A virtual file system (VFS) is constructed by reliably acquiring subsequent data corresponding to an information recording medium from a local storage unit, and thus, data reproduction is executed. A data processing unit configured to read out and reproduce data recorded in the information recording medium, and data stored in the local storage unit which is different from the information recording medium, is provided. The data processing unit executes processing of selecting data associated with the information recording medium from the local storage unit, as reproduction target data, executes directory name calculation processing in which a conversion function corresponding to a version of the information recording medium is applied to configuration data of a root certificate recorded in the information recording medium, at the time of performing the processing of selecting the reproduction target data, and selects data which is recorded in a directory having a calculated directory name from the local storage unit, as the reproduction target data.

Provided is a method of playing content stored in a storage device including requesting a conversion of the content to a content service server, receiving content key information and additional information for the conversion of the content from the content service server, and performing the conversion of the content based on the content key information and the additional information.

Provided is a method of playing content stored in a storage device including requesting a conversion of the content to a content service server, receiving content key information and additional information for the conversion of the content from the content service server, and performing the conversion of the content based on the content key information and the additional information.