These are mostly about PRNG, not true random sources.
brief funny story. My dad built the 5th computer in the UK, ICCE [0] and one of the tests they wanted to run was statistical analysis over random number fields.
They approached the General Post Office (GPO) which had an RNG called "ernie" [1] which ran the postal investment bond lottery. This is a true RNG, based on radio device avalanche diode behaviour (actually, neon tubes). It was dressed up as a computer but it was basically a detector device and A-to-D converter dressed up to look like one. They asked for a million truly random numbers to run some tests over. Interestingly, ERNIE was made by somebody who worked on Colossus at Bletchley.
The GPO refused to share a feed of numbers: They were concerned the team would discover some predictable event in the number field, and either destroy the post office bond scheme by revealing it, or use it to make millions.
ERNIE sounds kind of fascinating. And somewhat amusing.
Going off on a tangent: An oft-neglected issue is that, even when the random source (like avalanched diodes) is actually sufficiently random, any apparatus that captures that randomness for use inherently causes a bias in the observations.
Even if everything else is perfect (it usually isn't), in terms of signal processing, any observation window (e.g. a finite length of time of measurement) is an aperture which ends up getting convolved with the signal source being observed.
It sometimes helps to convert the skew into white noise with a "whitening" post-pass algorithm.
Using real life randomness is still a good thing to do, of course, it's just that are always real world issues with anything and everything.
( I travelled to Canada from Australia in the 1980s and interviewed William Tutte about codebreaking and the war, I missed out on an opportnity to talk to Tommy Flowers the following year and didn't return to the UK until after his death )
Like a lot of early machines, ICCE was made in part from ex-GPO relays. (ie, it was electromechanical.) Valves were more expensive and relays were flooding the market post-war.
Guess which WW2 activity used a very large number of relays, and was made by the GPO (who used relays heavily in telephony), and was subsequently discontinued by the GPO at wars end as things to do with encoding and decoding scaled back thus flooding the electronics market in the UK with relays...
Tommy Thomas (head of the ERCC in edinburgh where my dad wound up and I therefore lived) worked at Manchester on the Mark 1. He never talked about it and I never asked, subsequently. We both wound up in Australia at the CSIRO, where Radiophysics had been started by people in the radar space, and that bled into their interest in Computing. it's a small world. He was the head of the IT division and I was a lowly researcher, our paths didn't cross much. I wish I'd talked to him more, about this stuff and computer history.
Seems like a click baiting kind of question that I'd surely Bombe.
I ended up mainly doing geophysical field work with a lot of aquisition, processing, and interpretation coding work .. but I dabbled in symbolic computer algebra systems (in Australia) for a while and loitered a little in technical history of the borderline classified - I interviewed "for the record" Leonard Beadell, Jack Wong Sue, Mark Oliphant, people associated with the Mungalalu Truscott Airbase, etc.
I seem to recall a fair bit was done here with early over the horizon radar work but I didn't go far in that direction ending up more in radiometrics and resource | energy tracking.
In the pop-sci space, Robert Buderi's book on radar is really about a lot more than Radar, and covers off on the field really well including Taffy Bowen's work in Australia and the contribution to radioastronomy. (you probably know it)
brief funny story. My dad built the 5th computer in the UK, ICCE [0] and one of the tests they wanted to run was statistical analysis over random number fields.
They approached the General Post Office (GPO) which had an RNG called "ernie" [1] which ran the postal investment bond lottery. This is a true RNG, based on radio device avalanche diode behaviour (actually, neon tubes). It was dressed up as a computer but it was basically a detector device and A-to-D converter dressed up to look like one. They asked for a million truly random numbers to run some tests over. Interestingly, ERNIE was made by somebody who worked on Colossus at Bletchley.
The GPO refused to share a feed of numbers: They were concerned the team would discover some predictable event in the number field, and either destroy the post office bond scheme by revealing it, or use it to make millions.
[0] https://en.wikipedia.org/wiki/Imperial_College_Computing_Eng...
[1] https://en.wikipedia.org/wiki/Premium_Bond#ERNIE