JP2001211159A - Method and device for decipehring contents information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for contents information deciphering which can accurately reproduce (decipher) ciphered contents information only under regular restrictions. SOLUTION: Contents information is deciphered by using information on which a 1st key including ID information set as to obtain a specific authenticator value by a specific degeneration function is based and ciphered contents information generated by ciphering the contents information by using the 1st key generated from the information on which the 1st key is based and the specific authenticator value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a content key and a content information decryption method for reproducing (decrypting) encrypted content information encrypted using the content key, and a decryption apparatus. It is another object of the present invention to provide a content information decoding method and a decoding device that enable accurate reproduction (decoding) of content information only under proper restrictions.

[0002]

2. Description of the Related Art With the development of encryption technology, as a useful method of distributing audio and video digital data using a network, Japanese Patent Application Laid-Open No. 10-269289 discloses a digital content distribution management method, a digital content reproduction method and apparatus. There is. According to the present invention, the digital content distributor encrypts, compresses and processes the digital content, and transmits the processed digital content, the encrypted content key, and the encrypted billing information to the communication partner. Then, the usage fee collected based on the content usage information transmitted from the communication partner is distributed to the right holder. On the other hand, on the digital content reproducing side, the processed digital content is decrypted with the content key and decompressed and reproduced, and at the same time, the billing information is reduced and the content usage information is transmitted to the distribution side in accordance with the use of the content. So that the recorded content can be carried around.

In the information recording medium, recording apparatus, information transmission system, and decryption apparatus disclosed in Japanese Patent Application Laid-Open No. H10-283268, encrypted encrypted information and the encrypted information are decrypted into original information. And encryption key information obtained by encrypting the key information for use in recording the encryption key information, condition information for decrypting the encryption information in an unencrypted state is additionally recorded. You. That is, since device information and area information are included in the control information of the encryption key information, it is possible to prevent the user from directly copying the encrypted information to the HDD or optical disk and preventing unauthorized use. Like that.

[0004]

However, in the above-mentioned conventional method, the reproduction (decryption) of the encrypted content information is restricted so as to prevent the illegal reproduction (decryption) under a normal condition. However, the restriction information can be easily changed by a third party, and it has been difficult to properly prevent reproduction (decryption) under unauthorized conditions. The present invention provides a content information decoding method that more reliably prevents reproduction (decryption) of content information under unauthorized conditions, and enables accurate reproduction (decryption) under normal conditions.
And a decoding device.

[0005]

