JP2001216727A - Information recording medium, recorder, recording method, reproducing device, reproducing method, recording and reproducing method and transmitting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate special medium structure, to make reproduction impossible when contents recorded on a recording medium is copied wholly and to normally reproduce a medium recorded by normal recording. SOLUTION: Key information in a recording medium is enciphered double and recorded in a recording medium having a characteristic ID different by each medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus (drive) for writing and reading information by making a relative movement with respect to an information recording medium capable of high-density and large-capacity recording and reproduction.
TECHNICAL FIELD The present invention relates to an information recording medium, a recording device, a recording method, a reproducing device, a reproducing method, a recording / reproducing method, and a transmission method used for an information recording medium.

[0002]

2. Description of the Related Art DVDs have appeared as information recording media, but since information recorded on these media is digital information, a copy can be generated without deterioration if digital information can be easily copied. Since there is a risk of infringing the copyright holder's rights, various methods have been proposed for copy protection.

[0003] For example, with regard to copy guard in DVD-Video (read only), CSS (Content Sc) which is a basic method of copy protection of DVD is used.
ramble System) has been proposed. CS
Regarding S, for example, National Techn
Ial Report Vol. 43, no. 3,
(Jun. 1997), pages 118-122, "DVD Copyright Protection System" and the like. When the digital information is recorded on the DVD disk, the CSS encrypts the digital information using a three-layer encryption technology of a title key (key), a disk key (key), and a device key (key), and is licensed according to CSS. Only the DVD device (player) is capable of decrypting and reproducing the encrypted digital information.

[0004] Regarding the CSS, DVD-Video
An example of application to (ROM) will be described with reference to FIG.
Disc manufacturer (Disc Manufacture)
r) 100 converts a disc key (Disc Key) 101 determined by the content provider into a plurality of device keys (Device Key) 102-1 to 102-n.
The disk key block processing unit (Process
DKB) 103 generates a disk key block (DKB) 104 as a plurality of disk key groups.

[0005] This is because the disk key 101 can be decrypted and used with different device keys (one of the device keys 102-1 to 102-n) of a plurality of devices. Next, the DKB 104 is recorded in a predetermined area on the disk 105. Next, a title key 106 different for each title determined when recording the AV content is converted to a disc key 101 by the title key encrypting means 107.
And the encrypted title key (Encrypted TitleKey) is recorded on the disc 105.
Recorded as 108. Also, the recorded AV content 109 is a content encryption means (Contents
Encryption 110, the encrypted AV scrambled with a different title key 106 (before being scrambled) for each title determined when recording.
Content (Encrypted AV Content)
ts) 109 is recorded on the disk 105. The disk manufacturer 100 sells the disk 105 in this state.

Next, reproduction of the disk 105 will be described. The playback device 110 also has one of a plurality of device keys 102-1 to 102-n in advance, for example, 1
02-j. Prior to playback, the playback device 110 reads the disc key block (DK
B) 104, and reads out the disc key decryption unit (Disc)
In the key specification 111, the disk key block (DKB) 1 is set with the device key 102-j.
04 to obtain the disk key 101. Next, the encrypted title key 108 scrambled by the disk key 101 and recorded on the disk 105 is read out, and the title key decryption unit (Title KeyDecrypt) is read.
ion) 112, a disk key decryption unit (Disc K)
The original title key 106 is decrypted by using the disc key 101 output from the “eyeDecryption” 111. Next, the title key 106 is
AV content 109 scrambled by
Is read out, and the content decryption unit (Contents E)
The ncryption 113 performs descrambling using the decrypted original title key 106, restores the AV content 109, and reproduces the AV content.

The above-mentioned CSS is a DVD-Video (R)
This method is applicable only to read-only media such as OM), and is applicable to rewritable information recording media such as DVD-RAM and DVD-RW, and information recording media such as DVD-R that can be written only once. I can't. For DVD-RAM, which is a rewritable information recording medium, a copy guard system different from the CSS described above has been proposed. The DVD-RAM has a ROM (read-only) area and a RAM (rewritable) area, and DKB which is key information of a copy guard is pre-recorded in the ROM area, and cannot be overwritten or modified. .

An outline of a DVD-RAM copy guard system will be described with reference to FIG. A blank medium (an information recording medium before recording) will be described. Disc Maker 20
0 is a unique media ID (Unique MediaI) that differs for each disc (Media) 201.
D) Record 202. Next, the disc key 203 determined by the content provider is assigned to a plurality of device keys 204.
-1 to 204-n, the disk key encryption unit (Di)
An scKey Encryption 205 scrambles (encrypts) a disk key block (DKB) 206 which is a group of a plurality of disk keys. This is because the disk key can be decrypted and used with different device keys possessed by a plurality of devices. The generated DKB 206 is a unique / media / ID 202
At the same time, it is recorded in a predetermined area on the disk 201. The disk manufacturer 200 sells the disk 201 in this state as a blank disk. Next, recording of content will be described. One device key 204-j among a plurality of device keys 204-1 to 204-n is assigned to the recording device 207 in advance. First, the recording device 207 reads unique data (unique media / ID) 202 for each disk 201 before recording. Similarly, a disk key group (disk key block (DK)
B206)) is read out. Disc key decryption unit (Disc Key Decryption) in recording device 207
n) At 208, the disk key block (DKB) 206 is decrypted with the device key 204-j of the apparatus, and the disk key 203 is obtained. Decrypted disk key 203
Is a unique media key processing unit (Process Un
In the case of the same media key 209, the unique media ID 202 is read,
Unique disc key 202 for each disc 201
It is said.

A title key 210 that is different for each title determined when recording AV content is scrambled by a unique disc key 202 in a title key encryption unit 211, and an encrypted title key (Encryption Title Key) 21 is written to the disc 201.
Recorded as 2.

