Well, yes, of course it’s speculation. Precisely because there is not enough detail in your hypothetical to do anything but speculate. And such speculation remains worthless, because
- it’s vanishingly unlikely that your perfect-world scenario where the math, people, and implementations are 100% perfect will ever exist
and - the experts who actually do solidly know the challenges involved have almost universally said there is no good way to do it, and that trying to have both a secure system for individual users and one that can be broken at will by the government is trying to have your cake and eat it too. And that it would be silly to try, because you won’t be able to prevent the really secure encryption from being used by criminals.
If you really think you can look up something on StackExchange and prove all those experts wrong, well… good luck.
