JP2006100937A - Information distribution system and method, information processor and processing method, receiver and receiving method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate management of license because considerable time is required for searching a license. <P>SOLUTION: A group management device 11 forms a group ID<SB>G</SB>and a group key K<SB>G</SB>, and a content distribution apparatus 12 stores a content ID<SB>C</SB>, the group ID<SB>G</SB>, a content key K<SB>C</SB>encrypted with the group key K<SB>G</SB>, and a content encrypted with the content key K<SB>C</SB>and then transmits them to a reproducing apparatus 14. A license information distribution apparatus 13 transmits the group key K<SB>G</SB>encrypted with a common key K<SB>P</SB>, the group ID<SB>G</SB>, and a license ID<SB>L</SB>to the reproducing apparatus 14. The reproducing apparatus 14 decrypts the group key K<SB>G</SB>encrypted with the common key K<SB>P</SB>corresponding to the group ID<SB>G</SB>to which a content to be reproduced belongs, decrypts the content key K<SB>C</SB>encrypted with the group key K<SB>G</SB>with the group key K<SB>G</SB>, and decrypts an encrypted content with the content key K<SB>C</SB>. The invention is applicable to an information processor for distributing a content. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an information distribution system and an information distribution method, an information processing apparatus and an information processing method, a reception apparatus and a reception method, and a program, and in particular, an information distribution system, an information distribution method, and an information that can easily manage licenses The present invention relates to a processing device, an information processing method, a receiving device, a receiving method, and a program.

  Conventionally, a technique for preventing unauthorized use of content by issuing a license for each content has been disclosed (see, for example, Patent Document 1).

  However, when the number of contents to be managed is large, the number of licenses generated by the license generation apparatus increases in proportion thereto, and there is a problem that management is troublesome.

Therefore, a method for generating one license for a plurality of contents has been proposed.
JP 2003-216828 A

  However, when reproducing a content in a system that generates one license for a plurality of contents, there is a problem that it takes a long time for the reproducing apparatus to search for a license corresponding to the content to be reproduced. For example, in the OpenMG (trademark) system, since the license is encrypted, in order to search for a license corresponding to the content to be played, it is necessary to decrypt the encrypted license, and the number of licenses is There is a problem that it takes a long search time when there are many licenses or when the amount of license data is large.

  The present invention has been made in view of such a situation, and makes it possible to easily manage licenses.

  An information distribution system according to the present invention is an information distribution system including an information processing apparatus that distributes information and a reception apparatus that receives information distributed from the information processing apparatus, and the information processing apparatus is a group including a plurality of contents. Corresponding to a group ID generating unit that generates a group ID that is a unique ID, a group key generating unit that generates a group key corresponding to the group ID generated by the group ID generating unit, and a group ID of the group to which the content belongs Content key encryption means for encrypting the content key for encrypting the content using the group key to be encrypted, the content ID unique to the content, and the group of the group to which the content belongs Encrypted with the group key corresponding to the ID and group ID A distribution key storing the content key and the content encrypted with the content key as a distribution content, and a distribution content transmission for transmitting the distribution content stored in the distribution content storage unit to the receiving device Means, and a common key encryption means for encrypting a group key corresponding to the group ID to which the content of the distribution content stored in the distribution content storage means belongs with a common key held with the receiving device; A license information storage means for storing, as license information, a group key encrypted with the common key by the common key encryption means, a group ID corresponding to the group key, and a license ID that is an ID unique to the license information to be generated; Sends the license information stored in the license information storage means to the receiving device. A license information transmitting means for receiving, the receiving device is instructed to reproduce the distribution content transmitted from the distribution content transmitting means, the receiving means for receiving the license information transmitted from the license information transmitting means, A group key encrypted with a common key corresponding to the group ID of the group to which the content belongs is obtained from the license information received by the receiving means and decrypted with the common key held with the information processing apparatus A group key acquisition means for acquiring a group key in step S3, and a content key encrypted with the group key corresponding to the group ID is acquired from the distribution content and decrypted with the group key acquired by the group key acquisition means. Content key acquisition means for acquiring the content key with the content key and content encrypted with the content key. Content decrypting means for decrypting the content with the content key acquired by the content key acquiring means.

  An information distribution method of the present invention is an information distribution method of an information distribution system including an information processing apparatus that distributes information and a reception apparatus that receives information distributed from the information processing apparatus. A group ID generation step for generating a group ID that is an ID unique to a group consisting of content, a group key generation step for generating a group key corresponding to the group ID generated by the processing of the group ID generation step, and the content belongs A content key encryption step for encrypting a content key for encrypting content using a group key corresponding to the group ID of the group, a content encryption step for encrypting content with the content key, and a content-specific step Content ID, group to which the content belongs D, a content key encrypted with a group key corresponding to the group ID, and a distribution content storage for controlling storage in the distribution content storage unit so as to store the content encrypted with the content key as the distribution content A control step, a distribution content transmission step for transmitting the distribution content stored in the distribution content storage unit to the receiving device, and a group ID to which the content of the distribution content stored in the distribution content storage unit belongs. Corresponding to the common key encryption step that encrypts the corresponding group key with the common key held with the receiving device, and the group key and group key encrypted with the common key by the processing of the common key encryption step The group ID and the license ID that is unique to the license information to be generated are A license information storage control step for controlling storage in the license information storage unit so as to store the license information as license information, and a license information transmission step for transmitting the license information stored in the license information storage unit to the reception device. A distribution content reception step for receiving the distribution content transmitted by the processing of the distribution content transmission step, a license information reception step for receiving the license information transmitted by the processing of the license information transmission step, and reproduction. The group key encrypted with the common key corresponding to the group ID of the group to which the commanded content belongs is obtained from the license information received by the received license information reception step and held with the information processing device Decrypting with a common key A group key acquisition step for acquiring a loop key, and a content key encrypted with the group key corresponding to the group ID is acquired from the distribution content and decrypted with the group key acquired by the processing of the group key acquisition step. A content key acquiring step for acquiring the content key, and a content decrypting step for decrypting the content encrypted with the content key with the content key acquired by the processing of the content key acquiring step. .

  According to the first aspect of the present invention, the information processing apparatus generates a group ID and a group key corresponding to the group ID, encrypts the content key using the group key of the group to which the content belongs, and the content is the content key. Content ID, the group ID of the group to which the content belongs, the content key encrypted with the group key corresponding to the group ID, and the content encrypted with the content key are stored as distribution content and received. Sent to the device. The group key is encrypted with a common key held between the receiving device and the group key encrypted with the common key, the group ID corresponding to the group key, and the ID unique to the generated license information. The license ID is stored as license information and transmitted to the receiving device. Further, the receiving device receives the distribution content and the license information, and the group key encrypted with the common key corresponding to the group ID of the group to which the content commanded to play belongs is acquired from the license information, The group key is obtained by decrypting with the common key, the content key encrypted with the group key corresponding to the group ID is obtained from the content for distribution, the content key is obtained by decrypting with the group key, and the content key The content encrypted with is decrypted with the content key.

  The first information processing apparatus according to the present invention includes a group ID generation unit that generates a group ID that is an ID unique to a group including a plurality of contents, and a group ID that is generated by the group ID generation unit. Group key generation means for generating a group key used for encrypting a content key for encryption, grouping information for grouping a plurality of contents, a group ID, and a group key are associated with each other And group information storage means for storing the information as group information.

  Using a group key corresponding to the group ID of the group to which the content belongs, the content key for encrypting the content is encrypted, and content key encryption means for encrypting the content with the content key, Content ID storage unit for storing a content ID, a group ID corresponding to the group to which the content belongs, a content key encrypted with a group key corresponding to the group ID, and a content encrypted with the content key as distribution content And distribution content transmission means for transmitting the distribution content stored in the distribution content storage means to the receiving device.

  A common key encryption unit that encrypts a group key corresponding to a group ID to which the content of the distribution content stored in the distribution content storage unit belongs with a common key held with the receiving device, and a common key encryption A license information storage means for storing, as license information, a group key encrypted with a common key by the means, a group ID corresponding to the group key, and a license ID that is unique to the license information to be generated, and a license information storage means And license information transmission means for transmitting the license information stored in the receiving device to the receiving device.

  Content key encryption means, when the content does not belong to the group, the content for encrypting the content by using a temporary encryption key for encrypting the content key corresponding to the content ID unique to the content The content is encrypted with the content key, the content storage means for distribution encrypts the key with the content key, the content ID unique to the content, the content key encrypted with the temporary encryption key, and the content encrypted with the content key Can be stored as distribution content, and the distribution content transmission means can transmit the distribution content stored in the distribution content storage means to the receiving device.

  The common key encryption unit is a temporary encryption for encrypting a content key corresponding to a content ID unique to the content when the content of the distribution content stored in the distribution content storage unit does not belong to the group. The key is encrypted with the common key, and the license information storage means is a temporary encryption key encrypted with the common key by the common key encryption means, a content ID corresponding to the temporary encryption key, and an ID unique to the license information The license ID may be further stored as license information, and the license information transmission unit may transmit the license information stored in the license information storage unit to the receiving device.

  The grouping information stored by the group information storage means may further include a condition for grouping contents or a content ID belonging to the group.

  The license information stored in the license information storage means may further include a playback condition for the content that is permitted to be played back.

  The information processing method according to the present invention includes a group ID generation step for generating a group ID that is an ID unique to a group of a plurality of contents, and the group ID generated by the processing of the group ID generation step, and encrypts the contents. A group key generation step for generating a group key used for encrypting a content key for encryption, a grouping information for grouping a plurality of contents, a group ID, and a group key in association with each other, A group information storage control step for controlling storage in the group information storage unit so as to store the group information as group information.

  The first program of the present invention corresponds to a group ID generation step for generating a group ID that is an ID unique to a group consisting of a plurality of contents, and the group ID generated by the processing of the group ID generation step, A group key generation step for generating a group key used for encrypting a content key for encryption, and grouping information for grouping a plurality of contents, a group ID, and a group key are associated with each other And a group information storage control step for controlling storage in the group information storage unit so as to be stored as group information.

  In the second aspect of the present invention, a group ID that is an ID unique to a group of a plurality of contents is set, and a group key corresponding to the group ID and used for encrypting a content key for encrypting the content is The grouping information, group ID, and group key that are generated and group a plurality of contents are associated with each other and stored as group information.

  The second information processing apparatus of the present invention encrypts the content key for encrypting the content using the group key corresponding to the group ID of the group to which the content belongs, acquired from the group management device, A content key encrypting means for encrypting the content with a content key, a content ID unique to the content, a group ID corresponding to the group to which the content belongs, a content key encrypted with a group key corresponding to the group ID, and a content key A distribution content storage unit that stores the encrypted content as a distribution content, and a distribution content transmission unit that transmits the distribution content stored in the distribution content storage unit to the receiving device, To do.

  In the third aspect of the present invention, the content key is encrypted using the group key acquired from the group management device, the content is encrypted with the content key, the content ID, the group ID corresponding to the group to which the content belongs, The content key encrypted with the group key corresponding to the group ID and the content encrypted with the content key are stored as distribution content and transmitted to the receiving device.

  The third information processing apparatus of the present invention encrypts the group key corresponding to the group ID to which the content of the distribution content belongs, acquired from the content distribution apparatus, with the common key held with the reception apparatus. A license that stores, as license information, an encryption unit, a group key encrypted with a common key by the common key encryption unit, a group ID corresponding to the group key, and a license ID that is unique to the license information to be generated It is characterized by comprising information storage means and license information transmission means for transmitting the license information stored in the license information storage means to the receiving device.

  In the fourth aspect of the invention, the group key corresponding to the group ID to which the content acquired from the content distribution device belongs is encrypted with the common key held with the receiving device, and encrypted with the common key. A group key, a group ID corresponding to the group key, and a license ID that is an ID unique to the license information to be generated are stored as license information and transmitted to the receiving device.

  The receiving device of the present invention encrypts content encrypted with a content ID unique to the content transmitted from the information processing device, a group ID unique to the group to which the content belongs, and a group key corresponding to the group ID. And a distribution key consisting of a content key encrypted and a content encrypted with the content key, and corresponding to a group key and a group key encrypted with a common key held with the information processing apparatus A receiving unit that receives license information including a group ID and a license ID that is an ID unique to the license information, and a group key encrypted with a common key corresponding to the group ID of the group to which the content commanded to play belongs From the license information received by the receiving means A group key acquisition means for acquiring a group key by decrypting with a common key held between the device and a content key encrypted with a group key corresponding to the group ID from the distribution content, and a group key Content key acquisition means for acquiring a content key by decrypting with the group key acquired by the acquisition means, and content decryption for decoding content encrypted with the content key with the content key acquired by the content key acquisition means Means.

  The content key acquisition means acquires the content key encrypted with the common key from the license information and decrypts it with the common key held with the information processing apparatus when the content for which reproduction is instructed does not belong to the group Thus, the content key can be acquired, and the content decrypting unit can decrypt the content encrypted with the content key with the content key acquired by the content key acquiring unit.

  The license information received by the receiving means may further include a reproduction condition for the content to be permitted to be reproduced.

  The receiving method of the present invention encrypts content encrypted with a content ID unique to the content transmitted from the information processing apparatus, a group ID unique to the group to which the content belongs, and a group key corresponding to the group ID. A content key for encryption, and a distribution content reception step for receiving distribution content composed of content encrypted with the content key, and a group key encrypted with a common key held between the information processing devices, A license information receiving step for receiving license information consisting of a group ID corresponding to the group key and a license ID that is an ID unique to the license information, and a common key corresponding to the group ID of the group to which the content commanded to play belongs Receive the license information for the group key encrypted with A group key acquisition step for acquiring a group key by acquiring from the license information received by the processing of the step and decrypting with a common key held with the information processing device, and encryption with a group key corresponding to the group ID Content key acquisition step of acquiring the content key obtained from the distribution content and decrypting with the group key acquired by the processing of the group key acquisition step, and content encrypted with the content key Including a content decrypting step of decrypting with the content key acquired by the processing of the content key acquiring step.

