Patent ID: 7286446

Claim:
A track management method for managing recorded data using management data that includes (1) a play order table having a plurality of track information entries arranged in a pre-determined play order, (2) a track information table paying a plurality of track descriptors, each track descriptor including a decryption key and pointer information that points to one of a plurality of part descriptions in a part information table, and (3) the part information table having a plurality of part descriptors, each part descriptor including part pointer information, the method comprising: obtaining track information from the play order table, wherein the track information corresponds to a track to be deleted and points to a track descriptor in the track information table; obtaining the track descriptor from the track information table, said track descriptor including a decryption key corresponding to the track to be deleted; advancing the predetermined play order for a subset of said plurality of track information entries that follow said track to be deleted in said predetermined play order so as to account for a removal of said track to be deleted from said predetermined play order; reading the one of the plurality of part descriptors that corresponds to said pointer information in said track descriptor; separating in a file system a data block that is a part of a file specified by the part pointer information in said part descriptor from said file managed by the file system, and freeing said data block on said file system, said part pointer information pointing to a part of the file that includes a plurality of data blocks; freeing said part descriptor on said file system; and freeing said track descriptor on said file system.