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Yeah, there are many trivial systems out there that mostly provide legal protection. But there are also some pretty sophisticated DRM systems that are technolog

Yeah, there are many trivial systems out there that mostly provide legal protection. But there are also some pretty sophisticated DRM systems that are technologically quite well implemented and take a large effort to break. BD+ is one of these for example. And maybe going to platforms where the whole hardware is specialized is not what most people have in mind when they think DRM but the basic building blocks are similar. Microsoft's "Guarding Against Physical Attacks: The Xbox One Story" talk is also one of the few examples I know of where a manufacturer explains how they implemented such a system. [1] [1] https://www.platformsecuritysummit.com/2019/speaker/chen/ https://www.platformsecuritysummit.com/2019/speaker/chen/

grishka 6y ago
Thanks for linking this talk, it was indeed interesting. Especially the part where he said that "if the hack costs more than 10 games, we're fine". Indeed, you probably aren't breaking this thing unless you have millions of dollars worth of equipment and the expertise to use it. But then video game consoles are special. They were always these closed, tightly-controlled ecosystems. General-purpose devices, like phones and computers, typically lack this kind of integration between their components. Yes, there's ARM TrustZone, and that's about it. Thankfully. And I'm not aware of anything similar on x86 PCs (besides the Apple T2, which was recently compromised).
- vengefulduck 6y ago
  Intel SGX?
  - grishka 6y ago
    I've seen this name but still don't understand where's its root of trust. In other words: - How does the program making use of it make sure it's not been patched so the code that's supposed to run in the enclave runs without one? - How does it know it's not being run on an emulated CPU or in a VM? And that those checks haven't been patched out, too? - How does it make sure the OS is cooperating? I assume there is some cooperation required from the kernel at least.
- Mindwipe 6y ago
  Most GPUs now have hardware backed support for DRM. That's why those GPUs get 4K Netflix. The compromise of Apple's T2 chip was significantly overstated.

grishka 6y ago

Thanks for linking this talk, it was indeed interesting. Especially the part where he said that "if the hack costs more than 10 games, we're fine". Indeed, you probably aren't breaking this thing unless you have millions of dollars worth of equipment and the expertise to use it. But then video game consoles are special. They were always these closed, tightly-controlled ecosystems. General-purpose devices, like phones and computers, typically lack this kind of integration between their components. Yes, there's ARM TrustZone, and that's about it. Thankfully. And I'm not aware of anything similar on x86 PCs (besides the Apple T2, which was recently compromised).

vengefulduck 6y ago
Intel SGX?
- grishka 6y ago
  I've seen this name but still don't understand where's its root of trust. In other words: - How does the program making use of it make sure it's not been patched so the code that's supposed to run in the enclave runs without one? - How does it know it's not being run on an emulated CPU or in a VM? And that those checks haven't been patched out, too? - How does it make sure the OS is cooperating? I assume there is some cooperation required from the kernel at least.
Mindwipe 6y ago
Most GPUs now have hardware backed support for DRM. That's why those GPUs get 4K Netflix. The compromise of Apple's T2 chip was significantly overstated.