
Random Numbers from Astronomical Imaging (2005) - astrodev
https://www.cambridge.org/core/journals/publications-of-the-astronomical-society-of-australia/article/random-numbers-from-astronomical-imaging/5F41FF42864F2774A47A0B4B09A43989
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matt_wulfeck
> _Abstract This article describes a method to turn astronomical imaging into
> a random number generator by using the positions of incident cosmic rays and
> hot pixels to generate bit streams. We subject the resultant bit streams to
> a battery of standard benchmark statistical tests for randomness and show
> that these bit streams are statistically the same as a perfect random bit
> stream._

An honest question, but couldn't the exact same results be achieved with a
simple USB webcam pointed at... well, anything?

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altrego99
In both cases you'd need to know some properties of the distribution to get a
random bitstream.

Which pixel would you be looking at? Below what threshold would you call it a
0 rather than 1? How long till you can confidently say next reading will be
uncorrelated?

I don't know how the astronomical imaging solved these (and TBH cosmic ray
scanning seems a bit overkill to me too).

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greglindahl
USB webcams get hit by cosmic rays, too. This paper is interesting because
it's not just looking at the low bits of a normal image, but rather at at
exceptional events. It's a different sort of random.

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notum
This is very interesting, I love exploring all the "weird" sources of entropy
such as random number generators based on background radiation (easy to build
if you don't mind playing with high voltage), ones based on radio white noise
(easily tampered with) and others.

However my favorite is probably: a Nokia N9 + a laser pointer:
[https://www.sciencealert.com/physicists-have-created-a-
quant...](https://www.sciencealert.com/physicists-have-created-a-quantum-
random-number-generator-from-an-old-nokia-phone)

~~~
Terribledactyl
You might enjoy this:
[https://en.m.wikipedia.org/wiki/Lavarand](https://en.m.wikipedia.org/wiki/Lavarand)

~~~
notum
I did enjoy that, thanks!

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FrenchyJiby
Interesting : The book "His Master's Voice" by Stanislaw Lem depicts
astronomical imaging tapes as random number generator in use by mathematicians
and other professionals, until one of them sues the observatory for a lack of
randomness in the tape he received. Turns out the was a signal in there after
all, triggering a fascinating scientific investigation (and setting the whole
plot of the book into motion)

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bArray
Why not just take the least significant bit and build the random stream from
that?

As the comment from matt_walfeck suggests:

> couldn't the exact same results be achieved with a simple USB webcam

Random radiation flipping the least significant bit of the CMOS sensor should
be enough. If you're really worried about randomness, you can combine several
streams (XOR) and get an even distribution of bits.

~~~
jakobdabo
You won't get a perfect (~8 bit per byte) entropy required for a good PRNG
just by getting the least significant bit of the CMOS sensor (or an ADC), as
it will always have some kind of bias.

~~~
DamonHD
There are standard techniques to remove (eg DC) bias from such bit streams.

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tarikozket
Actually this is what I believe in life :) I believe, seed reference point of
the random theory is stars and that's because most of the times astrology is
accurate.

