How to password protect a PDF before sending it by email

A reader asks:

“Is there any way to password-protect and lock a sensitive PDF file before sending it as an attachment through email? I cannot afford Adobe Acrobat Pro and free primopdf didn’t work for me. Any help will be appreciated!”

The quickest way to do this is to ZIP the PDF file and protect the ZIP file, or use Microsoft Office’s built-in encryption tools to create a password. If you use Outlook, you can use Adobe Acrobat IX to password protect PDFs. You can also try programs like NitroPDF and PDF Encrypt to set the password protection to your PDF file without Acrobat.

For more on PDF and document encryption:

How to encrypt sensitive data? Put it in an encrypted containerHow to remove encryption from a PDF fileHow to encrypt and password-protect ZIP files the right way

This tip was originally published on IDG Answers, a reader-powered help desk for answering tech questions.