Aaron D. Campbell

Sometimes it’s a private blog, and that’s all there is to it. If all you want 
to do is limit your blog to only registered users, look no further. Simply 
install this plugin, and stop worrying.

Authenticate

Instantly requires that users be logged in to visit your site. Also serves as a good base for expansion. No interface, just activate and go!  Requires …

brijeshk89

WP Secure Login adds a security layer and 2 step authentication to your WordPress site by asking a One Time Password in addition to the username and password on the login page. The One Time Password is displayed on your smartphone using Google Authenticator app (available in market place for FREE). The One Time Password is re-generated at regular intervals which can be customized from admin panel. As soon as the new OTP is generated the old ones are marked as invalid.
One Time Password needs to be configured once by every user from Edit Profile page.
Features in WP Secure Login 1.1 include:
<ul>
<li>2 Step Authentication</li>
<li>Unique Secret key for each user</li>
<li>Configure/Re-Configure WP Secure Login</li>
<li>Unique One Time Passwords generated by Google Authenticator App</li>
<li>Supported on iOS/Android/Blackberry smartphones</li>
<li>Completely FREE</li>
<li>Licensed under GNU GPL version 3</li>
<li>Safe & Secure</li>
</ul>

WP Secure Login

WP Secure Login adds a security layer and 2 step authentication to your WordPress site by asking a One Time Password in addition to the username and p …

Authenticate vs WP Secure Login