HD optical formats hacked again

A new hacker has discovered a cryptographic key that can be used to circumvent copy restrictions on HD content stored on HD-DVD and Blu-ray discs.

The IDG News Service reported that the key, recently published on the Doom9.org discussion forum, is another step toward undermining the AACS (Advanced Access Content System) encryption system used by both optical disc formats.

Using the name Arnezami, the hacker said he discovered the key by examining his computer's memory functions while it processed HD-DVD video.

This winter, a different hacker, Muslix64, released software that could decrypt the discs. In that case, however, the user needed a unique volume key for the software to break the copy protection. Since then, more than 100 of these keys have been circulated, allowing the copying of such films as "King Kong," "Mission: Impossible III" and "Jarhead."

The latest hack reveals a processing key, making it far easier to find the volume key associated with each film. This, coupled with HDDVDBackup software, simplifies the copying of content on HD discs, Arnezami told his readers.

The recent hacks have been a major embarrassment for AACS encryption, which was introduced in 2005 and touted as being far stronger than the CSS encryption system used by SD DVDs. AACS is supported by such companies as Microsoft, Panasonic, Sony, Toshiba, Disney and Warner Bros.

A spokeswoman for the group that sets the AACS specification, called the AACS Licensing Administrator, told the IDG News Service that Arnezami's claims were being investigated but declined to provide further comment.