To my understanding, Widevine has two modes: L1 and L3. L3 is software protection where the browser protects against most simple reverse-engineering, but sends an unencrypted video stream to the OS' window compositor, so you can still screen record the content if you'd like. L1, on the other hand, requires a full chain of trust, meaning the encrypted video stream is sent to your GPU unit (or TV SOC), and the GPU has safeguards to prevent the OS from being able to capture that part of the screen, and most importantly has a HDCP handshake with the output device.

When a service is selecting which streams your client is granted a license to, if you claim L1 protection, the license request includes a signature from the GPU/chip doing the decryption, so the service will know whether your device only supports L3 software protection, or has a full chain of trust for the content and thus can protects against things like the user screen recording video content. Chances are the contracts rightsholders have with Netflix et al. require L1 for HD or UHD streams, and only allow L3 420p streaming (note that Netflix Originals seem to stream at 720p on L3, at least from what I've heard).

If you are really interested in scraping a copy, the HDCP keys were leaked at some point and you can buy "HDMI splitters <wink>" for ~$30 which will remove the encryption. Now trivially bypassed, and a pain in the butt for everyone else.

That was for an old version of HDCP up to 1080p, right ? Not to mention, capping and transcoding is tedious and will alter the quality. I doubt if anyone still does it as there seem to be better exploits for the determined.

There are splitters that can do 4K 60Hz HDCP 2.2. You have to really search for them because AliExpress will remove listings that mention this feature explicitly.

Due to the amount of very high quality files you have on torrenting sites, L1 is being broken already indeed, they just don't publish the methods and devices they are using for that so they don't get patched.

Yes, all the files you see on torrent sites are decrypted using L1 keys extracted from a nvidia shield using a TrustZone exploit.

> they just don't publish the methods and devices they are using for that so they don't get patched.

Well not exactly, it's hard to patch this when the keys leak from a very popular device.

Most AV Receivers have a "downgrade HDCP" feature where they get a HDCP 2.2 input and produce an HDCP 1.4 output.

Recording e.g., a 4K HDR movie off Disney+ is absolutely trivial this way.

Stupid question: is it also not possible to simply use VGA instead?

VGA won't create that "full chain of trust" parent is talking about. The GPU essentially says if it's outputting to an HDCP (encrypted) output and if so is expecting encrypted input. As an example if you use an HDMI -> DVI adapter or similar you'll get a scrambled-ish looking picture which is essentially you viewing the ciphertext picture.

This is pretty much inherently super lossy, so not a good bypass. You need to decrypt the actual WV stream for a good copy.

Wouldn't the only loss be from the re-encoding, which many webrips do anyways?

> Wouldn't the only loss be from the re-encoding

Which is pretty dramatic, assuming you don't want absurdly large files.

Where do you see webrips in 2022? Looking on BTN, I only see webrips for series that literally nobody cares about. Everything else is decrypted streams (WEB-DL).

> That said, it seems odd that silliness like this still exists.

It's only going to get worse. I don't think it's gonna take too long for corporations and governments to mandate locked down computers for everyone. Soon all software will require attestation against "tampering". Copyright industry wants this because "piracy". Banks wants this because "fraud". Messaging services want this because "terms of service". Maybe one day even ISPs will refuse to allow user controlled computers on their networks. Who knows what they could do, right? They might be a terrorist or pedophile running Tor and encrypting everything.