this post was submitted on 26 Oct 2023
182 points (97.9% liked)
Physics
1341 readers
4 users here now
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Say I'm restarting my phone, and it uses details like temperature fluctuations in CPU sensors as entropy. How would you know all the required values? Since I'm holding the phone in my hand, the temperature of my hand (and consequently body temperature) are relevant, not to mention the air around my phone. How would you find those values at the exact time the sensors are read?
You honestly think those values aren’t possible to estimate within a range then brute force?
That’s like asking “say I hit a button at a very specific time, how would you find that exact time?”
Yes, because 1) you'd need to know them with incredible precision, and 2) you can't brute force, because you only have one chance. Otherwise you can also brute force anything that's "truly random" as you put it.
That's the thing, it's not like that. It's more like "say I hit a button at a very specific time and roll hundreds of dice, how would I find that exact time and all the results of those dice".
Apart from the face that there are absolutely no “dice rolls” involved. They are known deterministic calculations. Because in order to add “dice rolls” you would need randomness. You can’t have a non deterministic calculation involved, because that isn’t how computers work.
You’re essentially saying “take a knowable input, add true randomness, output true randomness using nothing but knowable inputs!”
And you absolutely can brute force it. Why would you have a single chance? Because of arbitrary rules?
As for true randomness, you’re getting a range of “extreme low to extreme high” which isn’t currently brute forcible.
My dude, the "dice rolls" are all the small pieces of entropy that you'd have to know the environment to an unknowable degree for. They are conceptually absolutely involved, and if you can't understand that, we're done here, because you're handwaving over the difficult parts in a way that doesn't make sense.
Those “dice rolls” are not random though. The problem is you keep talking about these inputs as if they themselves are random. They aren’t. And just because you can’t fathom a way to know their values now, doesn’t mean they are unknowable. I point back to the timestamp issue, where at the time it was considered “enough” but was disproven as such years down the line.