Prevent Cheating on Javascript Game

Solution 1:

Make the page submit a complete replay of the game rather than just the final score. Given the random seed and a frame by frame record of user inputs, your server should be able to simulate and reconstruct the game and verify the score.

Obviously the replay can be faked too, but it would amount to so much work (actually playing the game and actually getting a good score, albeit with the unfair advantage of AI assistance, slowing down and other client hacks) that tool-assisted scores should deserve to be in the leaderboard.

Solution 2:

obfuscate their score by creating an equation that can only be calcuated on the server side.

Edit: RobG is correct in that it will need to be calculated on the client side.

I hacked the Angry Birds game when it launched on chrome:

http://wesbos.com/all-levels-html5-angry-birds/

However, they have since obfuscate the code so much that its impossible to figure out which function calculated hash..