Short description of Encrypt PDF Command Line 2.3: Encrypt PDF software is a very flexible and powerful program, Encrypt PDF software allows you to encrypt (using standard 40-bit or 128-bit supported by Acrobat Reader 5.0 and up) existing PDFs, set permissions, add user and owner password. For example you can encrypt a PDF without to allow to print it. The button to print the file will be disabled in Acrobat Reader application.