Simply by enabling the plugin can set up a basic auth to dashboard and login page.
WPF-Login allows a user to create a custom login page, or insert the default login form into the currently activated theme.
WP Modify Login Layout: A very simple plugin to modify login page of wordpress.
A simple way to control your WordPress Login Page.
Small and simple security plugin that allows you to change url of wp-admin
When someone gets a password wrong or uses the forgotten password form on your site, the administrator is emailed with the details that were entered.
Allows you to change the default wordpress logo and color on login page.
A tiny plugin which allows you to add a log-in form to your wordpress blog.
This WordPress plugin allows you to reach the login page by simply pressing Ctrl + L.
Customize your login form page and redirect to homepage
AVOID TO USE THIS PLUGIN! Change wp-admin and wp-login URL to any of your choice. Security by obscurity!