  The second program of the present invention is a content ID encrypted with a content ID unique to the content transmitted from the information processing apparatus, a group ID unique to the group to which the content belongs, and a group key corresponding to the group ID. A group encrypted with a common key held between the content key for encrypting the content and the distribution content receiving step for receiving the distribution content composed of the content encrypted with the content key and the information processing device A license information receiving step of receiving a license information including a key, a group ID corresponding to the group key, and a license ID that is an ID unique to the license information, and a group ID of the group to which the content commanded to play belongs. A group key encrypted with a common key is licensed A group key acquisition step of acquiring a group key by decrypting with a common key acquired from the license information received by the processing of the information reception step, and a group key corresponding to the group ID A content key acquisition step for acquiring the content key by acquiring the encrypted content key from the distribution content and decrypting it with the group key acquired by the processing of the group key acquisition step; And a content decrypting step for decrypting the content with the content key acquired by the processing of the content key acquiring step.

  According to the fifth aspect of the present invention, the distribution content includes the content ID, the group ID of the group to which the content belongs, the content key encrypted with the group key corresponding to the group ID, and the content encrypted with the content key. The group key encrypted with the common key, the group ID corresponding to the group key, and the license information including the license ID are received and the common key corresponding to the group ID of the group to which the content commanded to play belongs. The encrypted group key is decrypted with the common key to obtain the group key, the content key encrypted with the group key is decrypted with the group key, the content key is obtained, and the content key is encrypted with the content key Is decrypted with the content key.

  According to the present invention, licenses can be managed. In particular, according to the present invention, licenses can be managed more easily. A plurality of licenses can be managed in a group.

  Embodiments of the present invention will be described below. The correspondence relationship between the invention described in this specification and the embodiments of the invention is exemplified as follows. This description is intended to confirm that the embodiments supporting the invention described in this specification are described in this specification. Therefore, even if there is an embodiment that is described in the embodiment of the invention but is not described here as corresponding to the invention, the fact that the embodiment is not It does not mean that it does not correspond to the invention. Conversely, even if an embodiment is described herein as corresponding to an invention, that means that the embodiment does not correspond to an invention other than the invention. Absent.

  Further, this description does not mean all the inventions described in this specification. In other words, this description is for the invention described in the present specification, which is not claimed in this application, that is, for the invention that will be applied for in the future or that will appear and be added by amendment. It does not deny existence.

The information distribution system according to claim 1 is:
An information distribution system comprising an information processing apparatus that distributes information (for example, the information processing apparatus 251 in FIG. 28) and a receiving apparatus (for example, the playback apparatus 14 in FIG. 28) that receives the information distributed from the information processing apparatus. (For example, the information processing system 250 in FIG. 28),
The information processing apparatus includes:
Group ID generation means (group ID _G generation unit 103 in FIG. 3) that generates a group ID (for example, group ID _G ) that is an ID unique to a group including a plurality of contents;
A group key corresponding to the group ID generated (e.g., group key K _G) a group key generating means for generating (e.g., group key K _G generation unit 104 of FIG. 3) by the group ID generator,
Using the group key corresponding to the group ID of the group to which the content belongs, a content key (for example, content key K _C ) for encrypting the content is encrypted, and the content is encrypted with the content key. Content key encryption means (encryption unit 136 in FIG. 4);
A content ID unique to the content, the group ID of the group to which the content belongs, a content key encrypted with the group key corresponding to the group ID, and a content encrypted with the content key, Distribution content storage means (for example, the distribution content storage unit 138 in FIG. 4),
Distribution content transmission means (for example, the transmission unit 140 in FIG. 4) for transmitting the distribution content stored in the distribution content storage means to the receiving device;
A group key corresponding to a group ID to which the content of the distribution content stored in the distribution content storage means belongs is encrypted with a common key (for example, a common key K _P ) held with the receiving device. Common key encryption means (for example, the encryption unit 166 in FIG. 5),
The group key encrypted with the common key by the common key encryption means, the group ID corresponding to the group key, and a license ID (for example, license ID _L ) that is an ID unique to the license information to be generated License information storage means for storing the license information (for example, the license information storage unit 168 in FIG. 5);
License information transmission means for transmitting the license information stored in the license information storage means to the receiving device (for example, the transmission unit 170 in FIG. 5),
The receiving device is:
Receiving means for receiving the distribution content transmitted from the distribution content transmitting means and the license information transmitted from the license information transmitting means (for example, the receiving unit 204 in FIG. 6);
The group key encrypted with the common key and corresponding to the group ID of the group to which the content commanded to play belongs is acquired from the license information received by the receiving means, and a group key acquiring means for acquiring the group key by decrypting with the common key held (e.g., group key K _G acquiring unit 195 of FIG. 6) in,
The content key encrypted with the group key corresponding to the group ID is obtained from the content for distribution, and the content key is obtained by decrypting with the group key obtained by the group key obtaining unit. Content key acquisition means (for example, content key K _C acquisition unit 196 in FIG. 6);
Content decrypting means for decrypting the content encrypted with the content key with the content key obtained by the content key obtaining means (for example, a content decrypting unit 197 in FIG. 6) .

The information delivery method according to claim 2 is:
An information distribution system comprising an information processing apparatus that distributes information (for example, the information processing apparatus 251 in FIG. 28) and a receiving apparatus (for example, the playback apparatus 14 in FIG. 28) that receives the information distributed from the information processing apparatus. (For example, information processing system 250 in FIG. 28)
The information processing apparatus includes:
A group ID generation step (step S32 in FIG. 8) for generating a group ID (for example, group ID _G ) that is an ID unique to a group consisting of a plurality of contents;
Group key corresponding to the group ID generated by the processing of said group ID generating step (e.g., group key K _G) and group key generating step of generating (e.g., step S33 in FIG. 8),
A content key encryption step (for example, step of FIG. 10) for encrypting a content key (for example, content key K _C ) for encrypting the content using the group key corresponding to the group ID of the group to which the content belongs. S56)
A content encryption step (eg, step S57 in FIG. 10) for encrypting the content with the content key;
A content ID unique to the content, the group ID of the group to which the content belongs, a content key encrypted with the group key corresponding to the group ID, and a content encrypted with the content key, A distribution content storage control step (for example, step S59 in FIG. 10) for controlling storage in the distribution content storage unit to store as
A distribution content transmission step (for example, step S113 in FIG. 15) for transmitting the distribution content stored in the distribution content storage unit to the receiving device;
A group key corresponding to a group ID to which the content of the distribution content stored in the distribution content storage unit belongs is encrypted with a common key (for example, a common key K _P ) held with the receiving device A common key encryption step (for example, step S74 in FIG. 12),
The group key encrypted with the common key by the process of the common key encryption step, the group ID corresponding to the group key, and a license ID (for example, license ID _L ) As license information, a license information storage control step (for example, step S78 in FIG. 12) for controlling storage in the license information storage unit;
A license information transmission step (for example, step S153 in FIG. 18) for transmitting the license information stored in the license information storage unit to the receiving device;
The receiving device is:
A distribution content reception step (for example, step S93 in FIG. 14) for receiving the distribution content transmitted by the processing of the distribution content transmission step;
A license information receiving step (for example, step S133 in FIG. 17) for receiving the license information transmitted by the processing of the license information transmitting step;
The group key encrypted with the common key and corresponding to the group ID of the group to which the content commanded for reproduction belongs is acquired from the license information received by the processing of the license information receiving step, and the information processing A group key acquisition step (for example, step S223 in FIG. 21) for acquiring the group key by decrypting with the common key held with the device;
The content key encrypted with the group key corresponding to the group ID is acquired from the distribution content and decrypted with the group key acquired by the processing of the group key acquisition step. Content key acquisition step (for example, step S225 in FIG. 21),
A content decrypting step (for example, step S226 in FIG. 21) for decrypting the content encrypted with the content key with the content key acquired by the processing of the content key acquiring step. .

An information processing apparatus according to claim 3 is provided.
An information processing apparatus that processes information (for example, the group management apparatus 11 in FIG. 3),
Group ID generation means (group ID _G generation unit 103 in FIG. 3) that generates a group ID (for example, group ID _G ) that is an ID unique to a group including a plurality of contents;
A group key (for example, group key K _G ) corresponding to the group ID generated by the group ID generation means and used for encrypting a content key (for example, content key K _C ) for encrypting content. a group key generating means for generating (e.g., group key K _G generation unit 104 of FIG. 3),
Group information storage means (for example, in FIG. 3) that stores grouping information (for example, group conditions) for grouping a plurality of contents, group ID, and group key in association with each other. And a group information storage unit 106).

The information processing apparatus according to claim 4 is:
Using the group key corresponding to the group ID of the group to which the content belongs, a content key (for example, content key K _C ) for encrypting the content is encrypted, and the content is encrypted with the content key. Content key encryption means (encryption unit 136 in FIG. 4);
Content ID unique to the content (for example, content ID _C ), the group ID corresponding to the group to which the content belongs, the content key encrypted with the group key corresponding to the group ID, and the content key Distribution content storage means (for example, the distribution content storage unit 138 in FIG. 4) for storing the converted content as distribution content;
Distribution content transmission means (for example, the transmission unit 140 in FIG. 4) for transmitting the distribution content stored in the distribution content storage means to a receiving device.

The information processing apparatus according to claim 5 is:
The group key corresponding to the group ID to which the content of the distribution content stored in the distribution content storage means belongs is encrypted with a common key (for example, a common key K _P ) held with the receiving device. A common key encryption means (for example, the encryption unit 166 in FIG. 5);
The group key encrypted with the common key by the common key encryption means, the group ID corresponding to the group key, and a license ID (for example, license ID _L ) that is an ID unique to the license information to be generated License information storage means for storing the license information (for example, the license information storage unit 168 in FIG. 5);
License information transmission means (for example, the transmission unit 170 in FIG. 5) for transmitting the license information stored in the license information storage means to the receiving device.

7. The content key encryption means of the information processing apparatus according to claim 6, wherein when the content does not belong to a group, a temporary encryption key for encrypting the content key corresponding to the content ID unique to the content (For example, a temporary encryption key K ′ _C ) is used to encrypt a content key for encrypting the content (for example, E (K ′ _C , K _C ) is calculated), and the content is Encryption with the content key (for example, E (K _C , Craw) is calculated)
The distribution content storage means stores a content ID unique to the content, the content key encrypted with the temporary encryption key, and the content encrypted with the content key as distribution content (for example, FIG. 23). As distribution content),
The distribution content transmission unit transmits the distribution content stored in the distribution content storage unit to the receiving device.

The common key encryption unit of the information processing apparatus according to claim 7, when the content of the distribution content stored in the distribution content storage unit does not belong to a group, sets the content ID unique to the content. A temporary encryption key for encrypting the corresponding content key (for example, a temporary encryption key K ′ _C ) is encrypted with the common key (for example, E (K _P , K ′ _C ) is calculated) ,
The license information storage means includes the temporary encryption key encrypted with the common key by the common key encryption means, the content ID corresponding to the temporary encryption key, and a license unique to license information. The ID is further stored as license information (for example, license information in FIG. 24),
The license information transmitting unit transmits the license information stored in the license information storage unit to the receiving device.

The grouping information stored by the group information storage unit of the information processing apparatus according to claim 8 includes a condition for grouping contents (FIG. 9) or a content ID belonging to the group (FIG. 26). It is further included.

The license information stored in the license information storage unit of the information processing apparatus according to claim 9 further includes a playback condition (for example, a playback condition C _{L in} FIG. 13) of content to be permitted to be played back. It is characterized by that.

The information processing method according to claim 10 comprises:
An information processing method of an information processing apparatus (for example, the group management apparatus 11 in FIG. 3) that processes information,
A group ID generation step (step S32 in FIG. 8) for generating a group ID (for example, group ID _G ) that is an ID unique to a group consisting of a plurality of contents;
Corresponding to the group ID generated by the processing of the group ID generation step, a group key (for example, group key K for use in encrypting a content key (for example, content key K _C ) for encrypting content) _G ) for generating a group key (for example, step S33 in FIG. 8);
Group information (for example, group conditions) for grouping a plurality of contents, the group ID, and the group key are associated with each other and controlled to be stored as group information in the group information storage unit. And a group information storage control step (for example, step S35 in FIG. 8).

The program according to claim 11 is:
A program for processing information,
A group ID generation step (step S32 in FIG. 8) for generating a group ID (for example, group ID _G ) that is an ID unique to a group consisting of a plurality of contents;
Corresponding to the group ID generated by the processing of the group ID generation step, a group key (for example, group key K for use in encrypting a content key (for example, content key K _C ) for encrypting content) _G ) for generating a group key (for example, step S33 in FIG. 8);
Group information (for example, group conditions) for grouping a plurality of contents, the group ID, and the group key are associated with each other and controlled to be stored as group information in the group information storage unit. And a group information storage control step (for example, step S35 in FIG. 8).

The information processing apparatus according to claim 12 is:
A group ID (for example, group ID _G ), which is an ID unique to a group of a plurality of contents, and a content key (for example, content key K _C ) corresponding to the group ID for encrypting the content are encrypted. A group key (for example, a group key K _G ) used for processing and grouping information (for example, group conditions) for grouping a plurality of contents are associated with each other and stored as group information An information processing apparatus (for example, the content distribution apparatus 12) that exchanges information with a group management apparatus (for example, the group management apparatus 11 in FIG. 3),
The content key for encrypting the content is encrypted using the group key corresponding to the group ID of the group to which the content belongs, obtained from the group management device, and the content is encrypted with the content key. Content key encryption means (encrypting unit 136 in FIG. 4) to perform,
Distributing the content ID unique to the content, the group ID corresponding to the group to which the content belongs, the content key encrypted with the group key corresponding to the group ID, and the content encrypted with the content key Distribution content storage means (for example, the distribution content storage unit 138 in FIG. 4) that stores the content as the distribution content;
Distribution content transmission means for transmitting the distribution content stored in the distribution content storage means to a receiving device (for example, the transmission unit 140 in FIG. 4).

