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A comment on CU Randomness Beacon. Parent comment

Re:CU Randomness Beacon by svota on Tuesday July 08, 2025 @09:13AM (#44499648)
Because, firstly, this is a university, not some rando self-hosting, and secondly, you can't generate randomness from any classical computer, only pseudorandomness [0]. This means that a dedicated adversary can potentially work out what the outcome will be. For something like the use cases they mention - jury selection, lottery, etc. - you want actual randomness.

[0] - https://en.wikipedia.org/wiki/Pseudorandomness

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Re:CU Randomness Beacon by throw0101d on Tuesday July 08, 2025 @10:06AM (#44500113)
> […] you can't generate randomness from any classical computer, only pseudorandomness [0].

Back in 1999 Intel used amplified thermal noise from analog circuits on their chips to generate randomness:

* PDF: https://web.archive.org/web/20100714102630/https://www.crypt...

This was further refined and in 2011 they published how RdRand (formerly "Bull Mountain") works:

* https://spectrum.ieee.org/behind-intels-new-randomnumber-gen...

* https://en.wikipedia.org/wiki/RDRAND

* PDF: https://www.intel.com/content/dam/develop/external/us/en/doc...

So classical computers can generate randomness if you have the right circuits for it.

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Re:CU Randomness Beacon by treyd on Tuesday July 08, 2025 @10:43AM (#44500458)
> So classical computers can generate randomness if you have the right circuits for it.

That is by definition not a classical computer. It's not a quantum computer, but it's probabilistic in a limited sense.

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Re:CU Randomness Beacon by dekhn on Tuesday July 08, 2025 @04:17PM (#44503667)
I don't think anybody wrote a description of a classical computer that excludes components that generate harvestable random noise. Effectively all computers are probabilistic, it's just that the probabilities for instructions, memory fetches, bus transfers, etc, have such low error probabilities that you will likely go years without directly observing one.
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Re:CU Randomness Beacon by treyd on Wednesday July 09, 2025 @12:42AM (#44506401)
A classical computer is a pure mathematical object. No real-world computer completely embodies the concept, but they vary in how much they try to hide it. Rdrand is an admission that no they're really not classical computers, and it turns out that that is useful in certain scenarios.
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Re:CU Randomness Beacon by dekhn on Wednesday July 09, 2025 @11:54AM (#44511610)
oh you're talking about deterministic turing machines (have not heard that referred to as "classical" computer before- typically when people say that, they mean an actual physical real-world computer, not a theoretical model.
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Re:CU Randomness Beacon by sidewndr46 on Tuesday July 08, 2025 @01:51PM (#44502349)
I think you could just create something like this and sample it with the sound card as well https://en.wikipedia.org/wiki/Chua%27s_circuit
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Re:CU Randomness Beacon by dekhn on Tuesday July 08, 2025 @03:14PM (#44503081)
A zener diode- standard component- produces random noise. It needs to be mildly conditioned to be unbiased.
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