Accordingly, in order to solve the above-mentioned problems, the present invention provides the following methods and apparatuses. (1) information as a base of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function, and information as a base of the first key, A decryption method for decrypting the content information using encrypted content information obtained by encrypting content information using a first key generated from a specific authenticator value, wherein the first key From the ID information included in the information based on, to generate the specific authenticator value by the predetermined degenerate function,
The first key is generated from the generated specific authenticator value and information on which the first key is based, and the generated first key is generated.
Decrypting the encrypted content information with the key of (i) to obtain the content information. (2) An encryption obtained by encrypting at least the ID information part with respect to information serving as a basis of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. Of the content information using a first key generated from the information forming the first key and the information forming the first key and the specific authenticator value. A decryption method for decrypting the content information by using the encrypted content information, and decrypting the information that is the source of the encrypted first key to obtain the information that is the source of the first key. And obtaining the specific authenticator value from the ID information included in the decrypted first key information by the predetermined degenerate function. The first key is generated from the information on which the first key is based, and the generated first key is generated. A content information decoding method, wherein the content information is obtained by decrypting the encrypted content information with a first key. (3) An encryption obtained by encrypting at least the ID information portion with respect to information serving as a source of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. Of the content information using a first key generated from the information forming the first key and the information forming the first key and the specific authenticator value. A decryption device that decrypts the content information by using the encrypted content information, and decrypts the information that is the basis of the encrypted first key, and decrypts the information that is the basis of the first key. First key information decryption means for obtaining, and an authenticator value for generating the specific authenticator value by the predetermined degenerate function from the ID information included in the information on which the decrypted first key is based Generating means for obtaining the generated specific authenticator value and the decrypted first key; First key generation means for generating the first key from the generated information, and content information decryption means for decrypting the encrypted content information with the generated first key to obtain the content information. A content information decoding device, comprising: (4) Generated from information as a base of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function, and information as a base of the first key A decryption method for decrypting the content information using encrypted content information obtained by encrypting the content information using the obtained first key, the decryption method including: The specific authenticator value is generated from the ID information obtained by the predetermined degenerate function, the first key is generated from information on which the first key is based, and the specific authenticator value is Supplying the generated specific authenticator value and inputting the generated first key to a first key processing step of outputting the input without converting the input only when supplied; The encrypted content information is decrypted with the first key having passed through the Obtaining content information, the content information decryption wherein the. (5) An encryption obtained by encrypting at least the ID information portion with respect to information serving as a source of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. Using the information that is the source of the encrypted first key and the encrypted content information that is obtained by encrypting the content information using the first key that is generated from the information that is the source of the first key. A decoding method for decoding the content information,
Decrypting the information forming the basis of the encrypted first key to obtain the information forming the basis of the first key, wherein the ID information contained in the decoded information forming the basis of the first key; Generating the specific authenticator value from the predetermined degenerate function, generating the first key from the information based on the decrypted first key, and supplying the specific authenticator value. The first key processing step of supplying the generated specific authenticator value and inputting the generated first key to a first key processing step of outputting the input without converting the input only when the Decrypting the encrypted content information with the first key that has passed through to obtain the content information. (6) An encryption obtained by encrypting at least the ID information portion with respect to information serving as a source of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. Using the information that is the source of the encrypted first key and the encrypted content information that is obtained by encrypting the content information using the first key that is generated from the information that is the source of the first key. A decoding device for decoding the content information,
First key information decryption means for decrypting the information underlying the encrypted first key to obtain the information underlying the first key; An authenticator value generating means for generating the specific authenticator value by the predetermined degenerate function from the ID information included in the first information; and the first information from the information based on the decrypted first key. First key generating means for generating a key of the first type, and processing means for outputting an input without converting the input only when the specific authenticator value is supplied, wherein the generated specific authenticator value is supplied. Along with
Decrypting the encrypted content information with a first key processing unit to which a first key generated by the first key generation unit is input, and a first key output from the first key processing unit; And a content information decoding unit for obtaining the content information by using the content information decoding device. (7) Generated from information serving as a base of a first key including ID information set to obtain a specific authenticator value by a predetermined degenerate function, and information serving as a base of the first key A decryption method for decrypting the content information using encrypted content information obtained by encrypting the content information using the obtained first key, the decryption method including: Generating the specific authenticator value from the ID information obtained by the predetermined degenerate function, generating the first key from information on which the first key is based, and generating the specific authenticator It is determined whether or not the value is a valid authenticator value, and only when it is determined that the value is a valid authenticator value, the encrypted content information is decrypted with the generated first key and the content information is decrypted. A content information decryption method. (8) An encryption obtained by encrypting at least the ID information portion with respect to information serving as a source of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. Using the information that is the source of the encrypted first key and the encrypted content information that is obtained by encrypting the content information using the first key that is generated from the information that is the source of the first key. A decoding method for decoding the content information,
Decrypting the information forming the basis of the encrypted first key to obtain the information forming the basis of the first key, wherein the ID information contained in the decoded information forming the basis of the first key; Generating the specific authenticator value from the predetermined degenerate function, generating the first key from the information on which the decrypted first key is based, and generating the specific authenticator value. Determining whether or not the valid authenticator value, only when it is determined to be a valid authenticator value, decrypts the encrypted content information with the generated first key to obtain the content information, A content information decoding method, characterized in that: (9) A cipher obtained by encrypting at least the ID information portion with respect to information serving as a source of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. Using the information that is the source of the encrypted first key and the encrypted content information that is obtained by encrypting the content information using the first key that is generated from the information that is the source of the first key. A decoding device for decoding the content information,
First key information decryption means for decrypting the information forming the basis of the encrypted first key to obtain the information forming the basis of the first key; An authenticator value generating means for generating the specific authenticator value by the predetermined degenerate function from the ID information included in the first information; and the first information from the information based on the decrypted first key. First key generation means for generating the key of the above, a determination means for determining whether or not the generated specific authenticator value is a valid authenticator value, and the determination means being a valid authenticator value And a content information decrypting unit for decrypting the encrypted content information with the first key generated by the first key generating unit and obtaining the content information only when it is determined that Content information decoding device. (10) The ID information includes information on a region that defines one or more countries, regions, and spaces, information on an identification ID of an individual, information on an identification ID for identifying a group of a plurality of people, information on a rating, information on a device manufacturer, ID
Information, information about the content provider's ID, information about the time, information about the content author, information about the unique ID of the playback device that plays the content, information about the unique ID of the connected device, and the unique ID of the media on which the content is recorded (1) characterized in that the information is at least one of the following:
The content information decoding method described in the above, the content information decoding method described in the above (2), the content information decoding device described in the above (3), the content information decoding method described in the above (4), or the above ( 5) The content information decoding method described in the above, or the content information decoding device described in the above (6), the content information decoding method described in the above (7), or the content information decoding method described in the above (8), or The content information decoding device according to the above (9).

