You’re talking past each other, some Yubikeys have PGP apples for asymmetric encryption (public / private keypairs), and HMAC is a symmetric single key algorithm where the yubikey sends a resulting value to the PC/phone which is part of the key derivation inputs (even though the yubikey’s root key remains secret).
You’re talking past each other, some Yubikeys have PGP apples for asymmetric encryption (public / private keypairs), and HMAC is a symmetric single key algorithm where the yubikey sends a resulting value to the PC/phone which is part of the key derivation inputs (even though the yubikey’s root key remains secret).
HMAC is a what again?
Hash based message authentication code