A method and system are disclosed for matching input character sequences in a set of input patterns. The method comprises the steps of analyzing the set of input patterns, creating a pattern cluster look-up table (PCLT) based on said input patterns, and defining an offset value k. The PCLT is used to find, for each sequence s and offset k, a set of candidate patterns that can possibly match s, the set of candidate patterns is searched for patterns that match s, and all found matching patterns and sequences are reported.