random

[Marcin 'Qrczak' Kowalczyk]

Wed, 30 May 2001 17:31:24 +0200 (MET DST), Eugene Leitl <Eugene.Leitl at lrz.uni-muenchen.de> pisze:

> But /dev/random under Linux already uses an entropy pool internally, as
> opposed to /dev/urandom, which is just a plain random number generator.

No, they use the same entropy pool and the same algorithm for
delivering output. The difference is that /dev/random cares about the
estimate amount of true randomness in the pool: if it drops to zero
(because much more output was requested than noise was gathered),
it considers further output "not random enough" and blocks waiting
for more noise. /dev/urandom continues to deliver output without this
check, so it's "less random" if much data was requested and the system
was quiet during this time.

-- 
 __("<  Marcin Kowalczyk * qrczak at knm.org.pl http://qrczak.ids.net.pl/
 \__/
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QRCZAK