
HDCP cracked using $250 of gear and a lot of talent - barredo
http://www.theverge.com/2011/11/25/2586097/germans-crack-hdcp
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jevinskie
This has already been done before the master key leak, using ill-gotten keys.
[1] What is shown here isn't that groundbreaking. HDFury uses either an ASIC
or FPGA so the HDL for HDCP crypto has already been done, just not openly. The
stream cipher itself is quite simple. In HW it is very fast (just the PRNG
generator + XOR) and in SW it is feasible but slow. [2] The really impressive
work was done by whoever leaked the master keys - this project would have been
impossible without their work. Intel's statement that any HW decrypter would
be prohibitively expensive was just hot air to cover their asses. With the
leaking of the master keys their precious DRM was immediately broken forever
and they are just trying to save face.

[1]: <http://www.hdfury.com/> [2]: <http://www.cs.sunysb.edu/~rob/hdcp.html>

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CamperBob
Pretty funny, all right. The moment Digilent announced the Atlys, it was
obvious that it was tailor-made for a MIM attack against HDCP. I'm surprised
it took somebody this long.

~~~
nitrogen
How did I not know about that board before? Ever since HD displaced SD, I've
always wanted an FPGA platform to experiment with custom video processing a la
tvtime and DScaler. Now I know what to save up for.

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zitterbewegung
To look at this another way it took 10 years for this crack to be feasible.
Not many content protection systems can say that they have stood the test of
time for that long.

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ldar15
Yes and no. The content was cracked almost immediately. We don't need an HDCP
crack to rip blurays, so there wasn't much motivation to go after the pipe.
That said, I assume the "crack" was dependent on the key being released in
September, which basically demonstrates that these things are uncrackable, and
its your key security that's the determining factor.

However, the truest part of the article for me was "In the meantime, HDCP
continues to bother only a single group of people: those who buy stuff
legally."

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keeperofdakeys
In the case of HDCP, the master key wasn't found because of bad key security,
but because of the design of the encryption algorithm. The keys are matrices,
and given enough keys from devices that use HDCP, you can calculate the master
key using matrix algebra.

~~~
__david__
Interestingly, the algorithm is apparently the same as the 1394 (FireWire) 5c
"restricted authentication" encryption. I assume they have different seeds for
their matrices but if you can crack one of them you can crack the other.

If only anyone used 1394 any more (let alone 5c over 1394)...