[0006]

FIG. 1 shows a schematic configuration of a first embodiment of a content information decoding apparatus according to the present invention. In this description, a magnetic recording medium, an optical recording medium, a semiconductor memory and the like are referred to as a recording medium, and a transmission medium for transmitting signals such as an optical cable, an electric wire, and a wireless transmission path is referred to as a transmission path.

First, the recording side or the transmission side (transmission side) will be described. As shown in FIG. 1, a one-way function operation device 1
Creates a primitive key from a source information of the first key by using a one-way function. The information on which the first key is based is:
For example, as shown in FIG. 3, a 16-bit content provider ID and a 16-bit content
It consists of a total of 56 bits including an ID, a 4-bit maker ID, and 20-bit information unique to the system.

A one-way function can also be expressed as a one-way hash function. Given a function h and a certain value x in its domain, find y such that h (x) = h (y). Is a difficult function. After the content is compressed by a predetermined compression method such as MPEG, encryption such as DES is used. DES
The encryption system is a typical common key encryption system adopted in the United States Federal Government in 1977, and is a block encryption system that performs encryption and decryption in 64-bit units using a 56-bit key. Encryption uses 64 bit equivalence to 32
It is composed of transpose, permutation, non-linear function, and exclusive OR by dividing into bits. For example, in the case of DES, the encryption key has about 56 bits. Therefore, as the information that becomes the basis of the first key such that the number of output bits of the one-way function becomes 56 bits, for example, the entire length is 56-bit information as shown in FIG.

[0009] The primitive key generated by the one-way function operation device 1 is input to the content key generator 2. The content key generator 2 stores a predetermined authenticator value in an authenticator generator 3 having a memory or a CPU.
Is entered from

A predetermined authenticator value (specific authenticator value)
As described above, the ID information serving as a parameter of the degeneration function (the ID information included in the information on which the first key is based: A content provider ID, a 16-bit content author ID, and a 4-bit maker ID) are set. This ID information is disclosed only to authorized users, and can be called authorized ID information.

The content key generator 2 generates a first key (content key) by a predetermined function using the input information on the original key and the information on the authenticator. For example, as shown in FIG. 4, a first key (content key) is generated by calculating an exclusive OR of the primitive key information and the authenticator information.

Using the generated first key, the content information is encrypted by the content information encryption device 4.
Then, the encrypted content information is recorded or transmitted.
An encryption method such as DES is used for encryption.

The information recorded on the recording medium or transmitted by the transmission medium is the encrypted content information (encrypted content information) and the information on which the first key is based. It should be noted that the information that forms the first key is the information that forms the first key that is encrypted by encrypting at least the ID information portion (the information that forms the first encryption key). ) May be recorded or transmitted.

Next, the reproduction side or the reception side will be described.
A source key is generated by the one-way function calculation device 5 using a one-way function from information that is the basis of the first key reproduced from the recording medium or transmitted by the transmission medium. When the information that is the basis of the encrypted first key is supplied, the source key is generated after the information is decrypted to obtain the information that is the basis of the first key.

