On: It is high time we let go of the Mersenne Twister ...

[josephg]

My new phone is faster than my current desktop CPU. Faster everywhere except in embedded applications is still pretty compelling!

[ajross → josephg]

But your thermostat is not, and it probably needs a PRNG too.

[quiescant_dodo → ajross]

I'm honestly curious why any non-smart thermostat would need a PRNG. Can you give examples why it would be needed?

I'm assuming my thermostat is a input-output machine where the input is detected ambient temperature (computed internal to the device) and the output is either RUN_FURNACE or DO_NOT_RUN_FURNACE.

[garmaine → quiescant_dodo]

Many boring, everyday algorithms employ random choice or blinded inputs to prevent worst case execution.

[alanbernstein → garmaine]

Though I'm sure that's true, a simple thermostat can be built without any electronic components at all, using only the simplest of analog mechanisms, so it's hard to see how it's relevant.

[317070 → alanbernstein]

Well, these days they are actually often connected to the internet.

That on its own requires prngs.

[carlmr → 317070]

I think the point was that if they're fast enough to connect to the internet they will be fast enough to calculate PRNGs. If they're not connected to the internet, they don't need them.

[raverbashing → garmaine]

So it needs a PRNG, but not a cryptographically secure one

[sdenton4 → ajross]

Luckily, if it's anything like MY thermostat, the detected temperature is itself a PRNG.

[antonvs → sdenton4]

The idea of a thermostat using its own detected temperature as a random input to help set the temperature would be horrifying, if I weren't already convinced that that's how mine works.

[GuB-42 → sdenton4]

It is actually a true RNG. Thermal noise, or whatever is messing up with your thermostat can be used as a source of entropy by hardware RNGs.