According to one embodiment, there is provided a playback apparatus which
plays back content including an encrypted video object and an encrypted
resource file, including a memory including a file cache area, a module
configured to decrypt the video object, a playback process module
configured to play back the decrypted video object and to output a
resource file acquisition request, a module configured to determine
whether the resource file is decrypted, to decrypt the resource file, to
write the decrypted resource file over the encrypted resource file, to
update the management information, and to send the decrypted resource
file to the playback process module, and a module configured to determine
whether the resource file is decrypted, to encrypt the decrypted resource
file, to write the encrypted resource file over the decrypted resource
file, to update the management information, and to send the encrypted
resource file to the storage.