[ale] random number generators

[Alex Carver]

On 2019-03-19 13:31, Jim Kinney via Ale wrote:
> When the entropy pool gets low and all 200TB are encrypted, writes can
> slow down.
> 
> Looking at at hardware RNG devices. Found one that looks really cool,
> open, all the right buttons http://onerng.info/
> 
> Anybody used something like this?

I've seen mention more than once of using a Geiger counter with its
output tied to a serial port to generate random bits with a small
software shim to push them into entropy.  The advantage is that
radioactive decay is random and this kind of setup can't be influenced
from a distance.


Diode noise is not fully random, it has a specific energy distribution
so there will be bias in the results (in which case you're depending on
these guys to have smoothed/whitened the noise properly).  RF noise is
also not random when the receiver is stationary.  The RF landscape
doesn't change too much and also has inherent bias (cell towers, wifi
APs, lots of other transmitters that don't move and sit on the same
frequency).  The RF generator would depend on the features that do
change which are fewer and slower.