GitHub adds support for FIDO2 security keys for Git over SSH to fend off account hijacking and further its plan to stick a fork in the security bane of passwords. These portable security keys are used for SSH authentication to secure Git operations and to forestall the misery that unfurls when private keys accidentally get lost or pilfered. They provide an alternative to the one-time passwords provided by applications or sent via SMS. As it is, SMS SSH codes sent via text can be and have been intercepted.
Source: https://threatpost.com/github-security-keys-passwords/166054/