Abstract:
A credit card payment method and system ensures the security and robustness of payment transaction processing and validation procedure by utilizing an ordered list of supplementary credit card numbers and by requiring a card holder to present said supplementary credit card numbers, one by one, according to a pre-determined selection rules for consecutive payment transactions. Said credit card payment method and system further allows a supplementary credit card number to carry information regarding the transaction payment amount to enhance the security of payment processing. Also, said method and system is cost-effective to implement and highly compatible with the current credit card payment verification procedure.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to bank card, credit card, debit card, cash card, and other account verification devices.  
         [0002]     Consumers often use credit cards and debit cards to purchase merchandises at point-of-sale locations, via public telephones, or over the Internet.  
         [0003]     During a purchasing process, certain personal data are released, although in a limited way. Especially for payment transactions through telephones or over the Internet, the security of personal information is at risk.  
         [0004]     Even when not conducting transactions, personal data may also fall into wrong hands due to improper placement or disposition of documents. These factors may lead to unauthorized uses of bank cards. This situation is sometimes referred to as identity theft.  
         [0005]     To enhance the security of bank cards, issuing institutions assign card verification codes (CVC) and personal identification numbers (PIN) to bank card accounts. To implement the security, a merchant needs to ask the purchaser to present either a CVC or a PIN to verify the validity.  
         [0006]     In a way, this still constitutes a release of personal bank card information. It is only secure if all the parties involved in the transaction are trustable.  
         [0007]     Furthermore, there are still circumstances that merchants only use a credit card number to conduct payment transactions. They do not use a CVC or a PIN code.  
         [0008]     Some merchants that use a non-code payment method may be considered highly trustable by the issuing institution. They may also have special agreements with the issuing institution.  
         [0009]     Some merchants may take the risk themselves, in order to simplify the verification procedure. Examples include parking lots and self-service gas stations. These non-code users constitute a potential loophole in the verification process.  
         [0010]     For e-commerce transactions over the Internet, certain purchasers, because of unfamiliarity with the procedure or due to lack of patience, may issue an incorrect forward or backward command that causes a payment transaction to be processed more than once. This constitutes another potential problem for payment transaction processing.  
       BRIEF SUMMARY OF THE INVENTION  
       [0011]     This invention proposes a method and system to enhance the security and robustness of bank card transactions.  
         [0012]     This invention provides a method and system to prevent unauthorized usage of bank cards due to release of personal information during payment transaction processing or misplacement of documents.  
         [0013]     This invention provides a method and system for a purchaser to deliver a credit card number to a seller without compromising the security of subsequent usage.  
         [0014]     This invention proposes a method which is cost-effective and highly compatible with the current verification procedure.  
         [0015]     This invention further proposes a method which offers flexibility and tolerance for certain special handling procedures used by some merchants when processing credit card transactions.  
         [0016]     This invention further provides a method to prevent a transaction from being unintentionally processed more than once.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a diagram of a prior art bank card verification process.  
         [0018]      FIG. 2  shows a prior art bank card data structure.  
         [0019]      FIG. 3  shows a preferred embodiment of the present invention for a bank card data structure.  
         [0020]      FIG. 4  shows a preferred embodiment of the present invention for a bank card verification process.  
         [0021]      FIG. 5  shows a number of preferred embodiments of the present invention for a supplementary card number chart.  
         [0022]      FIG. 6  shows a number of preferred embodiments of the present invention for a card holder to carry a list of supplementary card numbers.  
         [0023]      FIG. 7  shows a preferred embodiment of the present invention for a card number storage device.  
         [0024]      FIG. 8  shows a preferred embodiment of the present invention for a card number maintenance device.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     The present invention will be illustrated with some preferred embodiments.  
         [0026]      FIG. 1  shows a prior art bank card verification process. Initially, an issuing institution  101  issues a bank card  102  to a consumer  103 . The bank card  102  contains a set of bank card data, such as a card number, a consumer name, an expiry date, and a card verification code. The issuing institution  101  keeps a consumer account record  104  in the account record database  105 . A consumer account record  104  contains an account number  111  and a card verification code  112 . It may also contain other account data such as an expiry date, a maximum limit amount, the current balance, the current status, the consumer name, the consumer address, previous transactions, and other reference data.  
