Technology Tutorials | Acrobat | Protecting PDF Documents
You can apply several security features to your pdf document.
A Watermark is a mark on a pdf document that cannot be changed by anyone else.
Encryption allows you to protect your document to prevent others from editing it without the proper authentication.
Password Encryption allows you to protect your pdf file so that a password will be needed to open the file.
Certificate Encryption allows you to protect your pdf file so that a specific key is needed to open and edit the file.