An increasing proportion of the world’s documents are distributed as PDF files, many of which are to a greater or lesser extent confidential. Banks don’t want their customers’ financial statements read by just anyone; software companies need to keep new product specifications from the eyes of their competitors; and most of us don’t want our love letters broadcast for the world to read.
Acrobat offers three types of security to control the opening and viewing of a PDF file:
Password security. You assign a password that is required to open the file. This is simple and effective and is the method we’ll discuss in this chapter.
Certificate security. This approach restricts the reading of the file to a specific list of people. ...