Isn't the natural solution to something like that just to do some redundant computation? I think that's how people deal with similar problems in services like M

Isn't the natural solution to something like that just to do some redundant computation? I think that's how people deal with similar problems in services like Mechanical Turk. It would, at worst, make the computation three or four times less efficient but would limit both active meddling and errors. Also, relying on a closed source for security is a bad policy anyhow.