Re: md5 question!

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Most sites save/allow an 8 character password.  Allowing alphanumerics and
underscore, period and pound (_, ., #), that is 39^8, or 5,352,009,260,481
or about 5 trillion possible passwords.  If you allow more than 8
characters, that number increases.


On Tue, 24 Jun 2003, Marco Tabini wrote:

> On Tue, 2003-06-24 at 09:36, JeRRy wrote:
> > Hi,
> >
> > Hmmm okay... So if the passowrd was.
> >
> [snip]
>
> There are ways to avoid this. Typically, you can add a random token (or
> a salt) to the password before you calculate its checksum. This way, two
> users with the same password will have two different hashes.
>
> However, a brute-force approach as the one suggested is *not* quite as
> simple and powerful as it looks. assuming that there are even just 62
> valid characters for the password (uppercase+lowercase+digits) to go
> over passwords as short as five characters you'd have to do 380,204,032
> iterations. Add one more digit and you're already up to 19,770,609,664.
> Sure, these are not insurmountable numbers, but they quickly add up with
> more and more characters (and I'm not even counting all the
> possibilities when it comes to making this more secure).
>
> Mt.
>
>
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Peter Beckman                                                  Internet Guy
beckman@purplecow.com                             http://www.purplecow.com/
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