It isn't quantum, but as far as I know https://www.random.org/ is sufficiently random for any purpose that I can think of for publicly verifiable random numbers.
(Most of the demand for random numbers, of course, comes from cryptography. In which case public verifiability of what the random thing was is the last thing that you want.)
How is random.org publicly verifiable? As far as I know, there's no way to prove that a certain set of numbers was produced by random.org at a certain time.
The public verifiability is the real "quantum" advance of this research; probably the title should say that. Of course, it's true that when you don't need public verifiability, your OS's entropy pool + PRNG is good enough for any currently known scenario.
Also it is possible for any group to agree that they will all sign messages at a given time about a given source, and stick them on a blockchain. This then becomes proof that this group all agreed on what was displayed, at that time. This becomes a kind of public verification of what was there.
For simple electronics circuits, reverse-biasing a transistor past its breakdown voltage will give you "noise" — an ADC will give you random values.
I don't know how statistically random it is — suspect it is quantum in nature though since we're dealing with transistors.
(EDIT: checked with ChatGPT, has a sense of humor: "Be careful not to exceed the maximum reverse voltage ratings, or you’ll get more “magic smoke” than white noise.")
Most any sensor attached to a realworld physical system can produce sufficient randomness. Put a vibration sensor on my clothes dryer, plug the output into an md5 hash, and voila. Or setup a webcam aimed at a tree blowing in a breeze. Or pour out some m&ms onto a table and photograph that. We dont need to go quantum when sufficiently random systems like turbulance exist in the macro world.
Thanks, I always associated it with GitHub (as having "done it first" but didn't really think to push further). I appreciate the correction, I like knowing the correct information.
i used software defined radios to make a few sets of one time pads with entropy. The randomness of proper SDR or even a webcam in a lightproof coffee can or something is demonstrable with any of the tools for "testing randomness"; sibling is correct, MEMS are notorious for "noise" and that noise is "random", one can use a GM tube to trigger interrupts and use the timing to get entropy.
I don't know how you'd prove something is truly random, though, just that it looks and acts "random" enough; fitness for use.
Some crypto algorithms need some random data in their construction. Typically "nothing up my sleeve" random numbers are used - digits of pi, sqrt(2), ...
(Most of the demand for random numbers, of course, comes from cryptography. In which case public verifiability of what the random thing was is the last thing that you want.)