Building Based Security (https://www.basedsec.io), a startup in the zero trust/identity space creating immovable, attestable, hardware backed identities that can be used for strong and continuous authentication but not moved from the device. We can guarantee the user and the device are known, the user is assigned the device they are using, and characteristics of the identity matches the defined policy. The initial product offering is tied to GitHub/GitLab, offering secure authentication for git over ssh operations with plans to expand to general ssh access and additional systems with pluggable access control.

That's really cool. Are you using OpenSSHes yubikey support or building your own?