Bloom Filter

• A probabilistic algorithm to quickly test membership in a large set using multiple hash functions into a single array of bits

• Developed in 1970 but not used for about 25 years

• Used to find words in a dictionary also used for web caching

• Small probability of false positives which can be reduced for different values of k, # hash funcs

• www.cs.wisc.edu/~cao/papers/summary-cache/node8.html – a good tutorial