Enable Two-Factor Auth for Cockpit with Google Authenticator | Cockpit is the awesome web interface to manage a Linux VM or server. For best security, one can setup two-factor auth with google authenticator for Cockpit. Here is a how-to for Fedora Linux 25!
Two-Factor Auth Using Key and Password with OpenSSH 6.2 or Higher | Now that most distros are shipping OpenSSH 6.2 or later, check out this feature to enable two-factor auth with a key and also a password!
Google Authenticator Two-Factor SSH Authentication for Debian Wheezy | Debian does not provide a package for Wheezy to use Google Authenticator as a pam module. However, you can grab and install the Jessie (Debian testing) deb. Here are some steps!
Use Google Authenticator For Two-Factor SSH Authentication in Linux | For a very secure and convenient way to add two-factor ssh auth to your Linux server, you can use Google Authenticator. I’ll show you how to set this up!