Check my comment here for some intuition: https://news.ycombinator.com/item?id=41115179 https://news.ycombinator.com/item?id=41115179 Basically the server does

Check my comment here for some intuition: https://news.ycombinator.com/item?id=41115179 https://news.ycombinator.com/item?id=41115179 Basically the server does not know, it just computes with every possible value. And the result turns out to be what the client was interested in.