networking and the internet and cybersecurity

These are questions about a Math game that I have to design for kids.

1 - Networking and Internet: how can you put your math game online in the Internet so that more kids can benefit from it? 

2- Cyber security: hacking and defending practices.

What preventative measures we would take to prevent out the game from being hacked?  

-          - If you are a hacker, how will you attack this math system?

-          - If you are a defender, how to improve your system to protect it from attacks?