PDF Security and Encryption
PDF Content Encryption enables PDF content protection with passwords. The Key Length of encryption can either be 40-bits or 128-bits. Owner can read and write PDF document, including making changes, while user can only read PDF document.
PDF Access Settings enable PDF content to be accessed with predefined rules. You may permit PDF document to be modified, copied, converted, commented, printed, signed, filled, accessed and assembled.
In this example, PDF file is password protected. One should use "User Password" to open and read this PDF file, and only the person who owns "Author Password" can make modifications to this PDF document.