A-PDF Password Security - Version 4.0 A-PDF Password Security is a desktop utility program that lets you change password security of existing Acrobat PDF files. That means you can protect PDF files with 128 bit encryption or remove the password protection. It can handle either single or batch documents. Another convenient features include password pool and hot directory.With A-PDF Password Security, you can set a PDF file if need a password to open, and/or if have access restrictions. For example, allow or not allow printing, copying content or changing file etc. You can modify metadata at the same time, includes author, title, subject and keywords. A-PDF Password Security even support disable/enable expiry function.A-PDF Password Security works with unencrypted or encrypted PDF files and does NOT require Adobe Acrobat.Password Pool: If you need unsecure a batch of PDF