Maly cytacik z forum doom9
at the beginning of the aacs decryption process of a HD-DVD or BD you need to know two data blocks:
A processing key suitable for the media key block version used on that disk, and the volume unique id of the disk to be decrypted. Both data together are used to calculate the volume unique key, which then is used to decrypt the title keys, and at last the title keys are used to decrypt the content on the disk.
To prevent a hacker from doing this, the firmware of a HD-DVD / BD reader normally will refuse to unconditionally tell you the volume unique id. Instead, the player software on your pc ( e.g. WinDVD or PowerDVD ) needs to authenticate itself as a "legitimate" application with a player key, which has to be send to the drive first. And only after the drive has accepted the player key as "valid", it will report back with the volume unique id.
If a player key is known to be compromised, it can be invalidated through an update mechanism included on newly released disks. A list of invalidated player keys is stored in the flash rom of the drive. So e.g. if the aacs authorities may find out the player key used by AnyDVDHD to authenticate itself as a legitimate application, they would be able to invalidate this key, which would make AnyDVDHD temporarily inoperationable ( until Slysoft integrates a new player key into AnyDVDHD, which should not take longer then a few hours
)
At this point, the patch provided by Oopho2ei comes into the game:
This patch modifies the drive firmware in a way that it will report the volume unique id without the need of an authentification with a player key. By doing so, one part of the aacs protection is completly knocked out, because it is no longer possible to prevent anybody from getting the volume unique id by invalidating the player key used by the ripping software.
C.U. NanoBot