Two-factor authentication For Increased Security

Two-factor authentication (TFA, T-FA or 2FA) is an approach to authentication which requires the presentation of two or more of the three authentication factors: a knowledge factor ("something the user knows"), a possession factor ("something the user has"), and an inherence factor ("something the user is").

Maybe with something like Yubikey from http://www.yubico.com/

http://en.wikipedia.org/wiki/Multi-factor_authentication