WO2001041026A1

WO2001041026A1 - Method and system for point of transaction credit card access validation

Info

Publication number: WO2001041026A1
Application number: PCT/US2000/032860
Authority: WO
Inventors: Tim Gorczyca
Original assignee: Andropolis Millennium Systems International
Priority date: 1999-12-03
Filing date: 2000-12-04
Publication date: 2001-06-07
Also published as: AU2059101A

Abstract

A system for credit/debit card use that requires the user to associate a PIN code with the account number on the card prior to carrying out a financial transaction. A vendor code and a unique transaction code are automatically associated with the card when the user identifies the PIN code. A credit/debit card (12) with magnetizable memory fields (20, 22, 24, 26) on the card carry a 'permanent' imprint of the account number and a rewritable imprint of the PIN code, the vendor code and the transaction code. At the time of a financial transaction, the appropriate PIN code, vendor code, and a unique transaction code are imprinted on the card magnetically and are carried with the account number to a card reader (16) wherein the codes are read and transmitted by electronic linkage (42) to a central card database (18).

Description

TITLE METHOD AND SYSTEM FOR POINT OF TRANSACTION CREDIT CARD ACCESS VALIDATION BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates generally to methods and devices for carrying out a financial transaction utilizing a credit based account . The present invention relates more specifically to methods and devices for utilizing a credit card in a manner that prevents the unauthorized use of the card by incorporating a removable access key placed on the card at the time of the transaction, while retaining the convenience and ease of use normally associated with credit cards. 2. DESCRIPTION OF THE RELATED ART Millions of dollars are written off as losses by credit card. companies annually because of the unauthorized use of credit cards. Charges made to a customer's account without permission or consent commonly occur when such cards are utilized after having been stolen or misplaced. In the period of time before the card owner becomes aware of the credit card being stolen or misplaced, many significant unauthorized financial transactions can be carried out. Although laws in most jurisdictions limit the liability of the card owner to $50.00 or so, the losses accumulated with a stolen credit card can easily exceed thousands of dollars. These losses are typically borne in major part by the credit card companies themselves. In the end these losses are paid for by increased interest rates and annual fees . The major reason for the large amount of lost dollars resulting from the unauthorized use of credit cards is the inherent convenience of utilizing the credit card. While some retail outlets take steps to assure that the individual presenting the credit card for use is in fact the credit card owner, many other retail outlets take no such steps to verify unauthorized use of the card. In fact, many modern credit card systems utilize no personal contact whatsoever in financial transactions and may only verify the validity of the credit card and the limit on the account. Most major credit card companies rely on credit card owners to notify them in a timely fashion if a card is lost or stolen in order to invalidate the card and thereafter prevent its unauthorized use. As indicated above, however, there is often a significant period of time before the credit card owner is aware of the loss of the card . During this time significant charges can accumulate and must be written off by the credit card company. An example of the ease of use of credit cards can be found in the "pay at the pump" type systems utilized at gas stations and the like . Many retail outlets are finding that customers pre fer the convenience associated with the full electronic transact ion that occurs by swiping the credit card through a magnetic card reader and waiting only for validation of the account over- a telecommunications data line . The ability of credit cards to be used by those who are unauthorized for such use is built into the credit cards themselves because of their "active " condition . Almost all credit cards are "active" and respond when swiped through a reader by merely transmitting an account number to the reader for validation . Once the account number has been confirmed to be valid by access and reference to a central credit card data bank, authorization is given to carry out the financ ial transaction . The one primary exception to this ease of use l ies in bank automatic teller machines wherein even for major credit cards or bank cards , the user is required to input a PIN (personal identification number) in order to receive cash drawn on the credit card account . This system is in place primarily because of the analogous system utilized in conjunction with debit cards or ATM cards of fered by the banks . In the case of an ATM, however, the user is required to input a PIN at the point of transact ion which in combination with the account number is transmitted to a central data bank for comparison and authorization . In the vast maj ority of financial transactions , however, credit cards are utilized without such PIN requirements , which results in the convenient and frequent unauthorized use of the card . Efforts in the past to prevent the unauthorized use of credit cards have focused on the variety of points in the financ i al transaction itself to assure authorized use . Examples of efforts in the past along these lines include the following . U. S . Patent No . 