JP2006048135A - Card deciding device, program and card deciding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discover a prepaid card in which stored fixed data are illegal. <P>SOLUTION: Numerical data for an arithmetic operation stored in a prepaid card and arithmetic result value data to be calculated by an arithmetic operation for applying the numerical data for arithmetic operation to a specific formula are acquired (a step S4), and an arithmetic operation is executed by applying the acquired numerical data for arithmetic operation data to the specific formula (a step S7), and the arithmetic result value data calculated by the arithmetic operation are compared with the arithmetic result value data acquired from the prepaid card, and when those data are not matched, it is decided that the prepaid card is an illegal card (a step S8). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a card determination device, a program, and a card determination method.

  Today, as an alternative to cash settlement, electronic settlement using electronic money stored in a prepaid card and having a monetary value equivalent to cash is widespread. With the spread of such electronic money payments, the damage caused by unauthorized payments by unauthorized prepaid cards has also become a problem.

  As the illegal prepaid card, there is a so-called dead copy card in which a regular prepaid card is copied as it is. Measures against such a dead copy card are performed as follows. For example, at the headquarters of a store chain having a plurality of stores, a large number of dead copy cards are available at the same time, and a plurality of prepaid cards having the same identification data such as serial numbers that are fixed data are used at the same time. Recognizing the abnormality, the prepaid card is determined to be an unauthorized card. Then, the prepaid card identification data is registered in an unauthorized card file, and the unauthorized card file is distributed to a merchandise sales data processing apparatus such as a POS terminal at each store. When a prepaid card is used, a so-called negative check is performed to determine whether the prepaid card to be used is registered in the fraudulent card file. To do.

JP 2000-242839 A

  In recent years, however, fraudulent cards that have been counterfeited with different pieces of identification data such as serial numbers, which are fixed data, differing from one fraud card to another have come out. Even if a large number of fraudulent cards with different identification data are used at the same time, it is difficult to notice that they are fraudulent cards because the identification data is different, and it is difficult to register them in the fraudulent card file. Therefore, such a fraudulent card can be used through a negative check, and the damage caused by fraudulent settlement is increased.

  Patent Document 1 discloses a technique for preventing the use of a fraudulent card in which the balance of electronic money has been fraudulently increased. However, a solution for a fraudulent card in which identification data that is fixed data as described above is manipulated is disclosed. Is not listed.

  An object of the present invention is to be able to find a prepaid card whose stored fixed data is invalid.

  The card determination apparatus of the present invention acquires first calculation numerical data that is fixed data stored in a prepaid card and calculation result value data obtained by calculation that applies the calculation numerical data to a prescribed mathematical expression. An obtaining means; a computing means for performing computation by applying the computation numerical data obtained by the first obtaining means to the prescribed mathematical formula; computation result value data of computation executed by the computing means; A first determination unit that compares the calculation result value data acquired by the first acquisition unit and determines that the prepaid card is an unauthorized card if they do not match.

  The program of the present invention is readable by a computer, and is numerical data for calculation which is fixed data stored in a prepaid card, and calculation result value data obtained by a calculation in which the numerical data for calculation is applied to a prescribed mathematical expression. A first acquisition function for acquiring the calculation, a calculation function for executing the calculation by applying the numerical data for calculation acquired by the first acquisition function to the specified mathematical formula, and a calculation executed by the calculation function A first determination function that compares the operation result value data with the operation result value data acquired by the first acquisition function, and determines that the prepaid card is an unauthorized card if they do not match; Is executed by the computer.

  The card determination method according to the present invention is a first method for acquiring numerical value data for calculation, which is fixed data stored in a prepaid card, and calculation result value data obtained by an operation in which the numerical value for calculation is applied to a prescribed mathematical expression. An acquisition step, an operation step for performing the operation by applying the numerical value data for operation acquired in the first acquisition step to the specified mathematical formula, an operation result value data of the operation executed in the operation step, and the A first determination step of comparing the calculation result value data acquired in the first acquisition step and determining that the prepaid card is an unauthorized card if they do not match.

  According to the present invention, a prepaid card whose stored fixed data is invalid can be found.

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view schematically showing a POS terminal 1 and a card reader / writer 2 which are card determination devices of the present embodiment. As shown in FIG. 1, the POS terminal 1 is disposed at a checkout location of a store and performs product sales data processing, and is placed on a drawer 12. A keyboard 13 and a receipt issuing port 11 a are provided on the upper surface side of the main body 11 of the POS terminal 1. On the back side of the main body 11, a cashier indicator 14 and a customer indicator 15 are provided. The POS terminal 1 is connected to a barcode scanner 16 and a card reader / writer 2 for optically reading a product code.

