If you have to share a file that has confidential information within the file, you can easily put a password on the file that will be required to open it.  For example, documents that contain bank account numbers, social security numbers, student information, etc. should not be readily attached to an email message and sent to someone.  In the worst case, a thief could intercept your email and open the attached file if it is not protected.

There are many ways to password protect a document, but here is one method that is fairly simple to do on a Mac.

  1. Open any file you want to convert to a password protected PDF.  It can be an MS Word, Excel, Keynote, Pages, or Google Doc.
  2. Go to File > Print, and click the “PDF” button in the lower left corner of the window to choose “Save as PDF…”
    Screen Shot 2016-04-28 at 11.22.44 AM
  3. Name the file as usual, and optionally, provide an author and title, then click the “Security Options” button near the bottom of the window.
    Screen Shot 2016-04-28 at 11.19.38 AM
  4. Check the box next to “Require password to open document” and enter a password, enter it again to verify, then choose “OK”
    Screen Shot 2016-04-28 at 11.20.12 AM
  5. Save the PDF document as usual

Once the file has been saved, locate the secured PDF that was just created. You will find the icon has changed from the normal PDF indicator icon to one with a lock on it, showing that it has been secured with password protection.

Opening the protected PDF in Preview app will bring up the following screen, informing the document is password protected and to enter it in order to view the contents of the file:

Screen Shot 2016-04-28 at 11.30.32 AM

Entering the correct password reveals the full contents of the PDF instantly.