An information processing apparatus according to claim 13 is provided.
A group ID (for example, group ID _G ), which is an ID unique to a group of a plurality of contents, and a content key (for example, content key K _C ) corresponding to the group ID for encrypting the content are encrypted. A group key (for example, a group key K _G ) used for processing and grouping information (for example, group conditions) for grouping a plurality of contents are associated with each other and stored as group information A group management device (for example, the group management device 11 in FIG. 3), a content ID unique to the content (for example, content ID _C ), the group ID corresponding to the group to which the content belongs, and the group corresponding to the group ID content key encrypted with a key (e.g., the content key K _C), and the co An information processing apparatus (for example, the license in FIG. 5) that exchanges information with the content distribution apparatus (for example, the content distribution apparatus 12 in FIG. 4) that stores the content encrypted with the content key as distribution content. An information distribution device 13),
A common key (for example, the common key K _P ) that holds the group key (for example, the group key K _G ) corresponding to the group ID to which the content of the content for distribution belongs, acquired from the content distribution apparatus, with the receiving apparatus. ) And a common key encryption means (for example, the encryption unit 166 in FIG. 5),
The group key encrypted with the common key by the common key encryption means, the group ID corresponding to the group key, and a license ID (for example, license ID _L ) that is an ID unique to the license information to be generated License information storage means for storing the license information (for example, the license information storage unit 168 in FIG. 5);
And license information transmission means (for example, the transmission unit 170 in FIG. 5) for transmitting the license information stored in the license information storage means to the receiving device.

The receiving device according to claim 14 is:
A receiving device (for example, the playback device 14 in FIG. 6) that receives information transmitted from the information processing device;
It corresponds to a content ID (for example, content ID _C ) unique to the content transmitted from the information processing apparatus, a group ID (for example, group ID _G ) that is unique to the group to which the content belongs, and the group ID. Content key (for example, content key K _C ) for encrypting the content encrypted with the group key, and distribution content (for example, the distribution content in FIG. 11) composed of the content encrypted with the content key And the group key encrypted with a common key (for example, common key K _P ) held with the information processing apparatus, the group ID corresponding to the group key, and the license information unique to the license information ID is a license ID (e.g., license ID _L) license information consisting of ( Eg to a receiving means for receiving the license information) of FIG. 13 (e.g., receiver 204 of FIG. 6),
The group key encrypted with the common key and corresponding to the group ID of the group to which the content commanded to play belongs is acquired from the license information received by the receiving means, and a group key acquiring means for acquiring the group key by decrypting with the common key held (e.g., group key K _G acquiring unit 195 of FIG. 6) in,
The content key encrypted with the group key corresponding to the group ID is obtained from the distribution content, and the content key is obtained by decrypting with the group key obtained by the group key obtaining unit. Content key acquisition means (for example, the content key K _C acquisition unit 196 in FIG. 6);
Content decrypting means for decrypting the content encrypted with the content key with the content key obtained by the content key obtaining means (for example, a content decrypting unit 197 in FIG. 6) .

The content key obtaining unit of the receiving device according to claim 15, when the content for which reproduction is instructed does not belong to a group (for example, when NO is determined in step S 219 in FIG. 21), from the license information, The content key encrypted with the common key is obtained, and the content key is obtained by decrypting with the common key held with the information processing apparatus (for example, step S221 in FIG. 21).
The content decryption unit decrypts the content encrypted with the content key with the content key acquired by the content key acquisition unit (for example, step S226 in FIG. 21).
It is characterized by that.

The license information received by the receiving unit of the receiving device according to claim 16 further includes a playback condition of content to be permitted to be played (for example, a playback condition C _{L in} FIG. 13). And

The receiving method according to claim 17 comprises:
A receiving method of a receiving device (for example, the playback device 14 in FIG. 6) that receives information transmitted from an information processing device,
It corresponds to a content ID (for example, content ID _C ) unique to the content transmitted from the information processing apparatus, a group ID (for example, group ID _G ) that is unique to the group to which the content belongs, and the group ID. Content key (for example, content key K _C ) for encrypting the content encrypted with the group key, and distribution content (for example, the distribution content in FIG. 11) composed of the content encrypted with the content key A content receiving step for distribution (for example, step S93 in FIG. 14);
The group key encrypted with a common key (for example, common key K _P ) held with the information processing apparatus, the group ID corresponding to the group key, and a license ID that is an ID unique to license information A license information receiving step (for example, step S133 in FIG. 17) for receiving license information (for example, license information in FIG. 13) consisting of (for example, license ID _L );
The group key encrypted with the common key and corresponding to the group ID of the group to which the content commanded for reproduction belongs is acquired from the license information received by the processing of the license information receiving step, and the information processing A group key acquisition step (for example, step S223 in FIG. 21) for acquiring the group key by decrypting with the common key held with the device;
The content key encrypted with the group key corresponding to the group ID is acquired from the distribution content, and the content key is decrypted with the group key acquired by the processing of the group key acquisition step. A content key acquisition step (for example, step S225 in FIG. 21) to be acquired;
A content decrypting step (for example, step S226 in FIG. 21) for decrypting the content encrypted with the content key with the content key acquired by the processing of the content key acquiring step. .

The program according to claim 18 is:
A program for processing information transmitted from an information processing device,
It corresponds to a content ID (for example, content ID _C ) unique to the content transmitted from the information processing apparatus, a group ID (for example, group ID _G ) that is unique to the group to which the content belongs, and the group ID. Content key (for example, content key K _C ) for encrypting the content encrypted with the group key, and distribution content (for example, the distribution content in FIG. 11) composed of the content encrypted with the content key A content receiving step for distribution (for example, step S93 in FIG. 14);
The group key encrypted with a common key (for example, common key K _P ) held with the information processing apparatus, the group ID corresponding to the group key, and a license ID that is an ID unique to license information A license information receiving step (for example, step S133 in FIG. 17) for receiving license information (for example, license information in FIG. 13) consisting of (for example, license ID _L );
The group key encrypted with the common key and corresponding to the group ID of the group to which the content commanded for reproduction belongs is acquired from the license information received by the processing of the license information receiving step, and the information processing A group key acquisition step (for example, step S223 in FIG. 21) for acquiring the group key by decrypting with the common key held with the device;
The content key encrypted with the group key corresponding to the group ID is acquired from the distribution content, and the content key is decrypted with the group key acquired by the processing of the group key acquisition step. A content key acquisition step (for example, step S225 in FIG. 21) to be acquired;
A content decrypting step (for example, step S226 of FIG. 21) for decrypting the content encrypted with the content key with the content key acquired by the processing of the content key acquiring step is executed on a computer. It is characterized by making it.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration example of an information processing system (information distribution system) 1 to which the present invention is applied.

  The information processing system 1 is provided with a group management device 11, a content distribution device 12, a license information distribution device 13, and a playback device 14. Each of the group management device 11, the content distribution device 12, the license information distribution device 13, and the playback device 14 is connected to a network (for example, the Internet) 15.

  The group management apparatus 11 manages group definitions (group conditions) determined for each service provider. The content distribution device 12 generates content for distribution. The license information distribution device 13 generates license information for distribution. These group management apparatus 11, content distribution apparatus 12, and license information distribution apparatus 13 are operated by a service provider that provides services. The content distribution device 12 exchanges data between the group management device 11 and the license information distribution device 13 via the network 15, and generates content to be distributed to the user side (for example, the reproduction device 14). That is, the playback device 14 is owned by the user who receives the service.

  The playback device 14 plays back content using the license information. The playback device 14 acquires content for distribution from the content distribution device 12 via the network 15 and acquires license information from the license information distribution device 13 via the network 15. Further, the playback apparatus 14 is provided with a content storage unit 21 and a license information storage unit 22. Content is stored in the content storage unit 21. For example, the content acquired from the content distribution device 12 is stored in the content storage unit 21. The license information storage unit 22 stores license information. For example, the license information storage unit 22 stores license information acquired from the license information distribution device 13. The playback device 14 plays back the content stored in the content storage unit 21 based on the license stored in the license information storage unit 22. Note that the content storage unit 21 stores not only the content distributed from the content distribution device 12 but also the content stored when the playback device 14 is manufactured, the content read from the recording medium, and the like.

  FIG. 2 is a block diagram showing a hardware configuration example of the group management apparatus 11 of FIG. The group management apparatus 11 is a personal computer, for example.

  A CPU (Central Processing Unit) 51, a ROM (Read Only Memory) 52, and a RAM (Random Access Memory) 53 are connected to each other via an internal bus 54. An input / output interface 55 is also connected to the internal bus 54.

  The CPU 51 executes various processes according to a program stored in the ROM 52 or a program loaded from the storage unit 58 to the RAM 53. The RAM 53 also stores data necessary for the CPU 51 to execute various processes as appropriate.

  The input / output interface 55 includes an input unit 56 including a keyboard and a mouse, an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube), an output unit 57 including a speaker, a storage unit 58 including a hard disk, a modem, and the like. A communication unit 59 including a terminal adapter and a drive 60 are connected. The communication unit 59 performs communication processing via various networks including a telephone line or CATV.

  A drive 60 is connected to the input / output interface 55 as necessary, and a removable medium 71 composed of a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is appropriately mounted, and a computer program read therefrom is It is installed in the storage unit 58 as necessary.

  Note that the hardware configuration of the content distribution device 12, the license information distribution device 13, and the playback device 14 is basically the same as that of the group management device 11 in FIG. In the following, FIG. 2 is also referred to as the configuration of the content distribution device 12, the license information distribution device 13, and the playback device 14.

  Next, functional configuration examples of the group management apparatus 11, the content distribution apparatus 12, the license information distribution apparatus 13, and the playback apparatus 14 will be described with reference to FIGS.

  FIG. 3 is a block diagram illustrating a functional configuration example of the group management apparatus 11 of FIG.

The group management apparatus 11, the main control unit 101, an operation input unit 102, the group ID _G generating unit 103, a group key K _G generation unit 104, writing and reading control section 105, the group information storage unit 106, receiving unit 107, and transmission A portion 108 is provided.

The main control unit 101, an operation input unit 102, the group ID _G generating unit 103, a group key K _G generation unit 104, writing and reading control unit 105 controls each unit of the receiver 107, and the transmitting unit 108. The main control unit 101 is realized, for example, when the CPU 51 of the group management apparatus 11 in FIG. 2 executes various processes.

  The operation input unit 102 receives an operation input from the service provider, and supplies a control signal based on the operation input of the service provider (a signal based on an instruction from the service provider) to the main control unit 101. The operation input unit 102 is realized, for example, when the input unit 56 of the group management apparatus 11 in FIG. 2 executes various processes.

The group ID _G generation unit 103 generates a group ID _G for identifying group conditions (group information) based on the control from the main control unit 101. The group ID _G is identification information unique to the group condition (group information) and is used to identify the group. Group key K _G generation unit 104 generates a group key K _G respectively corresponding to each group ID _G. Group key K _G is an encryption key used when performing processing related to contents belonging to the group identified by the group ID _G. Group ID _G generator 103 and the group key K _G generation unit 104, for example, CPU 51 of the group management apparatus 11 of FIG. 2 is realized by executing various processes.

The writing / reading control unit 105 controls writing of information to the group information storage unit 106 and reading of information from the group information storage unit 106. The writing / reading control unit 105 is realized by the CPU 51 in FIG. 2 executing various processes. The group information storage unit 106 stores group information based on the control from the writing / reading control unit 105. For example, the group information storage unit 106, the condition of the group, the group ID _G, and the group key K _G in association respectively is stored as group information. An example of group information stored in the group information storage unit 106 will be described later with reference to FIG. The group information storage unit 106 is realized by, for example, the storage unit 58 of the group management apparatus 11 in FIG.

  The receiving unit 107 receives information transmitted from each device (for example, the content distribution device 12, the license information distribution device 13, and the reproduction device 14) via the network 15. The transmission unit 108 transmits information to each device (for example, the content distribution device 12, the license information distribution device 13, and the reproduction device 14) based on the control from the main control unit 101. The receiving unit 107 and the transmitting unit 108 are realized, for example, when the communication unit 59 of the group management apparatus 11 in FIG. 2 executes various processes.

In the group management apparatus 11, when the content is music (for example, a song), the year, artist name, genre (classical, jazz, pop), etc. of the content are defined (set), and this is set. Manage as a group condition. This definition is entered by the service provider. The group management apparatus 11, to the condition of each group, assigns a group ID _G and group key K _G, manages conditions of the group, the group ID _G, and the group key K _G.

  FIG. 4 is a block diagram illustrating a functional configuration example of the content distribution apparatus 12 of FIG.

The content distribution apparatus 12 includes a main control unit 131, an operation input unit 132, a content ID _C generation unit 133, a content key K _C generation unit 134, a distribution content generation unit 135, an encryption unit 136, a write / read control unit 137, A distribution content storage unit 138, a reception unit 139, and a transmission unit 140 are provided.

The main control unit 131 includes the operation input unit 132, the content ID _C generation unit 133, the content key K _C generation unit 134, the distribution content generation unit 135, the write / read control unit 137, the reception unit 139, and the transmission unit 140. Control. The main control unit 131 is realized, for example, when the CPU 51 of the content distribution apparatus 12 in FIG. 2 executes various processes.

  The operation input unit 132 receives an operation input from the service provider, and supplies a control signal based on the operation input of the service provider (a signal based on an instruction of the service provider) to the main control unit 131. The operation input part 132 is implement | achieved, for example, when the input part 56 of the content delivery apparatus 12 of FIG. 2 performs various processes.

The content ID _C generation unit 133 generates a content ID _C for identifying content based on the control from the main control unit 131. The content ID _C is identification information unique to each content, and is used to identify the content. The content key K _C generation unit 134 generates a content key K _C corresponding to each content ID _C. The content key K _C is an encryption key used when processing the content corresponding to the content ID _C. That is, the content key K _C generation unit 134 generates a content key K _C for encrypting the content identified by each content ID _C. The content ID _C generation unit 133 and the content key K _C generation unit 134 are realized, for example, by the CPU 51 of the content distribution apparatus 12 in FIG. 2 executing various processes.

