1. A data system comprising: a signature database storing a plurality of signature strings wherein the signature strings are separated into a plurality of signature groups; a detector to detect common features for the signature strings for each of the signature groups, and input strings being input into the data system, respectively; and a match module to compare the detected common features for each of the signature groups with those of the input strings; wherein the input strings are matched with the signature groups if the detected common features for the signature groups match those of the input strings.