Message-Id: Comments: Authenticated sender is From: "Salvador Eduardo Tropea (SET)" Organization: INTI To: Francois Charton , djgpp AT delorie DOT com Date: Tue, 24 Mar 1998 15:48:27 +0000 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Re: real random numbers In-reply-to: <3517F669.53B2@pobox.oleane.com> Precedence: bulk Francois Charton wrote: > Salvador Eduardo Tropea (SET) wrote: > > > > I wrote: > > > > > I really doubt that such an AD system would produce a desirably random > > > series of numbers, ie a series which pass classical tests for randomness. > > > Has anyone tries it? > > > > Are you kidding! The noise generated in a diode junction IS NOISE and is > > generated by the combination of electrones, if you can predict it ... man > > you'll gain the next 100 Nobel prices ;-))). > > > Probably. But unpredictable does not mean random. Many phenomena known as > "noisy" or "chaotic", though absolutely unpredictable, still can show > intrinsic correlations which disqualify them as random sources. If I > remember correctly, Knuth even quotes the example of time between blips > on a Geiger counter (quantic noise, right?) as one of a *bad* RNG... In > mathematics, the series of primes is a well known example of non > predictable series (ie there is no formula giving the value of the next > one from that of the previous), however, it is known to possess many > statistical characteristics which do not make it predictable, but ruins > it as a "random" series. > > Randomness is a pure mathematical concept. The only way to know whether a > series is random or not is to test it. Hence my question: has anyone > tried to test such a "natural noise series" to classical tests for random > numbers (Knuth's spectral test for instance)? It would be a good way to > know whether such natural noise sources make good RNG or not (but again, > I suspect the latter). I never runned a test over the values. SET ------------------------------------ 0 -------------------------------- Visit my home page: http://set-soft.home.ml.org/ or http://www.geocities.com/SiliconValley/Vista/6552/ Salvador Eduardo Tropea (SET). (Electronics Engineer) Alternative e-mail: set-soft AT usa DOT net set AT computer DOT org CQ: 2951574 Address: Curapaligue 2124, Caseros, 3 de Febrero Buenos Aires, (1678), ARGENTINA TE: +(541) 759 0013