3 , 972 , 138 issued to Armbruster et al . on August 3 , 1976 entitled Credit Card . This patent describes an improved credit card construction that includes at least one indexing slot that physically carries at least one magnetizable signal carrying tab that can be moved to a variety of desi red index positions on the indexing slot. In order to be used, the credit card user must place the tabs in the correct index position to identify itself as the user of the card. U.S. Patent No. 5,811,771 issued to Dethloff on September 22, 1998 entitled Method and System for Paying With a Portable Data Medium Having Security Against Over Charging and Unauthorized Use. The system defined by this patent focuses primarily on debit cards and controlling the amount of the transaction to be carried out. In this case a memory section on the data card is provided to retain a transaction amount but limits the total to be deducted when the vendor carries out the transaction. In this manner the user of the card can specify a maximum amount or an exact amount that the transaction is to incur. The patent anticipates the use of a personal terminal with the data medium for establishing the fixed limit on the transaction. U.S. Patent No. 5,365,046 issued to Hay ann on Nov. 15, 1994 entitled Preventing Unauthorized Use of a Credit Card. Triis patent provides the combination of a credit card with an account number and a personal identification number (PIN) that is input into an electronic terminal at the point of transaction. Triis patent describes the basic method whereby the PIN code and the account number are compared with information stored in the central data base. If the PIN code corresponds to the account number, then the transaction is authorized. The primary purpose of the patent is to provide a new card validation system that prevents unauthorized use of a credit card immediately after it has been issued as it is intercepted before the authorized card holder receives it . In this case the PIN number is entered into a terminal at a point of sale, transaction, or an ATM or the like. U.S. Patent No. 5,317,137 issued to ilkins on May 31, 1994 entitled Magnetic Debit Card Reader Fraudulent Use Prevention. The system of this patent incorporates a magnetic reader/writer whose primary intent is to maintain a single credit card device within the reader during the transaction. Efforts are made to prevent the movement of the card so as to insure that the same card is utilized throughout a transaction. It anticipates that the credit card can be invalidated immediately after data is read therefrom and only revalidated if it is determined that the same card resides in the reader throughout the transaction. U.S. Patent No. 5,255,941 issued to Solomon on October 26, 1993 entitled Antifraud Credit Card Assembly. This patent also provides a moveable physical mechanism on the face of the card for mechanically changing the information provided by the magnetic stripe for selecting presenting to a scanning machine any other plurality of messages including a single legitimate message that allows the transaction to occur. In one embodiment the moveable device is a slide, and in a second embodiment the moveable device is a rotatable disk. U.S. Patent No. 4,711,993 issued to Kosednar et al. on December 8, 1987 entitled Fraud-Resistant Manual Magnetic Reader- Writer System for Debit Card Use. This device is also intended to prevent the removal of a card prior to an appropriate reduction in the credit or debit account according to the amount of the transaction. The process involves a validity indicator encoded on the magnetic stripe of the card that is automatically eradicated upon insertion of the card for carrying out the transaction. Only upon the appropriate reduction in the account is the validity indicator re-established on the card and removal permitted. U.S. Patent No. 4,432,567 issued to Stockburger et al. on February 21, 1984 entitled Authorization Card. This patent provides yet another device that includes mechanical slides on the face of the card that allows the user to select certain coded information that can be read by an automatic reading device. Various storage zones are defined on the credit card and associated with the mechanically manipulable adjustments on the face of the card. U.S. Patent No. 5,883,452 issued to Masuda on March 16, 1999 entitled Credit Card System and Method of Issuing Credit Card Using Such a System. This patent was directed primarily to a method for issuing credit cards through a comparison of various identifying information magnetically imprinted on the card. An input device for entering such identification number is required in order to confirm the appropriate user of the card. As indicated above, the primary shortcomings of previous efforts to require the use of PIN code in association with credit cards has been the necessity of providing a terminal for entering the PIN code, which terminal is in telecommunication with a central credit card database. In many instances it is not practical for the retail establishment to provide such a PIN terminal to each and every customer who wishes to use a credit card. The use of the PIN terminal necessitates an established hard wire telecommunication data link with a modem or other data type device that communicates with the central credit card database to verify the authorized use of the card. Such systems are cumbersome and quite inappropriate to utilize in a vast majority of retail financial transactions. It would be desirable if credit cards could be created that would require the use of a PIN code for authorization or validation but which would not require the use of a hardwired PIN terminal for implementing the authorization key or code for the credit card. It would be desirable if such a mechanism for providing a PIN code for use in association with a credit card account number could be carried out simply and efficiently by the card user without the necessity of the vendor providing additional hardware to carry out the steps of the process. It would be desirable if the credit card could bear the PIN code discreetly and without the necessity of providing manually manipulative features on the surface or within the substance of the credit card itself. It would be desirable if the use of a PIN code in conjunction with the credit card device could further be accompanied by the use of a vendor code imprinted on the card at the time of the transaction to verify that the location of the transaction is valid. Further, it would be desirable if the use of the PIN code and the vendor code were accompanied by the use of a unique transaction code, imprinted on the card at the time of the transaction such that accessing the credit card (using the card) could be accomplished on a transaction by a transaction basis. