Looking for an inexpensive alternative to Adobe Acrobat to protect your PDF files? Just give a try to Estelar PDF Defender once. Estelar PDF Defender is an easy to use tool with a user friendly interface to encrypt PDF files with Owner Password as well as User Password Protection to prevent unauthorized access to PDF documents. Using this PDF encrypter a user can set owner password to disable permissions like copying, editing, printing and page extraction of a PDF file as well as User Password to revoke complete access to a PDF document as per their own need. User can use this tool to encrypt PDF files with 40-Bit RC4 encryption to latest 256-Bit AES encryption. Estelar PDF Defender is a standalone utility that doesn?t need Adobe Acrobat to be installed on your system and also it can be run on almost every window platform including window vista and window 7. With batch processing feature you can protect multiple PDF files at once. Minimum System Requirements - Pentium II 400 MHz - 64 MB RAM - 10 MB Disk Space - Microsoft.NET Framework 2.0 Trial Limitation: Demo Version leaves a watermark sign on the secured PDF file by the name of ?Estelar PDF Defender Demo? on the secured PDF file.