Simon Blackbourn

This plugin redirects newly-registered users to the Admin -> Edit Profile page when they first log in. Until they have changed their password, they will not be able to access either the front-end or other admin pages. An admin notice is also displayed informing them that they must change their password.
New administrators must also change their password, but as a safety measure they can also access the Admin -> Plugins page.
<h4>Translations included</h4>
<ul>
<li>Català (Catalan)</li>
<li>中文 (Chinese)</li>
<li>Nederlands (Dutch)</li>
<li>Français (French)</li>
<li>Deutsch (German)</li>
<li>Ελληνικά (Greek)</li>
<li>Hebrew</li>
<li>Hindi</li>
<li>Magyar (Hungarian)</li>
<li>Italiano (Italian)</li>
<li>日本語 (Japanese)</li>
<li>Khmer</li>
<li>한국어 (Korean)</li>
<li>Lietuvių kalba (Lithuanian)</li>
<li>македонски јазик (Macedonian)</li>
<li>Polski (Polish)</li>
<li>Português do Brasil (Brazilian Portuguese)</li>
<li>Português (Portuguese)</li>
<li>Română (Romanian)</li>
<li>Русский (Russian)</li>
<li>Español (Spanish)</li>
<li>Türkçe (Turkish)</li>
</ul>
New translations are very welcome – please submit them via <a href="http://wp-translations.org/" rel="nofollow ugc">WP-Translations</a>. This plugin’s WP-Translations page is <a href="https://www.transifex.com/projects/p/force-password-change/" rel="nofollow ugc">transifex.com/projects/p/force-password-change</a>

Force Password Change

Require users to change their password on first login.

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.

Force Password Change vs wp-bcrypt