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and system for credit card use that requires the card user to associate a PIN code, a vendor code, and a unique transaction code with the credit card account code at the time of a financial transaction with the credit card. It is a further object of the present invention to provide a credit or debit card system that utilizes a PIN code, a vendor code, and a unique transaction code in conjunction with an account number and permits the association of the PIN code, vendor code and transaction code with the account number on a single transaction basis, thereby validating the card for that transaction alone and no subsequent transactions. It is a further object of the present invention to provide a method and system for use of a credit card and/or a debit card, which method and system utilize a PIN code, a vendor code, and a unique transaction code to provide access to the credit or debit account on a single transaction basis and which codes are overwritten on the card when a new transaction is initiated. It is a further object of the present invention to provide a method and system for use of a credit card or a debit card that incorporates on the credit card or debit card a PIN code memory area, a vendor code memory area, and a transaction code memory area, which memory areas permit the "imprinting" of the PIN code, the vendor code, and the transaction code on the card for use in a single financial transaction. It is a further object of the present invention to provide a credit card method and system that associates a PIN code with an account number and requires the use of such PIN code ( n conjunction with a vendor code and a transaction code) prior to an authorized transaction with the card, and yet implements such a method and system with relatively minor modifications or additions to existing credit card and debit card transaction devices. It is a further object of the present invention to provide a credit card method and system that associates a PIN code with an account number and requires the use of such PIN code ( in conjunction with a vendor code and a transaction code) prior to an authorized transaction with the card, and implements such a method and system without the need to provide for hardwired code input devices to the user of the card. In fulfillment of these and other objectives, the present invention provides a method and system for credit card or debit card use that requires the card user to associate a PIN code with the account number on the credit card prior to carrying out an individual f inancial transaction . A vendor code and a unique transaction code are automatically associated with the credit card when the user identifies the PIN code . A preferred embodiment of the invention utilizes a credit or debit card with magnetizable memory f ields on the card that carry a "permanent " imprint of the account number and a rewritable imprint of the PIN code , the vendor code and the transaction code . At the time of a financ ial transaction authorized by the user , the appropriate PIN code , vendor code , and a unique transaction code are imprinted on the card magnetically or otherwise , and are carried with the account code to a card reader wherein the codes are read and transmit ted by electronic linkage to a central credit or debit card database . The PIN code is verif ied as the code properly assoc iated with the account number . The vendor code is verif ied as valid (being a registered vendor for the specif ic credit/debit card system) . The transaction code is verif ied as being unique , that is , distinct from a previous transaction code associated with the account number . Upon use of the card in a single transaction, the transaction code is stored in the system database so as to prevent subsequent use of the credit or debit card without a new association or imprinting of the PIN code , vendor code , and a new transaction code thereon . The method and system prevent the unauthorized use of the credit or debit card by way of requiring that the PIN code appear in association with the account code before a transaction is authorized and by requiring a uni que transaction code for every transaction . The method and sys tem permit use of the credit card with a rewritable code memory area not only in new and novel situations where the card user might place the PIN code on the card with a portable imprinting devi ce but also permit the card to be utilized in " tradit ional " PIN code systems that are already in use . BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing the various basic components of the system of the present invention and their relationship during use of the credit card in a financial transaction. FIG . 2 is a flow chart showing the fundamental steps associated with carrying out the method of the present invent ion as it pertains to the issuance of the credit card and credit account . FIG. 3 is a flow chart showing the various steps associated with the appropriate use of a credit card according to the metbod of the present invention in an authorized financial transaction. FIG. 4 is flow chart showing the basic steps of the method of the present invention when utilized in conjunction with traditional point of sale PIN required transactions utilizing a credit or a debit card. