Real-world Application of HDCP CPTWG May 28, 2003
The problem DVI sensitive to capacitance and noise –Marginal installation – cable or connector out of spec, nearly out of spec, or loose –If HDCP turned on in such conditions, interface can fall into “perpetual snow” state Scope of problem –Legacy installed base of HDCP 1.0 transmitter/receiver pairs –Could be 1/1 billion, 1/1 million, 1/ten thousand of those installations
Ways to address problem Reauthenticate periodically Changes to specifications –Proposed HDCP changes for 1.1 may help –HDMI AV_MUTE state may address problem Reset HDCP state on consumer actions –Make it likely that any consumer action will display a useful picture and reset/reauthenticate HDCP –Provide positive visual feedback to consumers
“Cool” GUIs should be allowed
Existing interfaces (part 2)
Existing interfaces (part 3)
Always allowed
Possible Solution Assuming full screen video should be usually protected, Unencrypted video could be allowed for a short time during “mode changes”