Following requirements of GDPR I would like to set a password on a spreadsheet. Is it possible to do this?
Please be aware that passwords don’t work very well if you are saving to Excel file types. You can set them up, but others are able to access the files without them. They do work correctly if you are saving to the native .ods format.
That entirely depends on what is password protected, not the file format saved in. See my answer.
No, it very much does depend on the file format saved in. I have filed two bug reports detailing this behavior, and I don’t believe I checked all possible file formats. These were just the ones I tested and found did not work: https://bugs.documentfoundation.org/show_bug.cgi?id=118921 and https://bugs.documentfoundation.org/show_bug.cgi?id=118938.
Any sheet protection or document protection can be removed in any file format unless the file is saved with a password and thus encrypted. For this to happen check the Save with password box in the Save-As file dialog.
Yes. Menu File → Properties → Security → Protect → Enter Password.
@LibertyBelle makes an important point. If this answers your question, please click the check mark at left so that others will know.
That only sets a flag to prevent users from changing content when loaded in an application. It can be removed by anyone knowing how to edit a file format. It does by no means guard against unauthorized access of the data.
Wow. Thanks, @erAck, I didn’t realize that at all. I wonder why the option is even offered, as it is unsafe and misleading. Thanks.
The options there that can be activated and guarded with a password are Open file read-only and Record changes. I don’t see anything misleading about that. It does not say the file would be encrypted or otherwise not readable.
Yes, I see now. You are right of course. My expectations of the Protection option were, shall we say, overly optimistic, and I just assumed too much. Thanks, @erAck, for setting this straight.