hashtable

Um, isn't this the same problem as DRM? (which we all know cannot be solved.) The fact is, if my computer can execute the code and make the request, so can I. The only thing you can do is to try to mitigate the risk or make it more difficult.

Valuing research mathematics over everyday math is arbitrary and subjective.

or read Diamond Age?

I'm just a undergrad college student. I read a few articles online and decided to try the options trading simulation at cboe.com

But wouldn't the lose leave the game, leaving the previous winners to battle amongst themselves?

If you were on Linux, maybe you could do something with FUSE. Your FUSE driver could present the repository as a file system, with .commit_id directories for historical data.

For stocks, yes, but not for options/futures.