         [0027]     To make a purchase, the consumer  103  provides the seller  106  with the bank card data. The seller  106  transfers the bank card data through a verification terminal  107  to an account verifier  110  at the issuing institution  101  for verification. The seller  106  may also transfer the seller identification and the purchase amount together with the bank card data.  
         [0028]     The account verifier  110  at the issuing institution  101  verifies the validity of received bank card data by searching the account record database  105  for a matched consumer account record  104  which matches the received bank card number. If a matched record is found, the account verifier  110  verifies other account data for consistency and limitations. The issuing institution  101  then sends the verification results to the seller  106 .  
         [0029]      FIG. 2  shows a prior art bank card data structure. The front side  201  of the bank card contains a card number  202 , a consumer name  203 , and an expiry data  204 .  
         [0030]     The back side  211  of bank card contains a magnetic stripe  212  and a signature area  213 . It also contains a card verification code (CVC)  214 . Items  202 ,  203 ,  204 , and  214  may be classified as the primary bank card data.  
         [0031]     Associating with a bank card, a consumer also maintains secondary information which includes a personal identification number (PIN)  221  and other personal data  222  such as a mailing address and a telephone number. Items  221  and  222  may be classified as the secondary bank card data.  
         [0032]     Besides verifying the primary bank card data, some sellers also verify the secondary bank card data.  
         [0033]     For a consumer bank card, the card verification code (CVC)  214  is normally a 3-digit or 4-digit fixed numeric code. The personal identification number (PIN)  221  is also a fixed number, normally with 4 to 6 digits.  
         [0034]      FIG. 3  shows a preferred embodiment of a bank card data structure. The front side  301  of the bank card contains a primary card number  302 , a consumer name  303 , and an expiry data  304 . The back side  311  of the bank card contains a magnetic stripe  312  and a signature area  313 . It also contains a primary card verification code (CVC)  314 .  
         [0035]     In addition, there is a companion supplementary card number chart  321  supplied by the issuing institution.  
         [0036]     The supplementary card number chart  321  may be viewed as a list of supplementary card numbers such as  322 ,  323 ,  324 , and  325 . For each purchase transaction, the consumer selects a card number from the chart  321  to use as a transaction credit card number.  
         [0037]     In other words, for payment transactions that require special security, instead of using a primary credit card number, a consumer uses a different supplementary credit card number for each individual purchase transaction.  
         [0038]     Associating with a bank card, a consumer also maintains secondary information which includes a personal identification number (PIN)  331  and other personal data  332  such as a mailing address, a telephone number, and an email address.  
         [0039]     A card number in the supplementary card number chart  321  contains three parts. The first 6 digits constitute a business identification code. The next 9 digits constitute a transaction-specific code. The last digit is a checking digit.  
         [0040]      FIG. 4  shows a preferred embodiment of the present invention for a bank card verification process.  
         [0041]     An issuing institution  401  issues a bank card  402  and a supplementary card number chart  408  to a consumer  403 . The data structure of the bank card  402  and the supplementary card number chart  408  is as illustrated in  FIG. 3 .  
         [0042]     The issuing institution  401  keeps a primary consumer account record  404  in the account record database  405 . A primary consumer account record  404  contains an account number  411  and a supplementary card number descriptor  412 . It may also contain other account data such as an expiry date, a maximum limit amount, the current balance, the current status, the consumer name, the consumer address, previous transactions, and other reference data.  
         [0043]     The supplementary card number descriptor  412  contains a supplementary card number table  414  and a table index  413 . The supplementary card number table  414  contains a list of supplementary card number entries. The table index  413  points to an expected supplementary card number entry in the supplementary card number table  414 .  
         [0044]     To make a purchase, the consumer  403  selects the current supplementary card number from the supplementary card number chart  408 , as illustrated in  FIG. 3 . The consumer  403  provides the seller  406  with the current supplementary card number as the credit card number in the bank card data.  
