A system and method is disclosed for allowing content providers to protect against widespread copying of their content, while enabling them to give their customers more freedom in the way they use the content. In accordance with one embodiment, content providers identify their content as protected by watermarking the content. Consumers use compliant devices to access protected content. All of a user's compliant devices, or all of a family's devices, can be organized into an authorized domain. This authorized domain is used by content providers to create a logical boundary in which they can allow users increased freedom to use their content.

The invention, as shown by the system in FIG. 2, relates to a client-side content tracking system of media files, e.g. digital music files. Audio trackingor indeed multimedia trackingis shifted to a client-side perspective, with the client tasked with establishing use of a selected source audio track by trackingand then reporting uplink to the serverat least one of: entry and exit points associated with playing of at least one of said musical sections in the identified source audio track, and how the identified source audio track was used, performed or manipulated at the client device. Server functionality is designed, having regard to the reported tracking data and its link to a unique identifier to permit the media file (e.g. source audio track) to be selected and/or identified, to store or relaypossibly in the context of a subscription service and billing regime for content usetracking data related to use of at least a portion of the source audio track at or by the client device. In the context of audio, reporting of use at a client device can, in turn, cause streaming of related multi-media content from a third-party database to the client device. For music, reporting of entry and end points into and out of sections of complete audio tracks can coincide with musically seamless audio transitions between sections.

A playback method using a playback device that plays a system stream file is provided. The playback device includes an individual decryption key that is owned individually by each of playback devices, and a common decryption key that is owned in common by a plurality of playback devices. The system stream file includes a first system stream file configured to be played back using both the individual decryption key and the common decryption key, and a second system stream file configured to be played back using only the common decryption key among the individual decryption key and the common decryption key. The method includes identifying whether the system stream file to be playback is the first system stream file or the second system stream file, in accordance with a file extension of the system stream file, and selecting a decryption process of the system stream file.

The invention, as shown by the system in FIG. 2, relates to a client-side content tracking system of media files, e.g. digital music files. Audio trackingor indeed multimedia trackingis shifted to a client-side perspective, with the client tasked with establishing use of a selected source audio track by trackingand then reporting uplink to the serverat least one of: entry and exit points associated with playing of at least one of said musical sections in the identified source audio track, and how the identified source audio track was used, performed or manipulated at the client device. Server functionality is designed, having regard to the reported tracking data and its link to a unique identifier to permit the media file (e.g. source audio track) to be selected and/or identified, to store or relaypossibly in the context of a subscription service and billing regime for content usetracking data related to use of at least a portion of the source audio track at or by the client device. In the context of audio, reporting of use at a client device can, in turn, cause streaming of related multi-media content from a third-party database to the client device. For music, reporting of entry and end points into and out of sections of complete audio tracks can coincide with musically seamless audio transitions between sections.

A memory storing AV data for playing back encrypted video on a playback device is provided. The AV data includes a system stream file including encrypted video information, and a management information file. The system stream file includes a first segment in which is repeated a first data unit that can be individually decrypted using a first decryption key, and has a second data unit of the same data size as the first data unit but cannot be decrypted by the first decryption key. The system stream file also includes a second segment which can all be decrypted using a second decryption key that the playback device has in common with another playback device. The management information file has a time map in which are correlated I-picture serving as random access point, and a presentation clock time of the I-picture. The I-picture is multiplexed in the second segment.

An information processing device includes: a data processing unit that executes a process of reproducing content recorded in a medium; and a memory storing a content revocation list in which an identifier (ID) of revoked content is recorded, wherein the data processing unit compares a minimum allowable version of a content revocation list recorded in a token which is management data corresponding to content recorded in the medium with a version of a content revocation list acquired from the memory, and when the version of the content revocation list acquired from the memory is an old version lower than the minimum allowable version of the content revocation list recorded in the token, the data processing unit halts determination on revocation of content based on the content revocation list acquired from the memory and reproduction of content.

The invention, as shown by the system in FIG. 2, relates to a client-side content tracking system of media files, e.g. digital music files. Audio trackingor indeed multimedia trackingis shifted to a client-side perspective, with the client tasked with establishing use of a selected source audio track by trackingand then reporting uplink to the serverat least one of: entry and exit points associated with playing of at least one of said musical sections in the identified source audio track, and how the identified source audio track was used, performed or manipulated at the client device. Server functionality is designed, having regard to the reported tracking data and its link to a unique identifier to permit the media file (e.g. source audio track) to be selected and/or identified, to store or relaypossibly in the context of a subscription service and billing regime for content usetracking data related to use of at least a portion of the source audio track at or by the client device. In the context of audio, reporting of use at a client device can, in turn, cause streaming of related multi-media content from a third-party database to the client device. For music, reporting of entry and end points into and out of sections of complete audio tracks can coincide with musically seamless audio transitions between sections.

A memory storing AV data for playing back encrypted video on a playback device is provided. The AV data includes a system stream file including encrypted video information, and a management information file. The system stream file includes a first segment in which is repeated a first data unit that can be individually decrypted using a first decryption key, and has a second data unit of the same data size as the first data unit but cannot be decrypted by the first decryption key. The system stream file also includes a second segment which can all be decrypted using a second decryption key that the playback device has in common with another playback device. The management information file has a time map in which are correlated I-picture serving as random access point, and a presentation clock time of the I-picture. The I-picture is multiplexed in the second segment.

In a playback method of a playback device that plays a system stream file including encrypted video information, the system stream file includes a first segment in which is repeated a first data unit that can be decrypted using a first decryption key that the playback device has and a second data unit of the same data size as the first data unit but cannot be decrypted by the first decryption key, and a second segment which can all be decrypted using a second decryption key that differs from the first decryption key. The playback method reads the system stream file, and performs conversion processing to convert the system stream file that has been read out into a post-conversion system stream, in which the second data unit in the first segment in the system stream file that has been read out is replaced with a plurality of continuous invalid packets, and outs the post-conversion system stream.

When the terminal device attempts to use a special content, which has an attribute including information distinguishing the special content from regular contents and which is stored in the recording medium device, the recording medium device refers to the revocation information indicating terminal devices restricted from using the special content. When the recording medium device determines the terminal device as a terminal device to be restricted from using the special content based on the terminal identifying information of the terminal device, the usage information output unit of the recording medium device does not transmit the necessary information for using the special content to the terminal device.