Patent ID: 6857566

Claim:
A method for conducting a financial transaction over a communications network comprising a terminal, a payment network including a transaction authorization issuer, and a payment card having a chip, comprising: storing on said card account information having a first portion readable by a first machine-readable technology and a second portion readable by a second different machine-readable technology, said stored account information including a payment account number, an expiration date, a service code, and wherein said chip maintains a transaction counter, and receives a terminal challenge number from the terminal; securely storing on said chip a unique per-card cryptographic key; supporting on said chip a cryptographic algorithm for calculating an authentication code using at least said key, said authentication code to be used for verification by said transaction authorization issuer; wherein said authentication code is calculated using at least portions of said unique per-card cryptographic key, said account number, said expiration date, said service code, a value associated with said counter, and said challenge number, and employing both of said first and second technologies to capture said card account information for conducting said financial transaction.