HDCP support in monitors

Carbonite2M2

Junior Member
Apr 18, 2007
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Ok I am looking at the monitors now, I want to get one with this system I am building now. I see a couple that say they support HDCP. At first I thought, is this a new connection aside from dvi or analog. Then I look at the monitors specs, it only has dvi or analog. So I am then confused.

I check out the wiki for HDCP and it talks some stuff about it being a *copyright protection* or something. I am kinda lost, the technical mumbo jumbo here is off the charts.

1) Do I want to have HDCP support?

2) In laymens terms, what does it do?

3) Does it make the monitor look better/worse or does it stop things from displaying on the monitor. lol

I am totally lost guys, any help would be greatly appreciated.
 

Carbonite2M2

Junior Member
Apr 18, 2007
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Originally posted by: Thor86
High Definition Copy Protection = DRM.

But what does it do? Whats if for? Do I want to look for one without that, or with it.

The wiki says stuff like it limits the look of dvds that dont support it. So like I wont get as good a picture from dvds if I dont have hdcp support. I frankly just dont understand it.

If someone could explain it in laymens terms, I would be most grateful.
 

GregGreen

Golden Member
Dec 5, 2000
1,682
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You want to get it. It basically allows the monitor to "handshake" with the video card, so as to make sure there is nothing between the two capturing the information. It doesn't affect anything at this point besides HD video -- you need to have HDCP if you want to watch HD-DVDs or Blu-Ray discs over DVI. There is no reason not to buy a monitor with it
 

Carbonite2M2

Junior Member
Apr 18, 2007
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Originally posted by: GregGreen
You want to get it. It basically allows the monitor to "handshake" with the video card, so as to make sure there is nothing between the two capturing the information. It doesn't affect anything at this point besides HD video -- you need to have HDCP if you want to watch HD-DVDs or Blu-Ray discs over DVI. There is no reason not to buy a monitor with it

Thanks thats what I was looking for. So will a monitor that supports it work with a video card that doesnt have hdcp support or a dvd player that doesnt? I imagine its reverse compatable just like a dvd player can play cds right?
 

Aluvus

Platinum Member
Apr 27, 2006
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Originally posted by: Carbonite2M2
Thanks thats what I was looking for. So will a monitor that supports it work with a video card that doesnt have hdcp support or a dvd player that doesnt?

Yes.

HDCP is part of a DRM system. Some high-definition videos (in the future anyway) require that the video card/HD-DVD player and also the monitor support HDCP. If either of those components do not support HDCP, the video cannot be played back at full resolution.
 

RaiderJ

Diamond Member
Apr 29, 2001
7,582
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At this point, NOTHING requires HDCP. There is a slight possibility that you'll need it down the road to watch HD movies at their full resolution, but I doubt it.

Practically any new monitor supports it, so you should be fine.

HDCP = DRM = Crap
 

mercanucaribe

Banned
Oct 20, 2004
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Originally posted by: RaiderJ
At this point, NOTHING requires HDCP. There is a slight possibility that you'll need it down the road to watch HD movies at their full resolution, but I doubt it.

Practically any new monitor supports it, so you should be fine.

HDCP = DRM = Crap

I can't use my cable box through my monitor's DVI port, because the monitor doesn't have HDCP.
 

ribbon13

Diamond Member
Feb 1, 2005
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Originally posted by: mercanucaribe
Originally posted by: RaiderJ
At this point, NOTHING requires HDCP. There is a slight possibility that you'll need it down the road to watch HD movies at their full resolution, but I doubt it.

Practically any new monitor supports it, so you should be fine.

HDCP = DRM = Crap

I can't use my cable box through my monitor's DVI port, because the monitor doesn't have HDCP.

He's saying that next gen movie discs have the option of requiring HDCP handshaking, but probably won't make use of it en masse.

Not that I agree, but he may be right. Things like that piss off pirates and it will be cracked wide open even faster in such event.


edit: As far as your cable box... that's probably an anti-DVR implentation
 

RaiderJ

Diamond Member
Apr 29, 2001
7,582
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Originally posted by: ribbon13
Originally posted by: mercanucaribe
Originally posted by: RaiderJ
At this point, NOTHING requires HDCP. There is a slight possibility that you'll need it down the road to watch HD movies at their full resolution, but I doubt it.

Practically any new monitor supports it, so you should be fine.

HDCP = DRM = Crap

I can't use my cable box through my monitor's DVI port, because the monitor doesn't have HDCP.

