Security Key Series Flexible Authentication Choice of strong single-factor authentication (passwordless), two-factor authentication (2FA), or multi-factor authentication (MFA) Secure important accounts Most secure authentication for all U2F and FIDO2 compatible services Simple to use No additional software or battery is required. Authentication is simple, fast and reliable. Security Key NFC from Yubico Yubico's Security Key NFC combines hardware-based authentication, public key cryptography, U2F and FIDO2 as well as USB and NFC functions in one device. Thanks to these features, the series eliminates account takeovers on desktops, laptops and mobile devices. Works directly with Google, Microsoft, Twitter, Facebook and hundreds of other services Supports FIDO2 and U2F Improved injection molding process ensures a robust and long-lasting security key USB-A, NFC IP68 protection rating, durable , without batteries and moving parts Security Key C NFC from Yubico The Security Key C NFC from Yubico combines hardware-based authentication, public key cryptography, U2F and FIDO2 as well as USB and NFC functions in one device. Thanks to these features, the series eliminates account takeovers on desktops, laptops and mobile devices. Works directly with Google, Microsoft, Twitter, Facebook and hundreds of other services Supports FIDO2 and U2F Improved injection molding process ensures a robust and long-lasting security key USB-C, NFC IP68 protection rating, durable , without batteries and moving parts