1. A method of matching identification data comprising: acquisition of a data record comprising a plurality of fields; selection of matched records stored in a database, the matched records having fields of type corresponding to fields of the acquired data record, the selection comprising for each record of the database: comparison of at least one field with a corresponding field of the acquired data record, the comparison defining a discrete metric with at least three states of which a first state corresponds to an identity; and search for a match by traversal of a finite automaton in which each transition corresponds to at least one state of the comparison metric for at least one field, the finite automaton having at least two final states: matched and unmatched; wherein the discrete metric comprises 3 states, including the first state corresponding to an identity, a second state corresponding to a first level of differences between the compared fields, and a third state corresponding to a second level of differences between the compared fields, the second level of differences being distinct from the first level of differences, the first and second levels of differences being predefined as a function of the result sought and of the type of data processed.