HDCP Strippers

If you are here, it is because in some way or another, HDCP as come along your way and is somehow blocking you from enjoying your Blu-ray discs or HD-content on a non-HDCP compliant HDTV device.

But do High-bandwidth DCP Strippers and Converter Boxes really work in case your HDTV is not complaint? Can an HDCP stripper box serve as a solution to the many screwed-up early adopters of HDTV whose sets are not compliant with this high-bandwidth digital content protection mechanism?

Is your ‘old’ HDTV with a non-HDCP compliant HDMI or DVI, worthless?

So your DVI and HDMI inputs on your HDTV gear are not HDCP Complaint; is there a way to make these HDCP compliant?

The simple answer to this rather complex question is that there is no way you can convert a non-compliant DVI or HDMI enabled device, into an HDCP compliant one.

Mind you, we are not saying that it is not possible to make use of some dongle — or a software application on your PC — to successfully connect your non-compliant HDTV with an HDCP enabled DVI or HDMI port. Stripper devices that break the protection mechanism on protected HD content has long been available, but…

The truth is that behind this short statement, there is a full list of issues one needs to look at in order to fully appreciate what are the implications associated with the use of dongles or HDCP stripper boxes and PC software that promise to provide a solution to non-compliant devices.

What is the extent of the problem?

By the time HDCP became compulsory towards end 2004, it is estimated that 10% of all US households had a television set capable of displaying high definition content; most of these HDTV sets were not HDCP compliant.

Maybe you think that 10% does not represent a high penetration rate. This is true but in absolute terms, this implies several million units. Worst still is that a good portion of these non- compliant HDTVs and related HD gear are still in use today!

Is it just Blu ray and HD-DVD?

Consumers became more aware of the HDCP requirement mainly through the first HD DVD and Blu ray discs, yet there is more to the implications associated with HDCP. FCC and MPAA had mandated that HDCP/HDMI and HDCP/DVI become the inputs of necessity with HD content. This meant that all satellite and cable providers had to activate HDCP on their HD receivers. The result is that non-compliant HDTVs will only display a standard or enhanced video version of the respective HDTV content!

Is there even more to this dark side of HDCP reality?

The advent of HDCP meant that both Microsoft and Apple had to release operating systems (OS) that support the playback of true high-definition content; this represented a major step towards a more complete integration of the home PC with the rest of your entertainment system.

But to offer HD content, any device — irrespective of whether it is a TV or a PC — must ensure compliance with the specified HD policies. In other words, it must also be HDCP compliant!

But in the case of a PC, an HDCP compliant OS is not enough; the PC video card, motherboard, and the display device or monitor, have to be HDCP compliant as well, otherwise you will still be excluded from accessing high definition content on your home entertainment PC.

HDCP Converters and Stripper Boxes: Do these represent a solution?

There is no doubt, many early adopters of HDTV were screwed up with this HDCP imposition – with millions of these HDTVs still around! So… what can you do if you happen to still have one of these older HDTVs?

In these circumstances, it is only logical to look around for possible solutions that will extend the usability of your HDTV, at least till you are in a position to upgrade your gear.

As already noted earlier on in our article, there is no way a non-compliant HDCP device can become compliant. This means that there is no way you can use some ‘magical’ HDCP converter.

Similarly, you cannot use an HDCP-compliant HDMI enabled home theater receiver to switch an HDCP compliant source to a non-compliant display via one of the HDMI outputs on the receiver. The only possibility to connect an HDCP-compliant HDMI source to a non-HDCP display is simply by stripping away the HDCP encryption and send a bit-perfect copy of the original signal to your display device via either component video or a non-HDCP compliant HDMI port.

In this manner, you will be re-creating an exact restriction-free replica of the original high definition content. This is exactly what HDCP strippers do, irrespective of whether these come in the form of a small hardware box or a software program that runs in the background on your PC!

How do HDCP Strippers work?

