The Yubico cloud key allows OTP and PKI based strong authentication via contact and contactless interface due to its IC NXP® A7005/LPC11U24 IC bundle. Once you tap the cloud key to a NFC enabled device (phone/tablet) it launches the browser and provides an authentication to the application. Secure cloud access from any NFC or USB enabled device. Domain check avoids phishing attempts. Smallest possible smart card form factor. Compliant to FIDO Alliance U2F specification.