What is HDCP?
The Worst Consumer Nightmare or the best
Digital Content Protection?
HDCP is advertised by the industry as 'Technologies for protecting commercial entertainment content.' Yet it is also considered by many as the worst consumer nightmare brought about by DVI and HDMI interconnects!
Approved by the Federal Communications Commission (FCC) in August 2004 and fully embraced by the Motion Picture Association of America (MPAA), it is also seen as the most powerful form of digital content protection — despite its know flaws — ever devised by the industry in an attempt to protect providers of high definition content material.
Why High-bandwidth Digital Content Protection?
As far as the content industry is concerned, all channels of distribution — whether it be through over-the-air signals, Blu-ray or HD DVD, and cable and satellite HDTV — need to be secured.
Now, digital HD content delivered though DVI and HDMI represents the highest quality video available today. While great for us, it's also great for counterfeiters who can use DVI and HDMI connections to get at a perfect video signal.
This is the background to the birth of High-bandwidth Digital Content Protection. HDCP is based on a three-stage process: authentication, encryption, and key revocation. The scope is to control the video transmission and delivery up to the very end of the video display process. This means that technically speaking, HDCP is pure content protection, not copy protection; restrictions on copying, sharing, etc., have to be handled by other process in the signal chain e.g. cable and satellite TV boxes, high definition DVD players, etc.
What High-bandwidth digital content protection does is simply guarantees that whatever content restrictions are in place, these are enforced by authenticating both the transmitter and the receiver.
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HDCP Requirements for inter-operability
An HDCP source requires a compliant DVI or HDMI receiver for it to allow the transmission of high definition content. What's more, all active components in the HDTV connectivity chain must be fully compliant with this protection standard, otherwise you would not be able to enjoy high definition content. This applies both to source and display, as well as to all copper and fiber based extender units used to extend DVI and HDMI cables, switchers, repeaters, A/V receivers, and even to fully integrated self-powered HDMI and DVI fiber optic cables.
Some may think that it is possible to continue enjoying high definition content as in the early days of HDTV even if their 'old' HDTV is non-HDCP compliant, by using the analog component video connection on their equipment but...
It is true that some high definition boxes still support full high-definition through component video, but to prevent pirates from creating high resolution copies, the HDCP standard bans compliant products from converting protected content to full-resolution analog form unless specifically allowed for by the content provider.
What does this mean?
Connecting an HDCP source e.g. a Blu-ray player, to a non-complaint receiver will at best, force the source device to down-convert the video resolution through analog outputs to close to standard DVD quality; in a similar manner, DVD-Audio content is restricted to DAT quality on non-HDCP compliant digital audio outputs. At worst case, all you will get is just a blank output!
In other words, if you want to be certain you will always be in a position to enjoy the benefits of full resolution high definition audio and video content on your HDTV and sound system, your display device and AV receiver need HDCP support.
Why did High-bandwidth DCP turn out to be the greatest 'nightmare' for early adopters of HDTV?
Being HDCP implies the utilization of a digital interface; in particular, it implies the use of DVI and HDMI inputs and outputs. However, up to a few years ago, a DVI or HDMI interface did not necessarily imply compatibility with this content protection mechanism. Many major manufactures have come up during the early years of DVI and HDMI with products that are not DCP compliant.
Partly, the reason behind this anomaly is that High-bandwidth DCP was not always a requirement with HD content. In fact, this digital content protection protocol was adopted by the FCC almost a year after the first HDMI-enabled devices appeared on stores shelves, and at a time when DVI had already been around for a number of years.
In fact, it wasn't before August 2004 that the FCC approved this high-bandwidth digital content protection as a 'Digital Output Protection Technology', and it wasn't before January 2005 that the European Industry Association for Information Systems (EICTA) announced that HDCP is a required component of the European 'HD ready' label.
To a certain extent, this situation has transformed itself into one of the major problems many early adopters of HDTV had to face after paying top-dollar prices for the first HDTVs to hit the market. Those TVs are truly capable of displaying full high-definition content but they lacked the HDCP-compliant HDMI (or DVI) inputs necessary to digitally interface with the latest generation of high definition devices such as Blu-ray disc players and HD set-top boxes.
The end result is that at best, what you will get on a non-compliant HDTV is a down-converted version of the high definition image via the component video out. The image is down-converted to 960x540; this is a quarter of the 1920x1080 resolution offered by 1080p HD. It is still slightly better than standard DVD quality ...but surely, it is not high definition!
The image constraint (down-converting) over the analog outputs is enforced by a special digital flag referred to as Image Constraint Token (ICT), within the digital rights management standard used by HD media e.g. Blu-ray; it is used to protect movies from unauthorized duplication. The down-converting applies only to the analog part; HDMI (or DVI) will still remain accessible at full resolution if HDCP support is available. The decision to set this flag to restrict the output via the players or set-top box video component output is left to the studio or content provider, who can choose to implement ICT on a disc-by-disc or content-by-content basis.
Fortunately, there is some sort of silver lining to this cloud of confusion. Content providers are aware of the difficulties that surround the implementation of high-bandwidth digital content protection with respect to the present consumer electronics base - especially the not so few early adopters of HDTV - millions of which are still in use today.
In an attempt to show some willingness to meet these consumers half way till they upgrade their HDTV gear, some studios had decided not to enforce analog down conversion on earlier versions. Sony Pictures Entertainment was the first to take this decision; this was soon followed by Universal Studios. This meant that some of the first Blu-ray discs from Sony Pictures Entertainment and HD-DVDs from Universal Studios were still viewable at full high-definition resolution for all HDTV owners.
Be not everyone followed on the footsteps of Sony and Universal. For example, Warner Pictures — a proponent of ICT — still got ahead with implementing down-conversion on the first HD-DVD discs that were released at the time.