There are many ways to protectfiles containing confidential information. One of the most common ways is to use encryption. Encryption uses a mathematical key to scramble the information in a PDF file so only the intended viewers can access them. When a person validates that themselves as an intended viewer of the document, the file will be decrypted, meaning the scrambled information will be re-arranged into its original format. The two most common viewer validation techniques of an encrypted file are password encryption and certificate encryption.
Password encryption requires the author to provide a password when encrypting the document. This protection also allows the author to limit the rights of what the viewers of the document can do, such as editing, printing, and copying. The document will decrypt when a viewer provides the correct password. The viewer will then have access to the document based on the rights that the author defined during encryption.
Certificate encryption works very similarly. The difference is that the author does not provide a password during encryption, but instead specifies a digital certificate. A digital certificate is an electronic identification that establishes credentials on the Internet, which are provided by a certification authority. Using this method, only viewers with a specified digital certificate installed on their system can access the file.
Foxit PhantomPDF provides a user with both methods, allowing the user to determine which technique best meets their needs.
Foxit PDF Security Group