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I hate DRM, and I’m a free software advocate. However, if I were in the shoes of a TV content provider who relies on DRM, I would seriously consider lobbying sy

I hate DRM, and I’m a free software advocate. However, if I were in the shoes of a TV content provider who relies on DRM, I would seriously consider lobbying system designers to prevent firmware downgrades. I wouldn’t want consumers to downgrade their systems and exploit already-patched vulnerabilities in order to circumvent DRM. One could argue that DRM is evil and wrong, too. But then again, it enables subscriptions and renting and there’s arguably a market for both.

krageon 6y ago
The DRM module could be on a separate bit of memory from the actual OS, meaning that it would stay upgraded even if the rest was downgraded. It doesn't use fuses (AFAIK anyway), but f.e. the baseband on your phone works like this.
- Hackbraten 6y ago
  Wouldn’t the decrypted stream still have to go through the actual OS’s main memory?
- xg15 6y ago
  Isn't this effectively what a TPM is? But I think this only works to an extent as, if you want your DRM not be trivially circumventable, it will be a cross-cutting concern and not easily restricted to a module. E.g., the most secure TPM is useless if the OS simply ignores any responses and shows the movie anyway. What you could do is to close off the whole media path: The OS only sees the encrypted media, which it sends to some combined TPM/decoding hardware, which more or less sends it directly to the screen. I believe to some extent this is what is done in practice. You could technically see the TPM/graphics card/screen assembly as a "module" and can keep the OS separate of it - but this risks your "module" becoming so essentiall that it'll be unclear what is the dog and what is the tail.
xg15 6y ago
The problem I see is that this is a very slippery slope. There is a lot of money to be made and a lot of innovative business models to find on top of hardware that can be arbitrarily restricted. I'm not convinced at all this would stop with copy protection. In fact, we can already see things like unskippable commercials, apps with dark patterns and deliberate anti-features, smart TVs that suddenly gain banner ads, and political conflicts being played out in app stores. All of that stuff is only possible because consumer devices are locked down and answer first to the vendor, then to the user. You can say that all if this is an exciting new market that unlocks enormous amounts of innovation - I just don't think this is the kind of innovation that we should want.

krageon 6y ago

The DRM module could be on a separate bit of memory from the actual OS, meaning that it would stay upgraded even if the rest was downgraded. It doesn't use fuses (AFAIK anyway), but f.e. the baseband on your phone works like this.

Hackbraten 6y ago
Wouldn’t the decrypted stream still have to go through the actual OS’s main memory?
xg15 6y ago
Isn't this effectively what a TPM is? But I think this only works to an extent as, if you want your DRM not be trivially circumventable, it will be a cross-cutting concern and not easily restricted to a module. E.g., the most secure TPM is useless if the OS simply ignores any responses and shows the movie anyway. What you could do is to close off the whole media path: The OS only sees the encrypted media, which it sends to some combined TPM/decoding hardware, which more or less sends it directly to the screen. I believe to some extent this is what is done in practice. You could technically see the TPM/graphics card/screen assembly as a "module" and can keep the OS separate of it - but this risks your "module" becoming so essentiall that it'll be unclear what is the dog and what is the tail.

xg15 6y ago

The problem I see is that this is a very slippery slope. There is a lot of money to be made and a lot of innovative business models to find on top of hardware that can be arbitrarily restricted. I'm not convinced at all this would stop with copy protection. In fact, we can already see things like unskippable commercials, apps with dark patterns and deliberate anti-features, smart TVs that suddenly gain banner ads, and political conflicts being played out in app stores. All of that stuff is only possible because consumer devices are locked down and answer first to the vendor, then to the user. You can say that all if this is an exciting new market that unlocks enormous amounts of innovation - I just don't think this is the kind of innovation that we should want.