HD-DVD DRM seems to have been broken already
Posted: 2006-12-28 10:45am
from the Doom9 forums:
Further commentary from the SH/SC forum:muslix64 from the doom9 forums wrote:Hi everyone.
I was not aware of anyone having done that, so I did.
BackupHDDVD is a tool to decrypt a AACS protected movie that you own, so you can play it back later using
an HDDVD player software.
This is the first version, and it's not very stable yet.
This software don't provide any cryptographic keys, so you have to add your own keys.
Watch:
http://www.youtube.com/watch?v=_oZGYb92isE
Executable and source code:
http://rapidshare.com/files/8318838/...HDDVD.zip.html
Please read the FAQ before asking me any questions.
Merry Christmas everyone!
It *is* enough, as it turns out. Each title will have a title key. Those title keys are NOT revocable, though they can be changed by re-encrypting the movie and making a new 'glass master' for the pressing factory.Well that's the same way CSS was cracked (Thanks Xing!), but since he doesn't provide any information about how to get the title keys then all we have here is a reference AACS decoder implementation. Nice, but not useful. I don't know enough about AACS to know whether or not compromising the "volume unique key" is enough to break the whole format or if the key revocation list system is robust enough to survive a break of this magnitude.
However, in order to get the title key, a player must have a 'player key'. Those are revocable, so a revoked player key won't work on movies produced after it was revoked, as they cannot be used to decrypt the title key.
But so what? You can simply 'break' a player key, not tell anyone which was broken, and then send out title keys instead. The resultant tile key doesn't reveal which players key was used, so if the player key used is kept secret, it cannot be easily revoked. The title keys are very short, and easily distributed. Once a title key is out, no matter what, that movie can be decrypted for whatever purpose.
I suspect a title key 'scene' will appear, that will have crackers who pull keys out of software, off the firmware in players, or have contacts in china who pull them right off the pressing line for the disks.
These title keys will be trivial to distribute, and people can then use them as they see fit.