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Python function that generates true random numbers?

By true random numbers it also means that what every time I run python the seed I generate is different. How do I do this?

Charlie Parker
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Ali Hassan
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    No. Because true random number should never rely on a code or algorithm. – Sandrin Joy Sep 04 '20 at 18:37
  • The 'secrets" module would be the first step towards "truly random enough". You will always need an entropy-source. – sascha Sep 04 '20 at 18:41
  • https://stackoverflow.com/questions/22891583/can-i-generate-authentic-random-number-with-python – Prune Sep 04 '20 at 18:45
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    "Anyone who attempts to generate random numbers by deterministic means is, of course, living in a state of sin." - von Neumann – rossum Sep 05 '20 at 11:33

2 Answers2

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There are many ways of generating random numbers, with exactly 1 thing in common - they all require external input. Let's say you use a simple RNG like games use. The RNG takes an input (usually the system time, in seconds or milliseconds), and performs various wonky mathematical operations to produce a random-looking output.

Let's say, however, that your computer has hardware that can measure atmospheric noise - you could fairly easily do that with your built-in microphone on any laptop, or an external mic on a desktop... Or you can measure the randomness of the user's input - humans are known to be good sources of entropy... Or you could measure the decay of a subatomic particle - quantum mechanics is as random as it gets.

If you could do any of those things - and you can actually do all of them (#3 requires special hardware) you could pass those through a cryptographic hash (ex. SHA-256) to create a truly random stream of bytes with equal probability for every possible state. If you use SHA-256 it would be a good idea to hash at least 512 bits (64 bytes) of data if you want the most randomness possible.

Also, most modern systems have TRNGs (true random number generators) built into their CPUs; hardware manufacturers started doing this to address the need for better RNGs in cryptography. As such, many systems will default to a TRNG if one is available (using the python secrets module).

You can easily check if you have a TRNG on Linux by running cat /dev/random. If it stops and waits after a few seconds you don't and need to use another technique. If if keeps going the same as /dev/urandom, you have a TRNG already and can make truly-random numbers easily!

Update: The Python secrets module documentation can be found here. A quick example program:

import secrets
low = 10
high = 100
out = secrets.randbelow(high - low) + low # out = random number from range [low, high)
print(out) # Print your number

You can also use secrets to create a hex string directly, or produce a stream of random bytes. You can see its docs to learn more.

Linda Lawton - DaImTo
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Serpent27
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  • pip install quantumrandom I found this on a thread posted above. Currently, you are limited to blocks of 1024 but with a bit of simple programming and a little bit of time, you will be able to extend this limit to a large enough sample for most applications. – Ali Hassan Sep 05 '20 at 12:39
  • This is interesting! – Ali Hassan Sep 16 '20 at 13:05
  • Great answer for Python, with great background context. Super! – Fiddy Bux Jan 28 '23 at 07:56
  • what i want is that every time I run python the seed I generate is different. How do I do this? – Charlie Parker Feb 01 '23 at 20:53
  • as mentioned this is an excellent resource: https://stackoverflow.com/questions/22891583/can-i-generate-authentic-random-number-with-python – Charlie Parker Feb 01 '23 at 21:10
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There is a thing called true random numbers.
Check: www.random.org for more information.
Code example:

import requests
source = "https://www.random.org/integers/?num=1&min=1&max=100&col=5&base=10&format=plain&rnd=new"
number = requests.get(source)
number = int(number.text)
Egon Kirchof
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