System and method for authorizing a financial transaction

Abstract

A method of authorizing a financial transaction involves a payment terminal receiving, from a payment card interfaced with the payment terminal, application data in response to a predetermined authorization amount provided to the payment card by the payment terminal. The application data comprises an account number uniquely associated with the payment card. The payment terminal generates an adjusted authorization amount based on the account number and from a preliminary authorization amount received at the payment terminal, provides the payment card with the adjusted authorization amount, receives a cryptogram from the payment card in response, and provides notification of authorization of a financial transaction for the adjusted authorization amount in accordance with a confirmation that the cryptogram received at the payment terminal from the payment card was generated by the payment card from the adjusted authorization amount and from a cryptographic key uniquely associated with the payment card.

1 . A method of authorizing a financial transaction comprising:
 a payment terminal receiving, from a payment card interfaced with the payment terminal, application data in response to a predetermined authorization amount provided to the payment card by the payment terminal, the application data comprising an account number uniquely associated with the payment card;   the payment terminal generating an adjusted authorization amount based on the account number and from a preliminary authorization amount received at the payment terminal;   the payment terminal providing the payment card with the adjusted authorization amount, and receiving a cryptogram from the payment card in response; and   the payment terminal providing notification of authorization of a financial transaction for the adjusted authorization amount in accordance with a confirmation that the cryptogram received at the payment terminal from the payment card was generated by the payment card from the adjusted authorization amount and a cryptographic key uniquely associated with the payment card.   
     
     
         2 . The method according to  claim 1 , wherein the payment terminal is configured with a range of issuer identification numbers, and the generating an adjusted authorization amount comprises the payment terminal generating the adjusted authorization amount in accordance with a correlation between the account number and the range of issuer identification numbers. 
     
     
         3 . The method according to  claim 2 , wherein the cryptogram comprises an online cryptogram, and the providing notification of authorization of a financial transaction comprises the payment terminal transmitting over a payment network a transaction authorization request for online authorization of the financial transaction, the transaction authorization request including the adjusted authorization amount and the online cryptogram. 
     
     
         4 . The method according to  claim 2 , wherein the cryptogram is included in an offline certificate, the providing the adjusted authorization amount comprises the payment terminal transmitting to the payment card an offline cryptogram request for offline authorization of the financial transaction, the offline cryptogram request including the adjusted authorization amount, and the providing notification of authorization of a financial transaction comprises the payment terminal confirming that the payment card generated the offline certificate from the adjusted authorization amount and the cryptographic key. 
     
     
         5 . The method according to  claim 1 , wherein the providing notification of authorization of a financial transaction comprises the payment terminal validating the payment card and a bearer of the payment card, and initiating the authorization in accordance with an outcome of the validating. 
     
     
         6 . The method according to  claim 5 , wherein the card bearer validating comprises the payment terminal transmitting a personal identification number to the payment card, and receiving from the payment card a validation of the personal identification number. 
     
     
         7 . The method according to  claim 3 , wherein the providing notification of authorization of a financial transaction comprises the payment terminal receiving a transaction authorization from the payment network in response to the online transaction authorization request, the transaction authorization providing a confirmation of the payment card generating the online cryptogram from the adjusted authorization amount and the cryptographic key. 
     
     
         8 . The method according to  claim 7 , wherein the providing notification of authorization of a financial transaction comprises the payment terminal transmitting the transaction authorization to the payment card, and receiving from the payment card confirmation that an issuer of the payment card generated the transaction authorization. 
     
     
         9 . The method according to  claim 1 , wherein the cryptogram comprises an online cryptogram, and the providing the adjusted authorization amount comprises the payment terminal transmitting to the payment card a cryptogram request requesting the online cryptogram from the payment card, the cryptogram request including the adjusted authorization amount. 
     
     
         10 . The method according to  claim 1 , wherein the payment terminal receives the preliminary authorization amount from an electronic cash register. 
     
