IC CARD SYSTEM

Abstract: Application program data is sent with decryption key code data from an initializing IC card to an application program RAM (15) arranged in an IC card terminal (1). The terminal (1) is then initialized, and customer IC card reception preparation is completed.

Description: The present invention relates to an IC card system with an IC card terminal. When cash handling equipment such as an electronic cash register is used, a mechanical key lock mechanism is arranged to prevent a third party other than an authorized operator from using the equipment. In other words, electronic cash register will not operate unless the authorized operator releases the key lock using a master key, thus preventing illegal use of the register. A conventional key lock system of this type can also be applied to an IC card terminal which is used with an IC card. The conventional key lock system, however, has the following drawbacks: 1. Since the key lock mechanism is a mechanical one, the key can be easily copied. 2. A key lock mechanism must be arranged independently of the mechanism inherent in the system, and thus the overall system becomes expensive. 3. Since the key must be held in a corresponding key slot to continuously release the key lock state while the system is being operated, the key may be stolen. In addition, the number of keys needed is the same as that of the IC card terminals. FR-A-2526977 discloses an IC card system comprising a transaction apparatus and two kinds of cards C and C1. Card C1 stores a program for initializing the system, whereas card C has the function of a customer card. This system does not check the validity of the owner of card C1, when this card is connected to the transaction apparatus. From International Conference on Secure Communication Systems, 22-23 February 1984, pages 1-4, there is known an IC card system including a shop-keeper IC card and customer IC card. EP-A-0049650 discloses a system for distribution of articles including two data carriers each of the data carriers stores a secret code and an ID code, and calculates a resultant a from data (random code) sent from a main body of the system. Then, the resultant is transmitted to the main body, which judge whether the resultant is valid. In an IC card system, countermeasures against illegal use must be provided in the same way as for the electronic cash register. However, an effective countermeasure has not, so far, been realized. It is an object of the present invention to provide an IC card system with an IC card terminal, which prevents a third party other than an authorized operator from making illegal use thereof and which is operated with security. According to the present invention, there is provided an IC card system comprising an IC card terminal, an initializing means for supplying data defining an operation of the IC card terminal, and a customer IC card used with the IC card terminal, which IC card system is characterized in that the initializing means includes: first memory means for storing administrator identification number data, second memory means for storing decryption key code data, first comparing means for comparing the AIN data in the first memory means with an AIN data entered at said IC card terminal, and means for supplying the decryption key code data from the second memory means to the IC card terminal when the first comparing means detects a coincidence, that the customer IC card includes: memory means for storing predetermined data and encrypted data, and that the IC card terminal includes: decryption means for decrypting the encrypted data of the customer IC card by the decryption key code data supplied from the initializing means, second comparing means for comparing decryption result data by the decryption means with the predetermined data of the customer IC card, and means for performing transaction process using the customer IC card when the second comparing means detects a coincidence. According to the present invention, there is further provided a method of using an IC card terminal with a customer IC card for preventing illegal use, which method comprises the steps of: providing a terminal administrator with an initializing IC card storing decryption key code data; providing a customer with a customer IC card storing predetermined data and encrypted data of the predetermined data; supplying the decryption key code data to the IC card terminal after establishing the terminal administrator's identity; decrypting the encrypted data stored in the customer IC card, by the decryption key code data supplied from the initializing IC card, in the IC card terminal; comparing a decrytion result with the predetermined data stored in the customer IC card; and performing transaction process between the IC card terminal and the customer IC card when the comparison result makes a coincidence. A transaction using a terminal in the IC card system according to the invention is carried out as follows: At first, an administrator couples the initializing means to the terminal and inputs AIN data by means of the keys. The input AIN ist compared with the prestored AIN in the initializing means. When these two data coincide, the decryption key code data stored in the initializing means is transmitted to the terminal. According to this comparison, the authentication of the administrator who has the initializing means can be checked. This is the first step for preventing unauthorized use of the system. Next, when the customer's IC card is inserted in the terminal, the encrypted data stored in the customer's IC card is decrypted by the decryption