Just because it can't replace code on your machine through a custom driver does not make it impossible for the reader to violate your security. Let's say when

Just because it can't replace code on your machine through a custom driver does not make it impossible for the reader to violate your security. Let's say when you insert the card it makes that card available for signing anything on an RF network. Someone only needs to get within range of a (very low bandwidth) RF connection to use this. Hell, it's been demonstrated in the past that it doesn't even necessarily require an actual compromised driver. If one of the components acts as an antenna (happens all the time by accident) it may be possible to do that remotely without specific compromised RF components. It'd just be a "bad design" that responds to some frequency.