How can I prevent users from making changes to my Word documents and then
printing the document with the changes. This prevention has to be secure
because our ISSO auditor will be checking how well the documents are
controlled.
This question is common, and the answer is that you cannot absolutely prevent
printing of an altered Word document, or for that matter _any_ electronic or
paper document that you allow anyone else to see. A determined attacker with
sufficient time and resources can _always_ get around any protection you may
devise. The most you can do is make it reasonably difficult, which will prevent
casual or accidental alteration.
- Word has a feature that lets you digitally sign a document, which shows that
the document has not been altered since it was signed. This does _not_ prevent a
user from altering the document, printing the altered copy and discarding it,
and counting on you not to notice the difference between the original and the
printed copy until later.
- You can apply a password that must be entered to allow the document to be
opened; but once it's open, the user can do anything with it.
- You can apply "protection" to a document that prohibits any changes, and
supply a password that would be needed to turn off the protection. This is
easily defeated, just by using the Insert > File command to copy the content of
the document into a new, unprotected document.
- You could try saving the document as PDF, but there are dozens of programs
that can convert a PDF file back into Word.
- Even if all you supply is a paper document, that can be scanned and processed
with optical character recognition to retrieve an editable version.
I suggest you discuss this issue with the ISO auditor and agree on what measures
are considered sufficient to pass the requirements.
