System and method for detecting the inclusion of strings of words (records) in an input string of words. In a preparation phase, the records are pre-processed. Each record is represented by a string of chunks, each chunk composed of a pre-defined number of words. Each chunk found in at least one record is assigned a number of attributes, such as a “Begin of Record” attribute and an “End of Record” attribute. In the searching phase the input string is also divided in chunks, and for each input chunk, an Incremental Hash Function (IHF) is calculated for comparing with a prerecorded value ΔI. If the two values IHF and ΔI coincide for matching chunks with certain predefined attributes, a “probable match” is set, indicating a very high probability that a chunk was found in the records.