About a month ago I stumbled across
Duo Security's solution to two-factor authentication while looking at a viable way to give my wife VPN access to the home network. As passwords are usually one of the weakest link in security, I wanted to have a way to mitigate this by using a password (something you know), and an existing mobile phone (something you have). I must say that I really like the way this works, and that they make security easy to deliver and use.
Here is a link to the many integrations possible.
https://www.duosecurity.com/docs
I have a Cisco router that I configured to use RADIUS for login, and an Intel NUC Linux server that acts as my RADIUS server and DuoAuthProxy server. I've also tested integrations with RDP and LINUX logins (PAM and SSH), and I am pleased. Check it out.
