Right, but fiddling with probabilities is exactly what you want to do in that case right? I don't know if a hashing algorithm that has no collisions exists (I s

Right, but fiddling with probabilities is exactly what you want to do in that case right? I don't know if a hashing algorithm that has no collisions exists (I suspect the answer is no, maybe other than the identity function). If collisions start to become a problem, you can move that problem further out (much much farther out) by mixing more hashing functions in, which was my point. It's well documented (of course also by the link you posted), the super low likelihood of hash collisions, but I think (hope) the original poster knew that -- was trying to answer assuming that extraordinary case actually happened.