[REBOL] Re: Question about checksum/secure
From: lmecir:mbox:vol:cz at: 19-Nov-2001 22:35
Hi,
(...) The correct
> formula should be:
>
> m: 2 ** 160
> q: 1 * (1 - (1 / m)) * (1 - (2 / m)) * ... * (1 - (n - 1 / m))
> p: 1 - q
>
> , where Q is the probability that no collision occurs.
(...)
So the chance for a collision among n elements seems to be
1 - (m! / ((m-n)! * m^n))
--
Holger Kruse
[holger--rebol--com]
If I use the formula correctly, the probability of a collision in a set of 1
M samples is somewhere around 2 ** -120.