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.
Workbook protection in Excel is useful for preventing accidental edits, but it should not be considered strong security for sensitive GDPR-related personal data. In many cases, workbook structure protection and hidden sheets can still be bypassed with third-party tools or VBA-based methods, especially if the file itself is not encrypted.
If the workbook contains raw personal data, the safest approach is to completely remove that data before sharing the file, rather than relying only on workbook protection. Another good option is to store the sensitive source data in a separate secured workbook/database and only share the anonymized dashboard workbook with clients.
We recently covered similar concerns around data handling, AI workflows, and business security for eCommerce systems here: https://techniver.com/vhatgpt-for-magento-store-owners/
For GDPR compliance, assuming that hidden/protected worksheets are “completely safe” would be risky.