Newsgroups: sci.crypt Path: cactus.org!milano!cs.utexas.edu!zaphod.mps.ohio-state.edu!sol.ctr. + columbia.edu!destroyer!gatech!ncar!sage.cgd.ucar.edu!prz From: prz@sage.cgd.ucar.edu (Philip Zimmermann) Subject: Re: IBM-PC random generator, source included Message-ID: <1992Jun26.080402.27283@ncar.ucar.edu> Sender: news@ncar.ucar.edu (USENET Maintenance) Organization: Climate and Global Dynamics Division/NCAR, Boulder, CO References: <1992Jun23.080147.15804@cactus.org> <2808@accucx.cc.ruu.nl> + <1992Jun25.201323.20044@cactus.org> Date: Fri, 26 Jun 1992 08:04:02 GMT Lines: 13 Suppose we assume that Nico's generator produced 1 bit of "true" randomness for every, say, 3 bits of actual output. In other words, the output is impure randomness, with 1/3 of true randomness buried somewhere in the output stream, with the other two thirds of output bits being predictible by some highly sophisticated modeling of the physical system. (my ratio of 3-to-1 is just an arbitrary assumption for this example). Okay, so let's collect 384 bits of Nico's output and reduce it to 128 bits by running it through MD5. We have thus captured the true randomness that is holographically smeared through his output and distilled it down with MD5 to the essential undiluted randomness. We aren't just using MD5 to mix it up-- we are using it to distill it down.