Features and Limitations
Users must have either found decryption keys themselves or obtained them elsewhere for most versions of BackupHDDVD to work. The utility reads a text file containing volume or title keys and attempts to find a set of corresponding keys for the inserted disc. Through a standard AES library, it then decrypts each video file on the disc using the appropriate keys and writes the results to a location specified by the user. Direct file decryption allows the utility's functionality to remain unaffected by device key revocation and its performance unencumbered with AACS overhead.
Originally intended to be a proof of concept, BackupHDDVD is severely limited in its ability to produce fully functional copies of commercial discs. Early versions were unable to properly decrypt discs which used the in-movie experience technology. New versions work around this limitation by excluding interactive content from decrypted copies. The utility cannot process HD DVD navigation functionality which enables menus, chapters, secondary audio tracks and subtitles, so these features are inaccessible in copies created by BackupHDDVD. Most versions provide no validation for keys and will still attempt to decrypt a disc's contents with an incorrect key, resulting in corrupt files.
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