How do I password-protect a PDF document that doesn't let me change the security settings?
I want to password-protect my PDF document (so when I email it, it can only be opened/read by intended recipients as it contains confidential/sensitive information) but when I go into document security, I'm unable to change the Security Method (which is currently set to 'No Security' - not by me). There's a 'show details' icon but it's grey so I can't click on it. What can I do to protect this document from being opened by non-intended recipients?