     
         11 . A computer-readable medium comprising computer processing instructions stored thereon for execution by a payment terminal, the computer processing instructions, when executed by the payment terminal, causing the payment terminal to perform the method of  claim 1 . 
     
     
         12 . A payment terminal comprising:
 a card interface for interfacing a payment card interfaced with the payment terminal; and   a transaction processor coupled to the card interface, the transaction processor being configured to:
 (i) receive, from a payment card interfaced with the card interface, application data in response to a predetermined authorization amount provided to the payment card by the payment terminal, the application data comprising an account number uniquely associated with the payment card; 
 (ii) generate an adjusted authorization amount based on the account number and from a preliminary authorization amount received at the payment terminal, provide the payment card with the adjusted authorization amount, and receive a cryptogram from the payment card in response; and 
 (iii) provide notification of authorization of a financial transaction for the adjusted authorization amount in accordance with a confirmation that the cryptogram received at the payment terminal from the payment card was generated by the payment card from the adjusted authorization amount and a cryptographic key uniquely associated with the payment card. 
   
     
     
         13 . The payment terminal according to  claim 12 , wherein the payment terminal is configured with a range of issuer identification numbers, and the transaction processor is configured to generate the adjusted authorization amount in accordance with a correlation between the account number and the range of issuer identification numbers. 
     
     
         14 . The payment terminal according to  claim 13 , wherein the cryptogram comprises an online cryptogram, and the transaction processor is configured to provide notification of authorization of a financial transaction by transmitting over a payment network a transaction authorization request for online authorization of the financial transaction, the transaction authorization request including the adjusted authorization amount and the online cryptogram. 
     
     
         15 . The payment terminal according to  claim 13 , wherein the cryptogram is included in an offline certificate, the transaction processor is configured to provide the adjusted authorization amount by transmitting to the payment card an offline cryptogram request for offline authorization of the financial transaction, the offline cryptogram request including the adjusted authorization amount, and the transaction processor is configured to provide notification of authorization of a financial transaction by confirming that the payment card generated the offline certificate from the adjusted authorization amount and the cryptographic key. 
     
     
         16 . The payment terminal according to  claim 12 , wherein the transaction processor is configured to provide notification of authorization of a financial transaction by validating the payment card and a bearer of the payment card, and initiating the authorization in accordance with an outcome of the validating. 
     
     
         17 . The payment terminal according to  claim 16 , wherein the transaction processor is configured to authenticate the bearer of the payment card by transmitting a personal identification number to the payment card, and receiving from the payment card a validation of the personal identification number. 
     
     
         18 . The payment terminal according to  claim 14 , wherein the transaction processor is configured to provide notification of authorization of a financial transaction by receiving a transaction authorization from the payment network in response to the online transaction authorization request, the transaction authorization providing a confirmation of the payment card generating the online cryptogram from the adjusted authorization amount and the cryptographic key. 
     
     
         19 . The payment terminal according to  claim 18 , wherein the transaction processor is configured to provide notification of authorization of a financial transaction by transmitting the transaction authorization to the payment card, and receiving from the payment card confirmation that an issuer of the payment card generated the transaction authorization. 
     
     
         20 . A method of authorizing a financial transaction comprising:
 a payment terminal receiving, from a payment card interfaced with the payment terminal, application data in response to a predetermined authorization amount provided to the payment card by the payment terminal, the application data comprising an account number uniquely associated with the payment card;   the payment terminal generating an adjusted authorization amount based on the account number and from a preliminary authorization amount received at the payment terminal, and transmitting to the payment card a cryptogram request requesting an online cryptogram from the payment card, the cryptogram request including the adjusted authorization amount;   the payment terminal receiving the online cryptogram from the payment card in response to the cryptogram request, and transmitting over a payment network a payment authorization request for online authorization of a financial transaction for the adjusted authorization amount, the payment authorization request including the online cryptogram; and   the payment terminal receiving a transaction authorization from the payment network in response to the payment authorization request, the transaction authorization providing a confirmation of the payment card generating the online cryptogram from the adjusted authorization amount and a cryptographic key uniquely associated with the payment card.