The recorded AV contents 213 are encrypted by the contents encrypting means 214 with the encrypted AV contents (Encrypted) scrambled with a different title key 210 for each title determined at the time of recording.
AV Content 215 as the disc 20
1 is recorded. Next, reproduction of the recorded content will be described. One of the plurality of device keys 204-1 to 204-n, for example, 204-k is assigned to the playback device 216 in advance. Here, since the disk key block (DKB) 206 encrypts one disk key 203 with a plurality of device keys 204-1 to 204-n (Encrypt), the playback device 21
6 device key 204-k and recording device key 2
There is no problem in decoding or the like even if it is different from 04-j. Disc key decryption unit (Disc KeyDecryption)
n) At 217, the disk key block (DKB) 206 is decrypted with the device key 204-k and the disk key 203 is decrypted.
Get. The decrypted disk key 203 is a unique disk key 20 for each disk 201 used on the recording side.
2, the unique media key processing unit (Process UniqueMedia) uses the unique media ID 202 read from the disk 201.
Key) 218 and unique disk key 2
02 is obtained. Next, the encrypted title key 212 scrambled by the unique disk key 202 recorded on the disk 201 is read out, and the title key decryption unit (Title Key Decision) 21 is read.
9 at the unique media key processing unit (Process
The original title key 210 is decrypted by using the unique disk key 202 output from the unique media key (218). The AV content 215 scrambled and recorded by the title key 210 is read out from the disc 201, and the content decryption unit (Con) is read.
Using the original title key 210 decrypted in the Tents Encryption 220, the AV content 213 is restored by reproducing the AV content 213 and the AV content is reproduced.

A DVD-R, which is a writable information recording medium, has the same disc structure as the DVD-RW (all RAM areas on the medium).
Due to the structure that can be recorded only once and cannot be rewritten, D
With VD-R, DKB can be recorded, but since it can be recorded only once, data after overwriting or alteration cannot be used, and illegal duplication can be prevented in a system similar to DVD-RAM.

[0012]

As described above, DVDs
In the RAM, since the ROM area and the RAM area are set separately as described above, it is difficult to balance the characteristics of the two areas, and the performance cannot be compatible. Are defined separately. Therefore, the structure of the DVD-RAM is special and complicated.

Although the DVD-R has a simple media structure, it is easy to manufacture, but since it can be recorded only once,
The usability of the recorder is limited.

DVD-R as a rewritable information medium
In W, there is no limitation for a user like DVD-R, but since the data recording area on the DVD-RW medium is rewritable, the same copy protection method as DVD-RAM and DVD-R can be taken. Absent. That is, DVD-R
W does not have a ROM area like DVD-RAM.
Since it does not have a write-once characteristic like -R, it is not possible to realize the same copy protection as that of a DVD-RAM copy guard system on a rewritable DVD-RW medium by the same method as before.

That is, for example, if the same method as the above-mentioned DVD-R is adopted as the copy guard method, the DVD-R
In W, since the DKB recording portion is rewritable, copying is possible by overwriting or altering data, and illegal copying cannot be prevented. DVD-RAM
Even if a ROM area such as that described above is created, the DVD-RW uses an Emb
It is difficult to achieve both oss Pit. If one of the performances is prioritized, a contradiction arises that the other performance cannot be set sufficiently, so that there is a problem that effective copy protection cannot be realized.

