JPH03271885A - Ic card system - Google Patents

Abstract

PURPOSE:To improve the security property by using a code, which cannot be read without a designated code, besides a fixed password number and changing this code in time series. CONSTITUTION:When the password number is transmitted to a computer 1 and coincides with that in the computer, the code which a code designating means 23 designates for preceding read/write is read out from an IC card 4; and when coincidence of the code is confirmed by a code decoding means 22, security is unlocked to set the readable/writable state. The code is changed in time series at each time of using the IC card 4. Therefore, the wrong use due to decoding or the like is more difficult in comparison with the use of a fixed code. Even if the wrong use is tried, it is impossible, and the card use of the right user is impossible to easily find the abnormality. Thus, the security property is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an improvement of a system for improving the security of an IC card system.

Note that in this specification, the term rICJ generally refers to LS
It is used in a broad sense, including those with a high degree of integration such as those called I.

<Prior art> In the IC card system for various credit cards, etc., the card has a built-in IC chip with CPU and memory functions.The card is connected to a computer via a terminal, and a password is sent to the computer. and is configured to communicate with the computer after unlocking the security of the card. Such IC cards generally have a control circuit that controls security procedures and the like configured by a general-purpose CPU, and have a feature of higher security than magnetic cards.

<Problem to be Solved by the Invention> However, it is possible for those who are familiar with the technology to decipher the security procedures and make copies of this type of card. Therefore, there is a possibility that the card will be misused, and there is a need for a card or system with higher security.

In addition, malfunctions may occur if the connection method or signal format between the IC card and the terminal is not appropriate.
Malfunctions such as erasure or alteration of data stored in a card are a major factor in compromising system security.

The present invention has focused on these problems and has been made with the aim of improving the security of the IC card system by reducing the possibility of unauthorized use or malfunction.

<Means for Solving the Problems> In order to achieve the above-mentioned object, this invention consists of a computer, a terminal, and an IC card connected to the terminal, and the security of the card is unlocked by a password signal. Then, in an IC card system that performs read/write processing between a computer or a terminal and an IC card, a code that cannot be read unless a specified code is used is written in the IC card.

Specifically, C installed in a computer or terminal
The PU is provided with a code deciphering means which reads the code specified at the time of previous read/write from the IC card when reading/writing with the IC card, and enables read/write only when the codes match.

The IC card is provided with a cipher specification means that determines the cipher to be used for the next read/write during reading/writing with the IC card and writes this cipher to the IC card. A read/write means is provided for reading/writing predetermined data including the above-mentioned code according to the code.

In addition, electromagnetic coils are provided on the IC card and the terminal in correspondence with each other for signal exchange between the IC card and the terminal, and the electromagnetic coupling between the card-side coil and the terminal-side coil enables contactless signal exchange between the two. It is configured to be performed with

Four electromagnetic coils each for power supply and clock signals, data write signals, data read signals, and command signals are provided in the IC card and the terminal, respectively.

Each of these electromagnetic coils can be constructed from a printed circuit board pattern formed by etching.

Furthermore, the CPU of the computer or terminal device is provided with a command signal generating means for outputting a command signal to be transmitted to the IC card in the form of a serial signal, and this command signal generating means generates a reset command when all bits are 0, a write command, and a write command. The address set command is a combination of bits in which any two bits are 1, and the read command is a combination of bits other than the reset command, write command, and address set command.

<Operation> In the IC card system of the present invention, in addition to the fixed password used in normal systems, a code that cannot be read unless a designated code is used is used. When reading/writing, read/write processing is possible only when this code matches, but this code is only used this time; during processing, a new code to be used next time is specified and written to the IC card. At the next read/write, the read/write process cannot be started unless this newly specified code is read from the IC card.

Since this code is difficult to learn simply by deciphering the security procedures or making a copy, the use of the IC card by unauthorized means is prevented.

In addition, since the cipher changes over time, even if the entire cipher is copied, if a legitimate user uses the card before it is used fraudulently, the next cipher will be specified and the copied card will be copied. Since the encryption is invalidated, unauthorized use is prevented. Further, if the unauthorized use occurs before the legitimate user, the unauthorized use is possible, but in this case, in 1, the next encryption will be specified at the time of this unauthorized use. For this reason, if a legitimate user uses the card after that, the already invalid code will be used as is, so communication will not be possible, and the user will easily notice that there is an abnormality in the card. Therefore, it becomes possible to promptly take measures such as prohibiting the use of the card, and it is possible to prevent continued unauthorized use.

In addition, since signals are exchanged between the IC card and the terminal without contact through electromagnetic coupling of the electromagnetic coil, there is no need for exposed contacts, which prevents malfunctions due to mechanical damage or poor contact due to oxidation or contamination. Prevented.

In addition, four of these electromagnetic coils are installed on each IC card and terminal.
By providing two electromagnetic coils, it is possible to send and receive power and clock signals, data write signals, data read signals, and command signals. By configuring these electromagnetic coils with printed circuit board patterns, it is small and reliable. A high electromagnetic coil can be obtained.