He's saying that next gen movie discs have the option of requiring HDCP handshaking, but probably won't make use of it en masse.

Not that I agree, but he may be right. Things like that piss off pirates and it will be cracked wide open even faster in such event.


edit: As far as your cable box... that's probably an anti-DVR implentation

A proprietary setup like an individual cable provider might make use of HDCP, but I got $10 that you won't see it being used on more mainstream items like HD-DVD's.

And, with AACS(?) being mostly compromised, the use of HDCP will just push more people towards downloading cracked discs.
 

Matthias99

Diamond Member
Oct 7, 2003
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Originally posted by: ribbon13
Speaking of that, the OP may find this interesting:
Slashdot | HD-DVD and Blu-Ray AACS DRM Cracked

Nobody "cracked" AACS (at least not in the same sense that the CSS encryption used on DVDs has been broken). The algorithms they use, while not perfect, are reasonably secure cryptographically and do not appear to be easy to break.

Someone found a flaw in a particular software player that allows you to extract the encryption keys for a particular piece of content when you play it back. The protocol is actually built to expect things like this; future titles can include blacklists of compromised software and hardware, and authorized players are required to check that they are not on such blacklists before decrypting the media keys.

Currently, HD-DVD and Blu-Ray discs do not require HDCP for full-quality playback, although I think they will try to use it if it is present. Since most people will be watching these things on HDTVs, and most recent HDTVs support HDCP, this may change at some point.

Your cable box may require HDCP over Firewire/DVI to view all digital channels, or only ones flagged as protected (usually pay channels, pay-per-view events, and most HD cable networks like ESPN-HD). I suppose they could always require it, but it seems kind of pointless.
 

zagood

Diamond Member
Mar 28, 2005
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Kind of surprised nobody's mentioned Vista. This is going to be the main driving factor in HDCP choices.

Digital Rights Management
Another common criticism concerns the integration of new forms of Digital Rights Management into the operating system, specifically the Protected Video Path (PVP), which involves technologies such as High-bandwidth Digital Content Protection (HDCP) and the Image Constraint Token (ICT). These features have been added to Vista due to an agreement between Microsoft and major Hollywood studios.[10] Microsoft claims that movie studios and other providers of "premium content" will only allow their data to be played back on PCs if sufficient protection is granted. This will concern, among other things, play-back of protected content on HD-DVD and Blu-ray discs.

In essence, the Protected Video Path mandates that encryption must be used whenever content marked as "protected" will travel over a link where it might be intercepted. This is called a User-Accessible Bus (UAB). Additionally, all devices that come into contact with premium content such as graphics cards have to be certified by Microsoft.[10] Before playback starts, all the devices involved are checked using a Hardware Functionality Scan (HFS) to verify if they are genuine and have not been tampered with. Devices are required to switch off or artificially degrade the quality of any signal outputs that are not protected by HDCP. Additionally, Microsoft maintains a global revocation list for devices that have been compromised. This list is distributed to PCs over the Internet using normal update mechanisms. The only effect on a revoked driver's functionality is that high-level protected content won't play ? all other functionality, including low-definition playback, is retained.

-z
 

RaiderJ

Diamond Member
Apr 29, 2001
7,582
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Originally posted by: Matthias99
Originally posted by: ribbon13
Speaking of that, the OP may find this interesting:
Slashdot | HD-DVD and Blu-Ray AACS DRM Cracked

Nobody "cracked" AACS (at least not in the same sense that the CSS encryption used on DVDs has been broken). The algorithms they use, while not perfect, are reasonably secure cryptographically and do not appear to be easy to break.

Someone found a flaw in a particular software player that allows you to extract the encryption keys for a particular piece of content when you play it back. The protocol is actually built to expect things like this; future titles can include blacklists of compromised software and hardware, and authorized players are required to check that they are not on such blacklists before decrypting the media keys.

Currently, HD-DVD and Blu-Ray discs do not require HDCP for full-quality playback, although I think they will try to use it if it is present. Since most people will be watching these things on HDTVs, and most recent HDTVs support HDCP, this may change at some point.

Your cable box may require HDCP over Firewire/DVI to view all digital channels, or only ones flagged as protected (usually pay channels, pay-per-view events, and most HD cable networks like ESPN-HD). I suppose they could always require it, but it seems kind of pointless.