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It is understood that the present invention may be implemented through a system incorporating various electronic components that are already in use for credit and debit card financial transactions, albeit that the complete set of components are not presently utilized in the manner and in the arrangement that the present invention describes. The basic components will be sufficiently described so as to identify the nature of their structure and function. Those skilled in the art will readily identify such off-the-shelf components that are utilized in other manners in various other systems associated with credit and debit cards. The appropriate utilization of such devices in the present invention will become clear upon a full reading of the following description of the preferred embodiments. Referencing FIG. 1, the basic components of the present invention are shown to include a credit card or debit card (12) having a magnetized/magnetizable area (19) on one side of the card, typically in the form of a stripe across the back of the card as is well known in the art. The primary additional requirement presented by the method and system of the present invention is that the magnetizable stripe (19) on the back of the card be segregated into at least two areas and preferably four areas (20) , (22) , (24) , and (26) that are designed to carry in either a permanent or a temporary fashion, certain bits of data associated with the account number, a PIN code, a vendor code, and a transaction code. It is anticipated that the physical geometry of standard magnetic stripes positioned on credit cards and the like would not need to be altered for purposes of the present invention. It is anticipated that the various codes which are permanently or temporarily placed on the magnetic stripe could easily be incorporated into the geometries and structures of present credit card and debit card systems that utilize such magnetizable material in the construction of the card. The second primary component associated with the method and system of the present invention is a magnetic card reader (16) as is typically found with vendors who are set up and established to receive and utilize credit cards in financial transactions at their places of business. Such magnetic card readers (16) typically allow the insertion of the card into an electronic device which senses the magnetic coding established on the back of the card, most typically reflecting the account number of the credit account or debit account. Alternative mechanisms involve swiping the card through a slot (40) which again incorporates a magnetic reader that detects and interprets the data stored in the magnetic fields on the card. While there are many "smart cards" in use currently, the present invention does not anticipate that the primary value of the methods and system of the present invention will be met in conjunction with such cards. One objective of the present invention is to easily implement the methods of the invention in conjunction with existing systems and with the economical forms of credit and debit cards, namely those with simple magnetic stripes positioned on one face of the card. A third essential element in the method and system of the present invention is the remote credit or debit card database (18) . Connection to the remote database is made through the card reader (16) , typically at a single point in a vendor's place of business or in an establishment's financial transaction system. The purpose of the magnetic card reader is to read the various informational data bits that are stored on the card either permanently (as in the form of an account number) or temporarily (as in the form of a PIN code, a vendor code, and/or a transaction code) . A final critical and unique element of the method and system of the present invention is a portable PIN terminal (14) that permits the user to imprint the PIN code on the card for the purposes of carrying out a single transaction. In addition, the portable imprinter (14) may be programmed to automatically place a vendor code on the card as well as a random transaction code at the same time the card user imprints the PIN code. In this manner the portable unit (14) places the card (12) in a valid, keyed, accessible condition suitable for a single transaction to be carried out. As will be described in greater detail below, it is the intent of the system that such temporary data fields on the card will be overwritten upon the initiation of a new transaction. Reference is again made to FIG. 1 for a brief description of the relationship of the above mentioned basic components of the system of the present invention. As indicated above, credit card (12) incorporates a plurality of magnetically imprintable fields (20) , (22) , (24) , and (26) positioned on at least one face of the credit card (12) . In order to implement the present invention in conjunction with existing credit card systems, the magnetic area (19) usable by the method of the present invention should be that area already defined by the magnetic stripe typically found on credit cards and debit cards . In the present invention, however, the magnetic stripe (19) positioned on credit card (12) is divided into a plurality of regions varying in number from 2 to 4 or more depending upon the particular steps that the system is arranged to carry out. In a minimal embodiment of the present invention, the magnetic stripe (19) associated with the credit or debit card contains two fields, one which holds the account number (26) and the second which may temporarily hold a PIN code (24) . In a preferred embodiment, the account number