Preventing Someone from Recreating a Protected Worksheet

Jack creates worksheets that he forwards to others in his group so they can input information, and then return the worksheet to him. He protects the worksheets, but has gotten burned a few times by users who have used copy and paste to recreate the worksheet in its entirety. Checking everything to make sure the returned worksheets are the originals is very time consuming, so Jack is looking for a way to remove the ability to copy and paste the worksheets.

Disabling copying and pasting is theoretically easy enough to do. All you need to do is use a short macro, like the following, in the ThisWorkbook object:

Private Sub Worksheet_Deactivate()
    If ActiveSheet.ProtectContents = True Then
        Application.CutCopyMode = False
    End If
End Sub

Using this macro essentially clears the Clipboard every time someone deactivates the worksheet by selecting another worksheet or another application.

Of course, this offers only the most rudimentary of protection. A determined user can still copy the worksheet by using Edit | Move or Copy Sheet, or they could disable macros when starting the workbook, and thereby disable your Clipboard-clearing routine.

Perhaps a better way is to look at how business is done in the organization. If you don't want people to copy the worksheet, tell them up front, and make sure they know that you won't accept any duplicates. There are very easy ways to check to see if what you get back is a duplicate. Here are a few of them:

• Put a formula in a cell, then hide the cell contents during your protection process. If you get the worksheet back and unprotect the worksheet, and the formula is not there, the worksheet is a copy.
• Protect the worksheet by using a password. If you cannot later unprotect the worksheet with the same password, you know that someone else copied the worksheet and used their own password.
• Have your worksheet use hidden formulas to access data on a hidden worksheet. If the user copies the worksheet, the hidden worksheet isn't copied to the new workbook, so the formulas won't give the correct answers.
• Insert a macro module in the workbook, and then protect the module. The module doesn't need to do anything, but if the workbook you get back doesn't have the protected module, it is a copy.
• Add something into the custom properties area of the workbook. If the custom property is not in the workbook you get back, chances are good that the workbook is not the original.

Another thing to try is to set the cell protection property to Hidden before password protecting your worksheet. Users can see the results of what is in the cells, but they cannot see the formulas. If they copy and paste the contents elsewhere, the formulas won't be transferred, only the results. This is very easy to spot in the returned workbook.