1. In an intrusion-prevention system for examining network traffic and identifying therein the presence of signature data patterns, a method comprising: providing a state-transition table representative of a predetermined data pattern, the state-transition table comprising a plurality of states, each state having a set of egress events, each egress event defining a transition from a current state to a next state; parsing the predetermined data pattern to identify a set of character strings therein; receiving a subject to be evaluated for the presence of the predetermined data pattern, and preprocessing the subject to find therein any instances of the identified character strings; populating a keyword table with a subset of the identified character strings, the subset consisting of those character strings found in the subject during preprocessing; while using the state-transition table to evaluate the subject for a presence of the predetermined data pattern, transitioning into a first state having a first one of the identified character strings as a first egress event thereof, the first egress event defining a transition from the first state to a second state; and responsive to transitioning into the first state, checking, by a processing unit, the keyword table for the first character string, and, responsive to finding the first character string in the keyword table, transitioning, by the processing unit, from the first state to the second state.