[0016]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a first area which is a non-rewritable non-data area in which medium-specific data is recorded, and a first key data area. A second area in which the first encrypted key data obtained by encrypting the first encrypted key data with the second key data and the second encrypted key data further encrypted with the medium-specific data are recorded; Rewritable third area
An information recording medium characterized by having an area (1) and (2). According to the present invention, there is provided a non-rewritable non-data area in which medium-specific data is recorded in order to solve the above-mentioned problem, and a first encryption scheme in which the first key data is encrypted with the second key data. An information recording medium characterized by further comprising a second rewritable area in which encrypted key data is further encrypted with the medium-specific data and user data is recorded. Further, the present invention has a non-rewritable area of data and a rewritable area of data in order to solve the above-described problems, medium-specific data is recorded in the non-rewritable area,
The first encrypted key data obtained by encrypting the first key data with a plurality of second key data groups is further transferred to the rewritable area by the second encrypted key data encrypted with the medium-specific data. What is claimed is: 1. A recording apparatus for recording content on an information recording medium recorded in advance, wherein said second key data group is allocated in advance to decrypt said first key data from said first encrypted key data. Storage means for storing a decryption key, reading means for reading the medium-specific data from the information recording medium, means for reading the second encryption key data from the information recording medium, First decryption means for decrypting the first encrypted key data using the medium-specific data and the read second encrypted key data; and the decryption key and the decrypted decrypted key. Second decryption means for decrypting the first key data using first encrypted key data, and generating intermediate key data from the decrypted first key data and the read medium-specific data Means for encrypting, third encryption key data different for each content determined by the user at the time of recording with the intermediate key data, and encrypting the content to be recorded with the third key data. A second encryption unit, the third key data encrypted by the first encryption unit, and the second key data;
Recording means for recording the content encrypted by the encryption means in the rewritable area of the information recording medium. In order to solve the above-mentioned problems, the present invention has a data non-rewritable area and a data rewritable area, and medium-specific data is recorded in the non-rewritable area. The first encrypted key data obtained by encrypting the key data with a plurality of second key data groups, and the second encrypted key data encrypted with the medium-specific data are recorded in the rewritable area in advance. A recording method for recording content on an information recording medium, wherein the medium-specific data is read from the recording medium, the second encryption key data is read from the recording medium, and the read medium-specific data and The first encrypted key data is decrypted using the read second encrypted key data, and is assigned in advance to decrypt the first encrypted key data. Decrypting the first key data by decrypting the first encrypted key data with any decryption key of the second key data group, and decrypting the decrypted first key data; Generating intermediate key data from the medium-specific data, generating third encrypted key data using the intermediate key data, and generating third encrypted key data that is different for each content determined by a user at the time of recording; Encrypting with the third encryption key data to generate an encrypted content; and recording the third encrypted key data and the encrypted content in the rewritable area of the information recording medium. Provide a recording method. In order to solve the above-mentioned problems, the present invention has a data non-rewritable area and a data rewritable area, and medium-specific data is recorded in the non-rewritable area. Key data of multiple second
An information recording medium in which the first encrypted key data encrypted with the key data group described above and the second encrypted key data encrypted with the medium specific data are recorded in the rewritable area in advance. When recording content,
The first encrypted key data obtained by decrypting the second encrypted key data with the medium-specific data, and further decrypting the first encrypted key data with any decryption key of the second key data group assigned in advance. Third encrypted key data obtained by encrypting third key data different for each content determined by a user at the time of recording with intermediate key data generated using the first key data and the medium-specific data; An information recording medium is provided, wherein an encrypted content obtained by encrypting the content using key data as a key is recorded in the rewritable area. In order to solve the above-mentioned problems, the present invention has a data non-rewritable area and a data rewritable area, and medium-specific data is recorded in the non-rewritable area. The first encrypted key data obtained by encrypting the key data with a plurality of second key data groups, and the second encrypted key data encrypted with the medium-specific data are recorded in the rewritable area in advance. In recording the content on the information recording medium, the first encrypted key data obtained by decrypting the second encrypted key data with the medium-specific data is assigned to the second key data group to which the second encrypted key data is assigned in advance. The intermediate key data generated using the first key data and the medium-specific data decrypted with any one of the first decryption keys, for each content determined by a user at the time of recording. Third encrypted the different third of key data
A reproduction device that reproduces the content from an information recording medium in which the encrypted key data and the encrypted content obtained by encrypting the content using the third key data as a key are recorded in the rewritable area. Storage means for storing any second decryption key of the second key data group allocated in advance to decrypt the first key data from the first encrypted key data; Means for reading the medium-specific data from the information recording medium, means for reading the second encrypted key data from the information recording medium, and the read medium-specific data and the read second encrypted key data Using first decryption means for decrypting the first encrypted key data using the second decryption key and the decrypted first encrypted key data. Second decryption means for decrypting the first key data; means for generating the intermediate key data from the decrypted first key data and the read medium-specific data; and 3 is read, and the read third key is read.
A third decryption unit that decrypts the third key data by using the encrypted key data and the intermediate key data, and reads the encrypted content from the rewritable area. And a fourth decryption unit for decrypting the content by using the decrypted third key data and the encrypted content. In order to solve the above-mentioned problems, the present invention has a data non-rewritable area and a data rewritable area, and medium-specific data is recorded in the non-rewritable area. The first encrypted key data obtained by encrypting the key data with a plurality of second key data groups, and the second encrypted key data encrypted with the medium-specific data are recorded in the rewritable area in advance. In recording the content on the information recording medium, the first encrypted key data obtained by decrypting the second encrypted key data with the medium-specific data is replaced with any one of the second key data group. A third key data, which is intermediate key data generated using the first key data and the medium-specific data decrypted with a first decryption key, and is different for each content determined by a user at the time of recording. And a third encrypted key data obtained by encrypting the content and an encrypted content obtained by encrypting the content using the third key data as a key. A reproducing method for reproducing, wherein the medium-specific data is read from the information recording medium, the second encrypted key data is read from the information recording medium, and the read medium-specific data and the read second cipher are read. Decrypting the first encrypted key data from the encrypted key data, and a second decryption key of any of the second key data groups allocated in advance for decrypting the first encrypted key data; Decrypting the first key data using the first encrypted key data;
Generating the intermediate key data from the decrypted first key data and the read medium-specific data; decrypting the third key data using the intermediate key data and the third encrypted key data; A reproducing method is provided, wherein the encrypted content is read from the rewritable area, and the content is decrypted using the decrypted third key data and the encrypted content. Further, the present invention has a non-rewritable area of data and a rewritable area of data in order to solve the above-described problems, and medium-unique data is recorded in the non-rewritable area, In the rewritable area, second encrypted key data obtained by encrypting first key data with a plurality of second key data groups and encrypting first encrypted key data with the medium-specific data is previously stored. A recording / reproducing method using a recorded information recording medium, wherein, when recording, the medium-specific data is read from the recording medium, the second encrypted key data is read from the recording medium, and the reading is performed. The first encrypted key data is decrypted by using the read medium-specific data and the read second encrypted key data, and is assigned in advance to decrypt the first encrypted key data. And that of the second key data group of any decryption key and a first said decoded
Decrypts the first key data using the encrypted key data of the above, generates intermediate key data from the decrypted first key data and the read medium-specific data, and determines the user during recording. Encrypting third key data different for each content with the intermediate key data to generate third encrypted key data, encrypting the content to be recorded with the third key data to generate encrypted content, Recording third encrypted key data and the encrypted content in a rewritable area of the recording medium;
When reproducing, the medium-specific data is read from the recording medium, the second encryption key data is read from the recording medium, and the read medium-specific data and the read second encryption key are read. Decrypting the first encrypted key data from the data; and a second decryption key of any of the second key data groups previously allocated to decrypt the first encrypted data and the decrypted key. Decrypting the first key data using the first encrypted key data, generating the intermediate key data from the decrypted first key data and the read medium-specific data, and rewriting the recording medium. The third key data is decrypted using the third encrypted key data and the intermediate key data read from a possible area, and the recording medium is rewritable. To provide a recording and reproducing method, characterized by decrypting the content using the third key data the encrypted content and then the decoded read from the area. Further, according to the present invention, in order to solve the above-mentioned problems, medium-specific data is recorded in advance in a non-rewritable area, and first key data is stored in a data rewritable area. The non-rewritable area in which first encrypted key data encrypted with a plurality of second key data groups and second encrypted key data encrypted with the medium-specific data are recorded in advance. And transmitting the second encryption key data from the rewritable area to the first encryption key using the transmitted medium unique data and the transmitted second encryption key data. Decrypting the encrypted key data, and using the decrypted first encrypted key data and the decryption key that is any key data of the second key data group assigned in advance, -Key data is generated, intermediate key data is generated from the decrypted first key data and the transmitted medium-specific data, and third key data different for each content determined by a user at the time of recording with the intermediate key data To generate third encrypted key data, encrypt the content with the third key data to generate encrypted content, and rewrite the third encrypted key data and the encrypted content. Provided is a transmission method characterized by transmitting to a possible area. Further, according to the present invention, in order to solve the above-described problem, medium-specific data is recorded in advance in a non-rewritable area, and first key data is stored in a data rewritable area. The non-rewritable area in which first encrypted key data encrypted with a plurality of second key data groups and second encrypted key data encrypted with the medium-specific data are recorded in advance. And transmitting the second encryption key data from the rewritable area to the first encryption key using the transmitted medium unique data and the transmitted second encryption key data. Decrypting the encrypted key data, and using the first decryption key and the decrypted first encrypted key data, which are the key data of any of the second key data groups assigned in advance. Decrypting first key data, generating intermediate key data from the decrypted first key data and the transmitted medium-specific data, and using the intermediate key data to generate a different intermediate key data for each content determined by a user at the time of recording; Encrypting the key data of the third key data to generate third encrypted key data; encrypting the content with the third key data to generate an encrypted content;
The encrypted key data and the encrypted content are transmitted to the rewritable area, and the medium-specific data is transmitted from the non-rewritable area, the second encrypted key data is transmitted from the rewritable area, and the third Transmitting the encrypted key data and the encrypted content, and decrypting the first encrypted key data using the transmitted medium-specific data and the transmitted second encrypted key data, Decrypting the first key data using a second decryption key which is any key data of the second key data group allocated in advance and the decrypted first encrypted key data; Generating the intermediate key data from the decrypted first key data and the transmitted medium specific data, and generating the intermediate key data and the transmitted third encrypted data. Decrypting the third key data using encrypted key data, and decrypting the content using the decrypted third key data and the transmitted encrypted content. .

