Forum Discussion
Is it really impossible to break workbook protection?
Hi,
I process personal data and need strict protection (GDPR). My raw data from a survey is copied to several worksheets in a workbook and the processed anonymous data (dashboards) is in other worksheets in the same workbook.
Before sending the whole workbook with the visible dashboards to my customers I delete some of the raw data worksheets and hide others. After that I protect the structure of the workbook with a code. Now only the worksheets with the dashboards are visible.
Will it at all be possible for my customers to break the protection and get access to the sensitive raw personal data or am I completely safe?
Thanks in advance to your reply!
Best regards Per
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.
25 Replies
Thanks for the ans
Excel workbook protection is helpful, but it’s not something you should fully rely on for protecting sensitive data. In most cases, workbook and worksheet protection in Excel are designed to prevent accidental changes rather than provide strong security. People with enough knowledge or the right tools can sometimes bypass this protection. If you are dealing with personal data under GDPR, the safest approach is to remove any sensitive raw data from the file before sharing it. Even hidden sheets can potentially be accessed if someone tries hard enough. A better practice would be to keep the raw data in a separate secure file or system and only share the dashboards or anonymized results with your clients. So workbook protection can add a basic layer of control, but it shouldn’t be considered a guarantee that the data is completely safe.
Thanks for your answer. It makes sense.
skundapuraMicrosoft
Excel workbook protection is not secure and can be bypassed, so you should never rely on it for GDPR‑level protection of personal data.
Yes, Excel protection is mainly to prevent mistakes, not to keep people out. If you hide a sheet and protect the structure, someone can still use formulas like =Sheet1!A1 in other sheets to access the hidden data. Finding the name of the hidden sheet is also pretty simple.
Excellent explanation—Excel’s workbook and sheet protection are mostly finesse-level barriers, not ironclad security. As you pointed out, hiding sheets or locking structure doesn’t stop users from referencing hidden data via formulas like =Sheet1!A1
easy installationWhile it's not entirely impossible to bypass workbook protection, it's important to understand that such protection is deliberately designed to prevent unauthorized changes to your Excel files. In cases where you have forgotten your password or need to regain access for legitimate reasons, there are methods—such as using VBA macros or third-party recovery tools—that might help remove or recover the protection. However, these techniques should only be used on workbooks you own or have explicit permission to modify. Attempting to break workbook protection without proper authorization can be unethical and may even violate legal guidelines.
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i buy crosshair c in microsoft store and not working what should i do?
- Hello,
Depending on the Excel knowledge of the customer you're sending the workbook to. You can hide all the sheet tabs that contains the sensitive raw information. Moreover, the person working with the workbook may in fact, do not know whether you've hidden some sheets if he or she isn't suspecting youThanks 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?
There are password utilities that can crack the encrypted passwords. They typically use brute force method to "guess" the password. If the password is random characters and special characters it makes it very, very hard to guess.
Afraid that's not exactly what GDPR is required.
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.
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?
IMHO, if you anonymised all names that's enough from GDPR point of view. Password gives another protection from unintentional access (however, it could be hacked). Deleting of previous versions gives nothing, that affects only internal environment.
I guess you are safe enough.
