Using Adobe Acrobat DC, is there a way to lock a pdf from copying, emailing, editing, and saving?
Open the PDF in Acrobat DC, click File > Properties > Security
Security Method: select Password Security from the dropdown menu and explore your options.
can I lock a pdf after I have filled a form to avoid the receiver being able to change it? I tried with password security on editing, but that only takes care of the text outside of the form fields that I have filled in manually. Is there a solution to this?
After filling the form fields you can disable form filling at password security.
The best way to do that is to digitally sign the file.