Method and device for generating a single-use financial account number

Abstract

A device for facilitating financial account transactions is described which includes a processing unit including a cryptographic processor. The device also includes an input unit, a display unit and a memory device connected to the processing unit. The memory device contains a private cryptographic key, a first data element and a second data element. The processing unit encrypts the first data element using the private cryptographic key and the second data element, modifies the second data element, combines the encrypted first data element and the second data element to generate a single-use financial account identifier, and displays the single-use financial account identifier. This identifier is then transmitted to a central processor for authorization of the transaction. The central processor extracts and decrypts data elements from the transmitted identifier using the private cryptographic key, compares those data elements with data elements stored in a memory, and verifies the single-use financial account identifier in accordance with the comparison.

1 . A method for implementing a limited use credit card system, the method comprising:
 allocating in a computer system a limited use credit card number constituting a different number than a customer account number of a user and functioning as an authorized substitute for the customer account number;   associating in the computer system the limited use credit card number with the customer account number and a set of conditions defined by the user, wherein the customer account number is not limited to said user defined set of conditions;   issuing the limited use credit card number;   detecting in the computer system a transaction using the limited use credit card number;   processing in the computer system the transaction in accordance with the set of conditions associated with limited use credit card number;   processing in the computer system the transaction against the customer account number; and   authorizing or not authorizing the transaction based on a result of said processing of both the limited use credit card number and the customer account number in the computer system.   
     
     
         2 . The method of  claim 1  further comprising:
 allocating in the computer system additional limited use credit card numbers upon a customer request and/or an event trigger.   
     
     
         3 . The method of  claim 2  wherein the event trigger is the use of more than a preset amount of limited use credit card numbers. 
     
     
         4 . The method of  claim 2 , wherein each of the additional limited use credit card numbers is respectively unique to each other and unique to the allocated limited use credit card number. 
     
     
         5 . The method of  claim 1  wherein the processing of the transaction comprises:
 authorizing or not authorizing the transaction by comparing in the computer system the transaction to the set of conditions associated with the limited use credit card number;   determining in the computer system whether a limited use event has occurred; and   deactivating in the computer system the limited use credit card number based on the limited use event and/or the set of conditions associated with the limited use credit card number.   
     
     
         6 . The method of  claim 5  further comprising:
 assigning in the computer system another limited use credit card number in response to deactivating the limited use credit card number; and   associating in the computer system said other limited use credit card number with the customer account number.   
     
     
         7 . The method of  claim 1  further comprising:
 maintaining in the computer system a queue of available limited use credit card numbers; and   assigning in the computer system the limited use credit card number from the queue.   
     
     
         8 . The method of  claim 1 , wherein the issuing of the limited use credit card number comprises:
 prestoring the limited-use credit card number on a smart card.   
     
     
         9 . The method of  claim 1 , further comprising:
 notifying a user about parameters of the limited use credit card system.   
     
     
         10 . The method of  claim 9 , wherein the parameters of the limited use credit card system comprise records in the computer system of limited use and other card transactions. 
     
     
         11 . The method of  claim 9 , wherein the parameters of the limited use credit card system comprise use in the computer system of the limited use credit card number in a credit card transaction. 
     
     
         12 . The method of  claim 9 , wherein the parameters of the limited use credit card system comprise a number of the limited use credit card number available to the user. 
     
     
         13 . The method of  claim 1 , wherein the set of conditions are defined by a user of the limited use credit card. 
     
     
         14 . The method of  claim 13 , wherein the set of conditions limits the use of the limited use credit card number to a pre defined user limit. 
     
     
         15 . The method of  claim 13 , wherein the set of conditions limits the use of the limited use credit card number to a particular merchant. 
     
     
         16 . The method of  claim 15 , wherein the particular merchant is selected from a merchant code number. 
     
     
         17 . The method of  claim 15 , wherein the particular merchant is prearranged by the user. 
     
     
         18 . The method of  claim 13 , wherein the set of conditions limits the use of the limited use credit card number to a single transaction for a maximum transaction value for a single purpose. 
     
     
         19 . The method of  claim 13 , wherein the set of conditions limits the use of the limited use credit card number to a set number of transactions for a maximum transaction value within a set time 
     
     
         20 . The method of  claim 13 , wherein the set of conditions limits the use of the limited use credit card number to a single purpose. 
     
     
         21 . The method of  claim 13 , wherein the set of conditions comprise at least one condition selected from the group consisting of transaction value conditions, time of transaction conditions, number of transaction conditions, and merchant conditions. 
     
