What is HDCP?

Do you use HDMI or DVI cables and get an occasional error when trying to display certain video content? In the process of buying a new TV did you wonder what HDCP stood for? Did you recently purchase a Blu-ray disc player and wonder why it won't play?

If one of the above scenarios described your situation then you likely have a HDCP compatibility issue or HDCP error.

High-bandwidth Digital Content Protection (HDCP) is a security feature developed by Intel Corporation that requires the use of HDCP-certified products in order to receive a HDCP-encrypted digital signal.

It works by encrypting a digital signal with a key that requires authentication from the transmitting and receiving product. If authentication fails then the signal fails.

Purpose of HDCP

The Digital Content Protection LLC (DCP), the organization that licenses HDCP, describes on their website the purpose of HDCP as protecting “digital entertainment content across the DVI/HDMI interface."

The most current version is 2.0, which was released in October 2008. New features to version 2.0 include wireless capability and locality checks.

Most products on the market will have a previous HDCP version, which is fine because HDCP is compatible across versions.

Sony Pictures Entertainment Inc., The Walt Disney Company, and Warner Bros. are the biggest content producers to adopt HDCP encryption technology.

Going beyond that is difficult to pinpoint content that has HDCP, but be certain it could be encrypted in any form of Blu-ray disc, DVD rental, cable/satellite service, or pay-per-view programming.

HDCP only affects HDMI and DVI interfaces, so if you use something else then HDCP is likely not an issue for you right now.

The DCP has licensed almost 600 manufacturers as adopters of HDCP.

HDCP is only relevant when using a digital cable - HDMI or DVI. If all products using these cables have HDCP then you shouldn't notice anything.

HDCP is supposed to prevent theft of digital content, which is another way of saying recording. As a result, there are limitations to how many components you can connect.

The issue at hand is the delivery of a digital signal through a digital cable to a digital viewing device, like a Blu-ray disc player sending a 1080p image to a 1080p HDTV via a HDMI cable.

If all products used in the above example are HDCP-certified then the consumer shouldn’t notice anything - business as usual. The problem is when using a product that isn’t HDCP-certified - no signal.

A key aspect of HDCP is that it isn't required by law to be compatible with every HDMI or DVI interface. It’s a voluntary relationship made between the DCP and various companies.

Still, it’s an unanticipated shock to the consumer who connected a Blu-ray disc player to a HDTV with a HDMI cable. The solution to this situation would either be to use component cables instead of HDMI or replace the TV.

That’s not the agreement most consumers thought they agreed to when they bought that HDCP-less HDTV.

Products with HDCP are sorted into three buckets - sources, sinks, and repeaters:

• Sources are products where the HDCP signal originates from. They are the ‘A’ point in an ‘A to B to C’ order of events. Products in this category include DVRs, set-top boxes, digital tuners, Blu-ray players, or DVD Recorders.

Sinks are products that receive the HDCP signal and display it somewhere. They are the ‘C’ point in an ‘A to B to C’ order of events. Products in this category include flat panel, rear projection and front projection TVs.

Repeaters are products that receive the HDCP signal from a source and send it to the sink. They are the ‘B’ point in an ‘A to B to C order of events‘. Products in this category include repeaters, splitters, switchers, AV receivers, and wireless transmitters.

For the curious consumer looking to verify if a product has HDCP, the DCP publishes a list of approved products on their website.