  The keyboard 13 is provided with a numeric key, a closing key, various settlement keys and the like for inputting an amount, a sales quantity, and the like. As a settlement key, an electronic money key for declaring settlement by electronic money stored in the prepaid card C, a cash key as a settlement key for declaring settlement by cash, a credit key for declaring settlement by credit Etc. are provided.

  FIG. 2 is a block diagram showing the electrical system of the POS terminal 1. As shown in FIG. 2, the POS terminal 1 includes a CPU (Central Processing Unit) that centrally controls each unit, a ROM (Read Only Memory) that stores fixed data such as a computer program in advance, and various data that can be rewritten. It has a POS control unit 17 composed of a RAM (Random Access Memory) or the like for storing. A communication interface 20 is connected to the POS control unit 17 via a bus 19. The communication interface 20 is connected to the card reader / writer 2 and a host device (not shown), thereby enabling communication between the POS terminal 1 and the card reader / writer 2 and the host device.

  The POS control unit 17 includes a printer 22 and a hard disk drive device serving as a storage unit together with the keyboard 13, the display units 14 and 15, and the barcode scanner 16 via the bus 19 and the I / O device control unit 21. (HDD) 18 is connected. The printer 22 is a receipt / journal printer built in the main body 11 of the POS terminal 1, and issues receipts from the receipt issuing port 11a in transaction units in accordance with merchandise sales data processing, and simultaneously prints on journal paper. Etc.

  The hard disk drive (HDD) 18 stores a product program master file F1, a POS sales file F2, a prepaid negative table T1, etc., in addition to a computer program that operates the CPU of the POS control unit 17. The product master file F1 stores product names and unit prices in association with product codes. The POS sales file F2 stores sales data in the POS terminal 1.

  FIG. 3 is an explanatory view schematically showing the prepaid negative table T1. The prepaid negative table T1 stores illegal card specifying data for specifying an illegal card which is an illegal prepaid card C. The illegal card specifying data includes a card issuer ID for specifying the issuer of the prepaid card C, a ticket type code for specifying the amount of electronic money when the prepaid card C is issued, an issue classification of the prepaid card C, a prepaid The card C issuance date, the issuing store number for specifying the store where the prepaid card C is issued, the card number (serial number) which is unique identification data set for each prepaid card C, and the like. As shown in FIG. 4, the prepaid negative table T1 stores, for each check number, a card issuer ID area 23a for storing a card issuer ID, a ticket type code area 23b for storing a ticket type code, and an issue classification. Issue classification area 23c, issue date area 23d for storing the issue date, issue store number area 23e for storing the issue store number, start card number area 23f for storing the first card number in the range of card numbers, card number An end card number area 23g for storing the last card number in the range is provided.

  The computer program stored in the hard disk drive (HDD) 18 is written into the RAM of the POS control unit 17 together with the product master file F1 and the like when the POS terminal 1 is started. It becomes possible.

  As shown in FIG. 1, a housing 31 of the card reader / writer 2 has a keyboard 32 configured by collecting various keys, a display 33 for displaying various information, and a reader / writer described later built in the housing 31. A card insertion slot 35 that allows the prepaid card C to be inserted into and removed from the unit 34 is provided.

  FIG. 4 is a block diagram showing an electrical system of the card reader / writer 2. As shown in FIG. 4, the card reader / writer 2 is a CPU (Central Processing Unit) that centrally controls each unit, a ROM (Read Only Memory) that stores fixed data such as computer programs in advance, and various data can be rewritten. The reader / writer control unit 41 is configured by a RAM (Random Access Memory) or the like stored in the memory. A communication interface 42 that manages communication with the POS terminal 1 is connected to the reader / writer control unit 41 via a bus 43. A reader / writer unit 34 is connected to the reader / writer control unit 41 through the bus 43 and the I / O device control unit 44 together with the keyboard 32 and the display device 33 described above. The reader / writer unit 34 reads and writes electronic money and various data stored in the prepaid card C, which is a magnetic card.

