Excel digital signatures

[lionelhill]

A nearby thread discusses excel security and hiding cells from users.

I use Excel to supply numerical data to clients. At the moment I use password protection, mostly just to avoid accidental mess-ups in the data. I'm aware this isn't the ideal security measure, and AnotherHiggins mentioned the subject again, which set me thinking.

Has anybody got experience with digital signatures in Excel? Are they reasonably secure? Do they create havoc for others trying to open the files, and are they easy to use for those creating files?

 

[combo]

Digital signature in excel can be added to saved file ('security' tab in 'options' dialog), it is removed when the user tries to save the workbook again, even in case of certificate owner. In this case you can see the warning message.
So it does not prevent from changing the workbook, it only informs that saved version is the same as when the signature was added. This information can be more important than cell protection added.
You can experiment with digital signature by generating it with selfcert.exe application (optional installation in office package).

The document signature behaves differently from signed VBA project (the signature in this case is kept until the macros change and the user is not the owner of signature attached).


combo

 

[lionelhill]

Thanks combo, sounds just what we need.
Best wishes!