Re: "All random number generators eventually exhibit periodicity"?????

From: Douglas A. Gwyn (
Date: 07/28/04

Date: Tue, 27 Jul 2004 23:38:48 -0400

Paul Rubin wrote:
> I think PRNG is supposed to mean about the same thing as a PRF from
> concrete security, that is, a function from N to {1,0} that can't be
> distinguished from random by any P-time computation.

No, for one thing that would make some ?RNGs not known
as to whether they are PRNGs or not. Traditionally, a
PRNG is *any* deterministic sequence generator whose
output is intended to have *some* degree of resemblance
to a random sequence. Note that even a true RNG isn't
necessarily uniform. If one wants to narrow down the
meaning to just generators with specific properties,
more must be stipulated than merely "(P)RNG".