| 摘要 |
1. A credit card system comprising means for maintaining a pool of credit card numbers which share identical formatting to numbers on existing credit cards and means for assigning at least one credit card number from said pool of credit card numbers to be a master credit card number, characterised in that there is provided means (120) for assigning at least one credit card number (126) from said pool of credit card numbers (124) to be a limited-use credit card number (126) which is desactivated by a disactivating command (210) upon a use-triggered condition subseqient, and means for associating said master credit card with said limited-use credit card number (126), while ensuring that said master credit card number having no mathematical relationship with respect to said limited-use credit card number, cannot be discovered on the basis of said limited-use credit card number (126). 2. A credit card system as claimed in claim 1, further comprising: means (206) for receiving notification that said limited-use credit card number has been used in a credit card transaction; means for determining whether a limited-use event has occurred based on said notification, and if so, generating the deactivation command (210); and means for deactivating said limited-use credit card (126) if said limited use event has occurred. 3. A credit card system as claimed in claim 1 or 2, wherein said limited-use event is satisfied when said limited-use credit card (126) is used only once. 4. A credit card system as claimed in claims 1 to 3, wherein said limited-use event is satisfied when said limited-use credit card (126) is used to accrue charges which are greater than a prescribed monetary amount. 5. A credit card system as claimed in claims 1 to 4, further comprising means for assigning another limited-use credit card number (126) in response to said deactivation command, and associating said other limited-use credit card number (126) with said master credit card number. 6. A credit card system as claimed in claims 1 to 5, further comprising means for receiving a request for another limited-use credit card number (126) from a user, and means for assigning another limited-use credit card number in response to said request. 7. A credit card system as claimed in claim 5 or 6, wherein said system (1) maintains a queue of available limited-use credit card numbers (126), and said means for assigning said other limited-use credit card number selects said other limited-use credit card number from said queue. 8. A credit card system as claimed in claims 1 to 7, wherein said system includes transmission means for downloading said limited-use credit card number (126) to a user, comprising a computer (120) connected to the telecommunications system (112), wherein said limited-use credit card number is encrypted prior to downloading. 9. A credit card system as claimed in any of claims 1 to 7, wherein said system includes dispensing means for dispensing a credit card containing said limited-use credit card number to a user, wherein said dispensing means comprises an automated teller machine (108). 10. A credit card system as claimed in claims 1 to 9, in which the means for assigning credit card numbers includes a database (302) of credit card numbers which share identical formatting; a master credit card number selector that can select at least one credit card number from said database (302) to be a master credit card number (304); and a credit card number allocator that can allocate at least one additional credit card number (312) from said database to said master credit card number. 11. A credit card system as claimed in claims 1 to 10, in which there are provided means for determining the limited use conditions for the limited-use credit card number comprising: a database of credit card numbers which share identical formatting; a database (406) of conditions; a master credit card number selector that can select at least one credit card number (402) from said database of credit card numbers to be a master credit card number; a credit card number allocator that can allocate at least one credit card number (402) from said database of credit card numbers to said master credit card number; and a condition allocator that can allocate at least one condition (404) to said credit card number and store said condition in said database of conditions (406), said condition (404) limiting the use of said credit card number (402). 12. A credit card system as claimed in claim 11, wherein the said database (406) of conditions comprises transaction value conditions, time of transaction conditions, number of transactions conditions, frequency of transactions conditions, and purpose conditions. 13. A credit card system as claimed in claims 1 to 12 comprising: a database of credit card numbers (124) which share identical formatting; a master credit card number selector that can select at least one credit card number from said database to be a master credit card number; a credit card number allocator that can allocate at least one credit card number from said database to said master credit card number; a master credit card computer (102), said master credit card computer and said credit card number allocator interconnected by a computer network. 14. A credit card system as claimed in claim 13, wherein said credit card number allocator is capable of distributing said credit card numbers to said master credit card computer (102) via said computer network 15. A credit card system as claimed in claim 14, wherein there is a credit card number processor (102) that can associate said master credit card number with said credit card number so that a merchant can perform a transaction without ever knowing said master credit card number. 16. A credit card system as claimed in claim 15, wherein the system further comprises a list of valid credit card numbers and conditions for each and means for removing (210) said credit card number from said list of valid credit card numbers after a use-triggered condition subsequent (206). 17. A credit card system as claimed in claims 1 to 16, wherein the system provides means for accessing account information, the system comprising: a database of credit card numbers (902) which share identical formatting; a master credit card number selector that can select at least one credit card number from said database (902) to be a master credit card number (904); a credit card number allocator that can allocate at least one credit card number (908) from said database (902) to said master credit card number; an account information provider, said account information provider using said credit card number as a personal identification number (912) to access account information for said master credit card number (904). 18. A method for managing a pool of credit card numbers, comprising the steps of: maintaining a pool of credit card numbers (302) which share identical formatting; assigning at least one credit card number from said pool of credit card numbers to be a master credit card number (304); assigning at least one credit card number from said pool of credit card numbers to be a limited-use credit card number (308) which is deactivated upon a use-triggered condition subsequent; and associated said the master card number (304) with said limited-use credit card number, while ensuring that said master credit card number having no mathematical relationship with respect to said limited-use credit card number cannot be discovered on the basis of said limited-use credit card number. 19. A credit card system for performing a credit card transaction characterised in that it is based on one of a master credit card number or a limited-use credit card number, wherein said limited-use credit card number is randomly chosen with respect to said master credit card number, but said limited-use credit card number includes identical formatting to said master credit card number and is associated with said master credit card number, said system comprising: transaction means for entering a transaction (702) on the basis of said master credit card number or said limited-use credit card (704) number to generate a transaction message; processing means for receiving said transaction message and processing said transaction, including: means for authorising (706) or denying (712) said transaction; means (718) for determining whether to deactivate the limiteduse credit card number when said limited-use credit card number was used to perform the transaction, and for generating a deactivation command in response thereto, wherein said means for determining whether to deactivate the limited-use credit card number determines whether a limited-use event pertaining to the use of the limited-use credit card number has occurred, and if so, generates said deactivation command when said limited-use event has occurred; and means for deactivating the limited-use credit card number based on the deactivation command. 20. A credit card system as claimed in claim 19, wherein said limited-use event is satisfied when said limited-use credit card (704) is used only once. 21. A credit card system as claimed in claim 19 or 20, wherein said limiteduse event is satisfied when said limited-use credit card (704) is used to accrue charges which are greater than a prescribed monetary amount. 22. A method for performing a credit card transaction characterised in that it is based on one of a master credit card number or a limited-use credit card number, wherein said limited-use credit card number (704) having no mathematical relationship with respect to said master credit card number, but said limited-use credit card number (704) includes identical formatting to said master credit card number and is associated with said master credit card number, said system comprising: entering a transaction on the basis of said master credit card number or said limited-use credit card number (704) to generate a transacti |
