enc-EK of the specific information EK is recorded in the SY5 of the fifth line and the SY7 of the tenth line of the right frame by a recording method using a digital watermark.
[0096]
Here, the recording method using an electronic watermark means that the double-encrypted title key Enc2-TK and the encrypted title key Enc-EK at the recording position are binary-added and recorded. The encrypted title key Enc-EK embedded by this addition process can form a state invisible from the content recorded on the recording medium 100. On the other hand, as a method for extracting the encrypted title key Enc-EK from the recording medium 100, the encrypted title key Enc-EK can be obtained by inversely calculating the encrypted title key Enc-EK embedded by the error correction processing of the ECC block.
[0097]
Therefore, in the present invention, the double-encrypted title key Enc2-TK is re-encrypted and re-decrypted only in the ODD drive A20 using the specific information EK. Even if the whole copy is performed, the content recorded on the recording medium cannot be decrypted (that is, the double-encrypted key cannot be decrypted unless the ODD drive A20 is used). It becomes possible to protect.
[0098]
As described above, the method of the present invention in which a special encryption key used for generation / recording and reproduction / decryption only in the ODD drive A20 is used for re-encryption of the content encryption key and both are recorded in the same ECC block is a conventional method. The copyright protection system can be greatly improved in terms of copyright protection.
[0099]
Therefore, the present invention may be used in an audio signal recording / reproducing system or the like in which a large number of files are required, the files need to be moved, and it is necessary to manage protection alone and measures against illegal whole copying are desired. The solution becomes possible.
[0100]
【The invention's effect】
As described above, according to the present invention, the specific information used only in the media drive is used as the key for double encryption of the content encryption key (title key), and the double encrypted title By recording the key in the ECC block of the recording medium and embedding the encryption key in which the specific information has been encrypted into the double-encrypted title key by recording with an electronic watermark, it becomes impossible to decipher the information except in the media drive. The work recorded on the media can be completely protected.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a digital information signal recording / reproducing system of the present invention.
FIG. 2 is a diagram showing an arrangement relationship between a content encryption key and a special encryption key according to the present invention.
FIG. 3 is a diagram showing an ECC-Block relationship in a recording medium of the present invention.
FIG. 4 is a block diagram of a signal processing step for a recording medium in the copyright protection system for DVD-video signals.
FIG. 5 is a diagram showing an entire configuration of a copyright protection system CSS (Content Scramble System) for a DVD-video signal used in a read-only medium of the DVD standard.
FIG. 6 is a diagram showing a CSS content encryption method.
FIG. 7 is an exemplary view showing content decryption in a DVD player for reproducing a disk on which encrypted content is recorded.
FIG. 8 is a diagram showing a configuration of a copyright protection system in the recording / reproducing device.
FIG. 9 is a schematic configuration diagram of a recording / reproducing apparatus.
FIG. 10 is a diagram showing a first illegal copy path for a whole copy.
FIG. 11 is a diagram showing a path of a second illegal copy with respect to a whole copy.
[Explanation of symbols]
10,16 random number generator
13,23 Master key part
18 Public key part
14, 24 disk key processing unit
21, 22 decoding unit
12, 26 descramble processing unit
27 A / V decoder section
11 A / V encoder
15, 17, 19, 20, 25 Encryption unit

Claims (10)

