Just use brute force...
md5('password') will ALWAYS produce the same output!
So, if I intercept a pmd5 encrypted password that looks like: SKHGDOIUYFB
then I could just say:
if (strcmp (md5('password'), SKHGDOIUYFB) == 0)
printf("Your password is: %s\n", password);
So, just start a loop going through all possible combinations od legal password
character and encrypt with md5, then compare.
Hard? Not at all, Time consuming, perhaps, but with 3+ Ghz processors coming
out you'd be surprised how quickly one could loop through billlions of possible
password combinations. Enter distributed environments and it is much fatser.
The key is not to rely on passwords but to rely on other system security
messures, use SSL, so it is hard to intercept in the first place, make sure
your system is secure so these passwords cannot be extracted from your DB
without you knowing about it, etc...
> Thanks, that's what I originally thought that it was
> one way. So websites that have the option to retrieve
> password don't use md5?
> I guess technically there MUST be a way to break the
> barrier where you can reverse it. If there is a way
> to make it there is always a way to break it, somehow.
> !!!! But what I have heard and read it's very tight
> and probably the best method to handle passwords for
> now, until something new is released. Which will
> happen when md5 is broken, like everything else after
> a little bit of time.
> --- Marco Tabini <[EMAIL PROTECTED]> wrote: > Hi
> > No, md5 is a one-way hash. That's why it's so
> > safe--because if someone
> > steals the information he still can't tell what the
> > passwords are.
> > You may want to reset the passwords upon your users'
> > request and send it
> > to them via e-mail instead.
> > Cheers,
> > Marco
> > --
> > php|architect -- The Magazine for PHP Professionals
> > Come try us out at http://www.phparch.com and get a
> > free trial issue
> > On Tue, 2003-06-24 at 08:35, JeRRy wrote:
> > > Hi,
> > >
> > > If I use md5 to handle passwords to my database is
> > > there a way to reverse the action if someone
> > forgets
> > > their password? Is there a way for me to decode
> > the
> > > 32bit to plain text?
> > >
> > > Jerry
> > >
> > > http://mobile.yahoo.com.au - Yahoo! Mobile
> > > - Check & compose your email via SMS on your
> > Telstra or Vodafone mobile.
> > --
> > Marco Tabini
> > President
> > Marco Tabini & Associates, Inc.
> > 28 Bombay Avenue
> > Toronto, ON M3H 1B7
> > Canada
> > Phone: (416) 630-6202
> > Fax: (416) 630-5057
> > Web: http://www.tabini.ca
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