Re: How to generate a random number?

[Erik Steffl <steffl@bigfoot.com>]

Alan Shutko wrote:
> 
> "Jeffrey W. Baker" <jwbaker@acm.org> writes:
> 
> > That is an extraordinarily bad idea.  Any person will be able to guess the
> > sequence of random numbers simply by guessing the time at which your
> > program was started.
> 
> And the impact of this depends on what the program is used for.  If
> you're seeding the RNG for a crypto program, yes, this is bad.  If
> you're seeding the RNG for a random sig generator, who cares?  Why use
> up entropy for programs which don't need it?

  :-) considering that no matter what you do the entropy will increase I
don't think you have to be concerned about wasting it...

  but: using /dev/urandom can significantly slow down the program - e.g.
xdm's standard debian config specifies /dev/urandom and it takes a long
time (a minute or two) for xdm to start, replace it by /dev/mem and the
problem's gone...

	erik