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention changes the DKB on a medium for each disk, and sets a different Unique for each disk.
By generating and recording the encrypted DKB using the Media ID, even if the entire disk including the DKB area is copied, the recorded content is reproduced because the ID is different for each disk. This makes it impossible to prevent unauthorized duplication. Further, even if the DKB on the medium is overwritten or altered, the key required for decrypting the content cannot be correctly restored, so that illegal duplication is prevented.

As described above, Readable Emb
In order to realize copy guard by conventional DKB recording on a DVD-RW for which the technology for recording the oss-pitt is not established at present, the conventional DKB is stored in the System Reserved area of the lead-in area of the DVD-RW. Unique MediaMediaID
Further encryption using different encryption media D
Record the KB. Disc manufacturers have added DKB to Uniqu
e Encrypt with Media ID and record the encrypted DKB on the disc (Pre-record) at the time of factory shipment,
Ship.

The recording device is Unique Media I
D and the encrypted DKB are read out, the DKB is restored and recorded according to the conventional method, and the playback device is likewise Unique Media.
The aID and the encrypted DKB are read, and the DKB is restored and reproduced.

For example, as shown in FIG.
Encrypted DKB A on Media ID A disk
Is generated and recorded on the disc, the encrypted DK
When decrypting B, Unique Media
a It is necessary that ID A is recorded. However, this disk is bit-by-bit Uniqu
If the e-Media ID B is recorded on the disc, the Unimedia Media ID B recorded on the disc is used when decrypting the encrypted DKB, so that correct decryption cannot be performed.

As shown in FIG. 9, the disk 2 has a lead-in area (Lead-in Area) from its innermost periphery.
a), user data area (User Data Are)
a) are sequentially arranged. The lead-in area is an area for storing data used for control during recording and reproduction.
The user data area is an area where encrypted contents (data) obtained by encrypting contents to be recorded and reproduced are arranged.

The lead-in area is a read-only (non-rewritable) BCA area (BCA Area), and a readable / writable (rewritable area) system reserved area (System reserved).
Area), a read-only (non-rewritable) control data area (Control DataA)
area). BCA area contains BCA
Data, that is, the above-described Unique Media ID, which is different for each disc 2
Is recorded. The reserved area is an area prepared for recording information (data) related to copyright and copy protection.
A different encrypted DKB is recorded on each of the discs 2 generated by encrypting using the media ID (BCA).

This encrypted DKB can be recorded not in the reserved area but in the user data area (rewritable area), and can be recorded in both the reserved area and the user data area. Good. When recording in the user data area, the recording position is a predetermined position in the user data area such as immediately after the lead-in area, at the end of the user data area, or at an arbitrary position in the user data area. It is also possible to record at the position. Such storage in the user data area and storage in the reserved area can coexist.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. (1) Blank Media First, blank media (information recording media before contents are recorded) will be described. Disc manufacturer (D
isc Manufacturer 1 is a disk (M
edia) Unique media data (U
nique Media ID) 3 is recorded on the disc.

When recording the unique media data 3, the disc key 4 determined by the content provider
Is encrypted by a plurality of device keys 5-1 to 5-n using a disc key encryption unit (Disc Key Encryption).
n) Scrambling (encrypting) at 6 to generate a disk key block (DKB) 7 as a plurality of disk key groups. This is because the disk key can be decrypted and used with different device keys possessed by a plurality of devices.

The processing related to scrambling in the above description can be performed by, for example, a scrambler 300 as shown in FIG. Specifically, an M-series PN random number is generated by the PN random number generating means 301 using key data as an initial value, and the input data to be scrambled is EX-ORed (exclusive OR) by the EOR means 302. I do. In the embodiment shown in FIG. 1, the plurality of device keys 5-1 to 5-n shown in FIG. By performing EX-OR (exclusive OR) processing of a certain disk key 4 and a PN random number by the EOR means 302, the disk key 4 can be scrambled. Note that the scramble processing in the following description can also be performed using the scrambler 300 shown in FIG.