key code data supplied from the initializing means. Then, the decryption result data is compared with the predetermined data stored in the IC card. According to this comparison, the validity of the customer's card is checked. This is the second step for preventing unauthorized use of the system. Thus, the system of the present invention executes a double check; i.e., it checks the validity of an administrator and the validity of a customer IC card. This results in that high security in using an IC card system is assured. Advantageous embodyments of the invention are defined in the subclaims. This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view showing an overall configuration of an IC card system according to an embodiment of the present invention; Fig. 2A is a block diagram showing a circuit arrangement of a terminal in Fig. 1; Fig. 2B is an address data format of a memory in Fig. 2A; Fig. 3 is a block diagram showing a circuit arrangement of an initialising IC card in Fig. 1; Fig. 4 is a block diagram showing a circuit arrangement of a customer IC card in Fig. 1; and Figs. 5 to 8 are flow charts for explaining the operations of the IC card system in Fig. 1. An IC card system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiment, application program data including system software and decryption code data is statically stored in an initializing memory arranged in an initializing IC card. At the time of system initialization, application program data is loaded in an IC card terminal. A transaction can then be performed using the customer IC card with the IC card terminal. Fig. 1 is a perspective view showing an overall configuration of an IC card system according to an embodiment of the present invention. Referring to Fig. 1, IC card terminal 1 is divided into terminal body 2 and key input section 3. Body 2 is electrically connected to section 3 through cable 4. Keyboard 5 and display section 6 are arranged in section 3. Body 2 has IC card insertion slot 7. Initializing IC card 8 and customer IC card 9 are selectively inserted in slot 7. Fig. 1 shows a state wherein card 8 is inserted in slot 7. Caution lamps A, B and C for indicating abnormal operations, and normal operation indicator lamp D are arranged on body 2. In this embodiment, assume that terminal 1 is installed in a store and that a customer with IC card 9 makes a credit purchase. Since body 2 is connected to section 3 through cable 4, the customer can input his personal identification number (PIN) without being watched by a store clerk standing near body 2. Connectors 10a and 10b are arranged on the surfaces of cards 8 and 9, respectively. When cards 8 and 9 are selectively inserted in slot 7, connectors 10a and 10b are electrically connected to connectors arranged in body 2, so that they are selectively coupled to an electronic circuit inside body 2. Section 3 also includes an alphanumeric input keyboard for entering transaction data, e.g., a total amount, an item name, the date of purchase, etc. The electrical circuit arrangements of body 2 and cards 8 and 9 will be described with reference to the accompanying drawings. The circuit arrangement of body 2 will be described with reference to Fig. 2A. Referring to Fig. 2A, interface section 11 has connectors which are to be connected to connectors 10a and 10b of cards 8 and 9. Section 11 is connected to system bus 12. Bus 12 is connected to card loading mechanism 13, for conveying card 8 or 9 inserted in slot 7 to a predetermined position in body 2 or for ejecting it from slot 7; main program ROM 14; application program data storage volatile RAM 15; lamp drivers 16a, 16b, 16c and 16d for driving lamps A to D; control circuit 17; registers 18, 19 and 20; keyboard 5 of section 3; and display section 6. Circuit 17 includes ROM 17a, RAM 17b and comparator 17c. These circuits discriminate whether the IC card inserted in slot 7 is card 8 or 9. For example, in ROM 17a is prestored code data representing the type of IC card. The corresponding code data is stored in cards 8 and 9. The code data read out from cards 8 and 9 is temporarily stored in RAM 17b, and is then compared with the data from ROM 17a by comparator 17c. When a coincidence between them is established, circuit 17 determines the type of IC card inserted in slot 7. All the access program for card 9 is loaded from card 8 into RAM 15 of terminal 1. But, a part of the access program may be preset in ROM 14. In this case, the remaining part of the card access program is loaded in RAM 15 from card 8, and circuit 17 performs addressing through ROM 14 and RAM 15. Fig. 2B shows an address data format for addressing ROM 14 and RAM 15 by circuit 17. The ROM section corresponds to ROM 14, and the RAM section corresponds to RAM 15. A primary account number (PAN) and encrypted data PAN' read out from card 9 are stored in registers 18 and 19, respectively. Decryption key code data is read out from card 8 and is stored in register 20. Data PAN' and the decryption key code data, respectively stored in registers 19 and 20, is supplied to decryption block 21. Block 21 decrypts data PAN' in accordance with the decryption key code data to obtain data PAN. The decrypted data PAN is stored in register 22 and is supplied to one input terminal of comparator 23. Data PAN stored in register 18 is supplied to the other input terminal of comparator 23 wherein data PAN from register 22 is compared with data PAN from register 18 by comparator 23. A comparison result is supplied to circuit 17. The connectors arranged in section 11 and mechanism 13 can be constituted by those described in U.S. Patent