Meet OpenSK, an Open-Source 2FA Security Key Platform from Google

Written in Rust, OpenSK supports both FIDO2 and FIDO U2F standards, and promises to allow security key manufacturers, researchers, and anyone else interested in better security for online accounts to make their own security keys with innovative features, just by flashing a firmware on a Nordic chip dongle. Under the hood, OpenSK runs on TockOS, an embedded operating system that provides the isolation needed between the security key applet, kernel, and drivers to create defense in depth.