[mythtv-users] Re: recording HD content

[Brad Templeton]

On Sat, Apr 23, 2005 at 07:45:55AM -0400, William wrote:
> > Tivo and other partner PVRs.   But sadly, not myth.  Of course we
> > can enjoy it while it lasts, for all I know it may last a while.
> > 
> > The Plug and Play regs continue to require them to provide 
> > the over the air stations in high-def unencrytped QAM without 
> > down-res.
> > 
> 
> Of course there is the strong possibility that shortly after the devices
> start expecting a qualified handshake some smart person will write code to
> emulate a qualified device and we will be able to receive all channels
> again. Something similar to the decss code for DVD decoding. Illegal in some
> places but still generally available.

You can't really "emulate" the handshake per se, it's based on cryptographic
keys and certified digital signatures I believe, with a fancy key revocation
system.

You might be able to get into the chips in compliant TVs and PVRs and
extract the keys.   It's a lot less likely (though not impossible) that
the cryptotsystem itself might be cracked, as was the case for CSS in DVDs.
But CSS was a pretty weak cryptosystem.  In the words of the CSS folks
when it was cracked, "We were surprised it took this long."

If you extract the keys and you put that in a published module, they will
revoke the keys, they say.   If you crack the system then they can't
stop you so easily.

There may be other flaws in their system, of course, we'll only see once
it gets subject to lots of attack.

As you suggest, use of either a hole in the system or a cracked key would
probably violate the law in the USA.