JPS60181892A - Preventing device of illegal access of ic card - Google Patents

Abstract

PURPOSE:To prevent an illegal or erroneous access to a data memory area of an IC card and its illegal use by storing a sign for identifying an IC card in itself, checking the sign by the card itself with that transmitted from an IC card input device before access to the data memory area, and destructing the data stored in the IC card at the time of dissident signs. CONSTITUTION:A code a12 received by an IC card is checked to be coincident with the code which the IC card itself stores, and when they are dissident, the data which a ROM stores are destructed. The sign checking frequency is preset, and when they are coincident within the specific access frequency, access start OK data are transmitted to a side A of an input device. A sign access area consisting of a sign memory area stores a sign to identify the IC card and the sign illegal access frequency. Thus when the sign dissident frequency reaches the specific value at the time of inputting an IC card, storage data in the data memory area are destructed, and by checking codes at the time of access to the important data memory area data safety can be made more complete.

Description

Detailed Description of the Invention (a) Technical Field The present invention relates to an IC card system consisting of an IC card with an IC embedded therein and an IC card input device that accepts the IC card and exchanges data. This invention relates to a device that prevents unauthorized access to an inserted IC card.

(b1 Background of the Invention IC cards with an IC embedded inside them have the potential to become widespread in the future as intelligent cards that have data processing capabilities.
The major difference between the IC card and the conventional MS card (a card with a magnetic stripe surface) is that the IC card itself is equipped with intelligent functions, its storage capacity has increased dramatically, and the stored data cannot be accessed from the outside. It simply becomes inaccessible. However, if it is possible to know the transmission protocol and the access steps required for an IC card by some method, access to the data storage area of the IC card becomes extremely easy.

(C1 Purpose of the Invention The purpose of this invention is to prevent unauthorized or erroneous access to the data storage area of an IC cart by using the data processing ability of the IC card itself, An object of the present invention is to provide an IC card unauthorized access prevention device that can prevent the IC card from being used illegally even if the protocol etc. of the IC card are known to the outside. Then, the IC card itself stores a code that identifies the IC card, and the IC card itself checks that the code matches the code sent from the I'C card input device before accessing the data storage area. , the data stored in the IC card is destroyed when the codes do not match.

According to this invention, the IC card itself records the code matching check code for identifying the IC card. '! This is done before accessing the area, that is, when inputting the 1c power.
Even if an IC card is handed over to another person, the code for identifying the IC card cannot be known from outside. That is, I.C.
Since the IC card itself performs a code check when the card is input into the IC card input device, the code stored in the IC card cannot be read out. Furthermore, even if an arbitrarily assumed code is entered into the IC card, the stored data will be destroyed if the code does not match.
Access to the data storage area becomes almost impossible unless by pure chance. Therefore, according to the unauthorized access prevention device of the present invention, it is possible to effectively prevent copying and tampering of stored data, which tend to occur in MS cards, and even if loss or theft occurs, the security of data protection is maintained. It has the advantage of being very expensive.

(El Example Figure 1 is an external view of an IC card.Plastic I
An IC2 is embedded inside the C card l, and a plurality of connectors 3 connected to the IC2 are formed exposed on the card surface. Further, an enhancer 4 is formed on the front surface, and a preliminary magnetic stripe 5 is formed on the back surface.

As shown in FIG. 2, the IC 2 includes a CPU 20 and a ROM 2 consisting of an electrically writable and erasable EEPROM.
1 and a RAM 22 used for work. The CPU 20 receives power supply from the terminals C4 and C8 of the connector 3, and receives a clock from the terminal C6. It also receives a reset pulse from terminal C7 or C9 and transmits data (serial data) via terminal C2. Terminals C1, C3
, C5 are spare terminals.

FIG. 3 is a schematic external view of an ATM (automatic transaction processing device) equipped with an IC card input device. On the front of the main body 6 is a CRT that displays messages etc. , an input key 8 for performing transaction operations, an IC card insertion slot 9 for inserting an IC card, and a slip 1 bill extraction slot 10 are provided.