  Here, the prepaid card C from / to which data is read / written by the card reader / writer 2 will be described. The prepaid card C is a magnetic card and stores card data in a magnetic storage unit (not shown). The card data includes variable data with variable data and fixed data with fixed data. The variable data includes electronic money. Electronic money is money amount data having a value equivalent to money, and when used, the money is subtracted and the balance is reduced. The fixed data includes the card issuer ID, the ticket type code, the issue classification, the issue date, the issue store number, the card number, etc., and these fixed data are numerical data. The card issuer ID, ticket type code, issue classification, issue date, issue store number, and card number are identification data for identifying the prepaid card C.

  Further, the prepaid card C stores calculation result value data which is fixed data. The calculation result value data will be described. First, one or a plurality of fixed data among the fixed data (card issuer ID, ticket type code, issue classification, issue date, issue store number, card number) of the prepaid card C described above is previously calculated as numerical data for calculation. Is set. In addition, it is desirable that the numerical data for calculation is plural. And the result calculated | required by the calculation which applied this numerical value data for calculation to a prescription | regulation numerical formula is calculation result value data, and this calculation result value data is also fixed data. The arithmetic numerical data may be used as it is, or a part of it may be used. The term “partial” refers to, for example, a case where a numerical value of a specific digit is used. The prescribed mathematical formula may be anything as long as it can obtain a numerical result by using the computation result value data. For example, an example using a hash function can be exemplified as an example of a prescribed mathematical expression. The prepaid card C is not limited to a magnetic card, and may be, for example, an IC prepaid card. In this case, a card reader / writer 2 that can read from and write to the IC prepaid card may be used.

  FIG. 5 is a flowchart showing the flow of merchandise sales data processing executed by the POS control unit 17 of the POS terminal 1 according to the computer program.

  In the merchandise sales data processing, first, it waits for the reading of the merchandise code with the barcode scanner 16 for the sales merchandise, the input of the merchandise code with the numeric keys of the keyboard 13, and the input of the sales quantity with the numeric keys of the keyboard 13 ( Step S1).

  If it is determined that there is an input of reading of a product code as product information by the barcode scanner 16 and an input of the number of sales by key input of the keyboard 13 (Y in step S1), sales processing is executed (step S2). In this sales process, sales data based on the product name and unit price obtained by searching the product master file F1 based on the input product code is stored in the RAM of the POS control unit 17, and the transaction such as the unit price is stored. The information is displayed on the display units 14 and 15. In addition, the total sales amount based on the sales data so far is calculated, stored in the RAM of the POS control unit 17 and displayed on the display units 14 and 15.

  The processes in steps S1 and S2 are performed until a payment method is selected, specifically, until it is determined that the electronic money key of the keyboard 13 is operated and electronic money is declared (Y in step S3), or The process is repeated until it is determined that a payment key other than the electronic money key such as a cash key or a credit key is operated and a payment other than the electronic money such as cash is declared (Y in step S15).

  If the electronic money key is not pressed (N in step S3) and a payment key other than the electronic money key such as a cash key or a credit key is pressed (Y in step S15), the electronic money key is set according to the pressed payment key. Payment processing other than electronic money payment such as cash payment processing and credit payment processing is executed (step S16).

  On the other hand, when the electronic money key is pressed (Y in step S3), card data is acquired from the prepaid card C using the card reader / writer 2 (step S4: first and second acquisition means, first And second acquisition function, first and second acquisition steps). Specifically, a card data request message is transmitted to the card reader / writer 2. The card reader / writer 2 that has received this card data request message allows the prepaid card C to be inserted from the card insertion slot 35 and waits until the prepaid card C is inserted. If the prepaid card C is inserted from the card insertion slot 35 by the cashier, the card data stored in the prepaid card C is read by the operation of the reader / writer unit 34, and the read card data is transmitted to the POS terminal 1. . The POS terminal that has received the card data from the card reader / writer 2 stores the card data in the RAM of the POS control unit 17.