An HDCP stripper box is placed between your playback device (e.g. Blu-ray player, etc) and your non-HDCP compliant display. It then behaves in a similar manner to a secure device. In order to achieve this, HDCP strippers use the same HDCP chips built into high definition displays. The HDCP source will see a compliant device, so after the authentication process, it will simply proceed to deliver its signal to the HDCP stripper, which will then create the non-restricted copy to forward to the sink device.

This means that a stripper box can effectively enable HDTV sources like Blu-ray Discs, to work at full high definition resolution with equipment using either analog or ‘unprotected’ DVI and HDMI inputs.

Are HDCP Strippers legal?

Strictly speaking, HDCP Strippers are in reality encryption countermeasure devices. Whether all that the user is doing is just removing the digital rights management from the original signal to be able to view it on his or her non-HDCP compliant HDTV is another story; yet there is no way how these devices can pass the Digital Millennium Copyright Act (DMCA).

Are these stripper boxes freely available on the market?

Probably, the first company that came with such a device was the German company Spatz-Tech, with its DVIMAGIC HDCP stripper in 2005.

This HDCP stripper was selling online at around $500 US — a rather expensive price tag by today standards; but at that time, a top-of-the-line 52-inch flat-panel HDTV would have easily sold for $3,000. In other words, $500 represented just a small price to pay for a working display! The DVIMAGIC HDCP stripper was sold and marketed as a DVI amplifier, yet its main attraction was its application as an HDCP stripper.

DVIMAGIC is no longer available, nor are we aware of any such hardware available from other suppliers. But if it is possible for you to drive your HDTV through your PC, then it is all a different issue. Software HDCP strippers are readily available; one such software is AnyDVD HD by SlySoft.com we already referred to in our HDCP article here.

But… do Stripper boxes really represent a solution?

Be careful – there is a very serious issue here that may put the money spent on an HDCP stripper box literally down the drain use – in an instant. Once an HDCP stripper hits the (black????) market, all a content provider needs to do to put that box out of use is simply revoke the encryption keys used by the device.

We will not go into the actual details of how HDCP works here. However, it is important to have an idea what key revocation is to fully appreciate why hardware-based HDCP strippers represent a risky short term answer. This is not the case with software HDCP strippers which can be easily updated to handle any new restrictions.

HDCP security is built around a three-stage authentication protocol:

Device authentication that will not allow non-compliant devices to receive HD content. During this process, source and sink devices exchange their ‘public’ key which they then use in conjunction with their set of special secret keys, in order to arrive at a common computed number that they will eventually use in the encryption process.

Encryption of the actual data that will flow over the link using the special computed number arrived at during the device authentication process.

Key-revocation procedures to ensure that any device which violates the license agreement could be relatively easily blocked from receiving HD data. Key revocation lists are encoded onto the media – meaning the newer the media – e.g. DVD disc – the larger will be the revocation list.

It is this key revocation process that makes HDCP sort of ‘future-proof’ when it comes to combating the use of fake or rogue hardware stripper devices. Through key revocation, HDCP gives the media, content, or even other devices, the ability to invalidate keys of devices known to be a problem.

This means that everything may be working fine with your HDCP stripper box and then one day, you discover your HDTV is refusing to show any picture. What happened is that your HDTV source has simply invalidated the keys used by your stripper box – hence it is no longer passing the authentication process.

Here crops another issue: What if the keys used by a genuine product have actually leaked out for use by a dongle manufacture to make a rogue device? Does this mean that at some point, a customer may end up with his genuine HDCP compliant Plasma TV blocked simply because the rogue device happens to make use of the same keys?

There is no clear answer to this, but we have never heard of any such issues, so we do not think this is something worth worrying about even though HDCP has the power to retroactively disable any HDCP-enabled device!

What about Software-based HDCP Strippers

As we have already stated, software-based HDCP strippers like Any DVD HD running in the background on a PC are less likely to get disabled as it is always possible to update the respective software. Software strippers seem the only available solution but they carry the inconvenience of having to play your Blu-ray disc on your PC, with the latter interfaced with your non-HDCP compliant HDTV.