Setting file Security
Sometimes you may want to lock a PDF document to prevent it from being edited. After your team has made all the required changes and you want to protect the file from accidental changes.
Setting file security:
Open your file in Adobe Acrobat.
Choose File > Save As, and choose Standard from the Security menu.
A dialog box appears asking you to specify up to two passwords -- one for opening the file and one for changing security options to the file. These passwords are case sensitive.
When you have finished press OK, another dialog box will appear and ask you to confirm the password to open the document.