  The distribution content generation unit 135 generates content for distribution based on the control from the main control unit 131. For example, the distribution content generation unit 135 generates content to be distributed to the playback device 14. The distribution content generation unit 135 is connected to the encryption unit 136 and controls the encryption unit 136 to execute various types of encryption processing or perform various types of processing, thereby generating content for distribution. Generate. Hereinafter, the content for distribution is referred to as “content for distribution”. An example of the distribution content generated by the distribution content generation unit 135 will be described later with reference to FIG. 11, for example. The encryption unit 136 encrypts various data based on the control from the distribution content generation unit 135. The distribution content generation unit 135 and the encryption unit 136 are realized, for example, by the CPU 51 of the content distribution apparatus 12 in FIG. 2 executing various processes.

The writing / reading control unit 137 controls writing of information into the distribution content storage unit 138 and reading of information from the distribution content storage unit 138. The writing / reading control unit 137 is realized by the CPU 51 of the content distribution apparatus 12 in FIG. 2 executing various processes. The distribution content storage unit 138 stores the distribution content based on the control from the writing / reading control unit 137. For example, distribution contents storage unit 138, the content ID _C, encrypted with the content ID _C group ID _G content belongs, group key K _G in the encrypted content key K _C, and the content key K _C Content data Craw is stored in association with each other. The content data Craw is raw data that constitutes content, which is composed of audio data and video data. The distribution content stored in the content storage unit 138 will be described later with reference to FIG. The content storage unit 138 is realized by, for example, the storage unit 58 of the content distribution device 12 in FIG.

  The receiving unit 139 receives information transmitted from each device (for example, the group management device 11, the license information distribution device 13, and the playback device 14) via the network 15, or in response to a command from the service provider. The content data supplied from the recording medium via the drive is received. The transmission unit 140 transmits information to each device (for example, the group management device 11, the license information distribution device 13, and the playback device 14) based on the control from the main control unit 131. The reception unit 139 and the transmission unit 140 are realized, for example, when the communication unit 59 of the content distribution apparatus 12 in FIG. 2 executes various processes.

The content distribution device 12 generates content for distribution. For example, the content distribution apparatus 12 generates a content ID _C and a content key K _C for content data (Craw) to be encrypted, and encrypts the content data (Craw) and all group IDs to which the content data belongs. _G, based on the content key K _C, and group key K _G, generates content for distribution.

  FIG. 5 is a block diagram illustrating a functional configuration example of the license information distribution apparatus 13 of FIG.

The license information distribution device 13 includes a main control unit 161, an operation input unit 162, a license ID _L generation unit 163, a common key K _P storage unit 164, a license information generation unit 165, an encryption unit 166, a write / read control unit 167, A license information storage unit 168, a reception unit 169, and a transmission unit 170 are provided.

The main control unit 161 controls the operation input unit 162, the license ID _L generation unit 163, the common key K _P storage unit 164, the license information generation unit 165, the write / read control unit 167, the reception unit 169, and the transmission unit 170. To do. The main control unit 161 is realized, for example, by the CPU 51 of the license information distribution apparatus 13 in FIG. 2 executing various processes.

  The operation input unit 162 receives an operation input from the service provider and supplies a control signal based on the operation input of the service provider (a signal based on an instruction of the service provider) to the main control unit 161. The operation input unit 162 is realized, for example, when the input unit 56 of the license information distribution apparatus 13 in FIG. 2 executes various processes.

The license ID _L generation unit 163 generates a license ID _L for identifying the license based on the control from the main control unit 161. The license ID _L is identification information (ID) unique to each license information to be generated, and is used to identify the license information. The license ID _L generation unit 163 is realized, for example, when the CPU 51 of the license information distribution apparatus 13 in FIG. 2 executes various processes.

The common key K _P storage unit 164 stores the common key K _P. This common key K _P is a common key held between the playback device 14 and the license information distribution device 13. That is, the playback apparatus 14 also, the license information distribution device 13 stores the same common key K _P and the common key K _P to hold. This common key K _P is stored in advance in the license information distribution device 13 and the playback device 14. The common key K _P storage unit 164 is realized, for example, by the storage unit 58 of the license information distribution apparatus 13 in FIG.

  The license information generation unit 165 generates license information based on the control from the main control unit 161. The license information generation unit 165 generates license information by controlling the encryption unit 166 to execute various encryption processes or by executing various processes. An example of the license information generated by the license information generation unit 165 will be described later with reference to FIG. The encryption unit 166 encrypts various data based on the control from the license information generation unit 165. The license information generation unit 165 and the encryption unit 165 are realized, for example, by the CPU 51 of the license information distribution apparatus 13 in FIG. 2 executing various processes.

The writing / reading control unit 167 controls writing of information to the license information storage unit 168 and reading of information from the license information storage unit 168. The writing / reading control unit 167 is realized by the CPU 51 of the license information distribution apparatus 13 in FIG. 2 executing various processes. The license information storage unit 168 stores license information based on the control from the writing / reading control unit 167. For example, the license information storage unit 168 stores the license ID _L and the corresponding reproduction conditions, the content ID _C included in the license ID _L , the corresponding content key K _C encrypted with the common key K _P , and the group ID. _G and the corresponding group key K _G encrypted with the common key K _P are stored. The license information stored in the license information storage unit 168 will be described later with reference to FIG. The license information storage unit 168 is realized, for example, by the storage unit 58 of the license information distribution device 13 in FIG.

  The receiving unit 169 receives information transmitted from each device (for example, the group management device 11, the content distribution device 12, and the playback device 14) via the network 15. The transmission unit 170 transmits information to each device (for example, the group management device 11, the content distribution device 12, and the playback device 14) based on the control from the main control unit 161. The reception unit 169 and the transmission unit 170 are realized, for example, when the communication unit 59 of the license information distribution apparatus 13 in FIG. 2 executes various processes.

The license information distribution device 13 generates license information for distribution. For example, the license information distribution device 13 generates a license ID _L, based license ID _L, reproduction condition C _L, the content ID _C, the content key K _C, the common key K _P, group key K _G, and the group ID _G To generate license information for distribution.

  FIG. 6 is a block diagram illustrating a functional configuration example of the playback device 14 of FIG.

The reproducing apparatus 14, the main control unit 191, an operation input unit 192, the group ID _G acquiring unit 193, a license condition processing unit 194, a group key K _G acquiring unit 195, the content key K _C acquiring unit 196, the content decryption unit 197, In addition to the decryption unit 198, the display control unit 199, the display unit 200, the common key K _P storage unit 201, the write / read control unit 202, the write / read control unit 203, the reception unit 204, and the transmission unit 205, the content storage unit 21 and the license An information storage unit 22 is further provided.

The main control unit 191, an operation input unit 192, the group ID _G acquiring unit 193, a license condition processing unit 194, a group key K _G acquiring unit 195, the content key K _C acquiring unit 196, the content decryption unit 197, the display controller 199, The common key K _P storage unit 201, write / read control unit 202, write / read control unit 203, reception unit 204, and transmission unit 205 are controlled. The main control unit 191 is realized, for example, by the CPU 51 of the playback device 14 in FIG. 2 executing various processes.

  The operation input unit 192 receives an operation input from the user and supplies a control signal based on the user's operation input (a signal based on a user command) to the main control unit 191. The operation input unit 192 is realized, for example, when the input unit 56 of the playback device 14 in FIG. 2 executes various processes.

Group ID _G acquiring unit 193, under the control of the main control unit 191, acquires the group ID _G. The license condition processing unit 194 executes processing related to license conditions based on the control from the main control unit 191. For example, the license condition processing unit 194 determines whether or not the content commanded to be reproduced can be reproduced based on the reproduction condition included in the corresponding license information. The group ID _G acquisition unit 193 and the license condition processing unit 194 are realized, for example, by the CPU 51 of the playback device 14 in FIG. 2 executing various processes.

Group key K _G acquiring unit 195 under the control of the main control unit 191 obtains the group key K _G. Group key K _G acquiring unit 195, or to execute various decoding process by controlling the decoding section 198, by executing various processes, to obtain the group key K _G. Contents key K _C obtaining unit 196 under the control of the main control unit 191, acquires the content key K _C. Contents key K _C acquiring unit 196, or to execute various decoding process by controlling the decoding section 198, by executing various processes to obtain the content key K _C. The content decrypting unit 197 decrypts the content based on the control from the main control unit 191. The content decryption unit 197 controls the decryption unit 198 to execute various decryption processes and performs various processes to decrypt the content. Group key K _G acquiring unit 195, the content key K _C acquiring unit 106 and the decoding unit 198, is, for example, CPU 51 of the reproducing apparatus 14 of FIG. 2 is realized by executing various processes.

  The display control unit 199 controls display on the display unit 200 based on the control from the main control unit 191. For example, the display control unit 199 controls display on the display unit 200 so that an image based on the reproduced content is displayed on the display unit 200. The display control unit 199 is realized, for example, when the CPU 51 of the playback device 14 in FIG. 2 executes various processes. The display unit 200 displays an image based on control from the display control unit 199. The display unit 200 is realized by the output unit 57 of FIG.

The common key K _P storage unit 201 stores the common key K _P. This common key K _P is a common key held between the playback device 14 and the license information distribution device 13. That is, the license information distribution device 13 also holds the same common key as the common key K _P held by the playback device 14. This common key K _P is stored in advance in the license information distribution device 13 and the playback device 14. The common key K _P storage unit 201 is realized by, for example, the storage unit 58 of the playback device 14 in FIG.

  The writing / reading control unit 202 is connected to the content storage unit 21 and controls writing of information to the content storage unit 21 and reading of information from the content storage unit 21. The writing / reading control unit 202 is realized by the CPU 51 of the playback apparatus 14 in FIG. 2 executing various processes. The content storage unit 21 stores content based on the control from the writing / reading control unit 202. For example, the content storage unit 21 stores content distributed by the content distribution device 12. An example of content stored in the content storage unit 21 will be described later with reference to FIG. The content storage unit 21 is realized by, for example, the storage unit 58 of the playback device 14 in FIG.

  The writing / reading control unit 203 is connected to the license information storage unit 22 and controls writing of information to the license information storage unit 22 and reading of information from the license information storage unit 22. The writing / reading control unit 203 is realized by the CPU 51 of the playback device 14 in FIG. 2 executing various processes. The license information storage unit 22 stores license information based on the control from the writing / reading control unit 203. For example, the license information storage unit 22 stores the license information distributed by the license information distribution device 13. An example of the license information stored in the license information storage unit 22 will be described later with reference to FIG. The license information storage unit 22 is realized and realized by, for example, the storage unit 58 of the playback device 14 of FIG.

  The receiving unit 204 receives information transmitted from each device (for example, the group management device 11, the content distribution device 12, and the license information distribution device 13) via the network 15. The transmission unit 205 transmits information to each device (for example, the group management device 11, the content distribution device 12, and the license information distribution device 13) based on the control from the main control unit 191. The receiving unit 204 and the transmitting unit 205 are realized, for example, by the communication unit 59 of the playback device 14 in FIG. 2 executing various processes.

  The playback device 14 plays back the content based on the content for distribution and the license information. For example, the playback device 14 is based on the content distributed from the content distribution device 12 and stored in the content storage unit 21 and the license distributed from the license information distribution device 13 and stored in the license information storage unit 22. Play content. More specifically, the playback device 14 plays back content using license information that permits playback of the content. In the case where audio data is included in the content, audio may be output from a speaker (not shown).

  Next, overall processing in the information processing system 1 of FIG. 1 will be described with reference to the flowchart of FIG.

In step S11, the group management device 11 executes a group information generation process based on a command from the service provider. Specifically, the group management apparatus 11, and generates a group ID _G and group key K _G to the conditions of the group, generates group information stored. Details of this processing will be described later with reference to FIG.

In step S12, the content distribution device 12 executes a content generation process. Specifically, the content distribution device 12 generates content ID _C and content key K _C and encrypts the content data (Craw), all group ID _G to which the data belongs, content key K _C , and group on the basis of the key K _G, to generate the content for distribution. Details of this processing will be described later with reference to FIG.

In step S13, the license information distribution device 13 executes a license information generation process based on a command from the service provider. Specifically, the license information distribution device 13 generates a license ID _L, and also generates a license ID _L , a reproduction condition C _L , a content ID _C , a content key K _C , a common key K _P , a group key K _G , and a group Based on ID _G , license information for distribution is generated. Details of this processing will be described later with reference to FIG.

  In step S14, the playback device 14 executes content acquisition processing based on a command from the user. Specifically, the playback device 14 acquires content (content for distribution) from the content distribution device 12. Details of this processing will be described later with reference to FIG.

  In step S15, the playback device 14 executes a license information acquisition process based on a command from the user. Specifically, the playback device 14 acquires license information from the license information distribution device 13. Details of this processing will be described later with reference to FIG.

  In step S16, the playback device 14 executes content playback processing based on a command from the user. Specifically, the playback device 14 plays back the content acquired in step S14 using the license information acquired in step S15. Details of this processing will be described later with reference to FIGS.

  With the processing of FIG. 7, the playback device 14 plays back the content.

  Next, details of the group information generation process in the group management apparatus 11 in step S11 of FIG. 7 will be described with reference to the flowchart of FIG. This process is a process executed by the group management apparatus 11 of FIG.

  In step S31, the operation input unit 102 of the group management apparatus 11 receives a group information generation command and a group condition based on an operation input from the service provider. The operation input unit 102 receives a group information generation command and a group condition (group definition) input by the service provider. For example, when the content is music (for example, a song), the operation input unit 102 accepts definitions such as the year, artist name, and genre (classic, jazz, pop) of the content as group conditions. That is, the group condition is information (grouping information) used for grouping contents. The operation input unit 102 supplies a control signal corresponding to the received operation input (group information generation command and group condition) to the main control unit 102.

In step S <b> 32, the group ID _G generation unit 103 generates a group ID _G corresponding to the group condition based on the control from the main control unit 102. The group ID _G is identification information unique to the group condition (group information to be generated). That is, when a plurality of group conditions are defined in the process of step S31, a group ID _G is generated for each group condition.

In step S33, the group key K _G generation 104, under the control of the main control unit 102, generates a group key K _G respectively corresponding to each group ID _G. Group key K _G is an encryption key used when processing contents belonging to the group identified by the group ID _G. That is, the same number as the number of groups ID _G generated in the process of step S32, the group key K _G is generated.

