Authentic flash game form submission

[theRemix]

What is the best way to accept game form submissions on your server.

The game will be embedded on many sites.

The server will be my own, PHP+mysql

I want players to be able to submit their name and high score to my server for tracking.

I want to ensure that the form submission comes from my game, and not a crafted form, to prevent cheating or any other abuse.

any recommendations?

tia.

[theRemix]

bump.

submitting forms from flash seems to be very common, does no one authenticate the source of their form submission via tokens or other means?