Furthermore, in the case of the above-mentioned signal exchange method, malfunction may occur if the electromagnetic coupling between the coils becomes insufficient due to improper insertion of the IC card or the like. However, in this invention, since the command signal is configured as described above, one of the write commands and address set commands is
Even if the bit changes to O,
There is a possibility that the command cannot be read or that it is changed to a reset command or read command and transmitted, all of which result in a safe malfunction. Therefore, fatal malfunctions such as data stored in the IC card disappearing or changing will not occur.

<Example> Next, one embodiment of this invention will be described.

FIG. 1 is a schematic diagram of the IC card system. 1 is a computer installed, for example, in a system center, 2 is a plurality of terminals connected to the computer 1 through a line 3, and 4 is an IC card owned by each of the plural users. General telephone lines, etc.
Appropriate wired and wireless channels are used.

The computer 1 is relatively large and has the function of controlling the entire system, and the terminal 2 is interposed between the computer 1 and the IC card 4 and has the functions necessary to perform predetermined operations. There is. The CPU 21 of this terminal 2 includes a code decoding means 22 and a code specifying means 23 according to the present invention.
and command signal generating means 24 are provided. Note that the computer 1 and the terminal 2 are also appropriately provided with a storage device, peripheral equipment, etc. (not shown). Further, the above-mentioned code decoding means 22, code specifying means 23, and command signal generating means 24 may be provided in the computer 10 CPU (not shown) instead of the terminal device 2.

The cipher decoding means 22 is configured to read the cipher written at the time of the previous connection -17518 from the IC card 4 and can start reading/writing only when the ciphers match. The IC card 4 is configured to randomly determine a code to be used next time during reading/writing with the IC card 4 and to write this code into the IC card 4.

Further, the command signal generating means 24 outputs various command signals necessary for read/write processing with the IC card 4 in the form of serial signals, and the structure of the command signals will be described later.

The IC card 4 is provided with an IC chip 41 having a storage means 42 and a control means 43. The storage means 42 is, for example, an EEFROM in which data can be written and erased, and the control means 43 is an IC card 4.
A logic circuit configured using a gate array for controlling the operation of the memory 42, which writes data to a predetermined address of the storage means 42 in response to a command signal from the command signal generation means 24, or writes data at a predetermined address. It is configured so that it can be read and erased.

2 to 4 show an example of the structure of the IC card 4 and the structure of the connecting portion between the card 4 and the terminal device 2. FIG. The IC chip 41 is embedded in the card board 4a, and coils 44a to 44d provided at the edge of the card board 4a are connected to the IC chip 41. 44a is a power supply coil, 44b is a command coil, 44c is a data input coil, and 44d is a data output coil. The coils 25a to 25d provided in the terminal are electromagnetically coupled to each other.

The coil 44a receives driving power and clock signals from the coil 25a, the coil 44b receives various command signals from the coil 25b, the coil 44c receives various data signals from the coil 25c, and the coil 44d receives the storage means 4.
The data signal read from the coil 25d is sent to the coil 25d.

In FIG. 4, 44 indicates a card-side coil, 25 a terminal-side coil provided at a position where the coil 44 is inserted, and 26 a printed circuit board on the terminal 2 side. Each of these electromagnetic coils is a small flat coil wound with thin wire, for example.

Alternatively, it can be obtained by forming a coil pattern obtained by etching a printed circuit board and using a through-hole technique, and is covered with a suitable protective material so as not to be exposed. When the card side coil 44 is inserted to a position where it overlaps with the terminal side coil 25, both coils are electromagnetically coupled.

This makes it possible to supply power and exchange signals without contact.

Next, the general operations in this type of card system will be omitted, and the fifth section will focus on the characteristic parts of this invention.
The operation will be explained with reference to the flowchart shown in the figure.

The operation starts when the user inserts the IC cart 4 into the card insertion section of the terminal 2 (step Sl).

First, in step S2, a password signal is transmitted to the computer 1, and only when the password signals match, the process proceeds to the next step S3. In this step S3, the code specified by the code specifying means 23 at the previous time of 17518 is read from the IC card 4, and the security is unlocked only when the code decoding means 22 confirms that the codes match. It is now ready for writing. In this way, the process advances to step S4, where read/write processing is started, necessary processing is performed, and the process ends at step S7.

In this invention, at an appropriate time during the read/write process, the code to be used for the next process is determined by the code specifying means 23.
is specified and transmitted to the IC card 4, and written into the storage means 42 (step S5). This cipher specification can be done by transmitting an cipher signal from the CPU 21 and writing it as it is into the storage means 42, or by storing a plurality of types of ciphers in advance at predetermined addresses in the storage means 42, and selecting the cipher signal to be used next time. An appropriate method can be adopted, such as a method of specifying an address. Further, in step S6, the previous code designation is deleted, but it is not always necessary to delete the previous code designation, and it is also possible to leave it as it is and, for example, to stack the codes one after another.