As for the PN random number generating means 301 described above, for example, the PN random number generating section 5 shown in FIG.
00 can be used. The PN random number generation unit 500 connects four D flip-flops 501, 502, 503, and 504 in cascade, and sets the initial value to
The data is supplied to the flip-flops 501, 502, 503, and 504, and a serial PN random number can be obtained.

More specifically, the PN random number generating means 301 is a pseudo random number generating circuit using an M-sequence (longest linear code sequence). The circuit is a shift register or a delay element of a certain length (in the embodiment, a 4-bit code). D-FF) and a circuit that calculates the state of a plurality of registers and feeds it back to the input of the register (EOR and inversion circuit in the embodiment).

As will be described later, the bit pattern appearing in the output of the M series differs depending on the clock of the register depending on the initial value to the register and the configuration of the feedback circuit.
A pseudo random number pattern having a period of -1 (2 to the power of n-1) is obtained. Taking advantage of this characteristic, it is possible to start data scramble as in the present application, and to the communication field (spread spectrum system, etc.)
It is frequently used in

When the PN random number generating means 301 shown in FIG. 4 is loaded with, for example, "0000" bin as the initial value of the register and the bit of the register is shifted every clock with the PN code length of 15 clocks, the output becomes As shown in FIG. 10, a pseudo random number starting from 0 and having 15 clocks as one cycle is obtained. When "1001" bin is loaded and the register is bit-shifted every clock,
As shown in FIG. 11, a pseudo random number having a different pattern from that shown in FIG.

If the pseudo random number obtained in this way is used for the scrambler 300 shown in FIG. 2, even if the input data is the same, the data to be output will be the PN random number generating means 301 as shown in FIGS. If the initial value of the PN random number generation means 401 and the configuration of the feedback circuit are not known by the descrambler 400 in FIG. 3, the original data cannot be restored correctly. This makes it possible to keep the data confidential.

In the above embodiment, since the register length of the PN random number generating means 301 is 4 bits, the pseudo random number generation cycle is 15 clocks. However, the register length is made longer, for example, 40 bits or 64 bits. As a result, the pattern cycle of the PN random number generation means 301 is greatly increased,
The pattern of the pseudo-random number to be output is more complicated and has a longer period, so that the output of the scrambler 300 is more difficult to decipher and the confidentiality is enhanced.

In order to create a unique disk key group for each disk 2, unique data (unique media ID) recorded for each disk 2 recorded on the disk 2
Multiple disk keys scrambled using 3
(Disk key block (DKB)) 7 is encrypted by the encryption means (E
The encrypted DKB (Encrypted DKB) 9, which is a group of a plurality of doubly scrambled disk keys, is re-scrambled by an Ncryption 8
Is recorded in a predetermined area on the disk 2. For this scramble processing, for example, the scrambler 300 as shown in FIG. 2 described above can be used. The disk manufacturer 1 sells the disk 2 in this state as a blank disk.

(2) Recording Device The recording device 10 has a plurality of device keys 5-1 in advance.
One of the device keys 14 (5-j) is assigned to the device key 14-5-n, and is stored in a storage unit such as a memory, for example. The recording device 10 reads unique data (unique media ID) 3 for each disk 2 recorded in a predetermined area of the disk 2 before recording, and encrypts data recorded in a predetermined area of the disk 2. Read out the modified DKB9.

In the scramble disk key decryption means (DKB Decryption) 11 of the recording device 10,
The encrypted DKB 9 read from the disk 2 is descrambled with the unique medium ID 3 read from the disk 2 to obtain a disk key group (disk key block (DKB 12)). The descrambling process in the above description can be performed by, for example, a descrambler 400 as shown in FIG. The descrambler 400 generates an M-sequence PN random number in the PN random number generation unit 401 using the key data as an initial value, similarly to the scrambler 300 shown in FIG. If an OR (exclusive OR) process is executed, data can be restored (descrambling process).

In the embodiment shown in FIG. 1, the PN random number generating means 401 is input with the unique media ID 3 shown in FIG. 1 as an initial value as key data, and a PN random number is generated. Chemical DKB9
EX-OR (exclusive OR) processing of PN and PN random numbers
By performing the processing in the R means 402, the encrypted DKB 9 can be descrambled to restore the DKB 12. It should be noted that the descrambling process in the following description is also described in FIG.
Can be processed using the descrambler 400 shown in FIG. Also, the PN random number generation unit 401 described above
As described above, for example, as shown in FIG.
An N random number generator 500 can be used.

Next, a disc key decryption means (Disc Key Decryption) 13 provided in the recording apparatus 10.
Decrypts (descrambles) the disk key block (DKB) 12 (corresponding to DKB 7) with the device key 14 of the recording apparatus 10, and decrypts the disk key 15 (disk key 4).
). For this descrambling process, for example, the descrambler 300 shown in FIG. 3 described above can be used.

The decrypted disk key 15 is used as a unique media key processing unit (ProcessUnique Me).
In the dia key 16, processing is performed using the unique medium ID 3 read from the disk 2, and a unique disk key 17 is provided for each disk 2. More specifically, for example, as shown in FIG. 5, the disc key 15 output from the disc key decryption unit 13 is input to the EOR 601 as key information, and the unique / media / ID3 reproduced from the disc 2 is used for medium identification. EX-OR (Exclusive OR) input to EOR 601 as information
By executing the processing, a unique disk key 17 is output.

In the title key encrypting means 19, A
The title key 18 that is different for each title determined when recording the V content is scrambled by the unique disc key 17 and the encrypted title key (E
ncryption Title Key) 20. For the scramble process, for example, the above-described scrambler 200 shown in FIG. 2 can be applied.

