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.
no, you're not safe.
Excel's workbook protection is designed to prevent accidental edits, not secure sensitive data. There are free tools that can crack it in seconds, and hidden or deleted sheets can often still be accessed once protection is removed.
For GDPR compliance, the fix is simple:
Never send raw personal data in the same file as your dashboards, even hidden. Instead, copy your dashboard sheets into a brand new, clean workbook (paste as values only) and send that. No raw data ever enters the file, so there's nothing to expose.
If your customers only need to view the dashboards, exporting to PDF is even safer.
Protect your customers by keeping the data separate from the start, not by locking it after.