HTML5 Multiplayer Game Security Solutions

Question

Now that there are a couple of neat canvas demo's of both classic platform and even 3D fps games in HTML5, the next step might be to try developing a multiplayer HTML5 game. HTML5 socket support makes this relatively straight-forward, but with client-side source being viewable by anyone in the browser, what are some solutions for basic game security features for a HTML5-frontend multiuser game -- such as being able to prevent a faked high-score submit?

Answer 1

The simple answer is: You can't trust the data from client, which means that the high score submit can't come from the client.

Since the code client is available for anyone to inspect, there's no way of trusting the data that the client sends your server. Even if you encrypt the data with a per-user encryption key (which is possible), the user can simply alter your code within the browser and change the values it's sending to the server.

Since your game is multiplayer, this might be possible IF the server generates all the scoring events. If the server generates all the scoring events, the client never sends score data to the server which means that the high score data can't be faked.

You'll still have to deal with cheating, which is even more challenging, but that's another issue...