FIG. 4 is a block diagram of the control section of the ATM. The main control unit 11 includes an IC card input device 12. CRT control section 13
．． Numeric keypad control section 14. Slip issuing machine 152 Bill discharging machine 1
6. Each line control unit 17 is controlled. Each element is divided into blocks and has a master-slave control system configuration with the main control section 11. IC card input device 12
accesses the IC card input through the IC card insertion slot 9 and exchanges data. The CRT control unit 13 controls the display of the CRT 7. Numeric keypad control section 14
receives the input data operated by the input key 8 and sends it to the main control section 11. At the end of the transaction, the slip issuing machine 15 releases the slip with transaction data printed thereon to the takeout port IO. The banknote dispensing machine 16 discharges a desired amount of banknotes into the outlet 10 when a payment transaction is performed. Line control section 17
controls transmission between the center and the center that has large-capacity data files.

FIG. 5 is a diagram showing the types of transmission data exchanged between the IC card and the IC card input device. Side A of the figure does not show the IC card input device side. The B side in the figure shows the IC card side. When IC card 1 is input, first the IC card
Transmission data a1 is sent from the card input device 12 to the IC car 1-'1.

This transmission data consists of a start mark a11, a code a12, and an access area a13 that specifies the storage area on the IC cart side where the code a12 is stored.

The code a12 is a code for identifying the IC card, as will be described later. A code storage area is allocated to a predetermined area of the IC card 1 and ROM 2, and the code is stored in the area. The access area a13 is data that specifies the area in which the code is written.

When the IC card 1 receives the transmission data a1, it performs a check between the received code a12 and the code stored in itself. If the encryption check means B1 does not match the encryption, the data stored in the ROM is destroyed. The number of encryption checks is a predetermined number of times, and whether to destroy the data or respond is determined based on the number of times the sent encryption a12 is incorrect, that is, whether the number of unauthorized accesses to the encryption reaches a certain number. . If the codes match within a certain number of accesses, transmission data b1 is sent to the 1c card input device A side. This transmission data b
1 is access start OK data indicating that subsequent access to the data area will be accepted. When IC card input device 12 receives this data, it sends transmission data a2. This data a2 is composed of access type data a21, data a22 corresponding to the access type, and a code a23 added when the data in the access area is important data. The code a23 is the same as the code a12 accessed for the first time. On the IC card side B, the encryption checking means B2, which is the same as the encryption checking means B1, performs an encryption check in the same manner as in the case of B1, and determines whether to respond or destroy the data. Note that the access type data a21 sent from the ICC card bagging device side specifies each access mode such as data reference, rewriting, addition, and deletion. When the cipher checking means B2 determines that the ciphers match until the number of cipher mismatches reaches a predetermined value, the access result data b2 is sent to the IC card input device side A. Subsequently, the IC card input device side sends transmission data a3 in which NULL data data 2 follows after the eight spatula end mark a31, and the IC card side B sends access end OK data b3 to the ICC card input device side.

FIG. 6 is a partial configuration diagram of the ROM 21 included in the IC2. A code for identifying the IC card is written in the code access area MA that constitutes the code storage area t1. has been done. The number of unauthorized accesses to the code is recorded in the area MB.

Area MC-ME and area MG constitute a data storage area, and each area stores data to be accessed. Of these, important data is stored in area MG. Area MF stores the same code as the code stored in area MA. This cipher is used when performing a cipher check by the cipher checking means B2 (FIG. 5).

FIG. 7 shows the operating procedure on the IC card side.

When the IC card 1 is inserted through the IC card insertion slot 9 and the connector 3 contacts the contacts provided on the ICC card bag insertion device, power is supplied from the connectors C4 to C8. Further, the CPU 20 is set to the initial state by receiving a recent pulse from the connector c7. Next, connector c2
When the data is in a waiting state and the data is available at step nl (step ni is simply referred to as n+), the data specifies the access area MA and determines whether or not it contains an encryption ( n2).

