Not going to get much simpler than 1's and 0's, is it? It seems a bit ridiculous to suggest that a species would enter a digital era and not know such a basic language. Why would they not find simpler old codes even easier to decode than we do? We are talking an advanced species are we not? It's a bit like saying when they add 1 + 1 they do not get 2. I am afraid that indeed, they do. No matter what planet "they" might come from.
Do you honestly, for one second, really believe that this is how another species would communicate? A Crop Circle??
As stated before yes they would KNOW of such codes BUT to reply in the most simplistic way is to reply with the exact same code we sent the message with so we could read it brainiac