The recorded AV contents 21 are encrypted by the contents encrypting means 22 with the encrypted AV contents (Encrypted) scrambled by a different title key 18 (before being scrambled) for each title determined at the time of recording. AV Contents 31 is recorded on the disc 2. For the scramble process, for example, the above-described scrambler 200 shown in FIG. 2 can be applied.

(3) Reproducing Apparatus The reproducing apparatus 23 also has a plurality of device keys 5-1 in advance.
To 5-n, for example, the device key 24 (5-
k) has been assigned. As described above, the disk key block (DKB7) encrypts one disk key 4 with a plurality of device keys 5-1 to 5-n (Encrypt).
t), the device key 24 (5
-K) may be a device key different from the device key 14 (5-j) of the recording apparatus.

Prior to playback, the playback apparatus 23
Unique data (unique media, I
D) Read 3 and read the encrypted DKB 9 recorded in a predetermined area of the disk 2.

The scrambled disk key decryption unit (DKB Decision) 25 in the reproducing apparatus 23 decodes the double-scrambled disk key group 9 read from the disk 2 with the unique medium ID 3 read from the disk 2 as well. Scramble the disk key group (disk key block (DKB)) 26
(Corresponding to DKB7). It should be noted that, for example, the descrambler 300 shown in FIG. 3 can be applied to the descramble processing described above.

Next, a disc key decryption unit (Disc Key Decryption) 27 in the reproducing apparatus 23 decodes a disk key block (DKB) 26 with a device key 24 of the reproducing apparatus 23 and disc keys 28 (corresponding to the disk key 4). Restore).

In order to match the decrypted disk key 28 with the unique disk key 17 for each disk 2 used on the recording side, a unique medium key processing is performed using the unique medium ID 3 read from the disk 2. (Process Unique Media Ke
y) Processed at 29 to obtain a unique disk key 17. In this processing, for example, the EO shown in FIG.
It is possible to apply the processing by R601. In this case, the unique disk key 17 can be restored by inputting the disk key 28 as the key information and the unique / media / ID3 as the medium identification information into the EOR 601.

Next, the encrypted title key 20 recorded on the disk 2 is read. Since the encrypted title key 20 is encrypted with the unique disc key 17,
Unique media key processing unit (Process Uni)
The title key decryption unit (Title Key Decryption) 30 decrypts the encrypted title key 20 into the original title key 18 using the unique disc key 17 output from the “que Media Key” 29.

From the disk 2, the encrypted AV contents 31
Since the encrypted AV content 31 is scrambled with the title key 18, the content decryption unit (Contents Encryption) 32 descrambles using the decrypted title key 18 to obtain the AV content 21.

In the above description, the scrambler performs processing by generating an M-sequence random number with key data as an initial value and taking EOR with data to be scrambled.
On the other hand, the descrambler, like the scrambler, generates an M-sequence random number with key data as an initial value and performs EOR with the data to be scrambled, so that the M-sequence data is synchronized with the scrambler, so that the data is restored. be able to. In addition, a unique disk key can be obtained by taking a unique key, a medium ID, and an EOR different for each disk.

According to the present invention, as described above, unique data (unique media ID) is recorded for each disc, and a plurality of disc key groups (DKB) scrambled by the ID are scrambled twice. Therefore, the scrambled DKB data on the medium is different for each disc. Therefore, even if the entire disc is copied to another disc including the scrambled content data or the title key data including the scrambled DKB data, the unique media / ID of the copy destination is not changed to the copy source. Unique
The disk key block cannot be restored correctly because it is completely different from the media ID. If the disk key block cannot be correctly restored, the title key data and the scrambled content data cannot be restored, thereby preventing copy.

Unlike DVD-RAM, M of DVD-RW
Although the KB recording area is rewritable, even if the double-encrypted disk key block written therein is altered, the relationship between the unique media / ID and the double-encrypted disk key block is changed. Unless the (encryption algorithm) is known, correctly modified disk key block data cannot be obtained. In other words, a DVD-RW medium that is rewritable in all areas on the medium is a DV-RW medium without using an Emboss-pitt, which has no technical prospect.
The same copy protection as the D-RAM can be realized.

Since the present invention has the above-described configuration,
It is not necessary to use a medium having a special structure that balances the performance of the ROM area and the RAM area, such as a DVD-RAM, and also achieves the compatibility of the performance. The medium can be rewritten in all areas (Unique). Media ID
It is possible to realize copy protection of a rewritable medium as it is (except for the area), and since the area is rewritable in all areas on the medium, there is no need to separate standards between the ROM area and the RAM area. Uniq such as BCA
Since the data in which the disk key block is double-scrambled according to the ue Media ID is different for each disk, even if the entire disk including the DKB area is copied, the disk key block cannot be recovered correctly, so that the content data cannot be recovered. That is, since the data recorded on each disk is a scrambled DKB, the strength against hacking is increased as compared with the case where the conventional DKB data is recorded. Further, since the disk key block is used, the device key may be different between the recorder and the player.

[0052]

Since the present invention has the above-described configuration, it is possible to realize copy protection of a rewritable medium, and since recorded data is different for each disc, even if the entire disc is copied, the content data is not changed. Since restoration cannot be performed correctly, strong copy protection becomes possible, and furthermore, since the disk key block is used, regular reproduction is possible even if the device key is different between the recorder and the player.

[0053]

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a scrambler.

FIG. 3 is a diagram illustrating an example of a descrambler.

FIG. 4 is a diagram illustrating an example of a PN random number generation unit.

FIG. 5 is a diagram illustrating an example of a calculation process.

FIG. 6 is a diagram illustrating an example of application of CSS to DVD-Video (ROM).

FIG. 7 is a diagram illustrating copy guard of a DVD-RAM.

FIG. 8 is a diagram for explaining bit-by-bit copy.

FIG. 9 is a diagram showing a physical layout of a disk.

