To password protect a PDF in Adobe Acrobat Reader, you'll need the paid Pro version, which starts at $14.99 a month.

In the digital age, business documents can be easily leaked or altered. Adobe's portable document format allows strong encryption using a password, certificate or a rights management server as well as ...

You can sign PDF documents in Windows, completely electronically, using the PDF viewing program Adobe Reader. Here's how.

“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 ...