Digital Trends

Just as one company mandates an update to seal off known AACS copy protection cracks, a new crack appears to let Xbox 360 HD DVD drives bypass AACS on any HD DVD title.

This year has not been kind to the folks who manage the Advanced Access Content System (AACS) copy protection system used to prevent unauthorized copying of both Blu-ray and HD DVD tites. First, enterprising computing enthusiasts found a way to bypass AACS copy protection using keys obtained from the WinDVD software player. That crack was widened, and the AACS confirmed that valid title codes had been obtained for existing high-definition movie releases. The AACS recently announced it has expired the known-cracked codes, meaning they won't work in newly-minted players and software, and newly released high-definition titles won't work in compromised players; as part of that update, Corel mandated an update for WInDVD which addresses the security compromise.

That was just a few days ago; now, news is beginning to swirl that crackers have successfully compromised the AACS system using the Toshiba-made Xbox 360 HD DVD drive, and, furthermore, have adapted the technique so users can obtain the voume ID from any HD DVD title without the need to patch the drive's firmware. Users will be able to insert any HD DVD title to get the volume ID of the disc; with that key, users will be able to bypass the AACS system and use specialized utilities to decrypt and back up (or copy) the HD DVD content.

If the bypass proves successful, the AACS will have little choice but to revoke the keys used in existing Xbox 360 HD DVD drives, meaning those drives would be unable to play discs manufactured after the revocation date. The AACS may soon begin rolling out sequence key blocks (SKBs) in high definition titles, which encrypt a portion of the disc content with additional encryption keys; these keys would help enable the AACS to identify more quickly which players and hardware had been compromised.