You can completely hide your website content, everything else and show a password protection page to everyone on internet including bots and search engines etc. Hide My Site is a new powerful WordPress plugin that enables a password protection page and netizens can only visit your blog if they know the correct password required for opening your WordPress site.
zM Ajax Login & Register, is new WordPress plugin with which you can easily create a custom login and registration forms and display them using the shortcodes
[ajax_register] or you can use modal boxes in the “Advanced Usage” settings. Install and activate it, after activation visit Dashboard -> Settings -> AJAX Login & Register page and select your options.
Simple User Password Generator simply adds a secure password generator button on WordPress Add New & Edit User pages, using this new button site administrators can easily generate a secure password for their users.
WordPress allows you to publish password protected posts. You can add password protection in your blog post by using visibility option present in the Publish meta box on post’s add new/edit page; using this feature you can set a separate password on your post and share it with selected users. Now this tutorial explains you how you can set a global password which is applicable with all your password protected posts and pages.
Apocalypse Meow is a powerful WordPress plugin that helps you protect your admin area from getting hacked. It includes password strength requirements and brute-force log-in prevention.