     
         22 . The method of  claim 1 , further comprising:
 dispensing a credit card containing the limited use credit card number.   
     
     
         23 . The method of  claim 1 , further comprising:
 initiating the transaction in the computer system using the limited use credit card number via a telecommunications system.   
     
     
         24 . The method of  claim 23 , wherein the telecommunications system comprises a phone. 
     
     
         25 . A method for implementing a single-use credit card system, the method comprising:
 allocating in a computer system a single-use credit card number constituting a different number than a customer account number of a user and functioning as an authorized substitute for the customer account number;   associating in the computer system the single-use credit card number with the customer account number and a set of conditions defined by the user, wherein the customer account number is not limited to said user defined set of conditions;   issuing the single-use credit card number;   detecting in the computer system a transaction using the single-use credit card number;   processing in the computer system the transaction in accordance with the set of conditions associated with single-use credit card number;   processing in the computer system the transaction against the customer account number; and   authorizing or not authorizing the transaction based on a result of said processing of both the single-use credit card number and the customer account number in the computer system.   
     
     
         26 . The method of  claim 25  further comprising:
 allocating in the computer system additional single-use credit card numbers upon a customer request and/or an event trigger.   
     
     
         27 . The method of  claim 26  wherein the event trigger is the use of more than a preset amount of single-use credit card numbers. 
     
     
         28 . The method of  claim 26 , wherein each of the additional single-use credit card numbers is respectively unique to each other and unique to the allocated single-use credit card number. 
     
     
         29 . The method of  claim 25  wherein the processing of the transaction comprises:
 authorizing or not authorizing the transaction by comparing in the computer system the transaction to the set of conditions associated with the single-use credit card number;   determining in the computer system whether a single-use event has occurred; and   deactivating in the computer system the single-use credit card number based on the single-use event and/or the set of conditions associated with the single-use credit card number.   
     
     
         30 . The method of  claim 29  further comprising:
 assigning in the computer system another single-use credit card number in response to deactivating the single-use credit card number; and   associating in the computer system said other single-use credit card number with the customer account number.   
     
     
         31 . The method of  claim 25  further comprising:
 maintaining in the computer system a queue of available single-use credit card numbers; and   assigning in the computer system the single-use credit card number from the queue.   
     
     
         32 . The method of  claim 25 , wherein the issuing of the single-use credit card number comprises:
 prestoring the single-use credit card number on a smart card.   
     
     
         33 . The method of  claim 25 , further comprising:
 notifying a user about parameters of the single-use credit card system.   
     
     
         34 . The method of  claim 33 , wherein the parameters of the single-use credit card system comprise records in the computer system of single-use and other card transactions. 
     
     
         35 . The method of  claim 33 , wherein the parameters of the single-use credit card system comprise use in the computer system of the single-use credit card number in a credit card transaction. 
     
     
         36 . The method of  claim 33 , wherein the parameters of the single-use credit card system comprise a number of the single-use credit card number available to the user. 
     
     
         37 . The method of  claim 25 , wherein the set of conditions are defined by a user of the single-use credit card. 
     
     
         38 . The method of  claim 37 , wherein the set of conditions limits the use of the single-use credit card number to a pre defined user limit. 
     
     
         39 . The method of  claim 37 , wherein the set of conditions limits the use of the single-use credit card number to a particular merchant. 
     
     
         40 . The method of  claim 39 , wherein the particular merchant is selected from a merchant code number. 
     
     
         41 . The method of  claim 39 , wherein the particular merchant is prearranged by the user. 
     
     
         42 . The method of  claim 37 , wherein the set of conditions limits the use of the single-use credit card number to a single transaction for a maximum transaction value for a single purpose. 
     
     
         43 . The method of  claim 37 , wherein the set of conditions limits the use of the single-use credit card number to a set number of transactions for a maximum transaction value within a set time 
     
     
         44 . The method of  claim 37 , wherein the set of conditions limits the use of the single-use credit card number to a single purpose. 
     
     
         45 . The method of  claim 37 , wherein the set of conditions comprise at least one condition selected from the group consisting of transaction value conditions, time of transaction conditions, number of transaction conditions, and merchant conditions. 
     
     
         46 . The method of  claim 25 , further comprising:
 dispensing a credit card containing the single-use credit card number.   
     
     
         47 . The method of  claim 25 , further comprising:
 initiating the transaction in the computer system using the single-use credit card number via a telecommunications system.   
     
     
         48 . The method of  claim 47 , wherein the telecommunications system comprises a phone.