is permanently imprinted into a first magnetic area (26) of the stripe on the back of the card and is retained there throughout the many transactions that will be carried out during the lifetime of the card. The second area (24) of the magnetic stripe (19) is characterized as being temporary in nature and requires the imprint of a PIN code onto the area and the reading of that code in association with the account number in order to validate the financial transaction. Preferred embodiments of the present invention utilize (in addition to the PIN code and the account code) a vendor code (22) and a random transaction code (20 ) to further verify and validate the specific f inancial transaction . The vendor code is simply an identification code associated with the particular retail establishment at which the credit card is being utilized in the financial transaction . The use of a vendor code prevents the unauthorized removal of an activated or unlocked credit card by any party outside of the specif ic vendor that the card user has provided the card to at the time of the intended transaction. The random transaction code is a mechanism to prevent the repeated use of a validated card in more than the intended single transaction authorized by the card user . In the preferred embodiment , the transaction code is a four digit sequence of numbers randomly generated by digital circuitry as is well known in the art of calculators , digital clock/calendar devices and the like . As mentioned above , it is anticipated that current credit card technologies and geometries can easily incorporate the appropriate permanent magnetic data field associated with the account number and the temporary or rewritable magnetic data fields associated with the PIN code , the vendor code , and the transaction code . The portable card imprinter (14) of the present invention has three fundamental components. First, the imprinter has a card slot (34) within which is positioned a magnetic writing head (not shown) appropriately positionable over various portions of the magnetic stripe (19) associated with the credit card (12). Such magnetic writing heads are typical of systems that can temporarily program magnetic cards and the like with access numbers or other bits or information. Such programmable writing devices can be found in debit card issuing machines and the like, as well in motel room access card keys and the like. In other words, it is well known in the art to provide relatively simple devices capable of writing or imprinting data or other information onto the magnetic field of a credit card, debit card, or the like. The present invention utilizes such a writing device in conjunction with a small (handheld) portable mechanism for imprinting the PIN code, the vendor code, and a transaction code onto the card at the point of the financial transaction. A second primary component of the portable imprinter comprises a key pad (30 ) that permits the user to input the PIN code in privacy in order to prevent either the vendor or other parties around the transaction from securing the PIN code for later use . It is this feature of the present invention that maintains the convenience and ease of use that credit card users have become accustomed to . By permitting the user to remain disassociated from the hardwired terminal ( 16 ) that makes electronic contact with the system database (18 ) , the present invention maintains the ease of use that prior systems have enj oyed . The key pad (30 ) of the portable imprinter is, as is well known in the art , a standard 12 -button key pad bearing numbers 0 through 9 with a # sign and * for various funct ions related to the input of the PIN code . In most cases , the PIN code would be a simple four-digit number easily remembered by the card user but suf ficiently distinct from a significant number of other possible codes as to prevent the unauthorized user from merely guessing at the code and securing use of the card . The final primary component of the portable imprinter i s a display device (28 ) that allows the user to confirm the process of entering a PIN code and additionally prompts the user for such PIN code input . It is anticipated that the portable imprinter (14 ) of the present invention might be sized somewhat larger than a standard digital calculator and could, as in the case of a restaurant vendor, be incorporated into a small folder as is typically presented to patrons upon completion of a transact ion for payment . To carry forward the example of a f inancial transaction to be made in a restaurant environment , a waiter might bring a portable imprinter ( 14 ) to the table wherein the credit card or debit card owner would insert his or her card ( 12 ) into the portable imprinter ( 14 ) and key in the PIN number for imprinting on the card ( 12 ) . The portable imprinter ( 14) would have been preprogrammed with the vendor code which it retrieves from memory at the time the PIN code is entered . The transaction code would then be randomly generated as described above and would be writ ten to the rewritable fields on the card ( 12 ) in conjunction with the PIN code and the retrieved vendor code . The waiter would then take the imprinted "unlocked" card ( 12 ) to a magnetic card reader (16) for carrying out the financ ial transaction in ordinary fashion as is known in the art . Vari ous other environments might utilize other types or structures of the portable imprinter ( 14 ) described above without departing from the spirit of the invention . As indicated above , the magnetic card reader ( 16 ) utilized in the system of the present invention might be just such a reader already utilized in credit card and debit card financ ial transaction environments . Erasure of the codes af ter use is not required since the use of a unique transaction code prevents the repeated use of an "unlocked" card after the first recordal of the transaction . In this fashion, if the vendor ( the waiter, for example) did not properly swipe the card through the magnetic card reader or if for some other reason the card reader did not properly read each of the elements on the card, the vendor would not be required to return the card to the card user for a repeated placement of the PIN code on the card . Finally , in FIG . 