Application Serial No. 782,518. Fig. 3 shows the circuit arrangement of card 8 of Fig. 1. Interface section 31 has connector 10a. Section 31 is connected to other circuits through system bus 32. Bus 32 is connected to a ROM 33 storing system program data, a control circuit 34 including a CPU, and a register 35. Register 35 stores an administration identification number (AIN) entered at key input section 3. Input data AIN is supplied to one input terminal of comparator 36. Prestored data AIN is supplied from AIN memory 37 to the other input terminal of comparator 36. Memory 37 is constituted by, for example, a PROM such as EPROM or EEPROM. The PROM stores any AIN data entered by an administrator, i.e., an authorized store clerk, for terminal 1. Comparator 36 then compares the content of register 35 with that of memory 37. A comparison result is supplied to circuit 34 and to one input terminal of AND gate 38. Application program data and decryption key code data are prestored in data ROM 39. The application program data is data to be preset in terminal 1 to execute various transaction operations for card 9. The contents of the application program will be described below. The decryption key code data is the code data for decrypting the encrypted data read out from card 9. When a coincidence signal is generated by comparator 36, the data from ROM 39 is supplied to interface section 31 through gate 38 and system bus 32, and to terminal 1 through section 31. The application program is defined as a program for executing customer IC card processing such as a customer's arbitrary PIN registration at the time of issuance of a new customer IC card, re-registration of the registered PIN, a transaction data check operation, a card check operation, and the like. Fig. 4 shows the circuit arrangement of card 9. Referring to Fig. 4, interface section 41 has connector 10b of Fig. 1. Section 41 is connected to an internal electronic circuits in card 9 through system bus 42. Bus 42 is connected to system program ROM 43, control circuit 44 and register 45. Customer PIN entered at keyboard 5 is stored in register 45. This PIN data is supplied to one input terminal of comparator 46. Data PIN from memory 47 is supplied to the other input terminal of comparator 46. Memory 47 comprises, for example, a PROM such as EPROM or EEPROM. Comparator 46 compares the input PIN data from register 45 with the PIN data readout from memory 47. A comparison result is supplied to control circuit 44. PAN memory 48 and data memory 49 are also coupled to bus 42. Memory 48 comprises, for example, a PROM such a EPROM or EEPROM. Memory 48 stores customer account number PAN and data PAN' obtained by encrypting data PAN according to the RSA encryption method. Memory 49 also comprises a PROM such as EPROM or EEPROM. Memory 49 sequentially stores a date (DT) data of purchase and total amount AMT. The operation of the arrangements shown in Figs. 1 to 4 will be described with reference to flow charts of Figs. 5 to 8. When a terminal power switch (not shown) in the terminal in Fig. 1 is turned on, circuit 17 is operated in accordance with the main program stored in ROM 14 in Fig. 2A, and processing shown in the flow chart of Fig. 5 is executed. At the time of power ON, the storage contents of RAM 15 are lost, and terminal 1 thus does not have a processing function for card 9. Circuit 17 determines in step A1 of Fig. 5 whether or not an IC card is inserted in slot 7. If NO in step A1, circuit 17 waits until an IC card is inserted in slot 7. However, if YES in step A1, the flow advances to step A2 and circuit 17 awaits a key input. When data PIN is entered at keyboard 5 of section 3, the input PIN data is transmitted to the IC card in step A3. Circuit 17 then awaits data from the IC card in step A4. When signal data is sent back from the IC card, the flow advances to step A5. Circuit 17 checks in step A5 whether the signal from the IC card is an OK signal. In a store, card 8 is inserted in slot 7 in step B1 of Fig. 6 after a power switch of terminal 1 is turned on. In step B2, the AIN data is entered at section 3. The input AIN data from section 11 is supplied to section 31 of card 8 in step A3 of Fig. 5 and is set in register 35. When the AIN data is sent from terminal 1 to card 8, comparator 36 compares in step B3 of Fig. 6 the data set in register 35 with the AIN data prestored in memory 37 to check whether a coincidence therebetween is established. In other words, comparator 36 checks whether or not the user of card 8 is an authorized user. If YES in step B3, a coincidence signal from comparator 36 enables gate 38. In step B4, the application program data and the decryption key code data are sequentially read out from ROM 39. Both of the data from ROM 39 is supplied to terminal 1 through section 31. When OK data is transmitted from card 8 to terminal 1, the flow advances to step A6 in Fig. 5 to check whether the reception data is data from card 8. If YES in step A6, the flow advances to step A7. The reception data is stored in memory 15. In terminal 1, the application program data from card 8 is stored in RAM 15, and the decryption key code data is set in register 20. Thereafter, as shown in step A8 of Fig. 5 and step B5 of Fig. 6, card 8 is ejected from slot 7, and terminal initialization is completed. When initialization of terminal 1 is completed, processing for card 9 can be performed. If NO in step A5 of Fig. 5, the flow advances to step A9, and caution lamp B is turned on by driver 16b to indicate that the input AIN does not coincide with the prestored AIN. Thereafter, card 8 is returned in step A10, and