Encrypting results seems indistinguishable from holding the customer's data hostage. That's not a great place to be, especially if an event is in Outer Qlyphm and the participants want their results now, not when the caravan returns from civilization.

Just charge for the software, provide a download link, and have a simple activation step. Most of your users are not going to be technically capable of bypassing even a very simple registration system. And if they are, it will be very difficult to win that arms race without alienating your honest customers and destroying your product's reputation.

Choosing a good price and treating the customer fairly are the most effective anti-piracy measures you can take.