         [0045]     The seller  406  transfers the current supplementary card number through a verification terminal  407  to an account verifier  410  at the issuing institution  401  for verification. The seller  406  may also transfer the seller identification and the purchase amount together with the bank card data.  
         [0046]     The account verifier  410  at the issuing institution  401  verifies the validity of received bank card data by trying to link the received bank card number to a target primary consumer account record  404  in the account record database  405 .  
         [0047]     The linking procedure may be performed in a number of ways. The account verifier  410  may search through the account record database  405  to find a primary consumer account record  404  in which the expected supplementary card number matches the received bank card number.  
         [0048]     Alternatively, a verification system may maintain a current list of expected supplementary card numbers. The account verifier  410  searches through the current list to find an expected supplementary card number.  
         [0049]     Normally, a consumer  403  also provides the seller  406  with a consumer name, illustrated in FIG as  303 . The account verifier  410  may use the consumer name to identify a primary consumer account record  404 .  
         [0050]     If a target primary account record is found, the account verifier  410  verifies the received bank card number with the expected bank card number, indexed by the card number index  413 , in the card number table  414 .  
         [0051]     A verification system may allow two or more customers to use the same name, as long as the expected credit card numbers are different.  
         [0052]     The account verifier  410  may also verify other account data for consistency and limitations. The issuing institution  401  then sends the verification results to the seller  406 .  
         [0053]     If the transaction is successfully validated, the account verifier  410  modifies the card number index  413  to point to the next expected card number in the card number table  414 .  
         [0054]     The card number table  414  contains a limited number of card number entries. To operate the verification process on a continuous basis, a strategy is needed to either cycle through the card number entries, or to update the card number table contents as needed.  
         [0055]     For illustration purpose, the account verifier  410  may use a cycle-through policy. If the current card number table index is the last card number entry in the key table, after a successful transaction validation, the account verifier  410  resets the card number table index to point to the first card number entry.  
         [0056]     To use a table-updating policy, the account verifier  410  also needs to update the contents of the table with the next group of card number entries.  
         [0057]     On the card holder side, after each successful payment transaction validation, the card holder marks off the current card number value that has just been used on the card number chart. The next card number value now appears to be a current card number value on the chart.  
         [0058]     Most merchants, when receives the credit card information from a card holder, sends the credit card information to a verification institution for verification immediately.  
         [0059]     However, some merchants may defer the verification process of a payment transaction until a later time. Examples include hotels that defer credit card processing until check-out time, and rental car companies that defer credit card processing until car return time.  
         [0060]     To strictly ensure the security, a verification system may choose not to allow deferred processing.  
         [0061]     To allow more flexibility, a verification system may allow a number of card numbers, associated with deferred payment transactions, to be skipped. It will accept the next following card number as a valid card number.  
         [0062]     We may use the card number chart  321  in FIG. 3  as an example to illustrate the verification procedure. The card number chart  321  contains a list of card numbers.  
         [0063]     A card holder uses card number  322  in a first payment transaction. The card number  322  is sent by a first merchant to the verification system to be processed immediately.  
         [0064]     Afterwards, the card holder uses card number  323  in a second payment transaction. A second merchant defers the verification process. It does not send card number  323  to the verification system to be processed immediately.  
         [0065]     The card holder subsequently uses card number  324  in a third payment transaction. This time, a third merchant sends card number  324  to a verification system to be processed immediately.  
         [0066]     At this point, the verification system normally expects to receive card number  323 . To provide additional flexibility, the verification system also considers card number  324  to be an acceptable card number, assuming that card number  323  has been deferred by a merchant.  
         [0067]     At a later time, the second merchant sends the deferred card number  323  for verification. At this time, the verification system normally expects to receive card number  325 . It will also consider the deferred card number  323  to be an acceptable card number, as long as the deferred length of time is within a pre-defined reasonable time limit.  
         [0068]     A credit card account may not contain a primary credit card number, only a list of supplementary credit card numbers.  
         [0069]     For a credit card system with primary credit card numbers, the verification system may also allow a card holder, under certain environments, to use the primary card number to conduct payment transactions. This verification mode is essentially the same as a prior art credit card verification method.  