abnormal processing is completed. As described above, after the application program data is stored in RAM 15, and the decryption key code data is written in register 20, processing for card 9 can be performed. In this state, when the customer inserts his card 9 through slot 7 and enters his own PIN, the PIN comparison is performed and the validity of card 9 is checked as will be described later. If the OK signal cannot be obtained, the flow advances from step A5 to step A9 in Fig. 5. However, if the OK signal is detected, the flow advances to step A11 through step A6. Circuit 17 checks in step A11 whether the application program data is already written in RAM 15. When card 9 is used without setting the application program data in card 8 upon energization of terminal 1, the decision step A11 is determined to be NO. The flow advances to step A12, and driver 16a is driven to turn on lamp A, thereby signalling to the customer that the data is not set in card 8. In step A10, card 9 is ejected from slot 7 and is returned to the customer. However, when circuit 17 determines in step A11 that the application program data and the decryption code data are set in RAM 15, the flow advances from step A11 to step A13. The application program processing is designated, and item purchase processing (application program processing in Fig. 8 to be described later) in step A14 is performed. Thereafter, the flow advances to step A8, and card 9 is returned to the customer. Finally, the flow returns to step A1. When the customer purchases an item, he inserts card 9 in slot 7 of terminal 1 installed in a store and enters his own PIN at section 3, as shown in step C1 of Fig. 7. The input PIN is transmitted from section 11 to card 9 and is set in register 45 through section 41 and bus 42. When the PIN is set in register 45, the flow advances to step C2, and comparator 46 in card 9 compares the input PIN set in register 45 with the prestored PIN read out from memory 47. When a coincidence signal is generated by comparator 46, the OK signal is transmitted from circuit 44 to terminal 1 through section 41. When the OK signal from card 9 is received by terminal 1, terminal 1 checks validity of card 9 in step C3. In order to check the validity, terminal 1 reads out the personal account number PAN from memory 48 of card 9 and encrypted personal account number PAN' in step D1 in Fig. 8. The PAN data and the PAN' data are stored in registers 18 and 19, respectively. The flow advances to step D2. Encrypted personal account number PAN' is supplied from register 19 to block 21. Encrypted PAN' is decrypted in accordance with the decryption key code set in register 20. The decrypted personal account number (PAN) is stored in register 22. In step D3, the decrypted personal account number (PAN) written in register 22 is compared by comparator 23 with the personal account number PAN held in register 18. A comparison result is supplied to circuit 17. Circuit 17 discriminates in step D3 whether the PAN from register 22 coincides with that from register 18. If NO in step D3, the flow advances to step D4. Driver 16c is operated to turn on lamp C, thereby indicating that card 9 is invalid. In step D5, card 9 is returned to the customer, and abnormal processing is thus completed. When the coincidence signal is generated by comparator 23, the flow advances from step D3 to step D6, and driver 16d is driven to turn on OK lamp D. Subsequently, as shown in step D7 of Fig. 8 and step C4 of Fig. 7, application processing is performed. Date DT data of purchase and total amount AMT data are recorded in memory 49 in card 9. At the same time, the registration number of card 9 and the total amount are stored in terminal 1. The contents of memory 49 can be read out and displayed on display section 6, as needed. Thus, processing for card 9 is completed. In the above embodiment, the IC card is exemplified by a credit card. However, the IC card can also be used in other card systems such as a bank card. In the embodiment of Fig. 1, cards 8 and 9 are inserted in the same slot 7. The slot 7, however, can be used for only receive the customer card 9. In this case, the card 8 may be inserted in another slot (not shown) formed on the body 2 of terminal 1. Since, customer card 9 may be formed in accordance with the ISO standard, the slot 7 of Fig. 1 should also be formed in accordance with the ISO standard. The card 8 and the slot for receive the card 8, however, need not be formed in accordance with the ISO. According to the present invention as described above, a terminal initialization IC card is prepared. System software and/or personal identification data are supplied from the IC card to the terminal at the time of initialization of the IC card terminal. In this state, the IC card terminal can communicate with the customer IC card. The initialization IC card and the customer IC card can be operated by the same interface, thus eliminating a special locking mechanism. Furthermore, since the initialization IC card is used only for initialization, only one initialization IC card is required for a plurality of terminals. Since the personal identification data or the like is supplied to the initialization IC card, secrecy and security can be assured even if the terminal is stolen. Since the personal identification data is supplied to the terminal using the initialization IC card, the identification data can be easily added or modified. As is apparent from the above description, illegal use of IC cards and IC card terminals by third parties other than authorized operators can be prevented, thus providing high security.

