Security WordPress Plugins
Google Authenticator for WordPress
You can use the Google Authenticator app for your smartphone (iPhone, Android, Blackberry) to set-up two-factor authentication for your WordPress login.
Limit Login Attempts
Choose how many times a user can attempt to login before they are blocked from access to your WordPress site, to prevent brute force security attacks.
Rename wp-login.php
Make the URL of your login page a bit easier to remember and protect against certain kinds of brute force attacks by changing it.
UpdraftPlus
Easily backup your WordPress database, plugin and theme files to popular cloud storage services like Dropbox, Google Drive, and Rackspace, and then Restore with one click of a button.
Restricted Site Access
Access settings in the WordPress admin and add a single or a range of IP addresses, and chose what page to send users to if they are blocked from view.
Wordfence
Scan your site for any malicious code or errors that might be occurring. You can use the plugin to monitor live traffic, block certain IPs from accessing your site and enable quick fixes for any problems that might arise.
UK Cookie Consent
Let your users know about the use of cookies on your site with a simple to use and customizable fixed bar that informs every user to the site that cookies are being used, and links to a pre-populated page with more information.
SSL Insecure Content Fixer
Find the common problems that WordPress has when dealing with SSL certification, especially with external plugins and themes, and automatically fix them so that the HTTPS protocol is properly used.
Clef
Get rid of passwords altogether by using two-factor authorization. Install an app on your phone and use it to pair your smartphone to your site, automatically log in from trusted devices, and block everyone else.
WP Bouncer
If a user logs in from two devices at the same time, then they will be bounced to a login warning, stopping users from sharing their login information with others. Works automatically with several rounds of detection.
VaultPress
Provides security for your WordPress site, scanning your install for vulnerabilities and fixing them automatically. It also backups your site several times a day, so that you can restore it with a click of a button.
Email Address Encoder
Automatically encode every email address in your posts and pages to protect it from spammers and attackers. Uses decimal and hexadecimal entities so there's no Javascript or extra code.