1. a Novel Random Number Generator? (sound card mic input)
A short while back there was some discussion about the generation of random
numbers, & I just had a thought which *might* be useful:
If you turn an amplifier way up without any input attached, you get a "hiss"
which is essentially "white" (or "pink") noise, ie, a random distribution of
frequencies; so, since most current computers have a sound card, if you
turned the volume on the mic up all the way, and scanned it, you might get a
stream of random bits, which could then be turned into random numbers.
I haven't tried this, so I don't know if you can drive the mic amp high
enough by software control to get hiss or not, and I don't know if there's
any way to pick off the actual *output* that would be sent to the speakers
(which volume could be separately cranked up to get "better" hiss), instead
of just the mic input.
I got the idea from the "real" way to get truly random numbers for a
computer: set up a video camera to look at a lava lamp, & use some
measurement from that randomly changing image to generate random numbers.
Dan Moyer
2. Re: a Novel Random Number Generator? (sound card mic input)
----- Original Message -----
From: "Dan B Moyer" <DANMOYER at PRODIGY.NET>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Thursday, April 06, 2000 8:29 PM
Subject: a Novel Random Number Generator? (sound card mic input)
> A short while back there was some discussion about the generation of
random
> numbers, & I just had a thought which *might* be useful:
>
> If you turn an amplifier way up without any input attached, you get a
"hiss"
> which is essentially "white" (or "pink") noise, ie, a random distribution
of
> frequencies; so, since most current computers have a sound card, if you
> turned the volume on the mic up all the way, and scanned it, you might get
a
> stream of random bits, which could then be turned into random numbers.
White and pink noise aren't the same, but atm i don't remember the
difference, i think it's in the low frequency levels tho, which shouldn't
matter since you are interested in the level, not the audio frequencies. The
random numbers will be integers between 0 and 65536 (for a 16bit card), if
that range is good enough.
> I got the idea from the "real" way to get truly random numbers for a
> computer: set up a video camera to look at a lava lamp, & use some
> measurement from that randomly changing image to generate random numbers.
You could get pink noise from the video generator too, just with higher
frequencies. Would you believe someone has suggested the lava lamp before? I
still like my idea of taking random numbers of random pixels from video pink
noise, randomly doing lots of random math on them, and using that output as
the random number.
Kat
