[mythtv-users] cablecard

Jay R. Ashworth jra at baylink.com
Wed Apr 6 23:40:22 UTC 2005


On Wed, Apr 06, 2005 at 04:27:55PM -0700, Brad Templeton wrote:
> On Wed, Apr 06, 2005 at 03:25:02PM -0700, Joe Votour wrote:
> > Myself, I see Microsoft as the defining factor here. 
> > I figure that in order to integrate things as well as
> > they currently do (i.e. an On Screen Display), they're
> > going to need to decrypt that data somehow.  The PC
> > architecture is too open to allow that to happen.  So,
> > I think that based on Microsoft's lead is where things
> > will go.  If they get full access to the data from the
> > CableCard, then MythTV, with sufficient work can also
> > do so (even if it means completely reverse engineering
> > things).  Otherwise, I have to wonder if Microsoft
> > will just promote another XBox-like device that
> > performs the full Media Center functionality (by
> > XBox-like device, I mean a device that is closed in
> > nature, as opposed to a Media Center PC).
> 
> We can reverse engineer it but may not be able to legally use
> that information.
> 
> After all, the DVD CCA licenced DVD decryptor keys to the various
> makers of DVD playing software for PCs.   And yes, people were
> able to instrument those players and get those decryptor keys.
> But they can't legally make decoders using them.
> 
> (Of course, at the same time, people also found out how to break
> the encryption, without posession of those keys.  Unfortunately
> the software to do this is also illegal in the USA.)
> 
> The question is, will the cablecard folks be willing to accept
> the fact that if MCE gets the keys to talk to a cablecard, that
> people will be able to find them out?

One of us misunderstands how CableCard works.

I *think* it's you, but I'm not sure.

The decryption will be happening in the hardware device that the
CableCard plugs into needs to be able to read the card -- and that card
may be smart, doing chaining-block type stuff -- but the hardware
device will in fact be expected to protect the secrets of the *card*,
it just doesn't have to protect the secrets of the *stream*.

You don't talk to a cablecard, so you don't need keys.

The cablecard *is* the key, the tunercard is the *lock*.

Forgive me if this was all already obvious, and I just missed it.  :-)

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
Designer                          Baylink                             RFC 2100
Ashworth & Associates        The Things I Think                        '87 e24
St Petersburg FL USA      http://baylink.pitas.com             +1 727 647 1274

      If you can read this... thank a system administrator.  Or two.  --me


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