The authenticator value is generated by the degenerate function operation device 6 using the ID information included in the information on which the first key is based. The degeneracy function used in the degeneration function operation device 6 may be a different function from the one-way function used in the one-way function operation device 5.

The degeneration function is, for example, as shown in FIG.
16-bit content provider ID that is information,
Similarly, a function for calculating an exclusive OR of information of a 16-bit content author ID and a 4-bit manufacturer ID may be used.

The information on the primitive key generated by the one-way function calculating device 5 and the information on the authenticator value generated by the degenerate function calculating device 6 are input to the content key generator 7 and are subjected to a predetermined function. A first key (content key) is generated. The predetermined function may be, for example, a function that calculates an exclusive OR of two pieces of information of the primitive key information and the authenticator value information shown in FIG.

The generated first key (content key)
, The content information decrypting device 8 decrypts the encrypted content information reproduced from the recording medium or transmitted by the transmission medium. This makes it possible to reproduce the content information.

As described above, the value of the ID information included in the information based on the first key is set so that a predetermined authenticator value (specific authenticator value) can be obtained by a predetermined degenerate function. Have been. This ID information is disclosed only to authorized users. Therefore, even if an unauthorized user tries to decrypt the encrypted content information with the appropriate value of ID information,
Since a specific authenticator value cannot be obtained, decryption cannot be performed. In addition, since the information of the predetermined degenerate function is also disclosed only to the authorized user, even if the value of the ID information is leaked, it is not possible to immediately obtain the authorized specific authenticator value from the information. Absent. As described above, the above-described embodiment can more reliably prevent reproduction (decryption) of content information under unauthorized conditions, and can accurately reproduce (decode) content information under normal conditions. .

Next, a second embodiment will be described with reference to FIG. In this embodiment, on the encryption side of the content information, the authenticator value is not reflected in the generation of the first key (content key). 2, the same parts as those in FIG. 1 are denoted by the same reference numerals.

First, the recording side or the transmission side (transmission side) will be described. As shown in FIG. 2, the one-way function operation device 1
Creates a primitive key from a source information of the first key by using a one-way function. The information on which the first key is based is:
For example, as shown in FIG. 3, a 16-bit content provider ID and a 16-bit content
It consists of a total of 56 bits including an ID, a 4-bit maker ID, and 20-bit information unique to the system.

The original key generated by the one-way function operation device 1 becomes a first key (content key) as it is, and the content information is encrypted by the content information encryption device 4 using the first key. . Then, the encrypted content information is recorded or transmitted. An encryption method such as DES is used for encryption.

It should be noted that the ID information (the content provider ID, which is also 1
The content author ID of 6 bits and the manufacturer ID of 4 bits) are parameters of a predetermined degeneracy function on the reproduction side as in the first embodiment, and the value of the ID information is a predetermined predetermined value. The authenticator value (specific authenticator value) is set so as to be obtained by a predetermined degenerate function.
This ID information is of course disclosed only to authorized users.

The information recorded on the recording medium or transmitted by the transmission medium is the encrypted content information (encrypted content information) and the information on which the first key is based. It should be noted that the information that forms the first key is the information that forms the first key that is encrypted by encrypting at least the ID information portion (the information that forms the first encryption key). ) May be recorded or transmitted.

Next, the reproduction side or the reception side will be described.
A source key is generated by the one-way function calculation device 5 using a one-way function from information that is the basis of the first key reproduced from the recording medium or transmitted by the transmission medium. This primitive key is the first key (content key)
Becomes When the information that is the basis of the encrypted first key is supplied, the source key is generated after the information is decrypted to obtain the information that is the basis of the first key.

The authenticator value is generated by the degenerate function operation device 6 using the ID information included in the information on which the first key is based. The degeneracy function used in the degeneration function operation device 6 may be a different function from the one-way function used in the one-way function operation device 5.

The degenerate function is, for example, as shown in FIG.
6-bit content provider ID, 16-bit content author ID, and 4-bit manufacturer ID
A function that obtains the exclusive OR of the information of the two may be used.

