Trying to extract Widewine key: A journey to failure

Post by rowanG077 » Mon, Aug 02, 2021, 2:05 AM UTC

elcritch wrote: post #83

SilverRed wrote: post #64

Earlier quoted context omitted.

How can DRM ever be perfect? It relies on your computer to be able to decrypt the data so it an never be "mathematically perfect" like regular encryption can be. Current DRM is all about shoving the decryption part as deep in to a chip as possible and betting on the fact that it is physically too hard to extract that info. So it will always be exploitable with some amount of effort.

The DRM implementation and algorithm could be "perfect" in a mathematical sense, but as you point out they tend to rely on a PUF in the silicon hardware. Currently very hard to extract but not completely so. However, say a system had a quantum based PUF then it could be unclonable due to QM. Such a system could still be potentially cracked by causing issues in the processor itself like with the ESP32s. Which was my p…

Post by bigiain » Mon, Aug 02, 2021, 2:21 AM UTC

elcritch wrote: post #83

SilverRed wrote: post #64

Earlier quoted context omitted.

How can DRM ever be perfect? It relies on your computer to be able to decrypt the data so it an never be "mathematically perfect" like regular encryption can be. Current DRM is all about shoving the decryption part as deep in to a chip as possible and betting on the fact that it is physically too hard to extract that info. So it will always be exploitable with some amount of effort.

The DRM implementation and algorithm could be "perfect" in a mathematical sense, but as you point out they tend to rely on a PUF in the silicon hardware. Currently very hard to extract but not completely so. However, say a system had a quantum based PUF then it could be unclonable due to QM. Such a system could still be potentially cracked by causing issues in the processor itself like with the ESP32s. Which was my p…

Post by Wowfunhappy » Mon, Aug 02, 2021, 2:27 AM UTC

SilverRed wrote: post #65

realusername wrote: post #34

Earlier quoted context omitted.

Except that people who exploit L1 just never reveal how they do it, good luck with that. That's the beauty of the asymmetry against DRM, only a single decoded file (which will always happen) is enough for seeding to everybody.

This seems to be confirmed by the fact that most torrent sites have 4K copies of brand new streaming only content while no publicly known exploits exist. Since you are running the exploit locally without affecting other peoples machines, I imagine it would be close to impossible to work out what exploit they are using.

Post by Wowfunhappy » Mon, Aug 02, 2021, 2:32 AM UTC

bawolff wrote: post #74

YetAnotherNick wrote: post #59

Can someone explain what's the point of DRM for video streaming when you can do screen recording so easily. It could make sense in books and games but why is netflix such a heavy proponent for it?

Depending on the solution,it might involve watermarking so that they can trace where the streams that end up on the internet come from and cut off those users. If nothing else, im sure it shows up in the analytics if someone's netflix account is 24/7 streaming every episode of every show without break. Although the real answer is probably: studios require it in their contracts and netflix has to play nice.

Post by lmm » Mon, Aug 02, 2021, 2:47 AM UTC

Wowfunhappy wrote: post #95

SilverRed wrote: post #65

Earlier quoted context omitted.

This seems to be confirmed by the fact that most torrent sites have 4K copies of brand new streaming only content while no publicly known exploits exist. Since you are running the exploit locally without affecting other peoples machines, I imagine it would be close to impossible to work out what exploit they are using.

Are those actual decrypted copies of the original stream, though? Or did they just re-record the output? For the latter you'd only need to break HDCP, right?