[chrislipa]

You make a good point, but that's also a shortcoming of all of the purely computational techniques. I think the most you can hope for is 'democratizing' the computational methods, i.e. making them non-parallelizable.

Taking gwern's idea, what if the homomorphic computation is just incrementing your input repeatedly inside of a loop? It seems like that might be hard to parallelize. Or at least, I don't know enough to assume otherwise.