Advanced PDF Security Tool is a small desktop application which helps to Protect and Un-Protect PDF documents using password. Portable Document Format (PDF) is the global document format used across the world for sharing formatted information, images, etc. A PDF file may be some time needed to encrypted using password for security purposes; also some time we may be needed to decrypt the protected document by removing its password. Unfortunately, by using Acrobat Reader, it is not possible to perform functions like adding, removing or changing security settings. To answer these challenges, this handy tool will helps the end user to decrypt, encrypt and change the security settings of any PDF document in easy and efficient way.