One of the reasons I mentioned CIPHER's PRN is because it uses very good seed values (especially if you have the cryptographic co-processor).
Matt
-----Original Message-----
From: web400-bounces@xxxxxxxxxxxx [mailto:web400-bounces@xxxxxxxxxxxx] On Behalf Of Dave Odom
Sent: Tuesday, September 09, 2008 1:47 PM
To: Web Enabling the AS400 / iSeries
Subject: Re: [WEB400] Random String Generator
If you use the REXX RANDOM function and don't fill in a "seed", REXX will automagically pull the system time and use that for the seed, making the resulting random number, random.
Dave
Ralph Daugherty <rdjfc@xxxxxxxxxxxxx> 9/9/2008 10:33 >>>
But to be unpredictable, Nathan, in the sense that pseudo-random
generators generate consistent random number sets for a given seed
(although IBM's crypto level generator may already do something like
this), I plan on adding a concatentated job number and seconds to each
random number. It will throw the cracker algorithms off for those who
are able to obtain a few sequential generated numbers and make it
predictable. (The danger is one of them able to take control of
someone's session by predicting the session id.)
I have never used pseudo-random generator output. The only random
numbers I ever needed was for my Double Deck Pinochle dealing algorithm,
and random nuumber generators are nowhere good enough for that. In the
beginning I skipped around in my Z-80 object code on external events
(clock and key press intervals and modulos of the object code) but found
8086 object code wasn't any good for that, and so I generated 32k of
pseudo random numbers and jump around in that. On the other hand, that
wouldn't be good enough for session id's.
So I'll be using standard pseudo random generator and offsetting it
each time.
Not that anyone is going to go to all that trouble to break into my
Pinochle server and change the score or something. :)
rd
Nathan Andelin wrote:
Dave Odom wrote:
How about using the RANDOM function in REXX ...
I just looked up the RANDOM function in the reference guide and it
sounds like it would work well, too. It seems that a good seed is a key
to all the random number generators.
Nathan.
midrange.com
