[cryptography] [FORGED] Re: Kernel space vs userspace RNG

Ron Garret ron at flownet.com
Wed May 18 03:10:57 EDT 2016

On May 17, 2016, at 11:46 PM, Jon Callas <jon at callas.org> wrote:

> Sadly, people's prejudices get them overcomplicating the issue.


> It's certainly true that a geiger counter measures something that's truly random (for some suitable value of truly random) because of quantum effects. But so does a noisy diode or resistor noise. The difference is that radioactive decay is sexy because you have to get exotic and dangerous material, but a resistor is just carbon, and so people are quite sure that it doesn't actually have atoms or let alone quanta or quarks in it. Quanta are exotic. It's not like they make quantum computers out of atoms, right?
> Similarly, the lava lamp is cool, but you get just as good (and often better) real randomness out of the same camera pointed at a lava lamp, but with the lens cap on. That's because the sensor gets quantum crap in it caused by many things (from similar noise to the above to virtual particles) but with light coming in, the image washes out the quantum crap. But it doesn't *feel* random to take readings from a camera with a lens cap on.

It doesn’t feel very random to say “shhhh…” into your computer’s microphone either, but that is actually a very high quality source of entropy.


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