[7961] in cryptography@c2.net mail archive
Re: human failings question
daemon@ATHENA.MIT.EDU (John R Levine)
Fri Oct 13 00:17:26 2000
Date: Thu, 12 Oct 2000 11:20:21 -0400 (EDT)
From: John R Levine <johnl@iecc.com>
To: Ian Farquhar - NSW SE Team Leader <Ian.Farquhar@aus.sun.com>
Cc: coderpunks@toad.com, cryptography@c2.net
In-Reply-To: <200010120355.OAA25714@tolstoy.Aus.Sun.COM>
Message-ID: <Pine.BSI.3.91.1001012111745.6337U-100000@ivan.iecc.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
> >It would be interesting to find out how gaming machines generate their
> >"random" numbers. Do they use hardware of software?
>
> *Extremely* well-studied PRNG's, for the most part, implemented in
> software. Sometimes they're seeded by using physical timing, sometimes
> not. Sometimes output shaping is used to guarantee/limit return
> on the machines, which is when it all gets very complex.
There's a famous story about an early video poker machine in Nevada for which
they hired a student to write the software who used a PRNG with a very short
cycle time. I don't recall whether it was a coding bug or an inept use of a
lousy library routine, but many of the machines were cleaned out before they
figured out and fixed the problem.
Regards,
John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://iecc.com/johnl, Sewer Commissioner
Finger for PGP key, f'print = 3A 5B D0 3F D9 A0 6A A4 2D AC 1E 9E A6 36 A3 47
