From: Kirk Haines <khaines@...>
Date: 2004-05-22T01:48:48+09:00
Subject: Re: ISAAC Random Number Generator

On Sat, 22 May 2004 00:43:52 +0900, Paul Sanchez wrote

> How does ISAAC hold up under Marsaglia's "Die-Hard" test suite?  I 
> believe Ruby is currently providing an implementation of the 
> Mersenne Twister, which has aced the Die-Hard tests and has a cycle 
> length on the order of 10^600, so I don't see a compelling reason to 
> go with something else in terms of the quality of the random numbers.

I don't know.  I just downloaded diehard and am running a few tests.
The expected cycle length of ISAAC is 2^8287.  It is intended to be 
cryptographically secure.

> in the same place and same simulated time.  If everybody is drawing 
> from the same source of randomness, and there are different numbers 
> of objects in the two systems being compared, it's nearly impossible 
> to maintain synchronization.  The most common solution is to give 
> each object its own personal stream of random numbers, seeded 
> independently of all the others.  Synchronization is still non-
> trivial, but at least it's possible if you can have multiple 
> separately seeded generators.

You could do that with Crypt::ISAAC.  Seed each instance from the hardware 
random number generator or something, and then each will be an independent 
source of random numbers.


Kirk Haines