View Single Post
Old 5th September 2009, 03:50   #434  |  Link
KenD00
Registered User
 
Join Date: Jan 2007
Location: Internet
Posts: 378
Ok, once i again i should get some things straight here.

Basically there are two types of information we need to decrypt a disc, its Media Key and its Volume ID to calculate the Volume Unique Key. To get these two entities we need two different cryptographic elements.

First a non revoked Host Certificate and its Private Key to get the Volume ID. The recently found one (thanks Mike Chen and pynux) works for (i'm pretty sure) up to MKBv14, so with this one we can get the Volume ID of discs from MKBv1 up to MKBv14. If some day this one gets revoked (which will happen, i'm pretty sure about this) we can't get the Volume ID from ANY of these discs (this is a form of active revokation) until a new Certificate is found (or we use other ways to get it )!

Second we need a Processing Key to decrypt the Media Key. Currently we have Processing Keys for MKBv1 up to MKBv10. If they "revoke" a Processing Key it simply cannot decrypt new MKB versions but it still can decrypt the old ones (so this is a form of passive revokation). But if we can't get the Volume ID of a disc all our Processing Keys are worthless (see above).

To sum things up the current situation is Volume ID for MKBv14, Media Key for MKBv10, the common denominator is MKBv10, so this is the maximum MKB version we can handle now.

KenD00 is offline   Reply With Quote