Just as any media used to convey information, a PDF file needs applying security to protect its important or private content. Encrypting PDF files is one of the best and easy-to-use ways to protect your PDF documents from the unauthorized use. Using ReaSoft PDF Printer, you can limit access to your PDF documents to a specified set of users by using password protection and by restricting certain features, such as printing, copying and editing. Password protection You can protect your PDF documents with 40 and 128 bit RC4 encryption. File permissions You can add file permissions to restrict printing, copying, and future modifications to your PDF documents.