There are some claims here that encryption is illegal over amateur radio. That is not true in general. For example, this is what the FCC prohibits in their rule

There are some claims here that encryption is illegal over amateur radio. That is not true in general. For example, this is what the FCC prohibits in their rules: >messages encoded for the purpose of obscuring their meaning ... which can be read here: * http://www.arrl.org/files/file/Regulatory/March%208,%202018.pdf http://www.arrl.org/files/file/Regulatory/March%208,%202018.... So ultimate intent is what matters. A test bitcoin transaction is probably legal even if it were somehow incidentally encrypted.