def get(value: str) -> 'Protocol':
        """
        Return enum instance corresponding to input version value ('RsaVerificationKey2018' etc.)
        """

        for pktype in PublicKeyType:
            if value in (pktype.ver_type, pktype.authn_type):
                return pktype
        return None
Return enum instance corresponding to input version value ('RsaVerificationKey2018' etc.)