From: https://www.yubico.com/?gclid=EAIaIQobChMI4ZbJxK7r1AIVFxuBCh1WrAb5EAAYASAAEgI_MfD_BwE

Stopping attackers with a single touch

YubiKeys combat malware, phishing, and man-in-the-middle attacks by ensuring that the user is 
physically at their device to log in. With the Yubikey in the user’s possession, unauthorized 
users cannot unlock access to networks, accounts, and cloud-based services.

Prevent corporate account takeovers and get peace of mind with proven security your employees 
will love. Achieve strong two-factor authentication in two easy steps.