There are a very limited number of frequencies used for RC aircraft and I've never heard of the signal being encrypted (authenticated would be more important th

There are a very limited number of frequencies used for RC aircraft and I've never heard of the signal being encrypted (authenticated would be more important than encrypted anyway). I also think the control protocols are fairly standardized. The main exception would probably be the ones that are controlled over WiFi (which, as far as I've seen, are not normally encrypted either).