HDMI's HDCP Hacked

The digital rights management scheme that protects HDMI inputs has been undermined with the recent revelation of a master key that unlocks HDCP.

HDCP stands for High-bandwidth Digital Content Protection. It made its debut in DVI, the digital interface used by some older HDTVs, and was ported over to HDMI. HDCP assigns individual keys to both transmitting and receiving devices such as HDTVs, Blu-ray players, and set-top boxes. The use of a master key that would unlock any of those devices is a step backward for DRM and copyright holders. The master key is now being distributed on websites linked to Twitter.

The Blu-ray format is protected by three additional schemes: AACS/CSS, also used in DVD (long ago hacked); plus BD+ (hacked) and the BD-ROM Mark (rumored to be hacked). But even the accumulated weight of all those forms of protection hasn't prevented Blu-ray copying applications from circulating on the internet.

One interesting angle, as Engadget HD noted, is that the HDCP hack comes just as Hollywood is starting to use HDCP to limit playback of hot VOD titles to DRM-protected interfaces, namely HDMI, closing the so-called analog hole on a limited basis. But HDMI is not so protected now.

For further background on HDCP and the implications of the hack, see Ars Technica. The story notes that a new HDCP master key could be generated but this would incapacitate all HDCP-compliant devices currently on the market and in homes.

According to Wired, HDCP requires hardware as well as software, so the HDCP jack can come to fruition only if the black market comes up with illicit HDCP cards.