Next, the POS control unit 17 first performs a negative check as a process for determining the authenticity of the prepaid card C read by the card reader / writer 2 (step S5: second determination means, second determination means). Determination function, second determination step). The negative check is performed by the following three checks using the identification data among the card data of the prepaid card C stored in the RAM of the POS control unit 17.
(1) Among the identification data of the prepaid card C, the card issuer ID, the ticket type code, and the issue classification are handled as a set of check data, and it is checked whether or not this check data is registered in the prepaid negative table T1. That is, in the prepaid negative table T1, it is checked whether or not there is a check number in which the same prepaid card C and card issuer ID, ticket type code and issue classification are all registered. If the same check data is registered in the prepaid negative table T1, it is determined that the prepaid card C is an unauthorized card.
(2) Among the identification data of the prepaid card C, the card issuer ID, the ticket type code, the issue classification, the issue date and the issue store number are treated as a set of check data, and this check data is registered in the prepaid negative table T1. Find out if it is. That is, in the prepaid negative table T1, it is checked whether or not there is a check number in which the same prepaid card C and card issuer ID, ticket type code, issue classification, issue date, and issue store number are registered. . When the check data is registered in the prepaid negative table T1, it is determined that the prepaid card C is an unauthorized card.
(3) It is checked whether or not the card number among the identification data stored in the prepaid card C is registered in the prepaid negative table T1. When the check data is registered in the prepaid negative table T1, it is determined that the prepaid card C is an unauthorized card.

  If it is determined that the card is an illegal card in the above three checks (Y in step S6), the process proceeds to step S12 and error processing is executed. This error processing will be described later.

  On the other hand, if it is not determined in step S5 that the card is an unauthorized card (N in step S6), the calculation numerical data stored in the prepaid card C is used as a further process for determining the authenticity of the prepaid card C. Perform the operation check used. First, calculation result data is obtained by applying the above-described numerical value data for calculation to the prescribed mathematical expression among the card data of the prepaid card C stored in the RAM of the POS control unit 17 (step S7: calculation means) , Calculation function, calculation step). The calculation result value data thus obtained is compared with the calculation result value data included in the card data of the prepaid card C stored in the RAM of the POS control unit 17, and the prepaid card C is an unauthorized card. (Step S8: first determination means, first determination function, first determination step). If the fixed data (calculation numerical data, calculation result value data) stored in the prepaid card C is not falsified or the like and is normal, the calculation result value data matches. Therefore, when those calculation result value data match, it is not determined that the card is an unauthorized card. In this case, the prepaid card C is determined to be a legitimate card because it was not determined to be an unauthorized card in the negative check and the calculation check. On the other hand, when the calculation result value data do not match, it means that the fixed data (calculation numerical data, calculation result value data) stored in the prepaid card C is illegal because of manipulation such as falsification. . Therefore, when the calculation result numerical values do not match, it is determined that the prepaid card C is an unauthorized card.

  If it is determined that the prepaid card C is a legitimate card (N in step S8), the payment for the total sales amount, which is the payment target amount by electronic money of the prepaid card C, is accepted, and the following payment processing is performed. Execute. First, it is determined whether or not the balance of the electronic money of the prepaid card C stored in the RAM of the POS control unit 17 is equal to or greater than the total sales amount (step S9). When it is determined that the remaining amount of electronic money is equal to or greater than the total sales amount (Y in step S9), the total sales amount is subtracted from the remaining amount of electronic money stored in the prepaid card C stored in the RAM of the POS control unit 17. The renewal balance is calculated, and this renewal balance is written in the prepaid card C as a balance of electronic money using the card reader / writer 2 (step S10). Specifically, a balance update message having an updated balance is transmitted to the card reader / writer 2. The card reader / writer 2 that has received the balance update message updates the electronic money balance of the prepaid card C to the received update balance.

  Then, a tightening process is executed (step S11). In the closing process, the sales data stored in the RAM of the POS control unit 17 is stored in the POS sales file F2, and a receipt in which predetermined contents of the sales data are printed by the printer 22 is issued from the receipt issuing port 11a. Further, journal data composed of the total sales amount and the like is stored in the RAM of the POS control unit 17, and journal data relating to one transaction is created. When one transaction ends in this way, the journal data stored in the RAM of the POS control unit 17 is recorded on the journal paper using the printer 22. Note that the timing of executing the tightening process may be when waiting for the tightening key to be pressed between Step S10 and Step S11 and determining that the tightening key has been pressed.

  If it is determined in step S9 that the remaining amount of electronic money in the prepaid card C is not equal to or greater than the total sales amount (N in step S9), the prepaid card C stored in the RAM of the POS control unit 17 from the total sales amount. The remaining amount is subtracted to calculate the deficit amount, this deficit amount is written to the RAM of the POS control unit 17, and the remaining amount of 0 yen is written to the prepaid card C as the remaining amount of electronic money using the card reader / writer 2 (step S13). . Since this writing method is the same as step S10, the description thereof is omitted. Then, the shortage is displayed on the display units 14 and 15 (step S14). Thereafter, the process returns to step S3 and waits again until the settlement key is operated and a settlement method is selected (Y in step S3, Y in step S15). And the process after step S3 is repeated until the shortage is satisfied. Here, a payment means, a payment function, and a payment step are executed by steps S9, S10, and S13.