1 it is noted that by way of a telecommunications link (42 ) , a connection is made between the magnetic card reader ( 16 ) and the central credit /debit databa.se and processor ( 18) . Here again this connection and the mechanism for communication between card reader ( 16 ) and database/proces sor ( 18 ) are well known in the art . Reference is now made to FIGS . 2 and 3a - 3 c for a brief description of the method steps of the present invention. FIG . 2 represents the process of issuing a card and associated PIN code . In step (40 ) a card is issued with a specific account nurcύoer imprinted thereon . At step (42 ) a PIN code is issued, general ly apart from the issuance of the card . This is according to standard practice with bank debit cards and the like . At step (44 ) a correlation between the PIN code and the account number is stored in the central credit/debit database . Finally, in step (46 ) , the card user receives val idation not i ce for the new card/account . FIG . 3a discloses the primary steps associated with carrying out a financial transaction according to the method of the present invention . At step (50 ) a credit/debit card according to the descriptions above is provided. Likewise, at step (52) , a portable magnetic imprinter according to the system described above is also provided. At step (54) the card user inserts the card into the imprinter provided to him or her by the retail establishment. The portable magnetic imprinter then prompts the user to enter the PIN code at step (56) . The user enters the PIN code at step (58) , followed by the portable magnetic imprinter placing the PIN code onto the card at step (60) . Keyed by the input of the PIN code, the portable magnetic imprinter automatically places the vendor code onto the card at step (62) . Referencing FIG. 3b for a continuation of the method described above, the portable magnetic imprinter places a randomly generated transaction code onto the card at step (64) . The user then removes the card from the imprinter at step (66) and gives the card to the retail establishment. At step (68) a card reader and data modem are provided to the retail establishment. At step (70) the retail establishment inserts (swipes) the card through the card reader. At step (72) the card reader reads the account number for the transaction. This is followed by steps (74), (76) , and (78) wherein the PIN code, the vendor code, and the transaction code are read. Finally, in FIG. 3c are seen the remaining steps in the method of the invention. In step (80) the card reader makes a modem connection to the central database. Once the connection is established, the card reader transmits at step (82) the account number, the PIN code, the vendor code, and the transaction code. At step (84) the central processor/database confirms the correlation between the PIN code and the account number. Thereafter, at step (86) the central processor/database confirms the validity of the vendor code and the uniqueness of the transaction code. Finally, at step (88) , the central database/processor confirms that a transaction may be carried out or alternately rejects the transaction if any of the above indicated codes are invalid. In general , it should be noted that the system and method of the present invention permit the credit/debit card user to carry out financial transactions over the telephone and through Internet connections in a manner similar to current methods for such transactions . With telephone orders the card holding customer may choose to transmit the account number by voice to the individual taking the order over the phone. In the preferred method of the present invention, the card user will be required to enter the PIN code directly into his or her telephone keypad rather than by voice. In doing so, the PIN code entry will go directly into a dual tone multi-frequency (DT F) data translator within the retail business 's ordering system. This method of entering data is well known in the art as are various devices appropriate for receiving and translating such data. The PIN code entry would not be visually displayed to the person taking the card holder's order over the phone but would be accepted into the ordering system and would thereafter be matched with the account number for verification. Likewise, entry of a vendor code and a transaction code would occur at the retail business ' s processing system in the manner described above . Internet transactions would be carried out in a similar fashion. Entry of the card holder's account number over the Internet would be followed by entry of the PIN code, again in a manner that would prevent its display at either the local or remote site. Likewise, vendor codes and transaction codes would be retrieved and tagged to the transaction as is described above . Variations in both the system and the method of the present invention will be anticipated by those skilled in the art. As one objective of the present invention is to permit implementation in conjunction with existing credit card and debit card reading devices, it is understood that a number of different such devices are possible. In addition, slight departures from the method steps of the present invention are anticipated to accommodate additional data that a particular credit or debit card service might require. Likewise, some credit or debit card services may not require each of the bits of data identified above in the preferred embodiment .

