Forum Discussion
Is it really impossible to break workbook protection?
Yes, Excel protection is mainly the protection from the errors due to negligence. Simplest case, if you hide Sheet1 and protect structure, anyone could write in Sheet2 formulas like =Sheet1!A1 and pick-up information from hided sheet in protected structure. To find actual name of the Sheet1 is also not a big deal.
Sheet protection and Workbook protection are coded into the file's XML (Presuming you're using an xlsx workbook) and can be removed easily. If you want something stronger I'd recommend setting a password to open and/or modify. Also, there's Information Rights Management.
Thanks for your answer. It makes sense. However I have also protected the workbook with a password for opening and anonymised all names with random numbers. Finally I have deleted all content in the hidden worksheets and deleted all previous versions of the workbook before sending to customer.
Do you think all this gives 100% protection?
