Hmm, I'm interested with shinkan method of hiding the url, it came to me that why not use MP plugin to deliver the url string? This can be single flow process like below:
1)Peer: connect to host
2)Peer: on joined room, send message <browser.URL>
3)Host: on peer message, compare message with whitelist array, if true, send some screwed message.
4)Peer: on message, load the message into array, then compare with browser.URL
5) If equal, disconnect from signal, then start game.
Step 3&4 is redundant check. I think it would be hard for the thief to fabricate "send message", there's probably loophole here, but for me it's an interesting idea. The drawback would be having an always online host to enable the checking. What do you guys think?
I like the "flood with ads" idea!