FIG. 10 is a diagram showing an output of the PN random number generation means 301 when the initial value is “0000”.

FIG. 11 is a diagram showing an output of the PN random number generation means 301 when the initial value is “1001”.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disc maker 2 ... Disc 3 ... Unique media ID 4 ... Disc key 5-1 to 5-n ... Device key 6 ... Disc key encryption means 7 ... Disc key block (DKB) 8 ... Encryption means 9 ... Encrypted DKB 10 ... Recorder 11 ... DKB decryption means 12 ... DKB 13 ... Disk key decryption means 14 ... Device key 15 ... Disk key 16 ... Unique media key processing means 17 ... Unique disk key 18 ... Title key 19 ... Title encryption means 20 Encrypted title key 21 AV content 22 Content encryption means 23 Playback device 25 Device key 25 DKB decryption means 26 DKB 27 Disc key decryption means 28 Disk key 29 Unique media key processing means 30 Title key decryption means 31 ... Encrypted AV Content 32 ... AV content decoding means

Claims (11)

[Claims] 1. A first area which is a non-rewritable non-data area in which medium-specific data is recorded, and a first area obtained by encrypting first key data with second key data.
A second encrypted key data obtained by further encrypting the encrypted key data with the medium-specific data.
And an rewritable third area which is a user data recording area. 2. A non-rewritable non-data area in which medium-specific data is recorded, and a first key data obtained by encrypting first key data with second key data.
An information recording medium, further comprising: a second rewritable key data obtained by encrypting the encrypted key data with the medium-specific data; and a rewritable area in which user data is recorded. 3. The information recording medium according to claim 1, wherein the medium-specific data is a unique medium ID, the first key data is a single disk key, and the second key data is a single disk key. The key data is a plurality of device keys, the first encryption key data is an encryption disk key block obtained by encrypting the disk key with the plurality of device keys, and the second encryption key data is the encryption key data. Copy the disk key block to the unique media I
An information recording medium, which is a unique media encrypted disk key block encrypted in D. 4. A non-rewritable area having a data non-rewritable area and a data rewritable area, wherein the medium-specific data is recorded in the non-rewritable area, and the first key data is transferred to a plurality of second keys. A first encrypted key data encrypted by a data group, and a second encrypted key data further encrypted by the medium specific data;
A recording device for recording contents on an information recording medium in which said encrypted key data is recorded in said rewritable area in advance, for decrypting said first key data from said first encrypted key data. Storage means for storing any decryption key of the second key data group assigned in advance to the information storage medium; means for reading the medium-specific data from the information recording medium; Means for reading encryption key data; first decryption means for decrypting the first encryption key data using the read medium-specific data and the read second encryption key data; and the decryption key And second decryption means for decrypting the first key data using the decrypted first encrypted key data; and the decrypted first key data and Means for generating intermediate key data from the read and read medium-specific data; first encryption means for encrypting third key data different for each content determined by a user at the time of recording with the intermediate key data; Second encryption means for encrypting the content to be encrypted with the third key data, and the third key data encrypted by the first encryption means and encrypted by the second encryption means Recording means for recording the created content in the rewritable area of the information recording medium. 5. A non-rewritable area having a data non-rewritable area and a data rewritable area, wherein the medium-specific data is recorded in the non-rewritable area, and the first key data is transferred to a plurality of second keys. A first encrypted key data encrypted by a data group, and a second encrypted key data further encrypted by the medium specific data;
A recording method for recording content on an information recording medium in which encryption key data is recorded in the rewritable area in advance, wherein the medium-specific data is read from the recording medium; Reading the encrypted key data, decrypting the first encrypted key data using the read medium-specific data and the read second encrypted key data, and decrypting the first encrypted key data Decrypting the first key data by decrypting the first encrypted key data with one of the decryption keys of the second key data group assigned in advance for decrypting the first key data; And generating intermediate key data from the first key data and the medium-specific data. The third key data different for each content determined by a user at the time of recording is stored in the intermediate key. Generating third encrypted key data with the data, encrypting the content to be recorded with the third encrypted key data to generate encrypted content, and generating the third encrypted key data and the encrypted data. Recording a content in the rewritable area of the information recording medium. 6. A non-rewritable area having a data non-rewritable area and a data rewritable area, wherein the medium-specific data is recorded in the non-rewritable area, and the first key data is transferred to a plurality of second keys. A first encrypted key data encrypted by a data group, and a second encrypted key data further encrypted by the medium specific data;
An information recording medium in which the encryption key data of the above is recorded in advance in the rewritable area, wherein the first encryption key decrypts the second encryption key data with the medium-specific data when recording the content. Key data is further decrypted with the first key data decrypted with any decryption key of the second key data group assigned in advance and the intermediate key data generated using the medium-specific data. The rewritable area includes third encrypted key data obtained by encrypting third key data different for each content determined by the user, and encrypted content obtained by encrypting the content using the third key data as a key. An information recording medium recorded on a medium. 7. A medium having a data non-rewritable area and a data rewritable area, medium-specific data is recorded in said non-rewritable area, and first key data is transferred to a plurality of second keys. A first encrypted key data encrypted by a data group, and a second encrypted key data further encrypted by the medium specific data;
When recording the content on an information recording medium in which the encryption key data is recorded in advance in the rewritable area, the first encryption key obtained by decrypting the second encryption key data with the medium-specific data Data is recorded using the first key data decrypted with any of the first decryption keys of the second key data group to which data has been allocated in advance and the intermediate key data generated using the medium-specific data. The third encrypted key data obtained by encrypting third key data different for each content determined by the user, and the encrypted content obtained by encrypting the content using the third key data as a key are rewritable. A reproducing apparatus for reproducing the content from an information recording medium recorded in an area, wherein the first encrypted key data is converted to the first key data. Storage means for storing a second decryption key of any of the second key data groups allocated in advance for decrypting the data, means for reading the medium-specific data from the information recording medium, Means for reading the second encrypted key data from the information recording medium; and a first means for decrypting the first encrypted key data using the read medium-specific data and the read second encrypted key data. A second decryption unit that decrypts the first key data using the second decryption key and the decrypted first encrypted key data; and a second decryption unit that decrypts the first key data and Means for generating the intermediate key data from the read medium-specific data; reading the third encrypted key data from the rewritable area; Third decryption means for decrypting the third key data using the encrypted key data and the intermediate key data, reading the encrypted content from the rewritable area, and decrypting the encrypted content by the third decryption means. A fourth decryption means for decrypting the content using the third key data and the encrypted content. 8. A medium having a data non-rewritable area and a data rewritable area, medium-specific data is recorded in the non-rewritable area, and first key data is transferred to a plurality of second keys. A first encrypted key data encrypted by a data group, and a second encrypted key data further encrypted by the medium specific data;
