Page 170 - Microsoft Office Excel 2003 Programming Inside Out

Part 3: The Excel Object Model
Microsoft Office Excel 2003 Programming Inside Out

If you want to remove the protection from a workbook, you can do so through the Unprotect
method. The Unprotect method has a single parameter, the password required to unprotect
the workbook.

ActiveWorkbook.Unprotect Password:=password
Chapter 7
The following procedure lets the user attempt to unprotect a workbook:

Sub UnprotectThisWkbk()
Dim strPassword As String
If (ActiveWorkbook.ProtectStructure = True Or _
ActiveWorkbook.ProtectWindows = True) Then
strPassword = InputBox ("Type the password to remove protection from _
this workbook.")
ActiveWorkbook.Unprotect Password:=strPassword
Else
MsgBox ("The workbook is not protected.")
End If
End Sub

The UnprotectThisWkbk procedure checks to see if either the ProtectStructure or the
ProtectWindows property is set to True because it’s possible to protect one aspect of your
workbook and not the other.

Inside Out

Creating Passwords That Will Stand the Test of Time
The best passwords are random strings of characters, but random characters are hard to
remember. One good method of creating hard-to-guess passwords is to combine elements
of two words with a number in between. For example, you might have a password
prog#2003exce, which could be read as “programming version 2003 of Excel.” In any
event, avoid dictionary words in English or any other language, as they can be found easily
by password-guessing programs available on the Internet. The Excel encryption algorithm is
strong enough to force a cracker to spend around 30 days on average to find the key that
unlocks a workbook, but sensitive financial data has a significantly longer shelf life than a
month, so if your data is truly sensitive and you want to guard against theft or accidental
disclosure, you should use a stronger commercial encryption program.

144