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Microsoft PlayReady – Complete Client Identity Compromise

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Re: Microsoft PlayReady – Complete Client Identity Compromise

#131

Post by qingcharles »

jsheard wrote: post #100
grishka wrote: post #96

Earlier quoted context omitted.

Are subtitle tracks also encrypted? I've always had the impression that only video itself is. edit: But the subtitle tracks are also available on software-only DRM levels that are easy to break.

Actually now I think of it that doesn't matter since you could just pull the subtitles from the weakly protected 720p version then apply them to the higher resolution versions. Ripping the 4K video through LVDS or HDMI capture would still be annoying though.

I don't know the burden is as big as you imagine. I used to run a torrent site that was 99% recorded shows through capture and we still had every single broadcast show uploaded within minutes -- and no uploaders were getting paid, they were just bored and doing it for the Internet points.

edit: also to add, we would get employees at the studios send us discs with the new shows before release, but I had agreements with at least one studio to not allow uploads until after broadcast if we received any of their media

Re: Microsoft PlayReady – Complete Client Identity Compromise

#132

Post by utensil4778 »

squigz wrote: post #127
utensil4778 wrote: post #109

Earlier quoted context omitted.

No, that's where we are now. Not in the future, right now. It isn't working. You fundamentally can't prevent someone copying your file. It isn't possible, full stop. You can only make it maximally inconvenient. You can't encrypt a user's eyeballs, so the media has to be transmitted in the clear at some level. Be it intercepting the LVDS signal to your TV panel or just pointing a camcorder at the screen. The current t…

I wish I shared your certainty. I certainly don't share your faith in capitalism to solve anything.

Oh, don't get me wrong, I have zero faith in capitalism. After all, that's the entire reason we're in this situation.

However, market forces are actually very real. They just don't work the way capitalists think they do. Or rather, capitalists are convinced they can control the market through technology. Unfortunately for them, this is a technology that can't be solved or controlled.

Re: Microsoft PlayReady – Complete Client Identity Compromise

#133

Post by idle_zealot »

eddd-ddde wrote: post #44
somenameforme wrote: post #37

Earlier quoted context omitted.

If you approach it at the most fundamental level, it seems like a clearly impossible goal to achieve. You are having users playing back content on their private devices, and then want to try to prevent them from copying that. That's basically impossible to achieve on somebody's own machine, and literally impossible to do once two enter into the picture. In the absolute worst case a high resolution/hertz cam on one's…

I imagine in the future DRM is directly embedded in the viewers brain and if it detects pirate content it just fries you. I genuinely can't imagine any other form of DRM being successful.

You could require that all devices capable of video or audio display or capture embed models to detect copyright-protected content, and only proceed with playback or capture if they are connected to the internet and are able to verify some cryptographic liscense is valid. Put all this logic in some secure processor that self-destructs at the slightest sign of potential reverse-engineering or irregular behavior, along with physical anti-tampering measures that make phreaking or uncapping any components liable to trigger self-destruction. Then make the circumvention of any of these measures or attempts to create or import non-compliant display or capture video or audio content carry some heavy criminal penalty, such that any group well-resourced enough to attempt bypass would judge doing so foolish.

That would probably "work".

Re: Microsoft PlayReady – Complete Client Identity Compromise

#134

Post by qingcharles »

bobdvb wrote: post #82
gorkish wrote: post #46

Earlier quoted context omitted.

If you take the capitalistic lust of the corporate executive to its logical extreme, given the massive costs of the DRM tech you'd think that at least one of them would realize that they could make more money if they didn't have to pay for something that doesn't work. The economics of distributing the copies are such that it doesn't actually matter if it's easy or hard for 1 or 100,000 people to break the protection.

I work for a large streaming service and a significant part of my work is content protection. Honestly, tech folks misunderstanding of DRM and content protection is significant. There's some assumption that people are inherently honest and that we're just money grabbing. In the years that I've been doing this I've seen a lot of things and nothing has convinced me that if we turned off DRM we'd: 1) save money 2) not h…

I used to be the chief DRM guy at another large streaming service.

I can say 100% that the company did not want DRM as it was unreliable and customer-unfriendly, but it was the rights-holders that were badly educated and informed and would demand it in their contracts. I would suspect that is the case at a lot of other streamers too?

(the cost of the DRM was near-zero at our company)

Re: Microsoft PlayReady – Complete Client Identity Compromise

#135

Post by qingcharles »

xurukefi wrote: post #8
earth-adventure wrote: post #2

So this is pretty much about breaking the client side DRM, with a bad side effect of abusing someone else's Identity (as used within the DRM context) for nefarious purposes. Did I understand this correctly?