  If it is determined in step S5 or step S8 that the prepaid card C is a fraudulent card (Y in step S6 or Y in step S8), payment for the total sales amount by electronic money of the prepaid card C is not permitted. . That is, the process does not proceed to step S9. In step S12, error processing is executed. Thereby, the payment process by the prepaid card C after step S9 is not performed. In step S12, the following processing is performed. First, the balance of the electronic money of the prepaid card C is rewritten to “0” using the card reader / writer 2 to disable the use of the prepaid card C (impossible processing means, disabling processing function, disabling processing step). Specifically, a rewrite message for rewriting the balance of the prepaid card C to “0” yen is transmitted to the card reader / writer 2. The card reader / writer 2 that has received this rewrite message rewrites the balance of the electronic money of the prepaid card C to “0” yen, and then ejects the prepaid card C from the card insertion slot 35. Further, the POS control unit 17 displays on the display 14 that the prepaid card C is an unauthorized card, and the prepaid card C having the card number and the prepaid card C having the card number is an unauthorized card. Is recorded on journal paper using the printer 22. Further, the communication interface 20 is used to send a message to the host device that the card number of the prepaid card C and that the prepaid card C having this card number is an unauthorized card. Then, the process returns to step S3 and waits until the settlement method is selected again.

  As described above, in the present embodiment, the numerical value data for calculation stored in the prepaid card C and the calculation result value data obtained by the calculation in which the numerical value data for calculation is applied to a prescribed mathematical expression are stored from the prepaid card C. When the obtained numerical value data for calculation is applied to a specified mathematical formula, the calculation is executed, the calculation result value data obtained by this calculation is compared with the calculation result value data acquired from the prepaid card C, and they do not match. Determines that the prepaid card is an unauthorized card. As a result, the operation numerical value data and the operation result value data, which are fixed data stored in the prepaid card C, are manipulated to become invalid data, and the operation result value data obtained by the operation and the prepaid card C are stored. When the calculated result value data does not match, it is determined that the prepaid card C is an unauthorized card, so the stored numerical data for calculation and the calculated result value data are incorrect. Unauthorized prepaid cards can be found.

  In the present embodiment, payment for the payment target amount is executed by the electronic money stored in the prepaid card C. If the prepaid card C is an unauthorized card, the payment by the payment means is not permitted. Damage due to an illegal prepaid card C can be prevented.

  Further, in this embodiment, when the prepaid card C is an unauthorized card, the balance of the electronic money of the prepaid card C is set to “0” yen to disable the use of the prepaid card C. It is possible to prevent card damage from occurring at other stores.

  Further, in the present embodiment, identification data for identifying the prepaid card C, which is fixed data stored in the prepaid card C, is acquired, and the acquired identification data and a hard disk drive (HDD) 18 that is a storage unit are acquired. A pre-registered fraud card can be found by determining whether the prepaid card is a fraud card based on the fraud card identification data for identifying the fraud card stored in the prepaid negative table T1. It is possible to further prevent damage caused by an illegal prepaid card C.

  Further, in the present embodiment, since there are a plurality of arithmetic numerical data applied to the prescribed mathematical expression, the numerical value of the prepaid card C can be compared with the case where there is only one arithmetic numerical data applied to the prescribed mathematical expression. Since the fixed data to be checked increases among the fixed data, the prepaid card C in which the fixed data is invalid can be found more reliably.

  In the present embodiment, the various programs are stored in the hard disk drive (HDD) 18, but the present invention is not limited to this, and a magnetic storage medium such as a flexible disk or a magnetic tape, an MO Optical storage media such as CD, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-R, DVD-RAM, DVD-RW, DVD + RW, etc., Various types of media such as a semiconductor memory may be used as the storage medium. Various optical storage media such as CD-ROM and DVD-ROM, various magneto-optical storage media, and various magnetic storage media such as a flexible disk are fixedly provided on the POS terminal 1. However, it is possible to perform various processes by reading the program using various program reading devices (CD-ROM drive or the like) adapted to each medium.