In step S34, the main control section 101 is a condition of the group received in the processing in step S31, the group ID _G generated in the process of step S32, and the group key K _G generated in the process of step S33 Group Generate information.

  In step S35, the write / read control unit 105 stores the group information generated in the process of step S34 in the group information storage unit 106 based on the control from the main control unit 101, and ends the process.

  The group information can be stored in the group information storage unit 106 by the processing of FIG. Here, an example of the group information generated by the processing of FIG. 8 and stored in the group information storage unit 106 is shown in FIG.

In FIG. 9, “condition” is a group condition (group definition) accepted in the process of step S31, “group ID _G ” is a group ID _G generated in the process of step S32, and “group key K _G 'is a group key K _G generated by the processing in step S33.

In the case of the example of FIG. 9, the group ID _G1 and the group key _KG1 are associated with the group condition # 1, the group ID _G2 and the group key _KG3 are associated with the group condition # 2, and the group condition # 3 and group ID _G3 and the group key K _G3 is associated with, and so on, and group ID _Gn and group key K _Gn is associated with conditions #n group. Note that n is an arbitrary natural number.

Thus, the respective conditions of the group, and group ID _G identifies a condition of the group, and the group key K _G corresponding to each group ID _G are associated and stored is the group information.

  Next, details of the content generation processing in the content distribution device 12 in step S12 in FIG. 7 will be described with reference to the flowchart in FIG. This process is a process executed by the content distribution apparatus 12 of FIG. This process is a process executed for each piece of content data Craw.

In step S51, the receiving unit 139 of the content distribution apparatus 12 receives input of content data Craw to be encrypted. For example, the receiving unit 139 receives content data (raw content data (original data of content)) Craw supplied from a service provider via a drive. That is, the content data Craw is raw content data before being encrypted. For example, the receiving unit 139 receives content data Craw ₁ to be encrypted.

In step S52, the content ID _C generating unit 133 under the control of the main control unit 131 generates a content ID _C. Specifically, the content ID _C generation unit 133 generates a content ID _C unique to the content data Craw for identifying the content data Craw received in the process of step S51. For example, the content ID _C generation unit 133 generates a content ID _C1 corresponding to the content data Craw ₁ .

In step S53, the content key K _C generator 134, under the control of the main control unit 131 generates a content key K _C. Specifically, the content key K _C generation unit 134 generates a content key K _C corresponding to the content ID _C generated in the process of step S52. That is, one content data Craw is generated in association with a content ID _C and a content key K _C , respectively. For example, the content key K _C generation unit 134 generates a content key K _C1 corresponding to the content ID _C1 .

In step S54, the receiving unit 139 acquires the group ID _G assigned to all the groups to which the content data Craw belongs. For example, when the content distribution apparatus 12 inquires of the group management apparatus 11 about the group ID _G corresponding to the content data Craw received in step S51, the group management apparatus 11 identifies the group to which the queried content data Craw belongs. Based on the condition (FIG. 9), a search is made as to which group the content belongs to, and the group ID _G corresponding to all the groups to which the content belongs is transmitted. The receiving unit 139 inputs the group ID _G (for example, n group ID _G ) transmitted from the group management device 11 and corresponding to all the groups (for example, n groups) to which the content data Craw belongs. Accept. Note that n is an arbitrary natural number. For example, the receiving unit 139 acquires group IDs _{G1 to} ID _Gn corresponding to all the groups to which the content data Craw ₁ belongs.

Assuming that the content data Craw is managed together with the group information in the group management device 11, the content data Craw is supplied from the group management device 11 in step S51. In step S54, the content distribution device 12 inquires about the group ID. Instead, all the group IDs _G to which the content data Craw belongs may be supplied from the group management apparatus 11.

In step S55, the receiving unit 139, a group key K _G corresponding to the acquired group ID _G, acquires from the group management apparatus 11. For example, the main control unit 131 of the content distribution device 12, the group ID _G along with the request of the group key K _G, when transmitted to the group management apparatus 11 via the transmission unit 140, the group management apparatus 11 is hand, group since coming response a group key K _G (Fig. 9) corresponding to the ID _G, receiver 139 of the content distribution device 12 obtains the group key K _G corresponding to the group ID _G from the group management apparatus 11. In the case where the group ID _G there are n, n pieces of group key K _G is obtained. For example, the receiving unit 139 acquires group keys K _{G1 to} K _Gn corresponding to the acquired group IDs _{G 1 to} ID _Gn , respectively.

In step S56, the encryption unit 136 under the control of the distribution content generation unit 135 via the main control unit 131, the content key K _C respectively encrypted with the group key K _G. For example, if the group key K _G there are n, the encryption unit 136, in each of the n group key K _G, encrypts the content key K _G. That is, the encryption unit _{136, E (K G, K C} ) of calculating for each group key K _G. Thus, the encrypted content key K _C is generated by n different group key K _G. For example, the encryption unit 136 encrypts the content key K _C with the group keys K _{G1 to} K _Gn . In the following, encrypting B with A is described as E (A, B). Here, A is an encryption key and B is data to be encrypted.

In step S57, the encryption unit 136 encrypts the content data Craw with the content key K _C based on the control from the distribution content generation unit 135 via the main control unit 131. That is, the encryption unit 136 calculates E (Kc, Craw). For example, the encryption unit 136 encrypts the content data Craw ₁ with the content key K _C1 .

In step S58, the distribution content generation unit 135, a content ID _C, the group ID _G, encrypted content key K _C in each group key K _G, and on the basis of the encrypted content data Craw, the distribution content Generate. Specifically, corresponding content ID generated in step S52 _C, the content ID _C the corresponding content is the ID of the group to which belongs the group ID _G1 to the group ID _Gn, the group ID _G1 to the group ID _Gn The content key K _C encrypted with the group key K _{G1 to the} group key K _Gn to be collected and the content data Craw encrypted with the content key K _C are collected, thereby generating a distribution content. For example, the content generation unit 135 for distribution uses the content ID _C1 , the group ID _{G1 to the} group ID _Gn to which the content with the content ID _C1 belongs, and the group keys K _{G1 to} K _Gn corresponding to the group ID _{G1 to the} group ID _Gn , respectively. in the encrypted content key K _C1, and the content data Craw ₁ encrypted with the content key K _C1, and deliver content.

  In step S59, the write / read control unit 137 stores the distribution content generated in the process of step S58 in the distribution content storage unit 138.

  With the processing in FIG. 10, the content distribution device 12 can generate distribution content and store it in the distribution content storage unit 138. Here, FIG. 11 shows an example of the distribution content stored in the distribution content storage unit 138 by the processing of FIG.

In the case of the example in FIG. 11, “content ID _C ” is an ID unique to the content generated in the process of step S52, and “group ID _G ” is an ID unique to the group acquired in the process of step S54. , and the "group key K _G encrypted content key K _C 'has been encrypted in the process of step S56," encrypted content data Craw "is encrypted in the processing of step S57 It is a thing.

For example in FIG. 11, the content ID _C1, the group ID _G1 to the group ID _Cn it is associated, encrypted with the group key K _G1 to group key K _Gn corresponding to each group ID _G1 to the group ID _Gn content key K _C1 as (content key K _C1, which is generated in step _{S53), E (K G1,} K C1), E (K G2, K C1), E (K G3, K C1), ··· , E (K _Gn , K _C1 ) are further associated with each other. Further, E (K _C1 , Craw ₁ ) is further stored as the encrypted original content data Craw. Note that n is an arbitrary natural number.

Thus, for a single content data Craw, content ID _C, the group ID _G of all groups to which the contents belong, the group ID group key corresponding to _G K _G in the encrypted content key K _C, and Content for distribution consisting of content data Craw encrypted with the content key K _C is stored.

  Next, the details of the license information generation processing in the license information distribution apparatus 13 in step S13 of FIG. 7 will be described with reference to the flowchart of FIG. This process is a process executed by the license information distribution apparatus 13 of FIG. This process is a process executed for one license.

In step S71, the operation input unit 162 of the license information distribution apparatus 13 performs content ID _{C1 to} content ID that are content IDs of content that does not belong to the group corresponding to one license based on the operation input from the service provider. _cm, the group ID _G1 to the group ID _Gn is a group ID of the content belonging to the group, and receives an input of the reproduction condition C _L. For example, when there is content that is not group-managed by the group management device 11 (for example, content that does not meet the conditions in FIG. 9), the content ID of content that does not belong to the group is input to the operation input unit 162. . In this process, information regarding all contents corresponding to one license, and among those contents belonging to a group, a group ID is received by the operation input unit 162. The reproduction condition corresponding to one license (e.g., a license is valid duration) C _L is accepted by the operation input unit 162. The reproduction condition C _L is a condition for reproducing the content corresponding to the license. Note that n and m are arbitrary natural numbers. The license includes conditions to be given to the content that is permitted to be reproduced.

In step S <b> 72, the license ID _L generation unit 163 generates a license ID _L that identifies the license based on the control from the main control unit 161. The license ID _L is identification information unique to the license information generated in the current process of FIG.

In step S73, the receiving unit 169, a group key K _G1乃group key K _Gn corresponding to the group ID _G1 to the group ID _Gn received in the processing in step S71, acquires from the group management apparatus 11. For example, the main control unit 161 of the license information distribution device 13, the group ID _G1 to the group ID _Gn with request group key K _G, when transmitted to the group management apparatus 11 via the transmission unit 170, the group management contrast Since the device 11 responds with the group key K _{G1 to the} group key K _Gn (FIG. 9) corresponding to the group ID _{G1 to the} group ID _Gn , the receiving unit 169 of the license information distribution device 13 receives the group ID _{G1 to} the group ID obtaining the group key K _G1乃group key K _Gn corresponding to ID _Gn.

In step S74, the encryption unit 166 uses the common key K _P and the group key K _{G1 for} each group key K _G1 -group key K _Gn based on the control from the license information generation unit 165 via the main control unit 161. The group key _KGn is encrypted. That is, the encryption unit _{166, E (K P, K G} ) to operate on each group key K _G.

In step S75, the receiving unit 169 acquires the content key K _C1 to the content key K _Cm corresponding to the content ID _C1 to the content ID _Cm received in the processing in step S71. For example, when the main control unit 161 of the license information distribution device 13 transmits the content ID _{C1 to the} content ID _Cm to the content distribution device 12 through the transmission unit 170 together with the request for the content key K _C , content distribution is performed on the content ID _C1. device 12, so come in response to the content key K _C1 to the content key K _Cm corresponding to the content ID _C1 to content ID _Cm, receiver 169 of the license information distribution device 13 corresponding to the contents ID _C1 to the content ID _Cm The content key K _{C1 to the} content key K _Cm to be acquired are acquired.

In step S76, the encryption section 166, under the control of the license information generation unit 165 via the main control unit 161, to the content key K _C1 for each content key K _Cm, to the content key K _C1 with the common key K _P The content key K _Cm is encrypted. That is, the encryption unit 166 calculates E (K _P , K _C ) for each content key K _C.

In step S77, the license information generation unit 165, a license ID _L, reproduction condition C _L, the group ID _G, the common key K _P in an encrypted group key K _G, the content ID _C1 to content ID _Cm, and the common key K License information consisting of the content key K _C encrypted with _P is generated. Specifically, the license ID _L generated in the process of step S72, the reproduction condition C _L corresponding to the license received in the process of step S71, the group ID _{G1 to the} group ID _Gn received in the process of step S71, The group key K _{G1 to the} group key K _Gn encrypted with the common key K _P by the process of step S74, the content ID _{C1 to the} content ID _Cm received by the process of step S71, and the common key K _P by the process of step S76. The license information is generated by _collecting the content key K _{C1 to the} content key K _Gn encrypted in step ₁ .

  In step S78, the writing / reading control unit 67 causes the license information storage unit 168 to store the license information generated by the license information generation unit 165 in the process of step S77.

With the processing in FIG. 12, the license information distribution apparatus 13 can generate license information and store it in the license information storage unit 168. Since the content belonging to the group is included in the license information, the increase in the amount of information managed by the license information distribution apparatus 13 can be suppressed when the number of contents is large. Further, since the group ID _G and the content ID _C belonging to the license are not encrypted, it is possible to quickly search for the content and group included in the license information. Here, FIG. 13 shows an example of the license information stored in the license information storage unit 168 by the processing of FIG.

In FIG. 13, “License ID _L ” is the ID of the license generated in the process of Step S 72, and “Reproduction Condition” is the reproduction condition C _L of the content corresponding to the license accepted in the process of Step S 71. , “Group ID _G ” is the group ID _{G1 to} Group ID _Gn of the group to which the content belongs, which is accepted in the process of Step S71, and “Group Key K _G encrypted with the common key K _P ” The group key K _{G1 to the} group key K _Gn encrypted with the common key K _P by processing. Also, "content ID _C", the content ID _C11 to the content ID _Cm content that does not belong to a group that received in the processing in step S71, "common key K _P encrypted group key K _G", the processing of step S76 Thus, the content key K _{C11 to the} content key K _Gn encrypted with the common key K _P.

In the case of the example in FIG. 13, when the reproduction condition C _L is associated with the license ID _L and the content included in the license belongs to the group, it corresponds to the group ID _{G1 to the} group ID _Gn and the group ID _G. The group keys K _{G1 to} K _{Gn to} be encrypted are stored with the common key K _P encrypted. If the content included in the license does not belong to the group, the content ID _{C11 to} content ID _Cm of the content and the content key K _{C11 to} content key K _Gn corresponding to the content ID _C are the common key K _P The one encrypted with is stored.

As described above, the license ID _L for identifying one license corresponds to the reproduction condition C _L , the group ID _G corresponding to all the groups belonging to the license, and the group ID _G encrypted with the common key K _P. group key K _G, corresponding to a content that does not belong to the group with belonging to license content ID _C, and the common key K _P content key K _C corresponding to the encrypted content ID _C is stored as the license information.

  Next, details of the content acquisition process in the playback device 14 in step S13 in FIG. 7 will be described with reference to the flowchart in FIG. This process is a process executed by the playback device 14 of FIG. This process is a process executed for one content.

