K-independent hashing

In computer science, a family of hash functions is said to be ${\displaystyle k}$-independent or ${\displaystyle k}$-universal if selecting a function at random from the family guarantees that the hash codes of any designated ${\displaystyle k}$ keys are independent random variables (see precise mathematical definitions below). Such families allow good average case performance in randomized algorithms or data structures, even if the input data is chosen by an adversary. The trade-offs between the degree of independence and the efficiency of evaluating the hash function are well studied, and many ${\displaystyle k}$-independent families have been proposed.

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