Hal Finney wrote:



"By this point in our series on AACS (the encryption scheme used in
HD-DVD and Blu-ray) it should be clear that AACS creates a nontrivial
strategic game between the AACS central authority (representing the
movie studios) and the attackers who want to defeat AACS. Today I want
to sketch a model of this game and talk about who is likely to win..."

Felten focuses on the loss of revenue due to extraction of device keys
and subsequent file sharing of decrypted content.  AACS has a mechanism
called sequence keys to watermark content and allow it to be traced
back to the player that created it.  Felten assumes that attackers would
publish decrypted movies, AACSLA would then trace them back to the broken
device, and revoke that device in future releases.

I know I'm in over my head on this so my apologies, but if the key is used in one machine in a product line - Sony DVD players say - then if they find the one machine that it came from and disable it, wouldn't figuring out the key for the next machine in the production run be relatively trivial as the algorithm and hardware implementation used by all machines of a give run be the same? Therefore, couldn't one buy several of them and use them one after another as they are discovered and disabled?

So, in order to prevent any of those machines from being used they'd have to disable a whole lot of machines owned by ordinary individuals, right? What are the downside risks for Sony in doing this?

What am I missing in this picture?



The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]

Reply via email to