Claims: An IC card system comprising an IC card terminal (1), an initializing means (8) for supplying data defining an operation of said IC card terminal, and a customer IC card (9) used with said IC card terminal, characterized in that said initializing means (8) includes: first memory means (37) for storing administrator identification number (AIN) data, second memory means (39) for storing decryption key code data, first comparing means (36) for comparing the AIN data in said first memory means with an AIN' data entered at said IC card terminal, and means (38) for supplying the decryption key code data from said second memory means to said IC card terminal when said first comparing means detects a coincidence, said customer IC card (9) includes: third memory means (48) for storing predetermined data and encrypted data, and said IC card terminal (1) includes: decryption means (21) for decrypting the encrypted data of said customer IC card by the decryption key code data supplied from said initialising means, second comparing means (23) for comparing decryption result data by said decryption means with the predetermined data of said customer IC card, and means (17) for performing transaction process using said customer IC card when said second comparing means detects a coincidence. An IC card system according to claim 1, characterized in that said initialising means (8) further includes means (38, 39) for supplying application program data to said IC card terminal. An IC card system according to claim 2, characterized in that said initialising means (8) comprises an initializing IC card. An IC card system according to claim 3, characterized in that said IC card terminal (1) includes means (17) for distinguishing said customer IC card from said initializing IC card. An IC card system according to claim 2, characterized in that said customer IC card (9) further includes: fourth memory means (47) for storing personal identification number (PIN) data, third comparing means (46) for comparing the PIN data in said fourth memory means with a PIN' data entered at said IC card terminal, and means (44) for permitting said IC card terminal to read out the predetermined data and the encrypted data stored in said third memory means. An IC card system according to claim 5, characterized in that the predetermined data in said third memory means is a personal account number (PAN) data, and the encrypted data in said third memory means is data obtained by encrypting PAN data according to the RSA encryption method. A method of using an IC card terminal (1) with a customer IC card (9) for preventing illegal use characterized by comprising the steps of: providing a terminal administrator with an initialising IC card (8) storing decryption key code data; providing a customer with a customer IC card (9) storing predetermined data and encrypted data of the predetermined data; supplying the decryption key code data to the IC card terminal (1) after establishing the terminal administrator's identity; decrypting the encrypted data stored in the customer IC card, by the decryption key code data supplied from the initializing IC card, in the IC card terminal (1); comparing a decryption result with the predetermined data stored in the customer IC card (9); and performing transaction process between the IC card terminal (1) and the customer IC card (9) when the comparison result makes a coincidence. A method according to claim 7, characterized by further comprising the steps of: comparing personal identification number (PIN) data entered from a keyboard on the IC card terminal (1) with PIN data stored in the customer IC card (9); and permitting the IC card terminal (1) to read out the predetermined data and the encrypted data from the customer IC card (9).

Inventors: SHIGENAGA, YOSHIMI DEVELOPMENT DIVISION HAMURA R&D, Shigenaga, Yoshimi Development Division Hamura R&amp;D
Applicants: CASIO COMPUTER COMPANY LIMITED
Application year: 1986
Main classification: G07F7
IPC codes: G06Q40, G07F7, G07G1, G06F1, G06K17