The SCS152 is a third generation token card integrated circuit intended for prepaid applications. Typical applications of the SCS152 include disposable telephone cards, vending machine cards, low value debit cards, access control, and authentication. The SCS152 incorporates several security features, including an internal signature function and a long transport code. The SCS152 has two modes issuer mode and user mode. During wafer testing, it is placed in issuer mode for card manufacturing and transportation to the issuer. In issuer mode, the transport code is needed to program the device and, thus, is protected from unauthorized use before personalization by the issuer.