Re: Continuing /dev/random problems with 2.4

H. Peter Anvin
2002-02-02T01:50:44Z

Peter Monta wrote:

>>The point with the tests that have been mentioned is to derive such a
>>conservative estimate, and to raise a red flag if the output suddenly
>>becomes predictable.
>>
>
> Ah, I see; I was misled by the "truly random" remark, sorry. So a reasonable
> sanity test for a block of audio samples might be a standard deviation
> greater than a few LSB; this will catch constant or close-to-constant
> output.
>

However, those aren't the main failure modes you need to be concerned
with. Antenna effects may actually be your biggest problem -- picking
up deterministic signals from other parts of the system.

However, I believe this is a solved problem. It would definitely be
interesting taking rngd and figuring out a way to drive it from /dev/dsp
-- probably not too difficult a modification.

-hpa