Patent ID: 7895661

Claim:
A method for acquiring a media file for usage at a local machine from a central server machine, said method comprising: identifying a media file from a plurality of available media files, each of the media files having at least media content data; purchasing access to the identified media file; obtaining a download key that corresponds to the identified media file; downloading the identified media file in its encrypted form to the local machine; decrypting the identified media file to its unencrypted form using the download key; obtaining at least one user key, the user key being associated with a user of the local machine; generating a content key that is at least substantially random; encrypting the media content data of the identified media file with the content key; encrypting the content key with the user key to produce an encrypted content key; modifying the identified media file to further include a user key reference and the encrypted content key; and storing the modified media file to the local machine.