Identification system.

An identification system (100) wherein validity between a first unit (1) and a second unit (2) is identified when the first unit (1) is electrically communicated with the second unit (2). The first unit (1) includes a generator (12) for generating identification code information, a calculator (13) for calculating, based upon the identification code information, an estimation time required for processing the identification code information in the second unit (2), a time counter (14) for measuring an actual time required for completely processing the identification code information in the second unit (2), and an unit (15; 11) for identifying validity between said first and second units (1; 2) by comparing the actual processing time to the estimation processing time. The second unit (2) includes at least a processor (23) for processing the identification code information sent from the first unit (1).