Ask HN: Is taking input from your microphone a TRNG?

2 points by smalltorch 27 days ago | 1 comment

Working on a project where the goal is to generate a secure key from my device. Ive used dev/urandom in the past but it's always felt like a black box and I have no way to prove it's completely random.

Then it dawned on me while I was playing guitar...why don't I make a program that records audio and hashes the input. Is this not a TRNG? The input would never repeat since there will always be slight difference.

What am I missing?

gus_massa 26 days ago |

You can't use the microphone directly as a TRNG, you must processes and clean up the signal. I don't know the details, and probably neither you, but the guy/dal that dev/urandom know. So, look for more details, and then decide to use dev/urandom.