1. A computer-based method for matching a target string to a known string, comprising: matching respective one or more target terms, comprised in the target string, to a known term in an index tree, the index tree comprising one or more known terms from a plurality of known strings, respective known terms in the index tree associated with at least one known string identifier (ID), a known term that is associated with a known string ID appearing in a known string that corresponds to the known string ID; and matching the target string to the known string based at least upon the known string's corresponding known string ID associated with a desired number of occurrences in the matching of the one or more target terms, at least some of the method implemented at least in part via a processing unit.