High-Bandwidth Digital Content Protection (HDCP)

High-bandwidth Digital Content Protection (HDCP) Along with the introduction of DVI technology came the need to prevent the digital video data from being pirated, or copied without authorization.  In order to address this issue High-bandwidth Digital Content Protection (HDCP) was derived.  HDCP, developed by the Intel Corporation, implements a key encryption encoded into the DVI signal which, without the proper HDCP decoding mechanism, produces either extremely low resolutions or static.  To avoid this, both source and display devices must have DVI connections that support software key HDCP decoding.

HDCP, also used by the new HDMI technology, was strongly endorsed by the entertainment industry, for obvious reasons.  What makes this technique of key encryption possible is its renewability.  The Digital Content Protection LLC, an organization responsible for licensing of the HDCP technology, monitors the secret keys used to encrypt the data.  If at any time they believe a set of secret keys has been compromised by an unauthorized source, those keys are placed on a revocation list and new keys are provided to devices authorized by license.

HDCP also uses a method of authentication to ensure that the receiving device is licensed to receive HDCP encrypted data.  This authentication process repeats itself every few seconds in order to be certain that an illegal device has not been connected after the initial authentication.  If and when this authentication fails, the source device will immediately end all encrypted transmissions.