In recording the content on an information recording medium in which the encryption key data is recorded in the rewritable area in advance, the first encryption key data obtained by decrypting the second encryption key data with the medium-specific data Is the intermediate key data generated by using the first key data and the medium-specific data decrypted by any one of the first decryption keys in the second key data group, and Third encrypted key data obtained by encrypting third key data, which is different every time, and encrypted content obtained by encrypting the content using the third key data as a key are recorded in the rewritable area. A method of reproducing the content from the information recording medium, wherein the medium-specific data is read from the information recording medium, Reading the second encrypted key data from the medium, decrypting the first encrypted key data from the read medium-specific data and the read second encrypted key data, and decrypting the first encrypted key data. Of any of the second key data groups assigned in advance to
Decrypting the first key data using the decryption key and the first encrypted key data, generating the intermediate key data from the decrypted first key data and the read medium-specific data, The third key data is decrypted using the intermediate key data and the third encrypted key data, the encrypted content is read from the rewritable area, and the decrypted third key data and the encrypted And decoding the content by using the encrypted content. 9. A non-rewritable area having a data non-rewritable area and a data rewritable area, medium-specific data is recorded in the non-rewritable area, and a first rewritable area is written in the rewritable area. Recording using an information recording medium in which second encrypted key data obtained by encrypting first encrypted key data obtained by encrypting key data with a plurality of second key data groups with the medium-specific data is recorded in advance. A reproducing method, wherein when recording, the medium-specific data is read from the recording medium; the second encrypted key data is read from the recording medium; the read medium-specific data and the read second data are read. Decrypting the first encryption key data using the encryption key data of the second key data group, and the second key data group assigned in advance to decrypt the first encryption key data. And decrypting the first key data using the decryption key and the decrypted first encrypted key data, wherein the decrypted first key data and the read medium-specific data are decrypted. , Generating third encrypted key data by encrypting third key data, which is different for each content determined by the user at the time of recording, with the intermediate key data, and generating the third key data. Encrypting the data to generate encrypted content; recording the third encrypted key data and the encrypted content in a rewritable area of the recording medium; Reading the unique data, reading the second encrypted key data from the recording medium, and reading the read medium unique data and the read second Decrypting the first encrypted key data from the second encrypted key data, and performing a second decryption of any of the second key data groups previously allocated to decrypt the first encrypted data. Decrypting the first key data using a key and the decrypted first encrypted key data, generating the intermediate key data from the decrypted first key data and the read medium-specific data, The third key data is decrypted using the third encrypted key data and the intermediate key data read from the rewritable area of the recording medium, and the encryption read from the rewritable area of the recording medium is performed. Recording and reproducing the content using the encrypted content and the decrypted third key data. 10. A medium unique data is recorded in advance in a data non-rewritable area, and a first key data is encrypted with a plurality of second key data groups in a data rewritable area. The encrypted first encrypted key data, and the second encrypted key data obtained by further encrypting the encrypted first encrypted key data with the medium unique data are recorded in advance, and the medium unique data and the rewritable Transmitting the second encryption key data from the area, decrypting the first encryption key data using the transmitted medium-specific data and the transmitted second encryption key data, Decrypting the first key data using a decryption key that is any key data of the second key data group and the decrypted first encrypted key data; Generating intermediate key data from the transmitted first key data and the transmitted medium-specific data, encrypting third key data different for each content determined by a user at the time of recording with the intermediate key data, Generating encrypted key data; encrypting the content with the third key data to generate encrypted content; and transmitting the third encrypted key data and the encrypted content to the rewritable area. A transmission method characterized by the above-mentioned. 11. A data-unrewritable area has medium-specific data recorded in advance, and a data-rewritable area encrypts first key data with a plurality of second key data groups. The encrypted first encrypted key data, and the second encrypted key data obtained by further encrypting the encrypted first encrypted key data with the medium unique data are recorded in advance, and the medium unique data and the rewritable Transmitting the second encryption key data from the area, decrypting the first encryption key data using the transmitted medium-specific data and the transmitted second encryption key data, Decrypting the first key data using a first decryption key that is any key data of the second key data group and the decrypted first encrypted key data, Generating intermediate key data from the decrypted first key data and the transmitted medium specific data, encrypting third key data different for each content determined by a user at the time of recording with the intermediate key data, Generating the third encrypted key data, encrypting the content with the third key data to generate encrypted content, and transmitting the third encrypted key data and the encrypted content to the rewritable area. Transmitting the medium-specific data from the non-rewritable area, and transmitting the second encryption key data, the third encryption key data, and the encrypted content from the rewritable area; Decrypting the first encrypted key data using the medium-specific data and the transmitted second encrypted key data; Decrypting the first key data using a second decryption key that is any key data of the assigned second key data group and the decrypted first encrypted key data; Generating the intermediate key data from the decrypted first key data and the transmitted medium-specific data, and using the intermediate key data and the transmitted third encrypted key data to generate the third key data And decrypting the content using the decrypted third key data and the transmitted encrypted content.