Counting hash collisions with the birthday paradox

The birthday paradox observes that in a room of 23 people, the odds that at least two people share a birthday is 50% The same logic that drives matching birthdays also drives the probability that one can find collisions with a hash function. In other words, if you have a uniform hashing function that outputs a value between 1 and 365 for any input, the probability that two hashes would collide in a set of 23 values is also 50% Another useful calculation is the expected number of collisions for a...