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 . In a financial transaction system for use with at least one limited use credit card number, which is limited in use by a limited use credit card number issuer and by a user of the limited use credit card number, and which is associated with an account of the user, a method of controlling the authorization for use of the limited use credit card number comprising the steps of:
 issuing a limited use credit card number for use by a user in a limited use credit card number transaction, the limited use credit card number constituting a different number than the account of the user and functioning as an authorized substitute for the account of the user in a credit card transaction;   receiving information communicated by the user to the limited use credit card number issuer to establish limitations on the use of the limited use credit card number before the limited use credit card number can be used in a transaction by said user;   authorizing transactions which meet said established limitations and denying other transactions by comparing an attempted use of the limited use credit card number to the limitations on use established by the user and with the associated account as limited by the card issuer; and   debiting said associated account of the user by an amount of an authorized transaction of the user using the limited use credit card number.   
     
     
         2 . The method of  claim 1 , wherein said use limitations include a combination of a pre-set transaction amount limit and a merchant. 
     
     
         3 . The method of  claim 1 , wherein the account of the user is not revealed to a merchant when the limited use credit card number is used in a transaction by the user. 
     
     
         4 . The method of  claim 1 , wherein the limited use credit card number is formatted as a credit card number for processing by a merchant to whom the limited use credit card number is presented in a transaction by the user. 
     
     
         5 . The method of  claim 4 , wherein the user presents the limited use credit card number directly to the merchant in person or via a communication network through which a communication device of the user and a communication device of the merchant are communicatively linked. 
     
     
         6 . The method of  claim 4 , wherein the user presents the limited use credit card number directly to the merchant in person. 
     
     
         7 . The method of  claim 1 , wherein the limited use credit card number is a single-use credit card number. 
     
     
         8 . The method of  claim 1 , wherein the user is also a cardholder for the associated account. 
     
     
         9 . The method of  claim 1 , wherein the use limitations include a PIN of the user. 
     
     
         10 . The method of  claim 1 , wherein the use limitations include biometric data of the user. 
     
     
         11 . The method of  claim 1 , wherein the use limitations include the amount of the authorized transaction. 
     
     
         12 . The method of  claim 1 , wherein the use limitations include a merchant code number. 
     
     
         13 . The method of  claim 1 , wherein the user transmits the limited use credit card number to the merchant remotely. 
     
     
         14 . In a financial transaction system for use with at least one single use credit card number, which is limited in use by a single use credit card number issuer and by a user of the single use credit card number, and which is associated with an account of the user, a method of controlling the authorization for use of the single use credit card number comprising the steps of:
 issuing a single use credit card number for use by a user in a single use credit card number transaction, the single use credit card number constituting a different number than the account of the user and functioning as an authorized substitute for the account of the user in a credit card transaction;   receiving information communicated by the user to the single use credit card number issuer to establish limitations on the use of the single use credit card number before the single use credit card number can be used in a transaction by said user;   authorizing transactions which meet said established limitations and denying other transactions by comparing an attempted use of the single use credit card number to the limitations on use established by the user and with the associated account as limited by the card issuer; and   debiting said associated account of the user by an amount of an authorized transaction of the user using the single use credit card number.   
     
     
         15 . The method of  claim 14 , wherein said use limitations include a combination of a pre-set transaction amount limit and a merchant. 
     
     
         16 . The method of  claim 14 , wherein the account of the user is not revealed to a merchant when the single use credit card number is used in a transaction by the user. 
     
     
         17 . The method of  claim 14 , wherein the single use credit card number is formatted as a credit card number for processing by a merchant to whom the single use credit card number is presented in a transaction by the user. 
     
     
         18 . The method of  claim 17 , wherein the user presents the single use credit card number directly to the merchant in person or via a communication network through which a communication device of the user and a communication device of the merchant are communicatively linked. 
     
     
         19 . The method of  claim 17 , wherein the user presents the single use credit card number directly to the merchant in person. 
     
     
         20 . The method of  claim 14 , wherein the user is also a cardholder for the associated account. 
     
     
         21 . The method of  claim 14 , wherein the use limitations include a PIN of the user. 
     
     
         22 . The method of  claim 14 , wherein the use limitations include biometric data of the user. 
     
     
         23 . The method of  claim 14 , wherein the use limitations include the amount of the authorized transaction. 
     
     
         24 . The method of  claim 14 , wherein the use limitations include a merchant code number. 
     
     
         25 . The method of  claim 14 , wherein the user transmits the single use credit card number to the merchant remotely.