.htaccess Site Access Control
Try the limited free version out HERE!
Using the password protection will give you extra security layer of protection from brute force hacking attacks. Additionally, it's also an easy way to password protect your entire site, without needing to create separate WordPress users for each visitor.
When you enable the password protection, the user won't be able to see anything - not even see the protected page - until he/she inserts the username/password. You can password protect the whole website, including the administrator pages; you can password protect the administrator pages; or you can password protect the WordPress login page.