Method, apparatus and program for protecting content

• US 20060206945A1
• Filed: 06/17/2005
• Published: 09/14/2006
• Est. Priority Date: 06/18/2004
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kato, Taku, Ishihara, Atsushi
• Application Number:
  US11/154,716
• Publication Number:
  US 20060206945A1
• Time in Patent Office: Days
• US Class Current: 726/27
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

According to a first aspect of the present invention, a recording medium manufactured without using the latest key management information can be detected and accuracy of content protection can be improved. A license association apparatus generates a digital signature uniquely corresponding to the latest key management information and content data. A disc manufacturer apparatus writes this digital signature together with the key management information, encrypted content, content feature information onto a DVD. Accordingly, the recording media manufactured without using the latest key management information can be detected by confirming unique correspondence among the key management information, the content feature information and the digital signature and unique correspondence between the encrypted content and the content feature information, in advance of playback.

Claims

1. A method for protecting content using a key issuing device for issuing key management information and a media key corresponding to each other, and a media manufacturing apparatus for manufacturing recording media by recording encrypted content in which content data is encrypted to be decrypted on the basis of the media key and the key management information so as to generate the media key by means of an authorized playback device other than an unauthorized playback device onto recording media so as to prevent the encrypted content from being played by the unauthorized playback device, the method comprising:

generating the latest uniquely corresponded data uniquely corresponding to the latest key management information and the content data by means of the key issuing device in advance of manufacturing of the recording media; and

writing the latest uniquely corresponded data together with the key management information and the encrypted content to the recording media by means of the media manufacturing apparatus.

2. The method according to claim 1, wherein generating of the latest uniquely corresponded data includes:

receiving content correspondence data composed of a data amount smaller than that of the content data and uniquely corresponding to the content data from the media manufacturing apparatus; and

calculating the latest uniquely corresponded data on the basis of key management information correspondence data composed of a data amount smaller than that of the content data and uniquely corresponded to the key management information and the content correspondence data, and

writing to the recording media includes;

writing the content correspondence data together with the key management information and the encrypted content onto the recording medium.

3. A media manufacturing apparatus for manufacturing recording media by recording an encrypted content in which content data is encrypted to be decrypted on the basis of a media key and key management information so as to generate the media key by means of an authorized playback device other than an unauthorized playback device onto recording media, the media manufacturing apparatus being in communication with a key issuing device, the key issuing device capable of issuing key management information and a media key corresponding to each other and generating the latest uniquely corresponded data uniquely corresponding to the issued key management information and the content data, the media manufacturing apparatus comprising:

a content correspondence data generation device configured to generate content correspondence data composed of a data amount smaller than that of the content data and uniquely corresponding to the content data;

a key issue request transmitting device configured to transmit a key issue request including the content correspondence data to the key issuing device;

a latest information reception device configured to receive the latest key management information, the media key and the latest uniquely corresponded data from the key issuing device in accordance with transmission of the key issue request;

an encrypted content generation device configured to generate the encrypted content on the basis of the media key; and

a writing device configured to write the encrypted content, the latest uniquely corresponded data, the latest key management information and the content correspondence data onto the recording media.

4. A media manufacturing apparatus for manufacturing recording media by recording encrypted content in which content data is encrypted to be decrypted on the basis of a media key and key management information so as to generate the media key by means of an authorized playback device other than an unauthorized playback device onto a recording media, the media manufacturing apparatus being in communication with a unique data generation device, the unique data generation device capable of generating the latest uniquely corresponded data uniquely corresponding to the latest key management information and the content correspondence data, the media manufacturing apparatus comprising:

a storage device configured to store a plurality of pairs of key management information and the media key if necessary in a pair of key management information and the media key corresponding to each other;

a key management information selection device configured to select any key management information stored in the storage device;

a content correspondence data generation device configured to generate content correspondence data composed of a data amount smaller than that of the content data and uniquely corresponding to the content data;

a unique data generation request transmitting device configured to transmit a unique data generation request including key management correspondence information uniquely corresponding to the selected key management information and the generated content correspondence data to the unique data generation device;

a latest uniquely corresponded data reception device configured to receive the latest uniquely corresponded data from the unique data generation device;

an encrypted content generation device configured to generate the encrypted content on the basis of the media key corresponding to the selected key management information; and

a writing device configured to write the encrypted content, the latest uniquely corresponded data, the selected key management information and the content correspondence data onto the recording media.