If so, the receiver determines whether or not the received cipher matches the cipher stored in the area MA (n3). If they do not match, the number of times stored in area MB is incremented and the process returns to nl. Normally, the IC card input device side attempts to send the transmission data a1 again. If the codes match, the process proceeds to n3-h n6, and the number of unauthorized accesses to the area MB is compared with a constant value N. If the number of unauthorized accesses is N or more, the process advances to nil, destroys the data stored in areas MC-ME and MG of the ROM 21, and ends the process.

That is, from now on, even if the IC card is effectively accessed, the data cannot be read. ni
l constitutes the data destruction means of the present invention. If the number of unauthorized accesses exceeds a certain value N without the encryption being compromised at n3, the process proceeds to n5-=nll, at which point the data is destroyed.

If the number of unauthorized accesses is N or less, proceed to n7,
Send access start OK data b1 shown in FIG. IC
When the next data is input from the card input device, the process advances to nl'2 unless the data is transmission data a3. n1
Step 2 is a step of determining whether the access is to area M'G storing important data. Area N
If the access is from the C-NE, the data is not important, so the process goes to n15, and the same number of unauthorized accesses as in n6 above is determined again. If it is N or more, the data in the areas MC-ME and MG is destroyed at n16 in the same way as nil above, and the process ends. If it is less than or equal to N, a response to the access is made at n17. In this response, for example, access result data b2 is sent. After this, the process returns to n8 again and enters a waiting state for the next data.

n12-n if the access from the IC card input device is to the area MG that stores important data.
Proceed to 13. When accessing the area storing important data from the IC card input device side, the transmitted data a2 includes a code a23 as shown in FIG. Therefore, in n13, a match check is performed between this cipher a23 and the cipher stored in the area MF.

If they do not match, the number of unauthorized accesses is incremented at n14, and the process returns to n8. IC card manual device is n1 above.
As in the case of the processing in ~n5, if the codes do not match, transmission data a2 is attempted to be sent several times. If the codes match after being transmitted several times, n13 to n15
and proceed. Then, check the number of unauthorized accesses again.
If it is below, an access response is made (n17). If the number of unauthorized accesses is N or more, data is destroyed and the process ends.

As a result of the above operation, when the number of cipher mismatches reaches a predetermined value at the time of IC card input due to n1=n6, the area MC-ME, which is a data storage area.

MG's memory data can be destroyed. Further, in this embodiment, a cryptographic check is also performed when accessing an important data storage area using n12 to n16, and when the number of mismatches reaches a predetermined value, data in the area can be destroyed. Performing cryptographic checks when accessing important data storage areas further improves data security. Therefore, this embodiment can provide extremely complete protection against unauthorized use of the IC card. In addition, n4 and n
In 14, the number of unauthorized accesses to the area MB is accumulated, but the area MB may be reset when it progresses as n6-=n7 or when it progresses as n15→n17.

[Brief explanation of the drawing]

FIG. 1 is an external view of an IC card, FIG. 2 is a block diagram of the IC, FIG. 3 is a schematic external view of an ATM equipped with an IC card input device, and FIG. 4 is a block diagram of the control section of the ATM. Further, FIG. 5 is a diagram showing the types of transmission data exchanged between the IC card input device and the IC card.
The figure is a block diagram of the main parts of the ROM 21, and FIG. 7 is a flowchart showing the operation of the TC card. 1-IC card, 2-IC, MA-cipher storage area, MC
- ME, MG - data storage area. Applicant Tateishi Electric Co., Ltd. Agent Patent Attorney Hisao Komori Figure 1 Figure 2 Paulownia 3 l”1 Cap Figure 5 Figure 6

Claims (1)

[Claims] (11) An IC card consisting of an IC card with an IC embedded therein and an RC card input device that accepts the IC card and exchanges data with the IC card.
In the card system, the IC card is
Record of code to identify the card'1. ! In addition to providing a storage means having an area and a data storage area, a means for the IC card to receive a code from the IC card manual device when inputting the IC card, and a means for receiving the code from the IC card itself when inputting the IC card.
Unauthorized access to an IC card, comprising: a code checking means for determining whether or not the codes stored in the code match; and a means for destroying data stored in the storage means of the IC card when the codes do not match. Prevention device.