Claims

CLAIMS I Claim: 1. A system for carrying out a credit or debit financial transaction, the system comprising: a credit/debit card having a plurality of memory fields, said memory fields comprising at least one write protected memory field and at least one rewritable memory field ; a portable card imprinter for writing data to said credit/debit card; a card reader for reading data from said card; and a central system database/processor for receiving data rom said card reader.

2. The system of Claim 1 wherein said memory fields of said credit/debit card each comprise areas of magnetizable material exposed on a surface of said card.

3. The system of Claim 1 wherein said portable card imprinter comprises : a card receiver for receiving said credit/debit card and accessing said plurality of memory fields; an input panel for inputting a PIN code into said portable card imprinter; and a imprinting head positioned in said card receiver for imprinting said PIN code and other data into said plurality of memory fields on said credit/debit card.

4. The system of Claim 1 wherein said card reader comprises: a card receiver for receiving said credit/debit card and accessing said plurality of memory fields; a read head positioned in said card receiver for reading said data from said card; and a data communications link to said central system database/processor.

5. The system of Claim 1 wherein said central system database/processor is a remote device and comprises: a data storage device for maintaining records of valid codes and previous financial transactions; a digital processor for storing and retrieving data in said data storage device and for comparing and validat ing codes used in a f inancial transaction; a communications port for receiving and transmitting data to and from said remote card reader .

6 . The system of Claim 3 wherein said input panel of said portable card imprinter comprises a numeric keypad .

7 . The system of Claim 3 wherein said portable card imprinter further comprises an alphanumeric display for prompting said user for input and providing informational data to said user prior to said input .

8 . A method for carrying out a credit or debit financ ial transaction, the method comprising the steps of : providing a credit/debit card having a plurality of memory fields , said memory fields comprising at least one write protected memory field and at least one rewritable memory field; providing a portable card imprinter for writing data to said credit /debit card ; inserting said credit/debit card into said portable card imprinter; inputting a PIN code into said portable card imprint er , thereby causing said portable card imprinter to pl ace said PIN code , a vendor code , and a unique transact ion code into said plurality of rewritable memory fields on said card; reading said PIN code , said vendor code , said transact ion code , and an account code from said card with a card reader device ; transmitting said codes to a central sys tem database/processor for validation and recordal ; validating said PIN code with said account number ; validating said vendor code with a system registration; verifying a uniqueness of said transaction code ; and on said validation and verif ication, recording a financ ial transaction and transmitting to said card reader a val id transaction indication.

9 . The method of Claim 8 wherein said step of inputting a PIN code comprises entering a sequence of numerical digits on a numeric keypad on said portable card imprinter .

10 . The method of Claim 8 wherein said step of inputting a PIN code further comprises retrieving a vendor code stored in a memory device in said portable card imprinter and generating a random numeric sequence of digits to comprise said unique transact ion code .

11 . The method of Claim 10 wherein step of placing said PIN code , said vendor code , and said transaction code on said card compri ses writing digital magnetic data into said memory fields on said card.

12. The method of Claim 8 wherein said step of validating said PIN code comprises comparing said input PIN code with a PIN code stored in said central system database/processor in association with said account number and returning a valid indication to said card reader upon finding a valid match.

13. The method of Claim 8 wherein said step of validating said vendor code comprises comparing said input vendor code with a plurality of valid vendor codes stored in said central system database/processor and returning a valid indication to said card reader upon finding a valid match.

14. The method of Claim 8 wherein said step of verifying a uniqueness of said transaction code comprises comparing said input transaction code with a plurality of previous transaction codes stored in said central system database/processor in association with said account number.

15 . A method for carrying out a credit or debit financial transaction , the method comprising the steps of : providing a credit/debit card having a plurality of magnetic memory f ields , said memory fields compris ing at least one write protected memory f ield and at least three rewritable memory f ields ; providing a portable card imprinter for writing data to said credit/debit card, said card having a numeric keypad , an alphanumeric display, and a magnetic write head; inserting said credit/debit card into said portable card imprinter so as to align said rewritable memory f ields with said magnetic write head; inputting a PIN code into said key pad of said portable card imprinter, thereby causing said portable card imprinter to retrieve a stored vendor code and generate a random number transaction code and to thereafter place said PIN code , said vendor code , and said transaction code into said plurality of rewritable memory f ields on said card ; transporting said card to a remote card reader device ; reading said PIN code , said vendor code , said transact ion code from sid rewritable memory f ields , and an account code from said write protected memory f ield on said card with said card reader device ; establishing a communications link between said card reader device and a central system database/processor; transmitting said codes to said central sys tem database/processor for val idation and recordal ; validating said PIN code with said account number ; validating said vendor code with a system registrat ion database ; verifying a uniqueness of said transaction code; and on said validation and verification, recording a financial transaction and transmitting to said card reader a valid transaction indication.