5. A playback device for decrypting encrypted content and playing obtained content data on the basis of a recording media with:

the encrypted content in which the content data is encrypted so as to be decrypted on the basis of a media key;

content correspondence data composed of a data amount smaller than that of the content data and uniquely corresponding to the content data;

the latest key management information so as to generate the media key; and

the latest uniquely corresponded data uniquely corresponding to the key management correspondence information uniquely corresponding to the latest key management information and the content correspondence data recorded thereon, the playback device comprising;

a first verification device configured to verify validity of the content correspondence data and key management information read from the recording media on the basis of the latest uniquely corresponded data read from the recording media;

a content correspondence data generation device configured to generate the content correspondence data on the basis of the encrypted content data read from the recording media;

a second verification device configured to verify validity of the generated content correspondence data on the basis of the content correspondence data in the recording media; and

a playback prevention device configured to prevent the playback when at least one of verification results from the first and the second verification devices indicates an absence of the validity.

6. A program used for a computer of a media manufacturing apparatus for manufacturing recording media by recording encrypted content in which content data in a memory is encrypted to be decrypted on the basis of a media key and key management information so as to generate the media key by means of an authorized playback device other than an unauthorized playback device and stored in a computer readable recording medium, the media manufacturing apparatus being in communication with a key issuing device, the key issuing device capable of issuing the key management information and the media key corresponding to each other and generating the latest uniquely corresponded data uniquely corresponding to the content correspondence data, the program comprising:

a first program code for making the computer execute processing to generate content correspondence data composed of a data amount smaller than that of the content data in the memory and uniquely corresponding to the content data;

a second program code for making the computer execute processing to transmit a key issue request including the content correspondence data to the key issuing device;

a third program code for making the computer execute processing to receive the latest key management information, the media key and the latest uniquely corresponded data from the key issuing device in accordance with transmission of the key issue request;

a fourth program code for making the computer execute processing to generate the encrypted content on the basis of the media key; and

a fifth program code for making the computer execute processing to write the encrypted content, the latest uniquely corresponded data, the latest key management information and the content correspondence data into the recording media.

7. A program used for a computer of a media manufacturing apparatus for manufacturing recording media by recording encrypted content in which content data is encrypted to be decrypted on the basis of a media key and key management information so as to generate the media key by means of an authorized playback device other than an unauthorized playback device and stored in a computer readable recording medium, the media manufacturing apparatus being in communication with a unique data generation device, the unique data generation device capable of the latest uniquely corresponded data uniquely corresponding to the latest key management information and the content correspondence data, the program comprising:

a first program code for making the computer execute processing to write a plurality of pairs of key management information and the media key into a memory in a pair of the key management information and the media key corresponding to each other;

a second program code for making the computer execute processing to select any key management information stored in the memory;

a third program code for making the computer execute processing to generate content correspondence data composed of a data amount smaller than that of the content data and uniquely corresponding to the content data;

a fourth program code for making the computer execute processing to transmit a unique data generation request including key management correspondence information uniquely corresponding to the selected key management information and the generated content correspondence data to the unique data generation device;

a fifth program code for making the computer execute processing to receive the latest uniquely corresponded data from the unique data generation device;

a sixth program code for making the computer execute processing to generate the encrypted content on the basis of the media key corresponding to the selected key management information; and

a seventh program code for making the computer execute processing to write the encrypted content, the latest uniquely corresponded data, the selected key management information and the content correspondence data.

8. A program stored in a computer readable recording medium for use in a computer of a playback device for decrypting encrypted content and playing obtained content data on the basis of a recording medium with:

the encrypted content in which the content data is encrypted so as to be decrypted on the basis of a media key;

content correspondence data composed of a data amount smaller than that of the content data and uniquely corresponding to the content data;

the latest key management information so as to generate the media key; and

the latest uniquely corresponded data uniquely corresponding to key management correspondence information uniquely corresponding to the latest key management information and the content correspondence data recorded thereon, the program comprising;

a first program code for making the computer execute first verification processing to verify validity of the content correspondence data and key management information read from the recording media on the basis of the latest uniquely corresponded data read from the recording media;

a second program cord for making the computer execute second verification processing to generate the content correspondence data on the basis of the encrypted content data read from the recording media;

a third program cord for making the computer execute processing to verify validity of the generated content correspondence data on the basis of the content correspondence data in the recording media; and

a fourth program code for making the computer execute processing to prevent the playback when at least one of verification results among the first and the second verification processing indicates an absence of the validity.