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Old 5th February 2007, 22:33   #18  |  Link
noclip
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Join Date: Dec 2006
Posts: 154
Quote:
Originally Posted by arnezami View Post
The point I am trying to make is that it should only be hard for one (or a few) people while it should be easy for many. Only that way will you get people to keep gather volume unique keys. That means getting some crucial information (like the Media Key or even harder: an appropiate device key from a player's set of device keys) that can be used to decrypt discs. These discs also need specific information for decryption (the Volume ID) which can be obtained from outside the software player (by sniffing) thus making it impossible for the software player to make it harder and thus easier for the common Joes (who probably have many more movies than a few gurus have).

I do however (in principle) agree with you that it is not better (or worse) to go for the media in the memory of a player instead of the device keys. However its right now probably easier to retrieve the media key from memory than its is to extract a Device key (technically we only need a process key but thats a different matter.

Btw we should never (keep) releasing Device Keys. Its much better to release Media Keys. Unless somehow one version of an MKB can have multiple Media Keys (and as far as I understand that not the "rule").
To go after a device key with known plaintext you must first have a known plaintext (the media key). We should focus on working our way up the chain of command from Volume to Media to Device to possibly (but unlikely) Root key.

Last edited by noclip; 5th February 2007 at 22:38.
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