The official online scoreboards are complete and work has started on the steam, itch, and kartridge API's. At this time, I would like to briefly share the techniques I've incorporated into the game to deter hackers.
All major variables that affect gameplay have been given a duplicate to be checked against. If there is a difference between the two, the application will quit. The duplicated variable is encrypted using a math formula that is randomly generated each time the game starts; making it next to impossible for users to change variables in the game.
Communication between the application and the website hosting the scoreboards is encrypted using 256 bit encryption. The PHP scripts are also password protected. Anyone who is logging http requests will probably never be able to manipulate scores through that method.
Lastly for any skilled hackers with decompilers, I've obfuscated my code to make it hell to read. So players can feel confident that the online scoreboards reflect true scores.