A multi-function stored-value debit card system includes smart cards carried by a user, as well as associated hardware, software, and communications networks configured to allow a user of the system to carry out secure transactions. Smart cards are distributed to patrons by a business desiring the patrons to use them to carry out commercial transactions while visiting points of sale of the business. Patrons use the cards as stored-value debit cards and for other optional applications unique to the business. Monetary values are physically carried on the card. A card reader capable of sensing multiple identifiers is associated with the smart cards. At least one of the identifiers is visually perceivable, while at least one identifier is not visually perceivable. A processor is included for treating the sensed identifiers according to a predetermined algorithm to derive a unique code for use in generating a secure transaction.