Excel - Passwords

[C. Bailey]

I created an Excel 97 file, used the "Save As" option and input a password
(i.e. a put a "file open" password on the file). The password had 8 numbers
in it, one upper case letter, two lower case letters, and a special
character for a total of 12 characters long (you wouldn't find anything
resembling this in a dictionary). The on-line program at
secure.decryptum.com broke the password in only a couple minutes. Did it do
this through brute force or is it able to tell the contents of file through
another technique? It almost sounds like it can remove the Microsoft
security features.

If I want the contents of this file to be more secure, would I be further
ahead using the encryption that comes in products like Winzip, TrueCrypt,
Easycrypto, etc? Or is there an easier way within Excel or VBA to make them
secure?

It is an eye-opener how easy it is to get access to an Excel file!

Thank you,
Chris

 

[JE McGimpsey]

I use PGP when I need to secure a file.

XL's built-in protections are useful for preventing *inadvertent*
changes in your workbook. They are nowhere near adequate for preventing
the modestly skilled and curious user from accessing everything in it.

In fact, you don't even need XL to read a significant amount of most XL
files. Giving the file a password doesn't encrypt it, so any
garden-variety hex editor can display a good deal of your workbook.

 

[Leith Ross]

I created an Excel 97 file, used the "Save As" option and input a password
(i.e. a put a "file open" password on the file). The password had 8 numbers
in it, one upper case letter, two lower case letters, and a special
character for a total of 12 characters long (you wouldn't find anything
resembling this in a dictionary). The on-line program at
secure.decryptum.com broke the password in only a couple minutes. Did it do
this through brute force or is it able to tell the contents of file through
another technique? It almost sounds like it can remove the Microsoft
security features.

If I want the contents of this file to be more secure, would I be further
ahead using the encryption that comes in products like Winzip, TrueCrypt,
Easycrypto, etc? Or is there an easier way within Excel or VBA to make them
secure?

It is an eye-opener how easy it is to get access to an Excel file!

Thank you,
Chris

Hello Chris,

You don't mention what you want to do. Are you wanting to keep it safe
from others on a server? Are you planning to distribute your program?
Regardless, all of Excel's passwords and VBA's are easily broken. The
degree of security is relative to knowledge of the user. Find the
right people with some inside knowledge about any security feature,
and it can be defeated. That's why 2 people can keep a secret,
especially when one is dead. The level of security depends on your
needs, and the users knowledge. Using other measures, like you have,
will definitely keep your information more secure.

Sincerely,
Leith Ross

 

[C. Bailey]

Thank you,

I'm not planning to distribute this excel file - and it is doubtful anyone
has access or would have much of a desire to access it. I would just like
to think that if someone happened upon it, it would be a little harder than
a few key strokes to open it.

Chris