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HDCP FAQ

1.What is HDCP?

HDCP (High-bandwidth Digital Content Protection) is a technology developed to help protect digital entertainment content. HDCP has been implemented across both DVI and HDMI interfaces. HDCP gives content owners (e.g. movie studios) the ability to protect their HD content against unauthorized copying. If you want to be able to play high-definition content you should ensure that your HDTV and other HD devices are able to support HDCP-encrypted content.


2.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."

3.What is HDCP 2.2?

HDCP 2.2 is the latest evolution of copy protection. It's designed to create a secure connection between a source and a display. Ostensibly this is so you can't take the output from a source (a Blu-ray player, say) and plug it into some kind of recorder, to make a copy of the content. DRM, the encryption of the content itself, is a separate issue. HDCP doesn't care what goes across the cable, as long as that cable is secure.

It does this by creating encrypted keys between the source and the display (called the sink). Enabled repeaters, like receivers, can be in the chain as well. The source and the sink need to be in agreement, understanding their keys, or no content gets transferred. If you've ever hooked up gear and gotten a blank screen (or turned on gear in the wrong order and gotten a blank screen), this HDCP "handshake" is usually the issue.


HDCP isn't solely over HDMI. It can be implemented to work over DVI, DisplayPort, USB, and more.


4.What is new in HDCP 2.2?

The encryption on the keys in version 2.2 is more advanced than previous versions which, in theory, makes the whole chain harder to break. One other interesting change with 2.2 is a "locality check." The source sends a signal to the sink, and if the sink doesn't get that signal within 20ms, the source kills the connection. In theory, this shouldn't cause any issues in home setups, even over long HDMI runs (unless you have more than 3,740 miles of cable).


5.How HDCP Affects the Consumer?

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.

6.HDCP Products:

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.