Which of following statements are true

$$ Semantics of signed messages do not have any importance for countering attacks on the RSA digital signature protocol.

$$ In Elgamal cryptosystem the public key of the receiving side stays fixed, while the public ephemeral key of the sending side must be different for every encrypted plaintext.

$$ There are significantly more classical asymmetric cryptographic algorithms than symmetric cryptographic algorithms.

$$ Hash functions cannot be used in message authentication codes.