For _using_ WebAuthn, Linux without a TPM has the option of using a hardware key like a Yubikey or Nitrokey, or a virtual authenticator like what 1Password prop

For _using_ WebAuthn, Linux without a TPM has the option of using a hardware key like a Yubikey or Nitrokey, or a virtual authenticator like what 1Password proposes here: https://www.future.1password.com/passkeys/ https://www.future.1password.com/passkeys/ For _syncing_ WebAuthn passkeys, then virtual authenticators that sync over the wire like 1Password above is the only option. Using virtual authenticators means that your key material is in-memory alongside the OS and all running apps. That's why it's so critical that OSs expose pluggable sync fabrics; so that vendors like 1Password, or even YubiCo, can implement sync fabrics that roam through whatever hardware the current platform happens to have available.