System and method for the detection of counterfeit currency

Abstract

A system and method for detecting counterfeit currency are disclosed wherein a currency bill encoded with security data is scanned by a currency scanning terminal placed at a currency exchange location such as a store or a bank. The security data can include the currency bill's serial number and a corresponding code number, and is preferably magnetically encoded on a magnetic medium affixed to or embedded in the bill. The currency scanning terminal reads the security data and transmits it via a communications link to a programmable security computer. The security computer responds to receipt of the security data by comparing the transmitted security data with previously stored security data and generating a comparison result. If the comparison result is true, the security computer calculates an updated security code, stores the updated security code in the data store, and transmits the updated security code to the currency scanning terminal. The currency scanning terminal then writes the updated security data to the currency bill and generates a validation message. If the comparison result is false, the security computer invalidates the currency bill in the data store and transmits a rejection code to the currency scanning terminal. The currency scanning terminal then writes the rejection code to the currency bill and generates a rejection message. Because each currency bill must have valid security data stored in the data store, and because the security data is updated each time the currency bill is exchanged, counterfeiting is rendered virtually impossible.