Variationally universal hashing

The strongest well-known measure for the quality of a universal hash-function family H is its being -strongly universal, which measures, for randomly chosen h H, one's inability to guess h(m) even if h(m) is known for some m = m. We give example applications in which this measure is too weak, and we introduce a stronger measure for the quality of a hash-function family, -variationally universal, which measures one's inability to distinguish h(m) from a random value even if h(m) is known for some m = m. We explain the utility of this notion and provide an approach for constructing efficiently computable -VU hash-function families. Key words: Randomized algorithms, cryptography, hashing, universal hashing. 1 Background A hash-function family H = {h: A B} is a collection of hash functions, each h H having the same domain A and codomain B, with B finite. One assumes a hash-function family to be samplable: one can choose a random h from H. Carter and Wegman introduced hash-fun...

• Type: Journal
• Year: 2006
• Where: IPL
• Authors: Ted Krovetz, Phillip Rogaway
• Keywords: Hash-function Family, IPL 2006, Strongest Well-known Measure, Universal