The FIDO (Fast IDentity Online) Alliance has made additions to the FIDO 1.0 specifications with new transport protocols for FIDO U2F – Bluetooth Classic and Low Energy (BLE), and Near Field Communication (NFC). With these new transport specifications, FIDO U2F is appropriate for mobile and wireless applications, and devices that do not have a USB port.
The U2F Bluetooth transport specification allows the creation of special-purpose, Bluetooth Low Energy U2F devices that require just the press of a button to authenticate to an online service. In addition, phones and peripherals, which consume more power, can be programmed to act as U2F devices using either Bluetooth Low Energy or Bluetooth Classic.
The U2F NFC transport specification allows the creation of portable U2F devices such as credit cards and keyfobs that are simply tapped against the target device to authenticate to an online service. Alternately, a mobile phone with NFC capability can be programmed to act as an NFC U2F device. The user taps the mobile phone onto a target device to authenticate.