The primitive key generated by the one-way function operation device 5, that is, the information of the first key (content key), and the information of the authenticator value generated by the degeneration function operation device 6,
It is input to the content key processor 11. The content key processor 11 outputs the input first key (content key) information as it is only when the information of the predetermined specific authentication value element is supplied. When information other than the value element is supplied, the input first key information is processed (changed in value) and output.

Using the first key (content key) output from the content key processor 11, the encrypted content information reproduced from the recording medium or transmitted by the transmission medium is decoded by the content information decryption device 8. Decrypt.
If a legitimate specific authentication value element is supplied to the content key processor 11, a correct first key (content key) is input to the content information decryption device 8, thereby enabling the content information to be reproduced. Become.

As described above, according to the present embodiment, the encrypted content information cannot be decrypted unless a proper specific authentication value is obtained, and the reproduction (decryption) of the content information under an illegal condition is performed. This makes it possible to prevent the failure more reliably and to accurately perform reproduction (decoding) under normal conditions.

Next, a third embodiment will be described with reference to FIG. In the present embodiment, the encrypting side (recording side or transmitting side) of the content information is the same as that of the second embodiment shown in FIG. 2, so that the reproducing side or the receiving side will be described here.

A source key is generated by the one-way function calculating device 5 using a one-way function from the information which is the basis of the first key reproduced from the recording medium or transmitted by the transmission medium. . This primitive key becomes the first key (content key) as it is. When the information that is the basis of the encrypted first key is supplied, the source key is generated after the information is decrypted to obtain the information that is the basis of the first key.

Further, an authenticator value is generated by the degenerate function operation device 6 using the ID information included in the information on which the first key is based. The degeneracy function used in the degeneration function operation device 6 may be a different function from the one-way function used in the one-way function operation device 5.

For example, as shown in FIG.
6-bit content provider ID, 16-bit content author ID, and 4-bit manufacturer ID
A function that obtains the exclusive OR of the information of the two may be used.

The authenticator value generated by the degenerate function operation device 6 is supplied to the authenticator value validity judging unit 12, where it is judged whether or not the authenticator value is a specific authenticated authenticator. The determination result of the authenticator value validity determiner 12 is supplied to the content information decryption device 8a, and the content information decryption device 8a performs the decryption operation only when the determination result is “a specific specific authentication value child”. .

The result of the above determination is "authorized specific authentication value child".
In the case of, the content information decryption device 8a uses the first key (content key) generated by the one-way function calculation device 5 to reproduce the content information from the recording medium or to transmit the content information over the transmission medium. Decrypt the encrypted content information. This makes it possible to reproduce the content information.

As described above, according to the present embodiment, the encrypted content information cannot be decrypted unless a proper specific authentication value is obtained, and the reproduction (decryption) of the content information under an illegal condition is not performed. This makes it possible to prevent the failure more reliably and to accurately perform reproduction (decoding) under normal conditions.

The ID information included in the information forming the first key includes information on one or more countries, regions, regions that define a space, information on an individual identification ID, information on a plurality of persons, Information about the ID that identifies the group,
Information about the rating, information about the identification ID of the device manufacturer, information about the identification ID of the content provider, information about the time, information about the content author, information about the unique ID of the playback device that plays back the content, information about the unique ID of the connected device, It is conceivable to use at least one of information on a unique ID of a medium on which content is recorded, information on an ID for identifying the content, and information on billing.

[0039]

As described above, according to the present invention, the regular ID
Since the encrypted content information cannot be decrypted unless a specific authenticated authenticator based on the information is obtained, the reproduction (decryption) of the content information under an illegal condition is more reliably prevented, and the legitimate condition is satisfied. (Decoding) can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment.

FIG. 2 is a diagram showing a schematic configuration of a second embodiment.

FIG. 3 is a diagram illustrating a configuration example of information serving as a base of a first key;

FIG. 4 is an explanatory diagram of a content key generator on the encryption side shown in FIG. 1;

FIG. 5 is an explanatory diagram of a content key generator on the decryption side shown in FIG. 1;

FIG. 6 is a diagram illustrating an example of a degeneration function on the decoding side.

