harrym

WordPress uses phpass to store passwords. Because WordPress has to work everywere, it uses the portable version of phpass, 
which uses MD5 to hash passwords. MD5 is not a very good hashing algorithm for passwords, because it’s relatively fast.
This plugin switches over to bcrypt, which is the algorithm recommended by phpass, and is a much better option for password 
storage because it is much slower to produce. This makes it much harder for an attacker who’s managed to access your hashed 
passwords to obtain plain text passwords by brute-forcing, or by trying passwords from a dictionary.
Note: this plugin requires PHP 5.3.0 or newer
Be aware that if you use this plugin and then move to a host that does not support bcrypt, you will need to reset any user 
account that you want to log in with.

wp-bcrypt

wp bcrypt switches WordPress's password hashes from MD5 to bcrypt, making it harder for them to be brute-forced if they are leaked.

fullthrottledevelopment

Glenn Ansley

This plugin does one thing. If a page that is password protected has children pages, all children pages will be protected with the same password.
If the correct password is entered on the parent page or any of its children pages, all related pages will be viewable to the user.
The plugin protects unlimited levels of grandchildren pages via the $post->ancestors. It uses first ancestor that is password protected.
<h3>Additional Information</h3>
The plugin currently works by looking for parent pages that are password protected and applying the same restrictions the the currently being viewed child page. This means that the children pages do not actually get a password added to the database.
I’m trying to decide if this is the best way to proceeed or if I should take another route (such as adding / updating / removing passwords from children pages at the write or save post screen).
Please feel free to offer any suggestions or report any bugs here: [http://fullthrottledevelopment.com/password-protect-children-pages/]
Thanks!

FT Password Protect Children Pages

Applies the same protection to children pages applied to the parent page.

wp-bcrypt vs FT Password Protect Children Pages