Posted by Jeff Rife on 12/23/44 11:28

Howard (stile99@email.com) wrote in alt.video.dvd:
> > Sure, once you get it, you can play that disc on any player, but *only*
> > that disc. And, if the system uses a combination of hardware player ID
>
> One disc will make a million copies.

If all you want to do is pirate discs on an industrial scale, you can do
that with DVDs without even touching CSS. All CSS does is make a sector
"unreadable" because the entire raw sector (including CRC) is encrypted,
so the drive returns a CRC error unless it has been put into "CSS-decrypt"
mode by giving it a player key. But, if you tinker with the hardware of
the drive, you can get it to return the absolutely raw sectors, and then
you have a master ready to burn or stamp. The same thing will work with
BluRay or HD-DVD. So, this isn't the what the studios are trying to stop.

What they are trying to stop is not getting a piece of the pie for every
single player system out there. The system described is such that without
a hardware player that has the decryption algorithm *and* the keys, it
really doesn't matter how many copies of the disc you have. The whole
point of the central server and protected keys is that you can give away
the algorithm to anybody, and still have a secure system.

Now, if the powers that control BluRay and HD-DVD are dumb enough to allow
PC-based software players that don't require some kind of special hardware
(dongle, card, etc.), then it would be possible to do what has happened to
CSS, although you'd just replace the real central server key distribution
system with a pirate one.

The important part to the way CSS is broken is that any abitrary new disc
can be decrypted using brute force in a very short time, because of the
40-bit encryption and the fact that keys are not unique. This new system
would require distribution of the discovered key.

And, again, if the algorithm uses a combination of the player *and* the
disc, then learning one key gives you nothing, just like breaking one PGP
message gives you no leverage on the rest of the system.

Last, it's not impossible to give *every* copy of a disc a unique key that
unlocks it, and this can even be mass-produced using stamping systems
if you do it correctly. Even if you didn't use unique keys, but used
a system where 1000 discs get the same key, it'd still be a PITA to deal
with.

--
Jeff Rife |
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