PDF Security

Creating PDF versions of your documents has many advantages: They look the same regardless of the platform on which they are opened, outputs tend to look the same within the limits of your printing devices, and you don't have to worry about missing fonts or graphics. The problem is that once you give your PDF to others, they have a self-contained version of your document and can print as many copies as they want, post it on a Web site for anyone to see, or pass it on to as many friends as they like without your consent.

In some cases, that may not be a big deal, but without some protection, there's nothing to stop a client from taking the PDF that represents all of your hard work and skill and running off to another designer or printer without paying you for the job. Of course, most clients would never do something underhanded like that, but they might accidentally take a PDF proof with low-resolution images off for final output without realizing their mistake until the job is on press.

Tip

You can set one password to open a document and another for editing and printing. This is useful if you need to present a PDF that contains sensitive information to your client for proofing, and then will send the same PDF to your print shop for final output. You only have to make your PDF once, and your client can't print it without the extra password that you create for the printer to use.

Acrobat lets you add passwords to encrypt and control access to your PDF documents and set whether or not the document can be printed or edited. Here's how:

1.	Open the PDF you want to password-protect in Acrobat.
2.	Choose File > Document Properties.
3.	Click the Security tab.
4.	Choose Password Security from the Security Method pop-up menu.
5.	Check the box for "Require a password to open the document" (Figure 4.17) and enter a password to keep people from opening your PDF if they don't know the appropriate password. Figure 4.17. You can add passwords to your PDF documents in Acrobat. Adding a document password prevents anyone from opening your PDF without the correct password. You can also add a password that limits printing quality and editing capabilities in your document.

If you don't want to require a password to open the PDF, but instead want to prevent someone from printing or editing it, you can choose "Use a password to restrict printing and editing of the document and its security settings" instead.