[bluGill]

The kit is the GPS and the steering adaptor that reads the signal. GPS isn't encrypted. The protocol is proprietary, but if you can't reverse engineer it in a day you are a poor engineer. (I wrote the decode for one sub inch GPS, I don't know about our competitors, but I don't see why they would encrypt GPS)

What is encrypted is the steering algorithm to steering controllers. That is about safety, tractors have technically been level 4 self driving for 30 years - not even marketing says that though because the sprit of level 4 self driving is about safety and tractors are just as unready for self driving as any other car on safety grounds. By encrypting the steering control lawyers can ensure the safety warning is displayed. (Sometimes a university is given the encryption keys after legally verifying they won't be unsafe)

Looking again, you seem to be about Rtk. I'm not sure about that. Probably encrypted, but mostly for those who want to charge, you can buy your own base station.