FIG. 7 is a diagram showing a schematic configuration of a third embodiment.

[Explanation of symbols]

 1,5 One-way function operation device 2,7 Content key generator 3 Authenticator value generator 4 Encryption device 6 Degeneration function operation device 8 Content information decryption device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/173 630 H04L 9/00 673B H04N 5/92 H 7/167 Z (72) Inventor Kenjiro Ueda Kanagawa 3-12-12 Moriyacho, Kanagawa-ku, Yokohama, Japan (72) Inventor Seiji Higurashi 3-12-12 Moriyacho, Kanagawa-ku, Yokohama, Kanagawa, Japan F-term (reference) 5B017 AA03 AA07 BA07 BB09 CA16 5C053 FA13 FA22 FA24 FA29 GA11 GB22 GB37 JA21 5C064 BA01 BB01 BB02 BC17 BC22 BD04 BD08 CA14 5J104 AA07 AA12 EA26 JA01 JA18 KA03 NA02 NA11 PA11

Claims (10)

[Claims] 1. Information based on a first key including ID information set so that a specific authenticator value can be obtained by a predetermined degenerate function, and information based on the first key. A decryption method of decrypting the content information using encrypted content information obtained by encrypting content information using a first key generated from the first authenticator value and the first authenticator value; Generating the specific authenticator value by the predetermined degenerate function from the ID information included in the information on which the key is based, based on the generated specific authenticator value and the first key. And generating said first key from said information, and decrypting said encrypted content information with said generated first key to obtain said content information. 2. The method according to claim 1, wherein at least said ID information portion is encrypted with respect to information serving as a basis of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. And encrypting the content information using a first key generated from the encrypted information of the first key, the information of the first key, and the specific authenticator value. A decryption method for decrypting the content information using the encrypted encrypted content information, wherein the information that is the basis of the encrypted first key is decrypted to be the basis of the first key. Information, and the decrypted first key contains
From the ID information, the specific authenticator value is generated by the predetermined degenerate function, and the first key is obtained from the generated specific authenticator value and the information on which the decrypted first key is based. And generating the content information by decrypting the encrypted content information with the generated first key. 3. The method according to claim 1, wherein at least said ID information portion is encrypted with respect to information based on a first key including ID information set such that a specific authenticator value is obtained by a predetermined degenerate function. And encrypting the content information using a first key generated from the encrypted information of the first key, the information of the first key, and the specific authenticator value. A decryption device that decrypts the content information using the encrypted encrypted content information, and decrypts the information that is the basis of the encrypted first key to be the basis of the first key. First key information decryption means for obtaining information; and the key information decryption means included in the decrypted first key information.
An authenticator value generating means for generating the specific authenticator value from the ID information by the predetermined degenerate function; and determining from the generated specific authenticator value and information serving as a basis for the decrypted first key. A first key generation unit that generates the first key; and a content information decryption unit that decrypts the encrypted content information with the generated first key to obtain the content information. Characteristic content information decoding device. 4. An information serving as a base of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function, and information serving as a base of the first key. A decryption method for decrypting the content information using encrypted content information obtained by encrypting content information using a first key generated from the first key, wherein the information serving as a source of the first key is provided. Generating the specific authenticator value by the predetermined degenerate function from the ID information included in the ID information; generating the first key from information on which the first key is based; Supplying the generated specific authenticator value and inputting the generated first key to a first key processing step of outputting the input without converting the input only when the value is supplied; Decrypts the encrypted content information using the first key that has passed through the key processing step. The obtained content information, the content information decryption wherein the by. 5. A method according to claim 1, wherein at least said ID information portion is encrypted with respect to information serving as a source of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. And the encrypted content information obtained by encrypting the content information using the first key generated from the information forming the first key. A decryption method for decrypting the content information using the decrypted first key, and obtaining the information underlying the first key by decrypting the information underlying the encrypted first key; The key included in the key information
The specific authenticator value is generated from the ID information by the predetermined degenerate function, the first key is generated from the information on which the decrypted first key is based, and the specific authenticator value is Supplying the generated specific authenticator value and inputting the generated first key to a first key processing step of outputting the input without converting the input only when supplied; A content information decryption method, wherein the content information is obtained by decrypting the encrypted content information using a first key that has undergone a processing step. 6. A method according to claim 1, wherein at least said ID information portion is encrypted with respect to information serving as a basis of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. And the encrypted content information obtained by encrypting the content information using the first key generated from the information forming the first key. A decryption device for decrypting the content information using the first key information, the first key information being used to decrypt the information underlying the first encrypted key to obtain the information underlying the first key. Decryption means; and the decryption means includes the decrypted first key.
