Unintentional trick question :) SSH can use a ton of different crypto, so can passkeys (The actual Fido Spec if you want to read about it is webAuthn).
While they both support RSA, The WebAuthn default appears to be RFC-8152 https://www.rfc-editor.org/rfc/rfc8152 in an attempt to try to keep the sizes down.
Unintentional trick question :) SSH can use a ton of different crypto, so can passkeys (The actual Fido Spec if you want to read about it is webAuthn).
While they both support RSA, The WebAuthn default appears to be RFC-8152 https://www.rfc-editor.org/rfc/rfc8152 in an attempt to try to keep the sizes down.