Efforts that began in December 2006, and continued through February 2007, lead the way for the circumvention of the Advanced
Access Content System (AACS) HD DVD and Blu-ray Disc copy-protection scheme.
It started with the discovery of individual encryption keys
for specific movies titles that would allow the decryption and backup of the
protected media. Continued efforts eventually uncovered the Processing
Key, essentially a silver bullet that is able to defeat the copy protection
of all HD DVD and Blu-ray Disc media currently on the market.
Advanced Access Content System Licensing Administration
(AACS LA) acknowledged the effectiveness of the hack, but promised that it
would soon patch up the hole in future releases. “AACS LA has confirmed that
AACS Title Keys have appeared on public web sites without authorization,” read a statement
from the AACS website. “AACS LA employs both technical and legal measures to
deal with attacks such as this one, and AACS LA is using all appropriate
remedies at its disposal to address the attack.“
Beginning May 22, which is most notably the release date of
the Matrix trilogy on HD DVD, all high-definition titles will ship with
Media Key Block (MKB) v3 – a new encryption key version that would render the
previously discovered Processing Key obsolete.
“If a set of device keys is compromised in a way that
threatens the integrity of the system, an updated MKB can be provided by the
AACS LA that will cause a product with the compromised set of device keys to
calculate a different key than is computed by the remaining compliant products,”
as found written in AACS documentation. “In this way, the compromised device
keys are 'revoked' by the new MKB.”
However, it appears that the AACS’ updated copy protection
measures have already been circumvented even before the new software’s official
release. SlySoft, developers of a software used to
defeat the copy protections of DVD, HD DVD and Blu-ray Disc, have revealed that its latest
version of AnyDVD HD is able to sidestep the new MKB from the AACS.
According to posts in SlySoft's forums, the new AnyDVD HD version was successfully able to decrypt an
early-shipped release of the Matrix trilogy. Judging from how the protection
system works, the newly discovered exploit will also work with all upcoming
software until the AACS LA implements yet another patch.
The original Processing Key, found in February, recently
caused quite the stir. Attempts to censor a string of letters and numbers
stirred Internet users to overwhelm Digg.com in the first well-documented Internet Riot, leading
it and other websites to change their legal position on censorship.