Re: Feistel cipher, shorter string and hex to int - Mailing list pgsql-general

From Daniel Verite
Subject Re: Feistel cipher, shorter string and hex to int
Date
Msg-id 2c80afeb-7251-4b11-936d-a2b02dd61c1b@mm
Whole thread Raw
In response to Feistel cipher, shorter string and hex to int  (Ivan Sergio Borgonovo <mail@webthatworks.it>)
Responses Re: Feistel cipher, shorter string and hex to int
List pgsql-general
    Ivan Sergio Borgonovo wrote:

>     r2:=l1 # ((((1366.0*r1+150889)%714025)/714025.0)*32767)::int;
> -- but what about this? where does it come from?

This function:
(1366.0*r1+150889)%714025
implements a known method to get random numbers. I think it comes from
"Numerical recipes" by William Press.
Note that the algorithm is not tied to that function, it could be
replaced by something else (especially one that involves a private
key), but it has to be carefully chosen or the end result won't look so
random.

Best regards,
--
Daniel
PostgreSQL-powered mail user agent and storage:
http://www.manitou-mail.org

pgsql-general by date:

Previous
From: "Albe Laurenz"
Date:
Subject: Re: An example needed for Serializable conflict...
Next
From: durumdara
Date:
Subject: Re: An example needed for Serializable conflict...