In step S91, the operation input unit 192 of the playback device 14 receives an input of the content ID _C of the content to be acquired based on the operation input from the user. Here, the user is a user on the terminal side that receives the service. For example, the playback device 14 acquires and displays (for example, displays on the display unit 200) the ID _C and thumbnail image of the content stored as distribution content in advance from the content distribution device 12 or the like. Then, when the user is prompted to select content to be acquired and the user selects a thumbnail image of the content to be acquired, the content ID _C corresponding to the thumbnail image is accepted as the input of the content ID _C of the content to be acquired. . For example, the operation input unit 192 receives an input of the content ID _C1 of the content to be acquired based on the operation input from the user.

In step S92, the transmission unit 205 requests content corresponding to the content ID _C accepted in the process of step S91 based on the control from the main control unit 191. Specifically, the transmission unit 205 transmits the content ID _C to the content distribution device 12 together with the content request. For example, the transmission unit 205 transmits the content ID _C1 to the content distribution device 12 together with the content request.

  The processing of the content distribution apparatus 12 with respect to the transmission in step S92 by the playback apparatus 14 will be described with reference to the flowchart of FIG.

In step S111, the receiving unit 139 of the content distribution apparatus 12 receives the content request and the content ID _C. For example, the receiving unit 139 receives a content request and a content ID _C1 . In step S112, the main control unit 131 controls the write / read control unit 137 to acquire (read) the content corresponding to the content ID _C from the distribution content storage unit 138. For example, since the distribution content storage unit 138 stores the distribution content as shown in FIG. 11, the main control unit 131 is shown in FIG. 11 as the distribution content corresponding to the content ID _C1 . Get content for distribution. In step S <b> 93, the transmission unit 140 transmits the acquired distribution content to the playback device 14 based on the control from the main control unit 131. For example, the transmission unit 140 transmits the acquired content for distribution (FIG. 11) to the playback device 14. Thus, in the content distribution device 12, the distribution content corresponding to the requested content ID _C is transmitted. In the process of FIG. 15, the content ID _C1 associated with the group ID _G1 is requested as shown in FIG. 11, and the content of FIG. 11 is transmitted, but the content ID _C11 of the content that does not belong to the group. Is requested, the content ID _C11 and the content data Craw ₁₁ encrypted with the corresponding content key K _C11 are transmitted to the playback device 14.

Returning to FIG. 14, in step S <b> 93, the receiving unit 204 of the playback device 14 transmits the distribution content (FIG. 11) corresponding to the content ID _C transmitted from the content distribution device 12 (step S <b> 113 in FIG. 15). Receive.

  In step S94, the writing / reading control unit 202 stores the content (distribution content) received in the process of step S93 in the content storage unit 21 based on the control from the main control unit 191, and ends the process.

With the processing in FIG. 14, the playback device 14 can acquire and store content (distribution content) from the content distribution device 12 based on the content ID _C. Here, FIG. 16 shows an example of content stored in the content storage unit 21 of the playback device 14 by the processing of FIG.

In the data stored in the content storage unit 21, when the content with content ID _C belongs to a group, as shown in FIG. 16A, group ID _{G1 to} group ID _Cn are associated with content ID _C1. , as an encrypted content key K _C1 (contents key K _C that is generated in step S53 in FIG. 10) in the respective group ID _G1 to the group ID _Gn corresponding group key K _G1 to group key K _Gn, E (K _G1 , K _C1 ), E (K _G2 , K _C1 ), E (K _G3 , K _C1 ),..., E (K _Gn , K _C1 ) are further associated. Further, E (K _C1 , Craw ₁ ) is further stored as encrypted content data Craw. This data is the same as the distribution content stored in the distribution content storage unit 138 of FIG. On the other hand, when the content ID _C is not managed by a group, that is, content that does not belong to the group (content that does not meet the conditions in FIG. 9), content that is acquired from another content distribution device instead of the content distribution device 12 In this case, as shown in FIG. 16B, E (K _C11 , Craw ₁₁ ), E as content data encrypted with the content key K _{C11 to the} content key K _Cm respectively corresponding to the content ID _{C11 to the} content ID _Cm. (K _C12 , Craw ₁₂ ), E (K _C13 , Craw ₁₃ ),..., E (K _Cm , Craw _m ) are stored.

In this way, if the designated content is managed in groups, as shown in FIG. 16A, for one content data Craw, the content ID _C , the group ID _G corresponding to all the groups to which the content belongs, encrypted content key K _C in group key K _G corresponding to the group ID _G, and the content key K _C encrypted content data Craw is acquired and stored in the content storage unit 21. If the designated content is not managed in a group, the content ID _C and the content data Craw encrypted with the corresponding content key K _C are acquired and stored in the content storage unit 21.

  Next, the details of the license information acquisition process in the playback device 14 in step S14 in FIG. 7 will be described with reference to the flowchart in FIG. This process is a process executed by the playback device 14 of FIG. This process is a process executed for one license.

In step S131, the operation input unit 192 of the playback device 14 receives an input of the license ID _L of the license to be acquired based on the operation input from the user. Here, the user is a user on the terminal side that receives the service. For example, the playback apparatus 14 acquires and displays the license ID _L unique to the license and the corresponding content and group information from the license information distribution apparatus 13 or the like in advance (for example, displays on the display unit 200). Thus, the user is prompted to select a license to be acquired, and when the license ID _L to be acquired is selected by the user, the license ID _L is accepted as an input of the license ID _L of the license to be acquired. That is, in order to reproduce the acquired content, the user acquires a license that permits the reproduction of the content. In other words, even if the distribution content is acquired, the content cannot be reproduced unless the license information corresponding to the content is acquired.

In the process of step S131, the input of the license ID _L of the license to be acquired is accepted. However, the user may specify the content to be reproduced. An example of this case will be described later as appropriate.

In step S132, the transmission unit 205 requests license information corresponding to the license ID _L received in step S131 based on the control from the main control unit 191. Specifically, the transmission unit 205 transmits the license ID _L to the license information distribution device 13 together with the request for license information. At this time, for example, a billing process for purchasing a license is performed.

  The processing of the license information distribution apparatus 13 for the transmission in step S132 by the reproduction apparatus 14 will be described with reference to the flowchart of FIG.

In step S151, the reception unit 169 of the license information distribution apparatus 13 receives the license information request and the license ID _L from the reproduction apparatus 14. In step S152, the main control unit 161 controls the writing / reading control unit 167 to acquire (read) the license information corresponding to the license ID _L from the license information storage unit 168. For example, since the license information as shown in FIG. 13 is stored in the license information storage unit 168, the main control unit 161 uses the license information shown in FIG. 13 as the license information corresponding to the license ID _L. get. In step S <b> 153, the transmission unit 170 transmits the acquired license information to the playback device 14 based on the control from the main control unit 161. As described above, the license information distribution apparatus 13 transmits the license information corresponding to the requested license ID _L.

If the content to be played back is specified instead of inputting the license ID _L of the license acquired in step S131, the sending unit 205 sends the content ID _C corresponding to the content to be played back in step S132. Is done. Therefore, the license information distribution apparatus 13 searches the license information including the group ID _G of the group to which the content ID _C belongs or the content ID _C itself from all the license information, and specifies the license information. Then, in the process of step S153, the license information distribution apparatus 13 may transmit license information corresponding to the requested content. The license information distribution device 13 can quickly search for a license corresponding to the content requested to be reproduced.

Incidentally, from the content ID _C, when searching the license information for permitting a reproduction of the distribution content, first, all extracts content ID _C and group ID _G from distribution content, then, of all the license information Thus, the license information including the extracted ID may be searched. Further, since the IDs of the content ID _C and the group ID _G are not secret information, based on these IDs, the content ID _C and the group ID _{G that} are the target of the license information of the license ID _L and the license ID _{L in} advance are stored. A database may be created, and license information may be searched based on this database. As a result, the license information corresponding to the content ID _C can be quickly searched.

Returning to FIG. 17, in step S133, the receiving unit 204 of the playback apparatus 14 receives the license information corresponding to the license ID _L transmitted from the license information distribution apparatus 13 (step S153 in FIG. 18).

  In step S134, the write / read control unit 203 stores the license information received in the process of step S133 in the license information storage unit 22 based on the control from the main control unit 191, and ends the process.

With the processing in FIG. 17, the playback device 14 can acquire and store license information from the license information distribution device 13 based on the license ID _L. Here, FIG. 19 shows an example of content stored in the license information storage unit 22 of the playback apparatus 14 by the processing of FIG.

The data stored in the license information storage unit 22 in FIG. 19 includes the license ID of the requested license whose license ID _L is stored in the license information storage unit 168 of the license information distribution device 13 (see FIG. 13). _When it is the same as _L, it is the same as FIG. That is, as shown in FIG. 19, the reproduction condition C _L is associated with the license ID _L , the group ID _{G1 to the} group ID _Gn included in the license, and the group keys K _{G1 to} K _G1 to the group ID _G are included. A group key K _Gn encrypted with a common key K _P is stored. Also, the content ID _{C11 to} content ID _Cm (content ID _C of content not belonging to a group) included in the license and the content key K _{C11 to} content key K _Gn corresponding to the content ID _C are the common key K _P , respectively. The encrypted one is stored.

As described above, the license ID _L for identifying one license corresponds to the reproduction condition C _L , the group ID _G corresponding to all the groups belonging to the license, and the group ID _G encrypted with the common key K _P. The license information storage unit uses the group key K _G , the content ID _C corresponding to the content belonging to the license and not belonging to the group, and the content key K _C corresponding to the content ID _C encrypted with the common key K _P as license information. 22 is stored.

  Next, details of the content reproduction processing in the reproduction apparatus 14 in step S16 in FIG. 7 will be described with reference to the flowcharts in FIGS. This process is a process executed by the playback device 14 of FIG. Further, this process is, for example, a process executed after the processes shown in FIGS. 14 and 17 described above. That is, the process is started in a state where the content is stored in the content storage unit 21 and the license information is stored in the license information storage unit 22.

In step S211, the operation input unit 192 receives a content instruction to be played based on an operation input from the user. Note that a content ID _C command corresponding to the content to be played back may be received.

In step S <b> 212, the main control unit 191 acquires the content to be reproduced from the content storage unit 21 by controlling the writing / reading control unit 202. For example, the main control unit 191 acquires the content with the content ID _C corresponding to the content to be reproduced received in the process of step S211 from the content storage unit 21 by controlling the writing / reading control unit 202. For example, since the content as shown in FIG. 16 is stored in the content storage unit 21, the main control unit 191 acquires the content in FIG. 16A or FIG. 16B corresponding to the content ID _C.

In step S213, the group ID _G acquisition unit 193 determines whether there is a corresponding group ID _G in the content to be played back. Specifically, the group ID _G acquisition unit 193 determines whether or not there is a group ID _G of the content ID _C that specifies the content to be reproduced, based on the distribution content stored in the content storage unit 21. . That is, it is determined whether or not the content for which playback is commanded belongs to the group. For example, if the content ID _C of the content commanded to be reproduced matches the content ID _C1 of the content shown in FIG. 16A, it is determined that there is a corresponding group ID _G. Further, in the example of FIG. 16, when the content ID _C of the content to be reproduced is one of a content ID _C11 through _Cm is because it is the content shown in FIG. 16B, and there is no group ID _G content Determined. A content ID _C (any content ID _C among the content IDs _{C11 to Cm in} FIG. 16B) when it is determined that there is no corresponding group ID _G in this process will be described as a content ID _CJ below. Also, the group ID _G when it is determined that there is a corresponding group ID _G (either group ID _G of the group ID _G1 to ID _Gn in FIG. 16A), in the following describes a content ID _GK . Note that J and K are arbitrary natural numbers (however, in this embodiment, J is 11 to m and K is 1 to n).

If it is determined in step S213 that there is a group ID _G corresponding to the content to be reproduced, the process proceeds to step S214, and the group ID _G acquisition unit 193 performs the content to be reproduced based on the control from the main control unit 191. The group ID _GK corresponding to is acquired. For example, the group ID _G acquisition unit 193 acquires the group ID _G1 from the content shown in FIG. 16A. As shown in FIG. 16A, when there are a plurality of group IDs _G corresponding to the content to be reproduced, one arbitrary group ID _GK is acquired.

In step S215, the license condition processing unit 194 acquires license information including the group ID _GK acquired in the process of step S214 from the license information storage unit 22. For example, the license condition processing unit 194 receives license information of FIG. 19 corresponding to the license ID _L as license information including the group ID _G1 from the license information storage unit 22 via the main control unit 191 and the write / read control unit 203. To get.

On the other hand, in step S213, if it is determined that there is no group ID _G corresponding to the content, in step S216, the main control unit 191, the content ID _CJ on the basis of the (content ID _CJ playback is commanded in step S211) The corresponding license information is acquired from the license information storage unit 22 by controlling the writing / reading control unit 203. For example, the main control unit 191 acquires the license information of FIG. 19 corresponding to the license ID _L as the license information corresponding to the content ID _C11 from the license information storage unit 22.

After the process of step S215 or after the process of step S216, the process proceeds to step S217, and the license condition processing unit 194 determines whether or not the reproduction condition is satisfied. For example, the license condition processing unit 194 checks the playback conditions C _L included in the license information of FIG. 19 which has been acquired in step S215 or step S216, reproduction conditions (e.g., expiration date and, Views conditions) Is determined, that is, whether or not the content instructed to be reproduced is reproducible. If it is determined that the playback condition does not apply, the process proceeds to step S218, the main control unit 191 executes an error process, and then the process ends.

On the other hand, if it is determined in step S217 that the reproduction condition is satisfied, the process proceeds to step S219, and the license condition processing unit 194 determines whether or not the ID that matches the acquired license information is the group ID _GK. To do. Specifically, the license condition processing unit 194 determines whether the ID that matches the acquired license information is the group ID _GK or the license ID _CJ . If this process is after the process of step S215, that is, if YES is determined in step S213, the ID that matches the license information is determined to be the group ID _GK , and NO is determined in step S213. If the ID matches the license information, it is determined that the content ID is _CJ .

