Add Pdf Security Password Lock is a data encryption software that primarily focuses on the protection of PDF files. With this tool, you will be able to encrypt your PDF file and lock their access with a password. The application uses the RC4, 40-bit and 128-bit AES encryption algorithm to ensure the safety of your documents. In addition, you also have the option to apply restrictions to your PDF files to prohibit modification of the content. The proposed software is a shareware version compatible with Windows XP and Vista/2000/2003.