         [0070]     In other words, a verification system with primary card numbers may allow two verification modes: a primary card number verification mode and a supplementary card number verification mode.  
         [0071]     Usually, a merchant also requires the card holder to present a card verification code. The primary card verification code  314  may be used as the card verification code for all the supplementary card numbers.  
         [0072]     In a different embodiment, each supplementary card number may be assigned a different card verification code to provide additional security.  
         [0073]      FIG. 5  shows a number of preferred embodiments of the present invention for a supplementary card number chart.  
         [0074]     Supplementary card number chart  501  contains a list of supplementary card numbers, such as  502  and  503 . Each supplementary card number is assigned a 3-digit card verification code.  
         [0075]     To further enhance the security of payment transaction, a verification system may use a verification key to carry information about the payment transaction. Payment transaction information may include payment amount, payment date, or merchant identification. In this case, the verification system needs to receive the payment transaction information from the requester, along with the verification key to perform the validation.  
         [0076]     Since a verification key may be just a 3-digit number, it may not contain an actual payment amount. The verification key may only contain a combined signature of the verification code and the current payment amount.  
         [0077]     Supplementary card number chart  511  contains another list of supplementary card numbers, such as  512  and  513 .  
         [0078]     A card number in  511  contains four parts. The first 6 digits constitute a business identification code. The next 7 digits constitute a customer-specific account number. The next 2 digits constitute an intra-account transaction-specific code. The last digit is a checking digit.  
         [0079]     Using this type of assignment for card numbers, all the card number with the same leading 13 digits are assigned to the same card holder account. The 2-digit intra-account transaction-specific code identifies the individual transaction. This transaction-specific code may also be used to carry transaction information such as a signature for payment amount. The check digit also needs to be adjusted accordingly.  
         [0080]     The transaction-specific code, the checking digit, and the card verification code may be combined into a six-digit extended verification code. This extended verification code may also carry transaction information such as a signature for payment amount.  
         [0081]     In order to retain the functionality and compatibility, the check digit needs to be preserved. Only five digits in the six-digit extended verification code are effectively usable.  
         [0082]      FIG. 6  shows a number of preferred embodiments of the present invention for a card holder to carry a list of supplementary card numbers.  
         [0083]     Card number label set  601  contains a set of supplementary card number charts. The supplementary card numbers are printed on detachable labels. After each successful purchase validation, the corresponding supplementary card number label is physically detached from the card number chart.  
         [0084]     A card holder may use a personal digital assistant (PDA) device  602  to carry the list of supplementary card numbers. The list of card numbers are loaded into the PDA, either as directory entries, memo contents, or other data entries.  
         [0085]     A card holder may enter the card numbers on the PDA, or load the card numbers through a communication channel.  
         [0086]     After each successful purchase validation, the corresponding card number item may be deleted from the list.  
         [0087]     A card holder may also use a cellular telephone device  603  to carry the list of supplementary card numbers. The supplementary card numbers are loaded into the cellular telephone as directory entries. For a more complex cellular telephone, the supplementary card numbers may also be loaded as memo contents or other data entries.  
         [0088]     A card holder may enter the supplementary card numbers on the cellular telephone, or load the supplementary card numbers through a communication channel.  
         [0089]     After each successful purchase validation, the corresponding supplementary card number item may be deleted from the list.  
         [0090]      FIG. 7  shows a preferred embodiment of the present invention for a card number storage device. The upper portion of  FIG. 7  shows the external appearance. The lower portion of  FIG. 7  shows a structure block diagram.  
         [0091]     From the external appearance, the card number storage device  701  appears as a key chain attachment.  
         [0092]     From the internal structure, the card number storage device  701  contains a display unit  702  and a number of switches  710 . The card number storage device  701  keeps a list of card number values in a memory unit  712 .  
         [0093]     The memory unit  712  contains a card number table  714  and a card number index  713 . The card number table  714  contains a list of card number entries. The card number index  713  points to a current card number entry in the card number table  714 .  
         [0094]     A processor unit  711  controls the operation of the display unit  702 , the switches  710 , and the memory unit  712 .  