1 is an external perspective view schematically showing a POS terminal and a card reader / writer according to an embodiment of the present invention. It is a block diagram which shows the electrical equipment type | system | group of a POS terminal. It is explanatory drawing which shows a prepaid negative table typically. It is a block diagram which shows the electrical equipment system of a card reader / writer. It is a flowchart which shows the flow of a merchandise sales data process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Card determination apparatus, 18 ... Memory | storage part, C ... Prepaid card

Claims (15)

First acquisition means for acquiring numerical value data for calculation, which is fixed data stored in a prepaid card, and calculation result value data obtained by an operation in which the numerical value data for calculation is applied to a specified mathematical formula;
A computing means for performing computation by applying the numerical data for computation obtained by the first obtaining means to the prescribed mathematical formula;
The calculation result value data of the calculation executed by the calculation means is compared with the calculation result value data acquired by the first acquisition means, and if they do not match, the prepaid card is an illegal card First determining means for determining;
A card determination device comprising: Payment means for executing a payment for a payment target amount by electronic money stored in the prepaid card,
The card determination apparatus according to claim 1, wherein when the prepaid card is an unauthorized card, payment by the payment means is not permitted.   The card determination apparatus according to claim 1, further comprising an ineffective processing unit that disables the use of the prepaid card when the prepaid card is an unauthorized card. Second acquisition means for acquiring identification data that is fixed data stored in the prepaid card and for identifying the prepaid card;
A second determining unit that determines whether the prepaid card is a fraudulent card based on the identification data obtained by the second obtaining unit and the fraudulent card specifying data stored in the storage unit; A determination means;
The card determination device according to claim 1, further comprising:   5. The card determination device according to claim 1, wherein there are a plurality of the numerical data for calculation applied to the prescribed mathematical expression. A computer-readable program,
A first acquisition function for acquiring numerical value data for calculation, which is fixed data stored in a prepaid card, and calculation result value data calculated by applying the numerical value data for calculation to a specified mathematical formula;
A calculation function for performing calculation by applying the numerical data for calculation acquired by the first acquisition function to the prescribed mathematical formula;
The calculation result value data of the calculation executed by this calculation function is compared with the calculation result value data acquired by the first acquisition function, and if they do not match, the prepaid card is an illegal card A first determination function for determining;
A program for causing the computer to execute. Causing the computer to execute a payment function for executing payment for a payment target amount using electronic money stored in the prepaid card;
The program according to claim 6, wherein when the prepaid card is an unauthorized card, payment by the payment function is not permitted.   8. The program according to claim 6, wherein when the prepaid card is an illegal card, the computer executes an incapability processing function that disables the use of the prepaid card. A second acquisition function for acquiring identification data for identifying the prepaid card that is fixed data stored in the prepaid card;
A second determining unit that determines whether the prepaid card is a fraudulent card based on the identification data obtained by the second obtaining function and the fraudulent card specifying data stored in the storage unit; Judgment function,
The program according to claim 6, wherein the program is executed by the computer.   The program according to any one of claims 6 to 9, wherein there are a plurality of the numerical data for calculation applied to the prescribed mathematical formula. A first acquisition step of acquiring numerical value data for calculation, which is fixed data stored in a prepaid card, and calculation result value data obtained by calculating the numerical value data for calculation applied to a prescribed mathematical formula;
A calculation step of performing the calculation by applying the numerical data for calculation acquired in the first acquisition step to the prescribed mathematical formula;
The calculation result value data of the calculation executed in this calculation step is compared with the calculation result value data acquired in the first acquisition step. If they do not match, the prepaid card is an illegal card. A first determination step for determining;
Card determination method including A settlement step of performing settlement for a settlement target amount by electronic money stored in the prepaid card,
The card determination method according to claim 11, wherein when the prepaid card is an unauthorized card, payment by the payment step is not permitted.   13. The card determination method according to claim 11 or 12, further comprising a disabling process step of disabling use of the prepaid card when the prepaid card is an unauthorized card. A second acquisition step of acquiring identification data for identifying the prepaid card that is fixed data stored in the prepaid card;
A second determination is made as to whether or not the prepaid card is an unauthorized card based on the identification data acquired in the second acquiring step and the unauthorized card specifying data for specifying the unauthorized card stored in the storage unit. A determination step;
14. The card determination method according to claim 11, further comprising: The card determination method according to claim 11, wherein there are a plurality of the numerical value data for calculation applied to the prescribed mathematical expression.

Images