If you are hashing k unique elements, N=2lg(k) is a good rule of thumb for sizing your hash functions. A Birthday Attack [1] analysis provides the exact collisi

If you are hashing k unique elements, N=2lg(k) is a good rule of thumb for sizing your hash functions. A Birthday Attack [1] analysis provides the exact collision probabilities for arbitrary (k, N). [1] https://en.m.wikipedia.org/wiki/Birthday_attack https://en.m.wikipedia.org/wiki/Birthday_attack