If it is determined in step S219 that the ID that matches the license information is not the group ID _GK , that is, the content ID _CJ , the process proceeds to step S220, and the main control unit 191 corresponds to the content ID _CJ . The content key K _CJ encrypted with the common key K _P is acquired from the license information storage unit 22 by controlling the writing / reading control unit 203. For example, when the content ID _CJ is the content ID _C11 , the main control unit 191 acquires the content key K _C11 encrypted with the common key K _P corresponding to the content ID _C11 from FIG.

In step S221, the content key K _C acquisition unit 196 stores the content key K _CJ encrypted with the common key K _P acquired in the process of step S220 and stored in the common key K _P storage unit 201. The content key K _CJ is obtained by controlling the decryption unit 198 to decrypt using the key K _P. In this example, the common key K _P in an encrypted content key K _C11, using the common key K _P stored in the common key K _P storage unit 201, thereby decoding and controls the decoding unit 198 Thus, the content key K _C11 is obtained. Thereafter, the process proceeds to step S226.

On the other hand, if it is determined in step S219 that the ID that matches the license information is the group ID _G , the process proceeds to step S222. In step S222, the main control unit 191 acquires the group key K _GK corresponding to the group ID _GK and encrypted with the common key K _P from the license information storage unit 22 by controlling the writing / reading control unit 203. For example, when the group ID _GK is the group ID _G1 , the main control unit 191 uses the group key K _G1 (that is, E (K _P , K) encrypted with the common key K _P corresponding to the group ID _{G 1} from FIG. _{Get G1} )).

In step S223, the group key K _G acquisition unit 195 stores the group key K _GK encrypted with the common key K _P acquired in the process of step S222 in the common key K _P storage unit 201 (license). The group key K _G1 is obtained by controlling the decryption unit 198 to decrypt using the common key K _{P (} held with the information distribution device 13).

In step S224, the content key K _C acquisition unit 196 stores the content key K _C1 corresponding to the group ID _GK and encrypted with the group key K _GK via the main control unit 191 and the write / read control unit 202. Obtained from the unit 21 (see FIG. 16A). When the group ID _GK is the group ID _G1 , E (K _G1 , K _C1 ) in FIG. 16A is acquired.

In step S225, the content key K _C acquisition unit 196 uses the content key K _C1 encrypted with the group key K _GK acquired in the process of step S224, using the group key K _GK acquired in the process of step S223. The content key K _C1 is obtained by controlling the decryption unit 198 to perform decryption. In the case of the present example, E (K _G1 , K _C1 ) in FIG. 16A is decrypted with the group key KG ₁ to obtain the content key K _C1 .

Through the processing up to step S221 or the processing up to step S225, the content key K _C of the content that is instructed to be played back in the processing of step S211 is acquired.

After step S221, or after the processing in step S225, the process proceeds to step S226, the content decryption unit 197, the content data Craw encrypted with the content key K _C, using the content key K _C, The decoding unit 198 is controlled to perform decoding. Raw (unencrypted) content data Craw can be acquired by controlling the decryption unit 198 to decrypt using the content key K _C. If this process is after step S221, the content decryption unit 197, the content data Craw encrypted with the content key K _CJ in FIG. 16B, is decoded and controls the decoding unit 198 using the content key K _CJ . As a specific example, the content decryption unit 197, the content data Craw ₁₁ encrypted with the content key K _C11 of FIG. 16B, and controls the decoding unit 198 using the content key K _C11 to be decoded. Further, if this process after step S225, the content decryption unit 197, the content data Craw ₁ encrypted with the content key K _C1 in FIG. 16A, using the content key K _C1 obtained in the processing in step S225 Then, the decoding unit 198 is controlled to perform decoding. By this processing, content data Craw can be obtained.

  In step S227, the display control unit 199 controls to display an image based on the content data Craw decoded based on the control from the main control unit 191. Thereby, the content can be reproduced. When the content data Craw includes audio data, a speaker (not shown) or the like is made to output sound based on the audio data.

  20 and 21, the content can be reproduced based on the content (distribution content) stored in the content storage unit 21 and the license information stored in the license information storage unit 22.

  Further, since the group management apparatus 11 groups the contents, when there is a change in the contents, only the information held by the group management information apparatus 11 and the content distribution apparatus 12 needs to be changed. There is no need to reflect the change on the distribution device 13. Thereby, management of the license information of the license information distribution apparatus 13 can be simplified.

As described above, when a plurality of contents are reproduced with one license information distributed after the encryption process is performed, the group management apparatus 11 manages the plurality of contents in a group. Regardless of the number of contents included in the group, the license corresponding to suffices to hold only one encryption key (group key K _G ), thereby facilitating license management.

  In addition, a license for a certain content can be easily retrieved from a plurality of license information.

Furthermore, since a plurality of contents are defined as one group when generating one piece of license information that permits reproduction of a plurality of contents, the license information distribution apparatus 13 supports the group as license information. It is only necessary to hold the group ID _G and the group key K _G (encryption key), and it is not necessary to hold the content keys K _C of all the contents. Thereby, even if the number of corresponding contents becomes enormous, the data size of the license information held by the license information distribution apparatus 13 can be reduced.

Further, when searching for license information permitting reproduction of the distribution content from the distribution content, first, all the content ID _C and group ID _G are extracted from the distribution content, and then among all the license information. Then, the license information including the extracted ID is searched. For ID itself content ID _C and group ID _G is not secret information, based on these ID, a database of pre-license ID _L the content ID _C and group ID _G to be license information of the license ID _L The license information can be retrieved at a high speed.

  In the above example, the processing of the playback device 14 is divided between when the content belongs to a group and when the content does not belong to a group. You can do it.

First, the group management apparatus 11, the content ID _C, as a group containing the content only one, the group (content ID _C) content key temporary corresponding to K _C '(i.e., pseudo-content key K _C '). Further, the content distribution apparatus 12 generates content for distribution by associating the content ID _C , the content key K _C encrypted with the temporary content key K ′ _C , and the content data Craw encrypted with the content key K _C. . Further, the license information distribution device 13 includes the license information in which the temporary content key K ′ _C corresponding to the content ID _C is encrypted with the common key K _P held with the playback device 14. To do.

Specifically, the group management apparatus 11 holds information as shown in FIG. 22 in addition to the information related to the group of FIG. 9 managed by the processing of FIG. In FIG. 22, content IDs _{C11 to Cm} of contents that are not grouped, that is, do not belong to a group, and temporary content keys K ′ _{C11 to} K ′ _Cm corresponding to each of the contents are managed. That is, the group management apparatus 11 generates these temporary content keys K ′ _{C11 to} K ′ _Cm (processing corresponding to step S33 in FIG. 8).

On the other hand, the content distribution apparatus 12 generates content for distribution as shown in FIG. FIG. 23A shows the contents belonging to the group as in FIG. 11, and FIG. 23B shows the contents not belonging to the group described in this example. As shown in FIG. 23B, the content distribution device 12 (corresponding to step S56 of FIG. 10) is encrypted with the temporary content key K _'C11 corresponding content key K _C11 to the content ID _C11, the content data Craw ₁₁ Is encrypted with the content key K _C (corresponding to step S57 in FIG. 10). Then, the content distribution device 12 includes a content ID _C11, the encrypted content key K _C11 in the temporary content key K _'C11, the content data Craw ₁₁ encrypted by the content key K _C11, and stores the distribution content.

The license distribution device 13 generates license information as shown in FIG. License ID _L in FIG. 24, playback conditions C _L, the group ID _G, and group key K _G corresponding to encrypted group ID _G with the common key K _P to hold between the reproducing apparatus 14, similar to FIG. 13 However, the information shown on the right side of FIG. 24 is different. In the case of this example, the license distribution device 13 encrypts the temporary content key K ′ _C corresponding to the content ID _C with the common key K _P held with the playback device 14. That is, in the example of FIG. 24, the license distribution apparatus 13 encrypts temporary content keys K ′ _{C1 to} K ′ _Cm corresponding to the content IDs _{C11 to} ID _Cm , respectively, with the common key K _P.

  In this way, the playback device 14 acquires the distribution content shown in FIG. 23 and the license information shown in FIG. 24 and stores them in the content storage unit 21 and the license information storage unit 22, respectively. .

  The playback device 14 skips the process of step S213 of FIG. 20 after the processes of step S211 and step S212 of FIG. 20, and acquires license information corresponding to the content to be played back from the license information storage unit 22. If it is determined in step S217 that the reproduction condition is satisfied, the process of step S219 is skipped, and the process proceeds to step S222. In the case of FIG. 22 to FIG. 24, the determination in step 219 is not necessary, and the processing on the steps S222 to S225 side is performed in all cases (that is, the processing does not branch to the processing of steps S220 and S221).

Specifically, when the ID that matches the license information is the group ID _GK, it is the same as the example of FIG. 21 described above, but when the ID that matches the license information is the content ID _CJ , In step S222, the playback device 14 acquires E (K _P , K ′ _CK ) from the license, decrypts E (K _P , K ′ _CK ) with the common key K _P in step S223, and provisional content key K 'Get _CK . Then, the playback device 14 acquires E (K ′ _CK , Craw _K ) corresponding to the content IDC from the content (content storage unit 21) in step S224, and in step S225, E (K ′ _CK , Craw _K ) is obtained. The content key K _C is obtained by decrypting with the temporary content key K ′ _CK obtained in the process of step S223. Since the processing after that processing is the same as that described above, a description thereof will be omitted.

  In this way, as shown in FIGS. 22 to 24, when the content does not belong to a group, the playback device 14 manages the content as belonging to only one group, so that the playback device 14 The content can be played back by the same processing whether or not it belongs to the group.

In the case of this example, the group management apparatus 11 holds information as shown in FIG. 22, but as shown in FIG. 25, a group ID _G corresponding to one content ID _C is generated. it may further generate a group key K _G corresponding to the group ID _G.

Further, in the example of FIG. 9, the group management apparatus 11, in order to group the plurality of contents, "condition", "group ID _G", and has been configured to manage the "group key K _G ' Not only “condition” but also content ID _C of content belonging to each of group ID _G may be managed as shown in FIG.

For example in FIG. 26, with the group key K _G1 is associated with the group ID _G1, the content ID _C1 and the content ID _C2 to a group of the group ID _G1 is assumed to belong. Further, the group key K _G2 is associated with the group ID _G2, content ID _C3 to content ID _C5 is assumed to belong to the group of the group ID _G2. Furthermore, the group key K _G3 is associated with the group ID _G3, the content ID _C6 and the content ID _C7 is assumed to belong to the group of the group ID _G3. Similarly, with the group key K _Gn is associated with the group ID _Gn, the group in the content ID _Cr-1 and the content ID _Cr group ID _Gn is assumed to belong. Here, r is an arbitrary natural number.

  In the above example, the content storage unit 21 and the license information storage unit 22 are provided in the playback device 14, but the content storage unit 21 is replaced with the content storage device as shown in the information processing system 1 ′ of FIG. 21 'and the license information storage unit 22 may be the license information storage device 22'. Here, the playback device 14 ′ indicates the playback device 14 that does not have the content storage unit 21 and the license information storage unit 22. Each of these devices may be connected to the network 15. Further, the playback device 14 ′ is connected to the content storage device 21 ′ and the license information storage device 22 ′ via a LAN (Local Area Network), and the group management device 11 and the content distribution device via a network such as the Internet. 12 and the license information distribution device 13 may be communicated by the playback device 14 ′.

  Further, in the above example, the playback device 14 acquires the content for distribution via the network 15. For example, when the playback device 14 is manufactured, the content storage unit 21 (external HDD or the like) is added to the playback device 14. A configuration may be adopted in which only license information is acquired later. In this case, since the user only needs to acquire the license information via the network 15 after purchasing the playback device 14, the load on the network can be suppressed.

  In the above example, the service provider side manages the three devices, that is, the group management device 11, the content distribution device 12, and the license information distribution device 13. However, the information processing system 250 shown in FIG. As described above, the information processing apparatus 251 including the group management apparatus 11, the content distribution apparatus 12, and the license information distribution apparatus 13 may be managed. In this case, for example, the information processing apparatus 251 such as a server may have the functions shown in FIGS.

  Further, the information processing system 1 described above may be an information distribution system that distributes information, and each of the group management device 11, the content distribution device 12, and the license information distribution device 13 is an information processing device that processes information. Alternatively, the playback device 14 may be a receiving device that receives information.

  The encryption method described above may be any method as long as data is encrypted using an encryption key.

  The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed from a network or a recording medium.

  As shown in FIG. 2, this recording medium is not only constituted by a package medium consisting of a removable medium 91 on which a program is recorded, which is distributed to provide a program to a user separately from the computer. , A hard disk including a ROM 52 and a storage unit 59 in which a program is provided, which is provided to the user in a state of being pre-installed in the apparatus main body.

  In the present specification, the step of describing a computer program includes not only processing performed in time series according to the described order but also processing executed in parallel or individually even if not necessarily processed in time series. Is also included.

