HDCP copy protection? Don't break it - outsmart it!

German electronics company Spatz offers two new devices that seem to not have received the attention they deserve. As German IT magazine c't reports in its current issue, the "DVI HDCP" and "DVI MAGIC" hardware converters foil the movie studios' attempts to deliver HDTV signals over "secured" lines only in order to prevent high quality video copying.

The converters don't do anything to the "High-bandwidth Digital Content Protection" (HDCP) technology, licensed by Digital Content Protection, LLC, which works by modifying both display devices and host graphics systems to provide a protected link between the host (video transmitter) and the display device (video receiver) - see Wikipedia definition.

Instead, it uses the HDCP chips ususally built into high definition displays, so that HDCP "protected" signal sources uncomplainingly deliver their signal to the boxes. They then convert them to RGBHV or unprotected DVI signals.

This means that HDCP sources like HDTV, HD DVD or Blu-ray Discs can be made to work with equipment using analog or "unprotected" DVI inputs.

c't reports that when testing the boxes, a LCD TV set without HDCP support displayed pictures in all modi and resolutions, from PAL/PAL Progressive to NTSC/NTSC Progressive and 1080p (1920 x 1080 pixels) without problems. The built in HDCP chips' labels had been removed, so that it was impossible to find out where they came from. c't also reckons that chip supplier Silicon Image and its licencees will look more closely at whom they sell their parts in the future.

Which would be a pity, I might add.

Posted by Matthias Spielkamp at 09.07.05 18:12

It won't matter if Silicon Image stops making the chip. Reverse engineering them and using ASICs and FPGAs to do the same job would be hard, but not impossible. I can guarantee someone would post the relavent VHDL code and schematics to do this if they do stop making the chips. It's human nature.

Prediction: DRM by this method will become so pernicous that soon after laws to restrict the restrictions will be called for and piracy will increase exponentially..

Posted by: Joseph Perkins at 19.07.05 02:38

It wouldn't be the first time... Thanks for the additional information.

Posted by: Matthias at 19.07.05 07:44