![](/pics//07/feb/schema/ischema.jpg) | The red part is the hard part: getting the Media Key** (usually from a software player by debugging/memory snooping). But
this only has to be done once per MKB and can be done by a pro.
The yellow part is what I described above: we
either can (nearly) predict the Volume ID or we can get it via simple USB
sniffing (the software player can't do much about that apart from bus encryption
which is not implemented yet). The blue part is the
easiest: if we have the Volume ID (also called IDv) and the Media Key (Km) we
can calculate the Volume Unique Key (Kvu) and then the Title Keys (Kt). This of
course enables us to decrypt the content itself. |
|
A method to fully crack the Advanced Access Content System (AACS) has been
found,
according to some media reports and forum posts, which means that it is now
possible to extract copy-protected content from Blu-ray discs (BDs) and HD DVDs
and copy it without compromising quality. Earlier it was possible to copy only
limited amount of movies, which AACS keys had been leaked.
Last December,
a
hacker named 'Muslix64' circumvented HD DVD copy protection, resulting in
the release of pirated copies on the Internet. Less than one month later, the
same hacker, with the help of another hacker, was able to crack the encryption
on Blu-ray Discs. On Sunday, another Doom9 forum poster named 'arnezami'
presented the next great breakthrough in HD DVD and Blu-ray Disc decryption.
Previously, every HD movie needed its own unique key in order to be decrypted;
but with arnezami's discovery, there is now one key to rule them all -- at least
for now, until the Advanced Access Content System Licensing Administrator gets
on it.
The AACS copy protection system implemented into current BDs and HD DVDs
includes Device Keys, Media Key Block (MKB), Media Key, Processing Keys, Volume
IDs and Volume Unique Keys (VUKs) among others. Previously the "crack" of the
high definition video discs' AACS was based on knowledge of the VUKs, which are
needed to access the content, however, right now a way to calculate the VUK for
every single disc has been found.
Arnezami has found a Processing Key, which should work on any BD or HD DVD,
whereas Volume ID key appeared to be date and time of the disc production (e.g.
Volume ID for King Kong movie is 09 18 20 06 08 41, which means that the date
and time of its production is 09/18/2006, 08:41). Using the Processing Key and
some other data, the BD or HD DVD device calculates the Media Key, which, when
combined with the Volume ID, gives the Volume Unique Key (which are also
referred to as 'Title Keys') needed for decryption of the protected content.
Potentially, Arnezami's discovery means that it is now possible to create a
software that would calculate all the keys using publicly available algorithms,
which means that, if AACS licensing agent (AACS LA) and content producers do not
change the processing key and the Volume ID keys, all the future BD and HD DVD
releases face possibility of replication using already available burners,
sharing or even pirating.
Ed.note: FYI, SlySoft has released
AnyDVD
HD 6.1.2.0 beta. This version fixes a bug which prevents OpenSeason
R2 (UK & Netherlands) to rip correctly. As always, there are many other small
fixes and improvements.