worksheet password

V

Vincent

Hey guys,
After a year of not using this file, I suddenly have
urgent need to open it.
Problem: I do not have the password any longer.
I tried everyone that I have in my list, but to no avail.
Please help! I may miss a deadline at work because of
this.
Thanks in advance,
Vincent
 
G

Greg Wilson

Your post implies that it is File/Open password protection
that you need to break. This is very difficult. Worksheet
and workbook protection is trivial.

You can break File/Open protection using the "brute force"
method with VBA only if it is a relatively short password
and if you can greatly limit the character set. If it is
your own password then, if you're like me, you may be able
to sufficiently limit the character set. For instance, if
I carefully consider each letter of the alphabet
individually, I am confident that I have never used the
following letters in a password: b, j, l, p, q, v, x and
z. And if I combine numerics it is always limited to 1 and
2 - e.g. "greg2". I also always use lower case. Therefore,
in my case, I can limit the character set to 20.

Be advised that it took me 1 hr. 7 mins. to break the five
character password "greg2" using VBA and the character
set "acdefghikmnorstuwy12" with a 2.4 ghz processor. It
took only 3 mins. 22 seconds to break the password "greg".

I believe the time required is a function of the size of
the character set taken to the power of the number of
charactes in the password. Therefore, six charactes would
have taken theoretically 20 times as long. The order of
the characters is also critically important.

Hope this was of some help.

Regards,
Greg
 
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