Re: HDCP support in PCs is nonexistent now?

[Peter Gutmann]

John Gilmore <[EMAIL PROTECTED]> writes:

>Despite a bunch of PC graphics chips and boards having announced HDCP
>support, according to the above article, it turns out that none of them will
>actually work.  It looks like something slipped somewhere, and an extra
>crypto-key chip needed to be added to every existing board -- at
>manufacturing time.

The extra item was just a little serial EEPROM with per-device
keying/entitlement info.  All the HDCP stuff (the challenge-response handshake
over the DVI link and the actual content en/decryption and MAC'ing) are
performed by the DVI controller chip using data from the external EEPROM.
Since adding the EEPROM would have added a few tens of cents to the cost of
the hardware (the hardware itself, the manufacturing cost, the cost of
personalising and testing each EEPROM, and the fact all portions of the
manufacturing process that come into contact with keys require special
security measures), there was no clear idea when anyone could actually use it,
and there would no doubt be interop problems once devices did hit the market,
leading to product returns from dissatisfied customers, manufacturers skipped
the cost and overhead of adding it.  It makes sense really, why add something
that's both completely useless to users and a potential liability to
manufacturers?  If I were creating the devices, I'd have done the same thing.
It's like region coding in DVD players, you reduce cost and add value by *not*
including it.

Peter.

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

HDCP support in PCs is nonexistent now?

[John Gilmore]

http://www.firingsquad.com/hardware/ati_nvidia_hdcp_support/

HDCP is Intel-designed copy prevention that uses strong crypto to
encrypt the digital video signal on the cable between your video card
(or TV or DVD player) and your monitor.  There is no need for it --
you are seeing the signal that it is encrypting -- except for DRM.

Despite a bunch of PC graphics chips and boards having announced HDCP
support, according to the above article, it turns out that none of
them will actually work.  It looks like something slipped somewhere,
and an extra crypto-key chip needed to be added to every existing
board -- at manufacturing time.  My wild ass guess is that the
original design would have had software communicate the keys to the
board, but Hollywood has recently decided not to trust that design.

This is going to make life very interesting for the HD-DVD crowd.
Intel's grand scheme was to corrupt the PC to an extent that Hollywood
would trust movies, music, etc, to PCs.  Intel decided to learn from
an oligopoly what they know about extending a monopoly into the
indefinite future, by combining legislative bribery with technological
tricks.  Now it appears that even though they have largely succeeded
in pushing all kinds of crap into PC designs, Hollywood doesn't trust
the results enough anyway.  The result may well be that HD-DVDs that
contain movies can only be played on dedicated equipment (standalone
HD-DVD players), at least for the first few years.  Or, you'll need a
new video board, which nobody sells yet, when you buy your first
HD-DVD drive.  Or the DRM standards involved will have to be somehow
weakened.

Anybody know anything more about this imbroglio?

John

PS:  Of course, the whole thing is foolish.  DVD "encryption" has been
cracked for years, and circumvention tools widely distributed
worldwide, despite being too illegal to appear in out-of-the-box
products.  DVD encryption has provided exactly zero protection for DVD
revenues -- yet DVD revenues are high and rising.  In short, unless
Hollywood was lying about its motivations, DRM has so far been useless
to Hollywood.  Yet it has done great violence to consumers, to
computer architecture, to open competition, and to science.


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