Abstract: In a method and system for the iterative and simultaneous comparison of a flow of data with a group of reference data items, the reference data items are recorded in the form of logical entities in a two dimensional memory table, one entity per column, each line containing data elements of the same order of each reference entity. The elements of the flow of data are compared in parallel and successively with those contained in the lines of the table, according to a first function provided by a logic unit. Each time, the results of a comparison are combined with the results already obtained (or, in the case of the first comparison results, with a set of initial register states, typically a "transparent" all-true set of states to pass on the first results to the next combination step which is usually the first meaningful combination step) according to a second function provided by a second logic unit, the result of the method being, in the simplest case, given by the final comparison.