[opendtv] Re: New DVDs already sparking copy-protection confusion
- From: "Kilroy Hughes" <Kilroy.Hughes@xxxxxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Fri, 17 Feb 2006 19:05:23 -0800
The comment about degraded picture quality is probably a reference to a
video publisher's option to set a flag that forces players to "down res"
their video output to quarter HD resolution over unprotected outputs,
such as YPbPr and VGA and DVI. =20
DVDs are always decrypted and decoded in the player so image
correction/conversion can be applied before output encryption is
applied. Most DVD-V players output 480P30 theses days thanks to
deinterlacer chips, and in some cases output scaled 720P and 1080i.
People are aware that HDMI encryption can be broken, but
recording/encoding the > 1Gbps video stream, or viewing on a legacy
display aren't high priority threat models. Realtime HD capture/encode
of analog signals is a somewhat bigger risk and may not have
circumvention barriers. =20
First generation unprotected compressed video is the top threat, because
of internet and recordable media redistribution. Theatrical piracy is
damaging because of early availability at whatever quality, and
production piracy is the worst combination of early availability and
potentially high quality.
Kilroy Hughes
Sr. Media Architect
Digital Media Interoperability Team
Microsoft Corporation
-----Original Message-----
From: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx]
On Behalf Of Perry Mevissen
Sent: Friday, February 17, 2006 00:22
To: opendtv@xxxxxxxxxxxxx
Subject: [opendtv] Re: New DVDs already sparking copy-protection
confusion
Hi,
If you pay a short visit to the internet and search for HDCP, which is
the=20
global
standard for High-Bandwidth Digital Content Protection over HDMI or DVI,
you will soon find out
it is a joke and fairly easy to get around. Plenty of pages (linked from
http://en.wikipedia.org/wiki/HDCP)
will give you numerous methods to get around it. Root cause is that the=20
encryption
key is just a dot product of the private and public key.
With a little brute force one even claimed it possible to completely
break=20
it.
On the subject of "automatically degrade the DVDs' picture quality" I
feel=20
the urge
to comment that this is not entirely true. But in consumers eyes it may=20
seem so.
The matter is that receivers (TV/monitors) process the incoming imagery
to=20
improve the picture quality
with algorithms like noise reduction, MPEG artifact removal, sharpness,=20
contrast etc etc.
Those improvements are of course performed before the image goes to the=20
display.
But if the image is encrypted to be only decrypted in the display driver
then the improvement
algorithms can not access the video data to improve it. So if this is
the=20
case then protected
content looks of less quality then unprotected content, which did get=20
improved by the receiver.
Of course this it an extra drive for consumers to find a way to decrypt=20
and make an unprotected
copy again of their content, applying/buying the technology mentioned in
section above.
It seems as if those copy protection people never learn.
Perry
opendtv-bounce@xxxxxxxxxxxxx wrote on 2006-02-17 04:26:45 AM:
>=20
> New DVDs already sparking copy-protection confusion
>=20
> By John Borland
> Story last modified Thu Feb 16 08:18:19 PST 2006
>=20
> When the first high-definition DVDs finally hit shelves this spring,=20
> a mad scramble may ensue--not for the discs themselves, but to figure=20
> out what computers and devices are actually able to play them in=20
> their full glory.
>=20
> Unraveling the mystery won't be easy. Many, if not most, of today's=20
> top-of-the-line computers and monitors won't make the cut, even if=20
> next-generation Blu-ray or HD DVD drives are installed.
>=20
> That's because strict content protection technologies may=20
> automatically degrade the DVDs' picture quality, or even block them=20
> from playing at all, if the right connections and digital protections=20
> aren't in place. Even the most expensive computers sold today mostly=20
> lack those features.
>=20
> Indeed, the consumer backlash has already begun. Graphics-chip makers=20
> such as ATI and Nvidia are drawing criticism online for marketing=20
> products that are "ready" for these new copy-protection tools but=20
> that nevertheless lack critical features needed to let the discs play=20
> at top quality.
>=20
> ...
>=20
> http://news.com.com/2100-1025-6040261.html
>=20
>=20
>=20
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