Re: rand("state")

[Francesco Potorti`]

>If the use of /dev/random or /dev/urandom can produce all 19968 bits (624 
>32-bit integers) plus one integer in the range from 1 to 624, and these 
>are truly random and not limited by the time when they were recorded, then 
>I'm sure you are right.  But if the seed from /dev/urandom is only a 
>32-bit seed, there can be collisions.

Consecutive seeds do not produce consecutive random sequences, so I
don't think that the probability of a collision increases if you choose
the initial state from a 2^32 sample rather than a 2^32^625 one.

Sure, if you want to be on the safe side, you will use a 625-integers
array chosen from a uniform distribution.  But I see no reason to think
that choosing it from a much smaller sample would cause any real
difference.

Maybe someone on this list knows of studies on this topic?

-- 
Francesco Potortì (ricercatore)        Voice: +39 050 315 3058 (op.2111)
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