An authenticator value generating means for generating the specific authenticator value from the ID information by the predetermined degenerate function; a first key for generating the first key from the information on which the decrypted first key is based Key generating means, and processing means for outputting an input without conversion only when the specific authenticator value is supplied, wherein the generated specific authenticator value is supplied and the first authenticator value is supplied. A first key processing unit to which the first key generated by the key generation unit is input, and the content information by decrypting the encrypted content information with the first key output from the first key processing unit And a content information decoding unit for obtaining the content information. 7. A first key based information including ID information set so that a specific authenticator value can be obtained by a predetermined degenerate function, and a first key based information. A decryption method for decrypting the content information using encrypted content information obtained by encrypting content information using a first key generated from the first key, wherein the information serving as a source of the first key is provided. Generating the specific authenticator value by the predetermined degenerate function from the ID information included in the first key; generating the first key from information on which the first key is based; It is determined whether or not the authenticator value is a valid authenticator value. Only when it is determined that the authenticator value is a valid authenticator value, the encrypted content information is decrypted by using the generated first key and the content is decrypted. Content information decryption characterized by obtaining information Law. 8. A method according to claim 1, wherein at least said ID information portion is encrypted with respect to information based on a first key including ID information set to obtain a specific authenticator value by a predetermined degenerate function. And the encrypted content information obtained by encrypting the content information using the first key generated from the information forming the first key. A decryption method for decrypting the content information using the decrypted first key, and obtaining the information underlying the first key by decrypting the information underlying the encrypted first key; The key included in the key information
Generating the specific authenticator value from the ID information using the predetermined degenerate function; generating the first key from the information on which the decrypted first key is based; It is determined whether or not the value is a valid authenticator value. Only when it is determined that the value is a valid authenticator value, the encrypted content information is decrypted with the generated first key, and the content information is decrypted. A content information decryption method. 9. A method according to claim 1, wherein at least said ID information portion is encrypted with respect to information serving as a basis of a first key including ID information set so as to obtain a specific authenticator value by a predetermined degenerate function. And the encrypted content information obtained by encrypting the content information using the first key generated from the information forming the first key. A decryption device for decrypting the content information using the first key information, the first key information being used to decrypt the information underlying the first encrypted key to obtain the information underlying the first key. Decryption means; and the decryption means includes the decrypted first key.
An authenticator value generating means for generating the specific authenticator value from the ID information by the predetermined degenerate function; a first key for generating the first key from the information on which the decrypted first key is based Key generating means, and determining means for determining whether the generated specific authenticator value is a valid authenticator value. Only when the determining means determines that the authenticator value is a valid authenticator value, A content information decryption apparatus, comprising: content information decryption means for decrypting the encrypted content information with the first key generated by the first key generation means to obtain the content information. 10. The ID information includes information relating to a region defining one or more countries, regions, spaces, information relating to individual identification IDs, information relating to identification IDs identifying a plurality of groups, information relating to ratings, and equipment. Information about the manufacturer's ID, information about the content provider's ID, information about the time, information about the content author, information specific to the playback device that plays the content
The information is at least one of information on ID, information on a unique ID of a connected device, information on a unique ID of a medium on which the content is recorded, information on an ID for identifying the content, and information on charging. A content information decoding method according to claim 1, a content information decoding method according to claim 2, a content information decoding device according to claim 3, or a content information decoding method according to claim 4, or The content information decoding method according to claim 5, the content information decoding device according to claim 6, the content information decoding method according to claim 7, the content information decoding method according to claim 8, or the claim 9. Content information decryption apparatus.