In an anti-counterfeiting system and method, a set of identification codes are generated from data associated with units of a line of items. A manufacturer affixes machine readable forms of such identification codes to units of an item, and scans or reads the affixed identification codes before distribution of the units in order to flag only affixed identification codes as “active”. Thereafter, when a user scans or reads the machine readable form of an affixed identification code from a unit of some item, such as by using a “smart phone”, the identification code value is transmitted for verification and validation, and subjected to selected computer based tests to determine the authenticity of the identification code and thus of the associated unit. The user is provided with feedback as to the genuineness of the unit, or is contacted by or directed to contact a representative of the manufacturer if doubt exists.