Monday, July 18, 2011

HD Content Security - Repost from

The web page was taken down some time ago.

This is a repost what was online Oct 27, 2008 and goes along with an earlier article I did HDCP strippers

I am not even sure this really worked, or can work, it seems entirely too simple, but maybe it would be worth while getting a few broken TV's and seeing if this can indeed strip the HDCP off of HDMI video streams.



HD Content (720p & 1080p) sources (BluRay, Set Top Box, Gaming) are now popular in everyone’s house. HDMI connectivity is therefore now a MUST on all Consumer Electronic systems (DVD/BluRay Player, Recorder, Home Theater, Set Top Boxes, Gaming systems, TV and even portable applications like Digital Still Camera, Digital Video Camcorder, Portable Media Player and Mobile Phones).
What is HDMI?
From web site we can read that “ HDMI technology provides the highest possible signal to meet the needs of today’s – and tomorrow’s – HD entertainment systems. With a single cable, it transmits: digital video, multi-channel surround sound, advanced control data ). Does that mean that high value HD content cautioulsy protected from Content provider via Set Top Box, BluRay Players… is now easy to copy & broadcast….No, HDMI is encrypted with HDCP.
What is HDCP?
High-bandwidth Digital Content Protection (HDCP) is a specification developed by Intel Corporation to protect digital entertainment content across the DVI/HDMI interface. The HDCP specification is supposed to provide a robust, cost-effective and transparent method for transmitting and receiving digital entertainment content to DVI/HDMI-compliant digital displays.  HDCP is designed for protecting audiovisual content over certain high-bandwidth interfaces…but it looks like with new TV models giving straightforward access to decrypted HDMI signal from encrypted source, it did not reach its target.
Buy a 600$ new TV & get both a nice TV & an HDCP decrypting system
I just bought a new LDC TV featuring various useless things amongst which an optimized time to switch from the various HDMI inputs, also called Faster HDMI Switching. Although I did not care much about this feature because it happens to be gaining me 3 s four times a day, I tried to understand a little bit how this could work. First of all I realized that to make it happen I need to keep all my sources switched ON even if I am not using it. Argh, my PS3 has Power consumption on ~200W versus ~1W in Stand By….
Second, I opened my TV and discover that in front on the main TV chip, there is what you could call an HDMI 4 input to 1 output device. Your PS3 & BluRay are connected to the inputs and the output of this device is going to the unique input of the main TV chip. How could such simple device properly handle a complex mechanism like HDCP?
Let’s try. I cut an HDMI cable and soldered the High Speed links to the output of the HDMI switch.

I then connected my PS3 to the TV, and the output of the HDMI cable soldered inside the TV to a Black Magic HDMI acquisition card, capable only of reading non-HDCP content.  Surprisingly enough PS3 and BluRay content is in clear and can be read like if HDCP encryption did not exist any more…HDCP has disappeared in the 4:1 HDMI chip! Surprising, 8 basic soldering allowed to get rid of HDCP.

Anyway I was quite impressed of such a weakness in a major brand TV. So I tried to understand a bit further if this was a generic issue and tried on another TV with same kind of HDMI + main TV chip implementation….but unfortunately HDCP was still there at the output of the 3:1 HDMI bridge.

The only difference in term of features between the 2 TVs I tried was about this Fast HDMI switching stuff….whether this is related or not…still need ot investigate. If yes, that would be an easy way of knowing which TV suffers the same HDCP weakness.

By the way, if there is a link between this new feature & this HDCP weakness, it would be surprising because the new feature seems to be weel adopted on the market : InstaPort port switching technology will be featured in Samsung’s next generation TVs & is currently under evaluation at 9 of the top 10 TV manufacturers for next year’s models. A new world with free HD content is opening  now….we love new features!

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