Computer-readable, non-transitory medium storing digital content distributing program, computer-readable, non-transitory medium storing digital content playback program, digital content distributing apparatus and digital content playback apparatus

A computer-readable, non-transitory medium storing a digital content playback program causing a client on which playback is started of data of digital content including;

• data in which digital copyrighted work is stored, and a plurality of separation data separated from the data, the data having a header, which stores position information for specifying a separation region in which one of the plurality of separation data is separated, and each separation region in which the separation data is separated, stores position information for specifying other separation regions in an interlinked manner, and the data excluding the separation region is encrypted by a content key of the data, while the separation region of the data and the separation data separated from the separation region are encrypted respectively by a content key different for each separation data, to execute a process comprising:
• requesting a distribution of a content key for decrypting the data;
• requesting a distribution of separation data specified by an identifier when in response to the distribution request of a content key of the data, there is received the content key of the data, and the identifier for identifying the separation data separated from a separation region specified by the position information stored in the header of the data;
• requesting a distribution of separation data specified by an identifier when in response to the distribution request of the separation data, there is received the separation data, the content key of the separation data, and the identifier for identifying the separation data separated from a separation region specified by the position information stored in the separation region in which the separation data is separated;
• decrypting the data excluding the separation region by using the content key of the data, and decrypting the separation region of the data and the separation data by using the content key of the separation data;
• and
• playing back the data and the separation data based on the separation region specified by the position information stored in the header of the data and in each separation region.

A digital content distributing apparatus for distributing digital content including;

• data in which digital copyrighted work is stored, and a plurality of separation data separated from the data, the data having a header, which stores position information for specifying a separation region in which one of the plurality of separation data is separated, and each separation region in which the separation data is separated, stores position information for specifying other separation regions in an interlinked manner, and the data excluding the separation region is encrypted by a content key of the data, while the separation region of the data and the separation data separated from the separation region are encrypted respectively by a content key different for each separation data, the digital content distributing apparatus comprising:
• a transmitting unit for sending a content key of the data associated with a distribution request of the content key for decrypting the data, and an identifier for identifying the separation data separated from the separation region specified by the position information stored in the header of the data when there is the distribution request, and for sending separation data associated with a distribution request of the separation data specified by the identifier, a content key of the separation data, and an identifier for identifying the separation data separated from the separation region specified by the position information stored in the separation region in which the separation data is separated when there is the distribution request.

A digital content playback apparatus for playing back digital content including;

• data in which digital copyrighted work is stored, and a plurality of separation data separated from the data, the data having a header, which stores position information for specifying a separation region in which one of the plurality of separation data is separated, and each separation region in which the separation data is separated, stores position information for specifying other separation regions in an interlinked manner, and the data excluding the separation region is encrypted by a content key of the data, while the separation region of the data and the separation data separated from the separation region are encrypted respectively by a content key different for each separation data, the digital content playback apparatus comprising:
• a content information acquiring unit for requesting a distribution of a content key for decrypting the data when playback of data is started, and for requesting a distribution of separation data specified by an identifier when in response to the distribution request of a content key of the data, there is received the content key of the data, and the identifier for identifying the separation data separated from a separation region specified by the position information stored in the header of the data, and for requesting a distribution of separation data specified by an identifier when in response to the distribution request of separation data, there is received the separation data, the content key of the separation data, and the identifier for identifying the separation data separated from a separation region specified by the position information stored in the separation region in which the separation data is separated;
• a decrypting unit for decrypting the data excluding the separation region by using the content key of the data, and decrypting the separation region of the data and the separation data by using the content key of the separation data;
• and
• a content playback unit for playing back the data and the separation data based on the separation region specified by the position information stored in the header of the data and in each separation region.