datarumx

This WordPress plugin allows you to block access to static pages by one or more security questions. First, you have to create and add some questions with answers to the main list. Answers are case insensitive. Then, associate questions from list you created with pages you need to block. After question is associated with a page – page becomes blocked until user provides correct answers on questions associated with a page, if he does – access will be granted during current session.

Pageblocker "Seeya"

This plugin allows you to block access to static pages by one or more security questions.

lx6g

You can choose from upper and lower letters, digits and special characters to make your new hardcore passwords impossible to break. 
And yes, all the passwords are generated only within client’s browser session and are not saved anywhere on the server side, 
so it is absolutely safe to use in real world.
You can also specify the following attributes to tune the form’s appearance:
<ul>
<li><code>length=4..64</code> specifies the default length of a password. Allowed values range from 4 to 64. </li>
<li><code>upper=1</code> enables upper-case letters option. Activated by default.</li>
<li><code>lower=1</code> enables lower-case letters option. Activated by default.</li>
<li><code>digits=1</code> enables digits option. Activated by default.</li>
<li><code>special=1</code> enables special characters <code>,.:;_=</code> option. Disabled by default. </li>
</ul>
Plugin’s Official Site
<a href="http://lx6g.com" rel="nofollow ugc">Alex Granovsky Blog</a>

LX Password Generator

LX Password Generator is simple yet nifty password generation form to be placed in any page or post you like.

Pageblocker "Seeya" vs LX Password Generator