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Interestingly, DRM is also being used by Signal for privacy concerns over Windows Recall, as discussed on HN [0] previously. [0] https://news.ycombinator.com/i

Interestingly, DRM is also being used by Signal for privacy concerns over Windows Recall, as discussed on HN [0] previously. [0] https://news.ycombinator.com/item?id=44053364 https://news.ycombinator.com/item?id=44053364

sodality2 1y ago
"Used" is a strong term, they're not really utilizing the DRM codepaths, AFAIK it simply tells the OS that the window is software that does use DRM and thus should be excluded from any screenshots. The existence of DRM and desire of Windows to abide by its rules are what Signal relies on.
AnthonyMouse 1y ago
That's more of a double-edged sword hack than "using DRM". The theory of DRM is for the system to restrict the content from the user, i.e. the system is adversarial to the user and vice versa. What Signal is doing is trying to get the system to restrict the content from the rest of the system. Which might work as a transient hack but doesn't actually work to protect the user when the system is adversarial, because Microsoft (the adversary) has the DRM private keys. Even some hypothetical DRM system which is effective in oppressing the user wouldn't prevent Microsoft from purloining the user's data whenever they want because they're the ones who make the DRM.
- bitpush 1y ago
  Microsoft cant and will not break that trust, because then Netflix and others will stop serving content to Microsoft products. This is similar to HTTPS certificate chain of trust. The root signing authority needs to be trusted, but once you break that trust there's no going back. It is a self-regulating system.
  - AnthonyMouse 1y ago
    Why does Netflix care if Microsoft is hoovering up all the user's data? Why would they even care if Microsoft was giving itself access to the Netflix streams? Unlike with Signal there are no real secrets in there. Plus, what is Netflix even going to do? Stop supporting streaming on Microsoft platforms and then lose a bunch of subscribers for no benefit to themselves?
    - j-bos 1y ago
      I imagine it wouldn't be Netflix enforcing that decision but rather the hollywood studios.
      - AnthonyMouse 1y ago
        So ask the same question of them. Would you expect them to care about invasions of user privacy? To give up money over it?
      - lyu07282 1y ago
        But why does Hollywood even care about this DRM in the first place? I don't really understand why all this wasted effort, going so far with HDCP encrypted video signals.. I mean every new release is pirated within hours despite all of these protections anyway, so what exactly is the point? It's even easier and faster to just download a 4K torrent than to get Netflix in 4k working on many system configurations because of these overbearing DRM requirements.
        Mindwipe 1y ago
        Because that's not true. Pirates get very upset that 4K Netflix webrips often take weeks or months as hardware keys have to be burnt.
        AnthonyMouse 1y ago
        The DRM is still completely broken. What they're doing is using some watermarking technology to match the video with a particular device and then ban the device. But then the pirates just buy a device, rip thousands of hours of video using it and then post them all together. Each device can get them everything in the entire catalog that they want because they don't have to post any of it until they've coped all of it and banning the device after the fact is too late. They can even sell the device before the key is banned (or to anyone who won't notice/care) and use the money to buy another one, and then the company is only banning the keys of innocent people who might have been paying customers. And even that is assuming there is no way to remove the watermark, which there always is because multiple copies of the same video can't each be uniquely identifying without revealing what's different about them. Meanwhile the inconvenience to paying customers is real when their stuff doesn't work, and every customer who pirates your stuff because the paid offering doesn't work for them is an actual lost sale. It really does seem like the DRM vendors are taking them for a ride.
  - kevincox 1y ago
    I believe that they could just ignore the Signal app's request to DRM protect the content. Unless Signal is actually encrypting the whole app content before submitting it to Windows it is just a request. This is a bit different to encrypted video where it is actually being encrypted off device.
- Dylan16807 1y ago
  > because Microsoft (the adversary) has the DRM private keys Let's be clear here. That's a fine point in the generic sense, but in the Signal situation there are no private keys and it's not really DRM.
  - AnthonyMouse 1y ago
    It kind of is though? Suppose a third party app wants to make screen captures. Windows prevents it, because otherwise it could do the same thing to Netflix and capture the video. The thing preventing the app from bypassing that constraint is DRM. Whereas suppose Microsoft wants to distribute an update to the video rendering code in Windows. It will have access to the data on the screen because it's the thing converting it into pixels, so Microsoft signs the new code with their private keys and distributes it to your PC and it gets access to what's on your screen. Which they could also do with code designed to exfiltrate it.
    - Dylan16807 1y ago
      But Signal is not Netflix. Signal is not managing any digital rights with this toggle, and also the user has full control over the toggle. Also if Microsoft wanted to bypass it they could just ignore the function call, they wouldn't have to do any clever workarounds.

sodality2 1y ago

"Used" is a strong term, they're not really utilizing the DRM codepaths, AFAIK it simply tells the OS that the window is software that does use DRM and thus should be excluded from any screenshots. The existence of DRM and desire of Windows to abide by its rules are what Signal relies on.

