A method for storing and securely managing important information for a user in a database includes storing synchronizing information, which changes when a portion of the important information is updated, in the database together with the important information, and encrypting the synchronizing information; distributively storing the encrypted synchronizing information in a plurality of predetermined places; and combining and decrypting the synchronizing information stored in the predetermined places and determining whether the combined synchronizing information is identical to the synchronizing information stored in the database. A content file may include a header portion, including key-data for synchronizing information and synchronizing information distributively stored in a plurality of predetermined places of a hard disc, and a data portion. The header portion may also include key-data for Digital Rights Management (DRM) information and DRM information distributively stored in the plurality of predetermined places of the hard disc.