The "client" whose "identity" is abused here is not an end user. A "client" in this context is a program or library that talks to the license servers and receives the content decryption keys. On my Windows machine I see a "Windows.Media.Protection.PlayReady.dll", which I guess is the client that they cracked. Maybe there are also other clients that are widely accepted by license servers. The attack essentially means…

Does PlayReady now require a secure enclave/TPM on your PC? Otherwise as you say, the only thing protecting the keys is obfuscation. This has been the same way all the way back to the first Microsoft DRMv1 in 1998 (?).

The decryption keys have to be stored on your device so you can play your media or your game. So, the level of encryption is totally moot. The level of obfuscation is all that really protects the content.

Re: Microsoft PlayReady – Complete Client Identity Compromise

#136

Post by whoopdedo »

londons_explore wrote: post #6

Is there any video DRM scheme which successfully protects video content appearing on the pirate bay within 24 hours? I really don't see why so many millions (billions?) of dollars have been spent on technologies which so far have never kept the bad guys out.

I don't believe the "Digital Video Express"[1] (aka DIVX[2]) discs were ever cracked while they were on the market. But that's only because they were only sold for 1 year and nobody bought any. Even now finding information about the disc format is rare. Although anyone who has a reason to try probably should be able to do it easily since it was just 3DES.

[1] https://en.wikipedia.org/wiki/DIVX

[2] And this is when I remember that Wikipedia links are case-sensitive

Re: Microsoft PlayReady – Complete Client Identity Compromise

#137

Post by tithe »

squigz wrote: post #53

At some point this silly game of cat-and-mouse is going to escalate, and streaming players won't work unless your entire computer is locked down and "verified" by Microsoft or Apple.

> ...unless your entire computer is locked down and "verified"...

This is exactly what the WEI (Web Environment Integrity)[0] specification sought to achieve, but at the browser level.

[0] https://en.wikipedia.org/wiki/Web_Environment_Integrity

Re: Microsoft PlayReady – Complete Client Identity Compromise

#138

Post by dialup_sounds »

xyzzy123 wrote: post #47
gjsman-1000 wrote: post #31

Earlier quoted context omitted.

As long as it stops even 100,000 people from not downloading videos off of Netflix, from an executive’s perspective, it pays for itself. To them, it’s like saying Speed Limit signs are useless, because cars can go faster than the number posted by literally pressing a button. That’s not the point.

Yes if a particular group gets to externalise / socialise the costs of maintaining a protection then obviously from the perspective of the protected group then it's worth it. The question is, is it good for society overall. Who or what is being protected and what impact does that have on everyone else? Speed limit / stop signs represent a decent point of discussion I think.

There is no "particular group" or "everyone else". Everyone has rights over their own creative work, even if that's mildly inconvenient to others. It's part of the social contract of modern society.

Re: Microsoft PlayReady – Complete Client Identity Compromise

#139

Post by m4tu4g »

jsheard wrote: post #11
londons_explore wrote: post #6

Is there any video DRM scheme which successfully protects video content appearing on the pirate bay within 24 hours? I really don't see why so many millions (billions?) of dollars have been spent on technologies which so far have never kept the bad guys out.

4K streaming content is hit or miss because most services lock that behind Widevine L1, which requires implementors to use a secure enclave and the entire signal path to use strong encryption. If an L1 implementation gets compromised it quickly has its keys revoked and is downgraded to L2/L3, so piracy groups have a limited time window to dump as much 4K content as possible. Those lower Winevines tiers are permanentl…

To add more to this, not essentially 4K is the only thing behind L1, even HD streams can be with L1.

It's entirely the services' choice to use what they want, like they can even put SD stream behind L1 and leave 4K for L3 (this happens widely in lesser known services & L2 is hardly used). Also Amazon's 4K is different from Netflix's 4K considering the key revocation TAT. So everything changes from service to service.

Re: Microsoft PlayReady – Complete Client Identity Compromise

#140

Post by gjsman-1000 »

temac wrote: post #119
gjsman-1000 wrote: post #48

Earlier quoted context omitted.

I can get DRM, right now, for my videos, with 500,000 plays for $1665. That’s publicly available, commercial pricing. That’s a third of a cent per play. At Netflix scale, it’s probably cheaper. DRM is a drop in the bucket compared to normal costs. A Netflix subscription is, what, $10? That’s enough to pay for 3,300 encrypted plays. The same provider, if I was doing over 10,000,000 plays, will drop it to just under on…

Sharing with friend and family is not "serious theft". It is benevolent and what people do with books and DVD, without industry people becoming insane about.

I meant sending copies; where the next thing you know one purchased copy becomes thirty people holding copies.
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