AnthonyMouse 1y ago

That's more of a double-edged sword hack than "using DRM". The theory of DRM is for the system to restrict the content from the user, i.e. the system is adversarial to the user and vice versa. What Signal is doing is trying to get the system to restrict the content from the rest of the system. Which might work as a transient hack but doesn't actually work to protect the user when the system is adversarial, because Microsoft (the adversary) has the DRM private keys. Even some hypothetical DRM system which is effective in oppressing the user wouldn't prevent Microsoft from purloining the user's data whenever they want because they're the ones who make the DRM.

bitpush 1y ago
Microsoft cant and will not break that trust, because then Netflix and others will stop serving content to Microsoft products. This is similar to HTTPS certificate chain of trust. The root signing authority needs to be trusted, but once you break that trust there's no going back. It is a self-regulating system.
- AnthonyMouse 1y ago
  Why does Netflix care if Microsoft is hoovering up all the user's data? Why would they even care if Microsoft was giving itself access to the Netflix streams? Unlike with Signal there are no real secrets in there. Plus, what is Netflix even going to do? Stop supporting streaming on Microsoft platforms and then lose a bunch of subscribers for no benefit to themselves?
  - j-bos 1y ago
    I imagine it wouldn't be Netflix enforcing that decision but rather the hollywood studios.
    - AnthonyMouse 1y ago
      So ask the same question of them. Would you expect them to care about invasions of user privacy? To give up money over it?
    - lyu07282 1y ago
      But why does Hollywood even care about this DRM in the first place? I don't really understand why all this wasted effort, going so far with HDCP encrypted video signals.. I mean every new release is pirated within hours despite all of these protections anyway, so what exactly is the point? It's even easier and faster to just download a 4K torrent than to get Netflix in 4k working on many system configurations because of these overbearing DRM requirements.
      - Mindwipe 1y ago
        Because that's not true. Pirates get very upset that 4K Netflix webrips often take weeks or months as hardware keys have to be burnt.
        AnthonyMouse 1y ago
        The DRM is still completely broken. What they're doing is using some watermarking technology to match the video with a particular device and then ban the device. But then the pirates just buy a device, rip thousands of hours of video using it and then post them all together. Each device can get them everything in the entire catalog that they want because they don't have to post any of it until they've coped all of it and banning the device after the fact is too late. They can even sell the device before the key is banned (or to anyone who won't notice/care) and use the money to buy another one, and then the company is only banning the keys of innocent people who might have been paying customers. And even that is assuming there is no way to remove the watermark, which there always is because multiple copies of the same video can't each be uniquely identifying without revealing what's different about them. Meanwhile the inconvenience to paying customers is real when their stuff doesn't work, and every customer who pirates your stuff because the paid offering doesn't work for them is an actual lost sale. It really does seem like the DRM vendors are taking them for a ride.
- kevincox 1y ago
  I believe that they could just ignore the Signal app's request to DRM protect the content. Unless Signal is actually encrypting the whole app content before submitting it to Windows it is just a request. This is a bit different to encrypted video where it is actually being encrypted off device.
Dylan16807 1y ago
> because Microsoft (the adversary) has the DRM private keys Let's be clear here. That's a fine point in the generic sense, but in the Signal situation there are no private keys and it's not really DRM.
- AnthonyMouse 1y ago
  It kind of is though? Suppose a third party app wants to make screen captures. Windows prevents it, because otherwise it could do the same thing to Netflix and capture the video. The thing preventing the app from bypassing that constraint is DRM. Whereas suppose Microsoft wants to distribute an update to the video rendering code in Windows. It will have access to the data on the screen because it's the thing converting it into pixels, so Microsoft signs the new code with their private keys and distributes it to your PC and it gets access to what's on your screen. Which they could also do with code designed to exfiltrate it.
  - Dylan16807 1y ago
    But Signal is not Netflix. Signal is not managing any digital rights with this toggle, and also the user has full control over the toggle. Also if Microsoft wanted to bypass it they could just ignore the function call, they wouldn't have to do any clever workarounds.