The Advanced Access Content System (AACS) is a standard for content distribution and digital rights management, which will allow restricting access to and copying of the next generation of optical discs and DVDs.
The group developing it includes Disney, Intel, Microsoft, Matsushita (Panasonic), Warner Brothers, IBM, Toshiba, and Sony. The standard has been adopted as the access restriction scheme for HD DVD and Blu-ray Disc.
The proposal is based on broadcast encryption using Naor-Naor-Lotspiech subset difference trees. The proposal was voted one of the technologies most likely to fail by IEEE Spectrum magazine . Concerns about the approach include its similarity to past systems that failed, such as Content Scrambling System (CSS), and the inability to preserve security against attacks that compromise large numbers of players.
Indeed, Jon Lech Johansen (known colloquially as DVD Jon) who defeated the original CSS encryption expects AACS to be hacked by Winter 2006/2007. The specifications for the product have been publicly released (as of April 2005).
Jon Lech Johansen, the Norwegian hacker famous for developing the DeCSS tool which removes CSS encoding from DVDs, announced on the January 8, 2006 that he would be developing a piece of software called
DeAACS which would remove AACS encryption from Blu-ray and HD-DVD discs. He expects the software to be released by
March 2007.
From:
http://en.wikipedia.org/wiki/AACS