What is the difference between tags random and prng?

Question

Currently random has quite a vague tag wiki: "Governed by or involving equal chances for each item." prng doesn't have tag wiki at all.

When should tags prng and random be used?

Answer 1

I feel a bit cautious about using the word PRNG, since it is not always used the same way by everyone.

• Sometimes it is used to refer to the thing that you use to generate entropy for a random seed or a random crypto key (think: /dev/random or /dev/urandom or CryptGenRandom).

• Other times, it is used to refer to a crypto algorithm that accepts a short seed/key and produces a long sequence of pseudorandom output (think: RC4, AES-CTR).

• Still other times, it is used to refer to a non-cryptographic algorithm for pseudorandom numbers (think: rand()).

This means there is some opportunity for ambiguity in what prng refers to. Personally, I'm not sure we want to take a stance on this terminological question on this site.

Answer 2

PRNG should be used specifically when talking about PRNG, whereas Random can apply to any random source.

You can always edit in the tag wiki if you like :-)