Locality-sensitive hashing of permutations for proximity searching

Similarity searching is the core of many applications in artificial intelligence since it solves problems like nearest neighbor searching. A common approach to similarity searching consists in mapping the database to a metric space in order to build an index that allows for fast searching. One of the most powerful searching algorithms for high dimensional data is known as the permutation based algorithm (PBA). However, PBA has to collect the most similar permutations to a given query's permutation. In this paper, how to speed up this process by proposing several novel hash functions for Locality Sensitive Hashing (LSH) with PBA is shown. As a matter of fact, at searching our technique allows discarding up to 50% of the database to answer the query with a candidate list obtained in constant time.