Re:Convert standard Geiger counter to RNG
by stcredzero on Monday November 13, 2023 @08:14PM
(#38257620)
Actually building a PRNG yourself would still be hard though!
Well, coming up with a crappy one isn't hard. Coming up with a new good one, with good efficiency is hard, though.
It would be cool if modern devices had a solid state radiation detector for this purpose.
Don't current chips already do this with noise from a diode? Quick google: Yes. There are quite a number of these sorts of methods: https://en.wikipedia.org/wiki/Hardware_random_number_generat...
Nothing is perfect, it turns out.
Re:Convert standard Geiger counter to RNG
by eternityforest on Monday November 13, 2023 @09:03PM
(#38258022)
They do, but a regular diode noise source can't double as an actual radiation detector. I was thinking something like a SPAD diode or something, so everyone could have background radiation monitoring at all times and get an alert if someone mixed a cobalt source in the scrap metal used to make their furniture or whatever, or the nearby coal plant was puffing out radiation or something.
We also mix entropy in continually. Even if your sources only give you 1 bit per minute, within a few hours you'll have way too much entropy for attackers to decode anything before that window.
Plus, if you're using hashing, you can't figure out previous states from the current state.
Then on top of it people generally also use hardware RNGs built into all modern chips. On Linux I believe they don't trust it by itself but mix it with other sources.
Actually building a PRNG yourself would still be hard though!
It would be cool if modern devices had a solid state radiation detector for this purpose. Not so much because they actually need it, but anything security related often sells well, and it might let them put radiation sensing in consumer devices. I wonder how much stuff people would find!