OpenSSH has added support for FIDO/U2F hardware authenticators for hardware-based two-factor authentication to securely log into a remote system via the Secure Shell (SSH) Protocol. A physical security key adds an extra layer of authentication to an account on top of your password, and users can quickly log into their accounts securely just by inserting the USB security key and pressing a button. The announcement to deprecate SSH-RSA public key signature algorithm is also significant because SHA-1 hash algorithm can be cracked easily using fewer resources than ever before.
Source: https://thehackernews.com/2020/02/openssh-fido-security-keys.html