Hijack HDCP?

lambchops511

Senior member
Apr 12, 2005
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I'm not talking about doing anything illegal (or suggest u to do anything illegal) ... just something i thot about and want to know your opinions...

I think its possible . All that requires an HDCP enabled monitor you are willing to open up

Basic HDCP Standard Connection

HDCP DVI -> Monitor Input -> Silicon Image Chip (decodes and decrypts the signal) -> Unencrypted Signal -> LVDS Transmitter -> Panel

"Hijacked" HDCP Connection Method 1

HDCP DVI -> Monitor Input -> Silicon Image Chip -> Unencrypted Signal -> TA DA . you now have the datalines of unencrypted video data (8r, 8g, 8b, hsync, vsync, and 2 others i forgot, and ODCK (clock))

now take these rawlines of data and feed it back into the computer . i can think of a couple of crude and very messy ways to do it .


The Silicon Image Chip I'm familiar with is the Si1169 PanelLink, others are available
 

xtknight

Elite Member
Oct 15, 2004
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Seems obvious to me, but so far nobody has executed it this way.

Raw digital RGB data is great but you also lose quality as you still don't have the original stream. And, also you lose compression ability since you're working on already-compressed data. You also need very high bandwidth ($$$) to do this.
 

Banzai042

Senior member
Jul 25, 2005
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Wouldn't the mere act of doing this be illegal since it bypasses DRM? I do think it'd probably work though. Persionally I'm just waiting for somebody to crack the HDCP key from a popular HDTV/Monitor and force the movie industry to choose between disabling a popular display and pissing off lots of people or allowing a key to remain open and allow rips of HD movies to show up.
 

SexyK

Golden Member
Jul 30, 2001
1,343
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Illegal? Yes. Would it work? Maybe. Probably more hassle than it's worth though. If you have the cash to tear up an HDCP monitor, just buy a nice HDCP monitor and enjoy :)
 

lambchops511

Senior member
Apr 12, 2005
659
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Originally posted by: xtknight
Seems obvious to me, but so far nobody has executed it this way.

Raw digital RGB data is great but you also lose quality as you still don't have the original stream. And, also you lose compression ability since you're working on already-compressed data. You also need very high bandwidth ($$$) to do this.




the raw RGB data IS The original data stream . i can think of multiple ways to change this signal back into TDMS or something else that a computer can read


Why would this be illegal? I'm not cracking any DRM . im not sure about "bypassing" . im just taking a signal that my hdcp monitor outputs at a different position .

for example, lets say my hdcp monitor has a dead pixel or something . is it illegal to take apart a monitor and swap the original panel with perhaps another panel maybe even from another manufacturer?


ie . instead of the decrypted data going to a lcd panel . ill just have it goto some device which goes to my hard drive?
 

SexyK

Golden Member
Jul 30, 2001
1,343
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Originally posted by: aznium
Originally posted by: xtknight
Seems obvious to me, but so far nobody has executed it this way.

Raw digital RGB data is great but you also lose quality as you still don't have the original stream. And, also you lose compression ability since you're working on already-compressed data. You also need very high bandwidth ($$$) to do this.




the raw RGB data IS The original data stream . i can think of multiple ways to change this signal back into TDMS or something else that a computer can read


Why would this be illegal? I'm not cracking any DRM . im not sure about "bypassing" . im just taking a signal that my hdcp monitor outputs at a different position .

for example, lets say my hdcp monitor has a dead pixel or something . is it illegal to take apart a monitor and swap the original panel with perhaps another panel maybe even from another manufacturer?


ie . instead of the decrypted data going to a lcd panel . ill just have it goto some device which goes to my hard drive?

Section 1201(a)(1)(A) of the DMCA says, "no person shall circumvent a technological measure that effectively controls access to a work protected under this title."

Section 1201 (a)(3)(A) of the DMCA says "to `circumvent a technological measure' means to descramble a scrambled work, to decrypt an encrypted work, or otherwise to avoid, bypass, remove, deactivate, or impair a technological measure, without the authority of the copyright owner..."

Seems pretty clear that what you propose violates the DMCA, but it's an interesting question anyway because I assume we all believe HDCP will be cracked at some point one way or the other.