         [0095]     The Power switch  703  is a two-position switch which controls the power ON and OFF conditions. When the device power is turn on, the display unit  702  displays the current card number entry, indexed by the card number index  713 . The card holder may give the current card number entry value to the seller as a card number for a payment transaction.  
         [0096]     The Payment Complete switch  704  is also a two-position switch, normally set to the View Code position. After each successful purchase validation, the card holder toggles the Payment Complete switch  704  to the Payment Complete position. Upon this action, the processor unit  711  updates card number index  713  to point to the next card number entry in the card number table  714 , as a new current card number entry.  
         [0097]     Once the current card number value is updated, the card holder needs to toggle the Payment Complete switch  704  back to the View Code position to resume normal operation.  
         [0098]      FIG. 8  shows a preferred embodiment of the present invention for a card number maintenance device. The upper portion of  FIG. 8  shows the external appearance. The lower portion of  FIG. 8  shows a structure block diagram.  
         [0099]     The card number maintenance device  801  contains a display element  802  and an entry pad  810 . The card number maintenance device  801  keeps a list of card number values in a memory unit  812 .  
         [0100]     The memory unit  812  contains a card number table  814  and a card number index  813 . The card number table  814  contains a list of card number entries. The card number index  813  points to a current card number entry in the card number table  814 .  
         [0101]     A processor unit  811  controls the operation of the display unit  802 , the entry pad  810 , and the memory unit  812 .  
         [0102]     The Power button  803  controls the power ON and OFF conditions. When the device power is turn on, the display unit  802  displays the current card number entry, indexed by the card number index  813 .  
         [0103]     The operation of the Payment Complete switch  804  is similar to the operation of Payment Complete switch  704  described in  FIG. 7 .  
         [0104]     To provide more flexibility, the card number maintenance device  801  includes more buttons. A Display Code button  805  instructs the device to display the current card number entry value on the display unit  802 . A Last button  806  instructs the device to display the last card number entry value. A Next button  807  instructs the device to display the next card number entry value.  
         [0105]     In addition, the card number maintenance device  801  includes a real-time clock unit  820 . The real-time clock is used to keep a transaction history. At each payment completion, the processor unit  811  stores the transaction time in the memory unit  812 .  
         [0106]     Upon a Last button command, the display unit  802  displays the last transaction time along with the card number entry value. The Last button  806  and the Next button  807  are used to scroll backward and forward through previous transactions. The Display Code button  805  resets the display back to the current card number entry value.  
         [0107]     Besides keeping track of the transaction history, this feature may assist the card holder to recover from a situation that the Payment Complete switch  804  was un-intentionally touched, which led to an incorrect updating of the current card number value.  
         [0108]     With a card number verification system that allows deferred transaction processing, un-intentionally-skipped card number may also be simply considered as a card number that has been deferred, but never actually posted at a later time.  
         [0109]     By adding a group of number buttons, the card number maintenance device  801  may include a security protection feature. The card number maintenance device  801  may require the purchaser to enter a password code in order to access the card numbers.  
         [0110]     In addition, a consumer may enter a payment amount using the entry pad. For verification system with a card verification code, an intra-account transaction-specific code, or an extended verification code, as described in  FIG.5 , the processor unit  811  may use these special codes and the payment amount input to generate a final card number, and a final verification code, according to a pre-determined algorithm.  
         [0111]     The final card number and verification code contains a combined signature of the special codes and the current payment amount.  
         [0112]     The card number maintenance device  801  shown in  FIG. 8  may also include calculator functions, which complements the transaction processing operation.  
         [0113]     The present invention may be used in combination with either a card verification code (CVC) or a personal identification number (PIN). The CVC is also referred to, by different financial institutions, as a CVC2, CVV, CVV2, CVN, or CID. The term “verification code” or “verification key” are used to represent either a PIN or a version of the CVC numbers.  
         [0114]     A bank card, depending on the payment terms, is referred to a credit card, a debit card, a check card, a cash card, an ATM card, or a similar name.  
         [0115]     The verification of a payment transaction is also referred to as validation, authorization, approval, or a similar term.  
         [0116]     The present invention is cost-effective to implement and highly compatible with the current account verification procedure.