High-bandwidth Digital Content Protection (HDCP)
Phoenix
Joseph Ashwood
news:10e670bf-f6a7-45d0...@q18g2000vbm.googlegroups.com...
> And what about this?
Generally we don't post blind links, but assuming that link is to the
alleged HDCP master key, so what? Its been a very poorly kept secret for
years, there have been numerous groups that have acquired it through various
methods. I have no idea if the one publicly revealed is genuine, but it
won't make any difference, the key has been available for years to anyone
with a bit of techical know-how and enough money to buy a few devices.
Joe
Peter Gutmann
The key is apparently genuine (it was confirmed by Intel), but the hype about
it being the death of Blu-ray is kind of silly, unless you have your own chip
fab or access to a very fast FPGA you can't do much with it. Anyone who wants
to defeat HDCP just buys a $20 Chinese-made HDCP stripper (sold as HDMI
switches or repeaters) and doesn't bother with HDCP keys.
What evidence is there of the key having been available for years?
Peter.
Greg Rose
I guess it depends on what you mean by
"available". Neils Ferguson told the world that
the secret array was easily recovered a long time
ago now, but wouldn't reveal it (or how to do it)
for fear of prosecution under DMCA. However anyone
with understanding of linear algebra could figure
out the (presumably) same attack.
So I wonder how the $20 Chinese-made HDCP
strippers got their keys?
Greg.
--
Jan Panteltje
g...@nope.ucsd.edu (Greg Rose) wrote in <i72tp0$orj$1...@ihnp4.ucsd.edu>:
>
>So I wonder how the $20 Chinese-made HDCP
>strippers got their keys?
They don't need that key.
They can just use a monitor chip.
Peter Gutmann
>So I wonder how the $20 Chinese-made HDCP strippers got their keys?
Standard third-shift practices I'd guess. They're all bog-standard COTS
components, I've pulled the I2C signals off one of them and they just clear
the bit to turn on HDCP when they set up the HDMI ASIC config. If anyone's
going to the World Computer Congress next week and wants to play with one I'll
have one with me as a prop for a talk I'm doing.
Peter.
Jan Panteltje
pgu...@cs.auckland.ac.nz (Peter Gutmann) wrote in
<8fma9d...@mid.individual.net>:
Have a look at this, bit-sliced HDCP Encryption/Decryption Code for PC in C:
http://www.cs.sunysb.edu/~rob/hdcp.html