Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is produced so as to include a plurality of subtrees that are grouped in accordance with categories and managed by category entities. An EKB is produced so as to include data produced by selecting a path in the key tree and encrypting an upper-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. If a change occurs in state of a category tree capable of processing an EKB identified in the EKB type definition list, a notification of the change in state is sent to an entity that uses the EKB thereby making it possible for an EKB requester to perform processing in accordance with a newest EKB.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is formed so as to include a plurality of subtrees serving as category trees categorized in accordance with categories and managed by category entities. An EKB includes data produced by selecting a path in a tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. Distribution of EKB's is managed on the basis of an EKB type definition list representing the correspondence between an EKB type identifier and one or more identification data identifying one or more category trees that can process an EKB of an EKB type specified by the EKB type identifier.

Abstract: A system and method are realized which enables valid use of content by preventing unauthorized use of content which is caused by rewriting rights data. A structure is employed in which rights data including use-restriction information on content and DRM data including an encrypted content key are recorded in a digital data recording medium (media), and in which an integrity check value (ICV) for the DRM data can be stored in a recordable/playable area (protected area) by using only a dedicated IC. EKB distribution is used to execute the tree-structure key distribution to distribute keys for generating ICV-generation verifying keys. In this structure, unauthorized use of content by rewriting of the rights data is prevented.

Abstract: A system that allows secure processing in a case where a download-requesting terminal and a download-destination terminal are different devices is implemented. A content distribution server receives a ticket carrying a signature of a download destination from a terminal requesting downloading of content, and verifies the ticket to verify that a device serving as the download destination is a device authorized by the download-requesting terminal, thereby verifying the authenticity of the device serving as the download destination without directly authenticating the device serving as the download destination. Furthermore, a content-signing key [Ksig] or a hash value is exchanged as data that can be cryptographically processed only at the download-requesting device and the download-destination device, so that, for example, checking of the integrity of the content is allowed only at a legitimate download-destination device.

Abstract: An information processing system and method are disclosed in which information processing is performed using an enabling key block (EKB) in association with a tree structure including category subtrees. A key tree is produced, which include subtrees that are grouped in accordance with categories and are managed by category entities. The EKB includes data produced by selecting a path in the key tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path. The EKB is then provided to a device. A requester, which requests production of the EKB, may produce a root key or may request a key distribution center (KDC) to produce a root key. If the (KDC) produces the EKB, it may also request a category entity to produce a sub-EKB.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is produced so as to include a plurality of subtrees that are grouped in accordance with categories and managed by category entities. An EKB is produced so as to include data produced by selecting a path in the key tree and encrypting an upper-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. If a change occurs in state of a category tree capable of processing an EKB identified in the EKB type definition list, a notification of the change in state is sent to an entity that uses the EKB thereby making it possible for an EKB requester to perform processing in accordance with a newest EKB.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is produced so as to include a plurality of subtrees that are grouped in accordance with categories and managed by category entities. An EKB is produced so as to include data produced by selecting a path in the key tree and encrypting an upper-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. If a change occurs in state of a category tree capable of processing an EKB identified in the EKB type definition list, a notification of the change in state is sent to an entity that uses the EKB thereby making it possible for an EKB requester to perform processing in accordance with a newest EKB.

Abstract: When a player cannot play back data because a master key held by the player has a generation older than the generation of a master key having been used for recording the data, or when a recorder cannot record data because a master key held by the recorder has a generation older than the generation of a master key necessary for recording to a recording medium, the user is prompted to renew the master key for acquisition of the necessary master key, thereby enabling the data playback or data recording. The renewed master key is distributed in such a form that can be processed by a specific device via a transmission medium such as a recording medium, network, IC card, telephone line, for example, via a tree-structured distribution system.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is formed so as to include a plurality of subtrees serving as category trees categorized in accordance with categories and managed by category entities. An EKB includes data produced by selecting a path in a tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. Distribution of EKB's is managed on the basis of an EKB type definition list representing the correspondence between an EKB type identifier and one or more identification data identifying one or more category trees that can process an EKB of an EKB type specified by the EKB type identifier.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is formed so as to include a plurality of subtrees serving as category trees categorized in accordance with categories and managed by category entities. An EKB including data produced by selecting a path in a tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. Distribution of EKB's is managed on the basis of an EKB type definition list representing the correspondence between an EKB type identifier and one or more identification data identifying one or more category trees that can process an EKB of an EKB type specified by the EKB type identifier.

Abstract: A system that allows secure processing in a case where a download-requesting terminal and a download-destination terminal are different devices is implemented. A content distribution server receives a ticket carrying a signature of a download destination from a terminal requesting downloading of content, and verifies the ticket to verify that a device serving as the download destination is a device authorized by the download-requesting terminal, thereby verifying the authenticity of the device serving as the download destination without directly authenticating the device serving as the download destination. Furthermore, a content-signing key [Ksig] or a hash value is exchanged as data that can be cryptographically processed only at the download-requesting device and the download-destination device, so that, for example, checking of the integrity of the content is allowed only at a legitimate download-destination device.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is produced so as to include a plurality of sub-trees that are grouped in accordance with categories and managed by category entities. An EKB is produced so as to include data produced by selecting a path in the key tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path, and the resultant EKB is provided to a device. When a requester issues a request for production of an EKB is issued, the requester may produce a root key or may request a key distribution center to produce a root key. When the key distribution center produces an EKB, the key distribution center requests a category entity to produce a sub-EKB. Thus, the EKB can be produced and managed in a highly efficient manner.

Abstract: A system and method are realized which enables valid use of content by preventing unauthorized use of content which is caused by rewriting rights data. A structure is employed in which rights data including use-restriction information on content and DRM data including an encrypted content key are recorded in a digital data recording medium (media), and in which an integrity check value (ICV) for the DRM data can be stored in a recordable/playable area (protected area) by using only a dedicated IC. EKB distribution is used to execute the tree-structure key distribution to distribute keys for generating ICV-generation verifying keys. In this structure, unauthorized use of content by rewriting of the rights data is prevented.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is produced so as to include a plurality of subtrees that are grouped in accordance with categories and managed by category entities. An EKB is produced so as to include data produced by selecting a path in the key tree and encrypting an upper-level key in the selected path using a lower-level key in the selected path, and the resultant EKB is provided to a device. If a change occurs in state of a category tree capable of processing an EKB identified in the EKB type definition list, a notification of the change in state is sent to an entity that uses the EKB thereby making it possible for an EKB requester to perform processing in accordance with a newest EKB.

Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is formed so as to include a plurality of subtrees serving as category trees categorized in accordance with categories and managed by category entities. An EKB including data produced by selecting a path in a tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. Distribution of EKB's is managed on the basis of an EKB type definition list representing the correspondence between an EKB type identifier and one or more identification data identifying one or more category trees that can process an EKB of an EKB type specified by the EKB type identifier.

Abstract: When a player cannot play back data because a master key held by the player has a generation older than the generation of a master key having been used for recording the data, or when a recorder cannot record data because a master key held by the recorder has a generation older than the generation of a master key necessary for recording to a recording medium, the user is prompted to renew the master key for acquisition of the necessary master key, thereby enabling the data playback or data recording. The renewed master key is distributed in such a form that can be processed by a specific device via a transmission medium such as a recording medium, network, IC card, telephone line, for example, via a tree-structured distribution system.