The newest AACS attack(s) out there are more sophisticated than that. As I understand it, a simple key revocation will not defeat this latest crack. I don't believe that what is currently available will allow something like HD-DVD Decrypter to be produced, as it is a specific crack when using the XBox 360 HD-DVD drive. However, it is a big step towards a total defeat of AACS.

I also remember reading that HDCP has some fundamental flaws that would allow it to be bypassed as well. I imagine they have not yet been pursued due to the relative small impact that HDCP has made so far. Just wait until it is more widespread - it will be cracked as well.
 

Matthias99

Diamond Member
Oct 7, 2003
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Originally posted by: RaiderJ
The newest AACS attack(s) out there are more sophisticated than that. As I understand it, a simple key revocation will not defeat this latest crack. I don't believe that what is currently available will allow something like HD-DVD Decrypter to be produced, as it is a specific crack when using the XBox 360 HD-DVD drive. However, it is a big step towards a total defeat of AACS.

A little research turned up some more information.

Apparently the AACS protocol allows you to send one of the keys (not the exact decryption key, but something that can be used in part to derive it) in plaintext after you establish a "secure" connection. Someone with a packet sniffer in the middle can then pull this key out of the "secure" connection and potentially use it (along with some other information that is not as easy to get at) to be able to decrypt a particular piece of content. This seems like a pretty boneheaded move to make on their part, although it's not completely fatal.

The major problem they will keep running into is that it's not that hard to pull data out of memory on a PC, so securing a PC-based player is quite difficult. Even if the OS protects you from things like debuggers -- readily-available VM software allows you to 'freeze' the state of an entire OS and examine anything you want. Once you have the player's decryption key, and the other key mentioned above, it is possible (though time-consuming) to derive the decryption key for a particular piece of content. The "Trusted Computing" initiative does things that would, in theory, make it much harder to perform this sort of attack.

SlySoft, who makes AnyDVD, claims to be able to decrypt AACS-protected content. Someone over at doom9.org says, however, that they appeared to be using the player decryption key from PowerDVD (essentially pretending to be PowerDVD, which is an authorized player). It's not clear what they are really doing under the hood.

I also remember reading that HDCP has some fundamental flaws that would allow it to be bypassed as well. I imagine they have not yet been pursued due to the relative small impact that HDCP has made so far. Just wait until it is more widespread - it will be cracked as well.

There's a cryptography expert who claims to have broken HDCP, but won't publish his results for fear he'll be sued to death. Many people are skeptical about this claim.

There was a published paper about a weakness in the HDCP protocol -- but exploiting it requires having access to a fairly large number of device encryption/decryption keys. The weakness stemmed largely from HDCP only using 56-bit encryption keys -- this is too long to easily brute-force, but there are issues with the way the keys are structured that potentially allow you to eliminate some bits from consideration if you have access to a number of device keys. Device keys are not readily accessible in most cases, as it is all done in hardware and the protocol exchanges themselves are encrypted with AES.

There are HDCP strippers available -- but the current ones contain an "authorized" HDCP chip, which in theory could be blacklisted (HDCP works very similarly to AACS).
 

Oyeve

Lifer
Oct 18, 1999
22,055
880
126
Originally posted by: RaiderJ
At this point, NOTHING requires HDCP. There is a slight possibility that you'll need it down the road to watch HD movies at their full resolution, but I doubt it.

Practically any new monitor supports it, so you should be fine.

HDCP = DRM = Crap

Plus it'll be broken before anything that uses it is released. :) I think its broke already!
 

RaiderJ

Diamond Member
Apr 29, 2001
7,582
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I also read an interesting paper on how DRM like AACS/HDCP will push things to a point to where pirated material is actually of higher quality than retail/legal material. In fact, this is why I download TV shows rather than paying for cable. The quality of cable where I live (AK) is garbage. To get 7 or so HD channels would cost me over $60/mo. Newsgroup access is $15/mo.
 

mecroft

Junior Member
May 31, 2007
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If any one have HDCP issue like BLACKSCREEN on a no HDCP compliant device, he can also use HDCP stripper to get rid of it
 

Oyeve

Lifer
Oct 18, 1999
22,055
880
126
Originally posted by: mecroft
If any one have HDCP issue like BLACKSCREEN on a no HDCP compliant device, he can also use HDCP stripper to get rid of it

Yep, whatever they throw at us to thwart piracy will be cracked before its even put in place. I wish the entertainment companies would focus more on quality entertainment than on how to not have it copied/ripped/duped et...al.