It is a figure which shows the structural example of the information processing system to which this invention is applied. It is a block diagram which shows the structural example of the hardware of the group management apparatus of FIG. It is a block diagram which shows the functional structural example of the group management apparatus of FIG. It is a block diagram which shows the functional structural example of the content delivery apparatus of FIG. It is a block diagram which shows the functional structural example of the license information delivery apparatus of FIG. FIG. 2 is a block diagram illustrating a functional configuration example of the playback device in FIG. 1. It is a flowchart explaining the whole process of the information processing system of FIG. It is a flowchart explaining the group information generation process in the group management apparatus of FIG. It is a figure explaining the example of the group information memorize | stored in the group information storage part of FIG. It is a flowchart explaining the content delivery process in the content delivery apparatus of FIG. It is a figure explaining the example of the content for distribution memorize | stored in the content storage part for distribution of FIG. It is a flowchart explaining the license information delivery process in the license information delivery apparatus of FIG. It is a figure explaining the example of the license information memorize | stored in the license information storage part of FIG. 7 is a flowchart for explaining content acquisition processing in the playback apparatus of FIG. 6. It is a flowchart explaining the content delivery process in the content delivery apparatus of FIG. It is a figure explaining the example of the content for delivery acquired by the process of FIG. 7 is a flowchart for explaining license information acquisition processing in the playback apparatus of FIG. 6. It is a flowchart explaining the license information delivery process in the license information delivery apparatus of FIG. It is a figure explaining the example of the license information acquired by the process of FIG. 7 is a flowchart for explaining content reproduction processing in the reproduction apparatus of FIG. 6. 7 is a flowchart for explaining content reproduction processing in the reproduction apparatus of FIG. 6. It is a figure explaining the other example of the group information memorize | stored in the group information storage part of FIG. It is a figure explaining the other example of the content for distribution memorize | stored in the content storage part for distribution of FIG. It is a figure explaining the other example of the license information memorize | stored in the license information storage part of FIG. It is a figure explaining the further another example of the group information memorize | stored in the group information storage part of FIG. It is a figure explaining the further another example of the group information memorize | stored in the group information storage part of FIG. It is a figure which shows the other structural example of the information processing system to which this invention is applied. It is a figure which shows the further another structural example of the information processing system to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Information processing system, 11 Group management apparatus, 12 Content distribution apparatus, 13 License information distribution apparatus, 14 Playback apparatus, 21 Content storage part, 22 License information storage part, 101 Main control part, 103 Group ID _G generation part, 104 group The key K _G generation unit, 106 group information storage unit, 107 reception unit, 108 transmission unit, 131 main controller, 133 a content ID _C generating unit, 134 a content key K _C generation unit, 135 distribution content generation unit, 136 encryption Unit, 138 distribution content storage unit, 139 reception unit, 140 transmission unit, 161 main control unit, 163 license ID _L generation unit, 164 common key K _P storage unit, 165 license information generation unit, 166 encryption unit, 168 license Information storage unit, 169 reception unit, 170 transmission unit, 191 main control unit, 193 Group ID _G acquisition unit, 194 the license condition processing unit, 195 the group key K _G acquiring unit, 196 the content key K _C obtaining unit, 197 content decryption unit, 198 decoding unit, 199 display control unit, 200 display , 201 common key K _P storage unit, 204 reception unit, 205 transmission unit

Claims (18)

In an information distribution system comprising an information processing device for distributing information and a receiving device for receiving the information distributed from the information processing device,
The information processing apparatus includes:
Group ID generation means for generating a group ID that is an ID unique to a group of a plurality of contents;
Group key generating means for generating a group key corresponding to the group ID generated by the group ID generating means;
Content key encryption means for encrypting a content key for encrypting content using the group key corresponding to a group ID of a group to which the content belongs, and encrypting the content with the content key;
A content ID unique to the content, the group ID of the group to which the content belongs, a content key encrypted with the group key corresponding to the group ID, and a content encrypted with the content key, Distribution content storage means for storing as:
Distribution content transmission means for transmitting the distribution content stored in the distribution content storage means to the receiving device;
A common key encryption unit that encrypts a group key corresponding to a group ID to which the content of the distribution content stored in the distribution content storage unit belongs with a common key held with the receiving device;
A license that stores, as license information, the group key encrypted with the common key by the common key encryption unit, the group ID corresponding to the group key, and a license ID that is an ID unique to the license information to be generated Information storage means;
License information transmission means for transmitting the license information stored in the license information storage means to the receiving device;
The receiving device is:
Receiving means for receiving the distribution content transmitted from the distribution content transmitting means, and the license information transmitted from the license information transmitting means;
The group key encrypted with the common key and corresponding to the group ID of the group to which the content commanded to play belongs is acquired from the license information received by the receiving means, and Group key acquisition means for acquiring the group key by decrypting with the common key held in
The content key encrypted with the group key corresponding to the group ID is obtained from the content for distribution, and the content key is obtained by decrypting with the group key obtained by the group key obtaining unit. Content key acquisition means to perform,
An information distribution system comprising: content decrypting means for decrypting the content encrypted with the content key with the content key acquired by the content key acquiring means. In an information delivery method of an information delivery system comprising an information processing device for delivering information and a receiving device for receiving the information delivered from the information processing device,
The information processing apparatus includes:
A group ID generation step of generating a group ID that is an ID unique to a group of a plurality of contents;
A group key generation step for generating a group key corresponding to the group ID generated by the processing of the group ID generation step;
A content key encryption step of encrypting a content key for encrypting the content using the group key corresponding to the group ID of the group to which the content belongs;
A content encryption step of encrypting the content with the content key;
A content ID unique to the content, the group ID of the group to which the content belongs, a content key encrypted with the group key corresponding to the group ID, and a content encrypted with the content key, A distribution content storage control step for controlling storage in the distribution content storage unit to store as
A distribution content transmission step of transmitting the distribution content stored in the distribution content storage unit to the receiving device;
A common key encryption step of encrypting a group key corresponding to a group ID to which the content of the distribution content stored in the distribution content storage unit belongs with a common key held with the receiving device;
The group key encrypted with the common key by the processing of the common key encryption step, the group ID corresponding to the group key, and a license ID that is an ID unique to the license information to be generated are stored as license information. A license information storage control step for controlling storage in the license information storage unit,
A license information transmitting step of transmitting the license information stored in the license information storage unit to the receiving device;
The receiving device is:
A distribution content reception step of receiving the distribution content transmitted by the processing of the distribution content transmission step;
A license information receiving step for receiving the license information transmitted by the processing of the license information transmitting step;
The group key encrypted with the common key corresponding to the group ID of the group to which the content commanded for reproduction belongs is acquired from the license information received by the processing of the license information receiving step, and the information processing A group key acquisition step of acquiring the group key by decrypting with the common key held with the device;
The content key encrypted with the group key corresponding to the group ID is acquired from the distribution content and decrypted with the group key acquired by the processing of the group key acquisition step. Acquiring a content key;
A content decrypting step of decrypting the content encrypted with the content key with the content key obtained by the processing of the content key obtaining step. In an information processing apparatus that processes information,
Group ID generation means for generating a group ID that is an ID unique to a group of a plurality of contents;
A group key generating means for generating a group key corresponding to the group ID generated by the group ID generating means and used for encrypting a content key for encrypting content;
An information processing apparatus comprising: group information storage means for grouping information for grouping a plurality of contents, the group ID, and the group key in association with each other and storing them as group information. Content key encryption means for encrypting a content key for encrypting content using the group key corresponding to a group ID of a group to which the content belongs, and encrypting the content with the content key;
Distributing the content ID unique to the content, the group ID corresponding to the group to which the content belongs, the content key encrypted with the group key corresponding to the group ID, and the content encrypted with the content key Distribution content storage means for storing as content for use;
The information processing apparatus according to claim 3, further comprising: a distribution content transmission unit that transmits the distribution content stored in the distribution content storage unit to a reception device. A common key encryption unit that encrypts a group key corresponding to a group ID to which the content of the distribution content stored in the distribution content storage unit belongs with a common key held with the receiving device;
A license that stores, as license information, the group key encrypted with the common key by the common key encryption unit, the group ID corresponding to the group key, and a license ID that is an ID unique to the license information to be generated Information storage means;
The information processing apparatus according to claim 4, further comprising: license information transmission means for transmitting the license information stored in the license information storage means to the reception apparatus. The content key encryption means encrypts the content by using a temporary encryption key for encrypting the content key corresponding to the content ID unique to the content when the content does not belong to the group. A content key for encrypting the content, and encrypting the content with the content key,
The distribution content storage means stores the content ID unique to the content, the content key encrypted with the temporary encryption key, and the content encrypted with the content key as distribution content,
The information processing apparatus according to claim 4, wherein the distribution content transmission unit transmits the distribution content stored in the distribution content storage unit to the reception device. The common key encryption unit encrypts the content key corresponding to the content ID unique to the content when the content of the distribution content stored in the distribution content storage unit does not belong to a group. The temporary encryption key is encrypted with the common key,
The license information storage means includes the temporary encryption key encrypted with the common key by the common key encryption means, the content ID corresponding to the temporary encryption key, and a license unique to license information. The ID is further stored as license information,
The information processing apparatus according to claim 5, wherein the license information transmission unit transmits the license information stored in the license information storage unit to the reception apparatus. The information processing apparatus according to claim 3, wherein the grouping information stored by the group information storage unit further includes a condition for grouping contents or a content ID belonging to the group. The information processing apparatus according to claim 5, wherein the license information stored by the license information storage unit further includes a playback condition of content to be permitted to be played back. In an information processing method of an information processing apparatus for processing information,
A group ID generation step of generating a group ID that is an ID unique to a group of a plurality of contents;
A group key generation step of generating a group key corresponding to the group ID generated by the processing of the group ID generation step and used for encrypting a content key for encrypting the content;
A group information storage control step for controlling storage in the group information storage unit so as to store the grouping information for grouping a plurality of contents, the group ID, and the group key as group information in association with each other; An information processing method comprising: A program for processing information,
A group ID generation step of generating a group ID that is an ID unique to a group of a plurality of contents;
A group key generation step of generating a group key corresponding to the group ID generated by the processing of the group ID generation step and used for encrypting a content key for encrypting the content;
A group information storage control step for controlling storage in the group information storage unit so as to store the grouping information for grouping a plurality of contents, the group ID, and the group key in association with each other, A program for causing a computer to execute a process including A group ID that is an ID unique to a group consisting of a plurality of contents, a group key corresponding to the group ID and used to encrypt a content key for encrypting the contents, and a plurality of contents are grouped. In an information processing device that exchanges information with a group management device that is stored as group information in association with grouping information for each other,
The content key for encrypting the content is encrypted using the group key corresponding to the group ID of the group to which the content belongs, obtained from the group management device, and the content is encrypted with the content key. Content key encryption means for
Distributing the content ID unique to the content, the group ID corresponding to the group to which the content belongs, the content key encrypted with the group key corresponding to the group ID, and the content encrypted with the content key Distribution content storage means for storing as content for use;
An information processing apparatus comprising: distribution content transmission means for transmitting the distribution content stored in the distribution content storage means to a receiving device. A group ID that is an ID unique to a group consisting of a plurality of contents, a group key corresponding to the group ID and used to encrypt a content key for encrypting the contents, and a plurality of contents are grouped. Corresponding to grouping information for each other and stored as group information, a content ID unique to the content, the group ID corresponding to the group to which the content belongs, and the group ID In an information processing apparatus that exchanges information with a content distribution apparatus that stores a content key encrypted with the group key and a content encrypted with the content key as distribution content,
A common key encryption unit that encrypts a group key corresponding to a group ID to which the content of the content for distribution to which the content for distribution belongs is obtained from the content distribution device with a common key held with the reception device;
A license that stores, as license information, the group key encrypted with the common key by the common key encryption unit, the group ID corresponding to the group key, and a license ID that is an ID unique to the license information to be generated Information storage means;
An information processing apparatus comprising: license information transmission means for transmitting the license information stored in the license information storage means to the reception apparatus. In a receiving device that receives information transmitted from an information processing device,
A content ID unique to the content transmitted from the information processing apparatus, a group ID that is unique to a group to which the content belongs, and a content encrypted with a group key corresponding to the group ID Corresponding to the group key and the group key encrypted with a common key held between the information processing apparatus and a content key and the content for distribution composed of the content encrypted with the content key Receiving means for receiving license information comprising the group ID and a license ID that is an ID unique to the license information;
The group key encrypted with the common key and corresponding to the group ID of the group to which the content commanded to play belongs is acquired from the license information received by the receiving means, and Group key acquisition means for acquiring the group key by decrypting with the common key held in
The content key encrypted with the group key corresponding to the group ID is obtained from the distribution content, and the content key is obtained by decrypting with the group key obtained by the group key obtaining unit. Content key acquisition means;
A receiving apparatus comprising: a content decrypting unit configured to decrypt the content encrypted with the content key with the content key acquired by the content key acquiring unit. The content key obtaining unit obtains the content key encrypted with the common key from the license information when the content commanded to be reproduced does not belong to a group, and holds the content key with the information processing apparatus The content key is obtained by decrypting with the common key,
The receiving apparatus according to claim 14, wherein the content decrypting unit decrypts the content encrypted with the content key with the content key acquired by the content key acquiring unit. The receiving device according to claim 14, wherein the license information received by the receiving unit further includes a playback condition of content to be permitted to be played back. In a receiving method of a receiving device that receives information transmitted from an information processing device,
A content ID unique to the content transmitted from the information processing apparatus, a group ID that is unique to a group to which the content belongs, and a content encrypted with a group key corresponding to the group ID A distribution content receiving step of receiving a distribution key consisting of a content key and a content encrypted with the content key;
A license that receives license information including the group key encrypted with a common key held with the information processing apparatus, the group ID corresponding to the group key, and a license ID that is an ID unique to license information An information receiving step;
The group key encrypted with the common key corresponding to the group ID of the group to which the content commanded for reproduction belongs is acquired from the license information received by the processing of the license information receiving step, and the information processing A group key acquisition step of acquiring the group key by decrypting with the common key held with the device;
The content key encrypted with the group key corresponding to the group ID is acquired from the distribution content, and the content key is decrypted with the group key acquired by the processing of the group key acquisition step. A content key acquisition step to acquire;
A content decrypting step, comprising: decrypting the content encrypted with the content key with the content key acquired by the processing of the content key acquiring step. A program for processing information transmitted from an information processing device,
A content ID unique to the content transmitted from the information processing apparatus, a group ID that is unique to a group to which the content belongs, and a content encrypted with a group key corresponding to the group ID A distribution content receiving step of receiving a distribution key consisting of a content key and a content encrypted with the content key;
A license that receives license information including the group key encrypted with a common key held with the information processing apparatus, the group ID corresponding to the group key, and a license ID that is an ID unique to license information An information receiving step;
The group key encrypted with the common key corresponding to the group ID of the group to which the content commanded for reproduction belongs is acquired from the license information received by the processing of the license information receiving step, and the information processing A group key acquisition step of acquiring the group key by decrypting with the common key held with the device;
The content key encrypted with the group key corresponding to the group ID is acquired from the distribution content, and the content key is decrypted with the group key acquired by the processing of the group key acquisition step. A content key acquisition step to acquire;
A program causing a computer to execute processing including: a content decrypting step of decrypting the content encrypted with the content key with the content key acquired by the processing of the content key acquiring step.

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