RE: Was a mistake made in the design of AACS?

2007-05-12 Thread Ian Farquhar \(ifarquha\)
On Thu, May 03, 2007 at 10:25:34AM -0700, Steve Schear wrote: Well, there's an idea: use different physical media formats for entertainment and non- entertainment content (meaning, content created by MPAA members vs. not) and don't sell writable media nor devices capable of writing it for

Re: Was a mistake made in the design of AACS?

2007-05-09 Thread John Gilmore
Well, there's an idea: use different physical media formats for entertainment and non-entertainment content (meaning, content created by MPAA members vs. not) and don't sell writable media nor devices capable of writing it for the former, not to the public, keeping very tight controls on the

Re: Was a mistake made in the design of AACS?

2007-05-05 Thread Steve Schear
At 07:50 AM 5/4/2007, Nicolas Williams wrote: On Thu, May 03, 2007 at 10:25:34AM -0700, Steve Schear wrote: At 03:52 PM 5/2/2007, Ian G wrote: This seems to assume that when a crack is announced, all revenue stops. This would appear to be false. When cracks are announced in such systems,

Re: Was a mistake made in the design of AACS?

2007-05-05 Thread Hal Finney
Allen [EMAIL PROTECTED] writes: 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

Re: Was a mistake made in the design of AACS?

2007-05-04 Thread Allen
Hal Finney wrote: [snip] http://www.freedom-to-tinker.com/?p= 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

Re: Was a mistake made in the design of AACS?

2007-05-04 Thread Allen
Ian G wrote: Hal Finney wrote: Perry Metzger writes: Once the release window has passed, the attacker will use the compromise aggressively and the authority will then blacklist the compromised player, which essentially starts the game over. The studio collects revenue during the release

Re: Was a mistake made in the design of AACS?

2007-05-04 Thread Steve Schear
At 03:52 PM 5/2/2007, Ian G wrote: Hal Finney wrote: Perry Metzger writes: Once the release window has passed, the attacker will use the compromise aggressively and the authority will then blacklist the compromised player, which essentially starts the game over. The studio collects revenue

Re: Was a mistake made in the design of AACS?

2007-05-04 Thread Nicolas Williams
On Thu, May 03, 2007 at 10:25:34AM -0700, Steve Schear wrote: At 03:52 PM 5/2/2007, Ian G wrote: This seems to assume that when a crack is announced, all revenue stops. This would appear to be false. When cracks are announced in such systems, normally revenues aren't strongly effected.

Was a mistake made in the design of AACS?

2007-05-02 Thread Perry E. Metzger
Expanding my last message to make it clearer: Schemes like the AACS one work quite well for satellite TV broadcast protection. In such systems, one's goal is to disable the units owned by rogue subscribers, but the only inventory that one might ruin by a key invalidation is a bit of

Re: Was a mistake made in the design of AACS?

2007-05-02 Thread Florian Weimer
* Perry E. Metzger: This seems to me to be, yet again, an instance where failure to consider threat models is a major cause of security failure. Sorry, but where's the security failure? Where can you buy hardware devices that can copy HD disks? Or download software that does, with a readily

Re: Was a mistake made in the design of AACS?

2007-05-02 Thread Perry E. Metzger
Florian Weimer [EMAIL PROTECTED] writes: * Perry E. Metzger: This seems to me to be, yet again, an instance where failure to consider threat models is a major cause of security failure. Sorry, but where's the security failure? Where can you buy hardware devices that can copy HD disks? Or

Re: Was a mistake made in the design of AACS?

2007-05-02 Thread Hal Finney
Perry Metzger writes: I will again solicit suggestions about optimal strategies both for the attacker and defender for the AACS system -- I think we can learn a lot by thinking about it. It would be especially interesting if there were modifications of the AACS system that would be more hardy

Re: Was a mistake made in the design of AACS?

2007-05-02 Thread Ian G
Hal Finney wrote: Perry Metzger writes: Once the release window has passed, the attacker will use the compromise aggressively and the authority will then blacklist the compromised player, which essentially starts the game over. The studio collects revenue during the release window, and sometimes