I've been trying to do it myself as I was curious. I've run into a problem where I cannot take the SHA3-256 HMAC of something, or I am doing it wrong. window.crypto.subtle.importKey does not support SHA3 operations, and I'm having an incredible amount of trouble trying to use outside code (current was trying to use
http://caligatio.github.com/jsSHA/ as an alternative, but cannot get it to work).
Yeah, I had a try and it's a real pain in the ass. What would be ideal if devans could just expose a top level `bustaHash` and `hashToBust` function or something, I think it'd be super easy

The functions SHA256 and gameResultFromHash are now available in the script editor. They're pretty self-explanatory, but you can find a usage example
One thing to watch out for is that they both return a Promise rather than the result itself.