A digital information signal is encrypted in a predetermined block unit, an error correction code is generated for the block, and the encrypted digital information signal block and the error correction code block are recorded on a recording medium and reproduced. In a method for recording and reproducing an information signal,
An encoding unit for encrypting the first encryption key used for the encryption processing;
In the drive of the recording medium, the encrypted first encryption key is double-encrypted using a second encryption key, and the double-encryption first encryption key is used to correct the error in the recording medium. Recording in a code block; encrypting the second encryption key using a third encryption key; and encrypting the encrypted second encryption key in the double-encryption code recorded in the error correction code block. Recording the error correction code block on the recording medium by a digital watermark at a predetermined position of the first encryption key, and recording the error-correction code block at a predetermined position of the double encryption first encryption key by the digital watermark. Extracting and decrypting the encrypted second encryption key; and using the decrypted second encryption key, the double encrypted first encryption key recorded in the error correction code block of the recording medium. Decrypts the encryption key, and outputting a first cryptographic key encryption,
A decoder for decrypting the encrypted first encryption key; and decrypting the encrypted digital information signal block read from the recording medium using the decrypted first encryption key. And a method for recording and reproducing a digital information signal. A digital information signal is subjected to encryption processing in a predetermined block unit, an error correction code is generated for the block, and the encrypted digital information signal block and the error correction code block are recorded and reproduced on a recording medium. In the system,
An encoding unit for encrypting the first encryption key used for the encryption processing in the encoding unit;
In the drive of the recording medium, the encrypted first encryption key is double-encrypted using a second encryption key, and the double-encryption first encryption key is used to correct the error in the recording medium. A first recording means for recording in the code block; and a second encryption key for encrypting the second encryption key using a third encryption key, and the encrypted second encryption key is stored in the error correction code block. A second recording unit that records the predetermined position of the double-encryption first encryption key by a digital watermark, and reads the error-correction code block of the recording medium, and reads a predetermined position of the double-encryption first encryption key First decryption means for extracting and decrypting the encrypted second encryption key recorded at a position by an electronic watermark, and using the decrypted second encryption key, the error correction code of the recording medium. Recorded in the block Decoding the serial double encrypted first encryption key, a second decoding means for outputting a first cryptographic key encryption,
A decoder unit configured to decrypt the encrypted first encryption key by using a third decryption unit configured to decrypt the encrypted first information key and to read the encrypted digital information signal block read from the recording medium using the decrypted first encryption key; And a fourth decoding means for decoding the digital information signal. A digital information signal is encrypted in a predetermined block unit, an error correction code for the block is generated, and the encrypted digital information signal block and the error correction code block are recorded and read out on a recording medium by a media drive. ,
Receiving an encrypted first encryption key obtained by encrypting the first encryption key used in the encryption process, and generating a double-encryption first encryption key using the second encryption key; 1 encryption means,
First recording means for recording the double-encryption first encryption key in the error correction code block of the recording medium;
A second encryption unit that encrypts the second encryption key using a third encryption key to generate an encrypted second encryption key;
A second recording unit that records the encrypted second encryption key by a digital watermark at a predetermined position of the double encrypted first encryption key recorded in the error correction code block; First decryption means for reading out an error correction code block, extracting and decrypting the encrypted second encryption key recorded by a digital watermark at a predetermined position of the double encrypted first encryption key,
A second decryption unit for decrypting the double encrypted first encryption key recorded in the error correction code block of the recording medium using the decrypted second encryption key, and outputting the decrypted first encryption key to a decoder unit; A media drive comprising: 4. The media drive according to claim 3, wherein the second encryption key is information from a random number generator provided in a drive of the recording medium. 4. The media drive according to claim 3, wherein the second encryption key is encrypted with a public key from a public key unit provided in a drive of the recording medium. 5. The recording according to the digital watermark in the error correction code block, a value according to a result of addition of the double encryption first encryption key and the encryption second encryption key is recorded. Media drive. 7. The media drive according to claim 6, wherein when the error correction code block is read from the recording medium, the encrypted second encryption key is extracted by an error correction process. A digital information signal is encrypted in a predetermined block unit, an error correction code for the block is generated, and the encrypted digital information signal block and the error correction code block are recorded and read out on a recording medium by a media drive. In the recording and playback method,
Receiving an encrypted first encryption key obtained by encrypting the first encryption key used in the encryption processing, and generating a double-encryption first encryption key using the second encryption key; When,
Recording the double encryption first encryption key in the error correction code block of the recording medium;
Encrypting the second encryption key using a third encryption key to generate an encrypted second encryption key;
Recording the encrypted second encryption key by a digital watermark at a predetermined position of the double encrypted first encryption key recorded in the error correction code block;
Reading the error correction code block of the recording medium, extracting the encrypted second encryption key recorded by a digital watermark at a predetermined position of the double-encryption first encryption key, and decoding;
Using the decrypted second encryption key, decrypting the double-encryption first encryption key recorded in the error correction code block of the recording medium and outputting the decrypted first encryption key to a decoder unit. A recording / reproducing method for a media drive, comprising: The digital information signal is subjected to encryption processing in a predetermined block unit, an error correction code for the block is generated, and the encrypted digital information signal block and a recording medium on which the error correction code block is recorded, wherein the encryption is performed. A first encryption key obtained by encrypting the first encryption key used in the encryption process, a double encryption first encryption key is further generated using the second encryption key, and supplied; The double encryption first encryption key is recorded in the error correction code block of the recording medium;
The second encryption key is encrypted using a third encryption key to generate and supply an encrypted second encryption key, and the encrypted second encryption key is recorded in the error correction code block. A computer-readable recording medium recorded by a digital watermark at a predetermined position of the double encryption first encryption key. A digital information signal is encrypted in a predetermined block unit, an error correction code is generated for the block, and a media drive that records and reads the encrypted digital information signal block and the error correction code block on a recording medium is provided. In the controlling program,
A function of receiving an encrypted first encryption key obtained by encrypting a first encryption key used in the encryption processing and generating a double-encryption first encryption key using a second encryption key; When,
A function of recording the double encryption first encryption key in the error correction code block of the recording medium;
A function of encrypting the second encryption key using a third encryption key to generate an encrypted second encryption key;
A function of recording the encrypted second encryption key by a digital watermark at a predetermined position of the double encryption first encryption key recorded in the error correction code block;
A function of reading out the error correction code block of the recording medium, extracting the encrypted second encryption key recorded by a digital watermark at a predetermined position of the double-encryption first encryption key, and decoding;
Using the decrypted second encryption key, decrypting the double-encrypted first encryption key recorded in the error correction code block of the recording medium, and outputting the decrypted first encryption key to a decoder unit. A program characterized by the following.

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