HDCP may be fatally cracked

DRM Studios might want to rethink those plans to offer movies in a new early HD VOD window. Reports surfaced on Twitter last night alleging that the master HDCP encryption key had been discovered and released (h/t Engadget). While there is apparently some dispute as to the validity of the claim, if true it could permanently cripple the effectiveness of the DRM used to protect digital signals on Blu-ray Disc players, digital cable boxes, HDTV sets and other devices with HDMI connectors.

With the master key, anyone with the know-how can generate their own source and sink (i.e. display) keys to capture and decrypt digital signals as they pass between devices. The effect is similar to the analog hole, which allows unencrypted analog HD video signals to be captured and copied.

In an effort to plug the analog hole the studios have for years pushed to phase out analog inputs and outputs on CE devices, or alternatively to block their use by restricting HD content to HDCP-protected outputs. The MPAA recently secured permission from the FCC to use selectable output controls  to turn off the analog outputs on cable boxes for planned early VOD showings of movies immediately following their theatrical run.

Those plans could now be bollixed, along with a lot of others.

While HDCP device keys are designed to be revocable and renewable through subsequent content releases, renewing the system’s master key would require updating hundreds of millions of devices already in people’s homes around the world. Many, if not most of those devices, moreover, are effectively un-addressable because they lack Internet connectivity, essentially precluding the sort of firmware update required to reset the master key.

This could be the big one.

Further reading:

High-Bandwidth Digital Content Protection (HDCP) Could Be Fatally Busted

HDCP Master Key Reportedly Leaked. Would Kill Much of HDMI DRM