🚀 go-pugleaf

There was an very well written article by David Wood on pseudo random number
generators and the sorts of statistical tests that can be applied to test 
them in the June 1988 Amiga Transactor magazine (Vol. 1, Number 2, page 38).

The disk for that issue also contained C code that implemented the tests
mentioned - written for Lattice C but I have used it under Xenix with
only very minor changes.  The author emphasized that the more tests you can
perform on the PRNG the more confident you can be that it is "good".  FYI
the tests were:

- Frequency test / Equi-distribution test
- Serial correlation - between digits
- Serial correlation - between every Nth digit
- Poker test
- Gap test
- Runs up/down test
- Runs above/below mean test
- Kolmogorov-Smirnov test

If anyone is interested Mr Wood also gave a network address through which 
he might possibly be contacted:
!ihnp4!killer!pollux!wood


Another interesting idea that I saw in sci.crypt recently is to test a PRNG
by drawing pixels on a screen.  A good one will make something that looks
like snow on a TV.  The eye can very easily detect some patterns which are
caused by a poor PRNG.  BTW there was also some C source code for a "good" 
PRNG posted recently to sci.crypt.
-- 
Andrew Phillips (andrew@teslab.lab.oz{.au}) Ph. +61 (Aust) 2 (Sydney) 289 8712