[hackinthebochs]

I don't get where this question shows he's trying to "show off his expertise". I can see that some people might be sensitive to the situation having been through the type of interview you describe. But I think its going too far assuming thats his motivation for this question.

I think the best types of questions are the ones where you don't know the answer ahead of time. This is where you really get to see how someone thinks. The bloom filter is rare enough that its likely people won't have any exposure to it at all. This gives you a very objective look at how quickly people can grasp new concepts and then apply them. This is exactly what an interview should hope to discover about a candidate.

What I see in the responses to this question are people who aren't very interested in the science side of computer science and thus immediately get suspicious when a question heads in that direction. Perhaps unfortunately, questions like these are going to be biased towards someone who does have a high interest in it.