Note that when multiple terminals 2 are installed as shown in Figure 1, the code specified for the next use will be sent to all terminals 2.
, 2, . . . are controlled by the computer 1 so as to be effective.

Due to the above operating procedure, the code changes in chronological order each time the IC card 4 is used, making unauthorized use by decoding etc. more difficult than in the case of only a fixed code.

In addition, even in the unlikely event of unauthorized use, the abnormality will be easily discovered because the unauthorized use cannot be performed or the card cannot be used by a legitimate user.

In the above operation, various command signals sent from the CPU 21 of the terminal 2 to the IC card 4 are outputted by the command signal generating means 24 in the form of serial signals. 6th
The figure shows an example of the structure of a command signal, and in this embodiment, the command signal has an 8-bit structure. In the reset command, all eight bits are 0 (L),
The final bit of the read command is 1 (H). In addition, the second and final bit of the write command is 1 (H), and the two types of address set commands have two bits of 1 (H) and the other bits of 0 (L) as shown in the figure. It is a combination.

FIG. 7 is an explanatory diagram of the sensitivity when the positions of the card-side coil 44 and the terminal-side coil 25 are misaligned. ) as shown in the figure. Therefore, if the deviation exceeds the limit, a bit that should originally be 1, ie, H, will be received as 0, ie, L. For example, as shown in Figure 6 as an example of a modified signal, only the last bit of a write command may be 1, or all bits may be 0, and the last bit of an address write command may be O. There is also a possibility that this will happen. However, in this case, the state is the same as when a read command or reset command has been sent, or the command cannot be read, so a malfunction may occur where a read or reset is not performed or a prescribed operation is not performed. However, a write or address set will not be performed using a signal different from the original signal sent. For this reason I
A fatal malfunction such as data stored in the storage means 42 of the C card 4 disappearing or changing does not occur.

<Effects of the Invention> As is clear from the description of the embodiments above, the IC cart system of the present invention uses, in addition to a fixed password, a code that cannot be read unless a specified code is used. The code was made to change over time.

Therefore, it is more difficult to misuse the card by deciphering the security procedures or making copies than in a PIN-only system. In addition, it has the advantage of preventing continued unauthorized use, as it prevents unauthorized use and makes it easy to discover abnormalities and take prompt action, making it easier to prevent continued unauthorized use. This makes it possible to obtain an IC card system with higher security than the previous method.

Further, in a device in which signals are exchanged between the IC card and the terminal without contact through electromagnetic coupling of an electromagnetic coil, exposed contacts are not required. Therefore, there will be no mechanical damage to the contacts or poor contact due to oxidation or contamination.
Malfunctions caused by these factors are prevented, and the security of the system is improved.

In addition, four of these electromagnetic coils are installed on each IC card and terminal.
If the electromagnetic coils are individually installed, it is possible to send and receive power and clock signals, data write signals, data readout signals, and command signals. A highly reliable electromagnetic coil can be obtained.

Furthermore, the command signal sent to the IC card is a serial signal, and the reset command has all bits set to 0.

Each signal is made up of a combination of bits, with one bit set to 1 for a read command, and two bits set to 1 for a write command and an address set command. Therefore, even if a malfunction such as a 1 or H bit is missing due to a misalignment of the card or a disconnection of the coil occurs, the command signal will not be readable, or it will only be in the form of a write command or dress set command. and
Memory data will not disappear or change to other data will not occur. Therefore, the safety of the card as an external storage device is ensured, and the security of the system is improved.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a schematic configuration diagram of the system, Fig. 2 is a perspective view of an IC card, Fig. 3 is a block diagram of the IC card and the coil portion of the terminal, and Fig. 3 is a block diagram of the IC card and the coil portion of the terminal. Figure 4 is a perspective view of the connecting part between the IC card and the terminal, Figure 5
FIG. 6 is a flowchart of the operating procedure, FIG. 6 is a diagram showing an example of the structure of a command signal, and FIG. 7 is an explanatory diagram of sensitivity during signal transmission and reception. 1... Computer, 2... Terminal, 4... IC
Card, 21... CPU, 22... Encryption means,
23... Encryption designation means, 24... Command signal generation means, 25° 25a to 25d... Terminal side coil, 41.
. . IC chip, 42 . . . Storage means, 43 . . . Control means, 44° 44a to 44d . . . Card side coil.

Claims (6)

[Claims] (1) Consists of a computer, a terminal, and an IC card connected to the terminal. After unlocking the security of the card using a password, read/write processing is performed between the computer or terminal and the IC card. 1. An IC card system, characterized in that the IC card system is configured to write a code that cannot be read unless a specified code is used in the IC card. (2) The CPU installed in the computer or terminal device reads the code specified during the previous read/write from the IC card when reading/writing the IC card.
a cipher decoder that enables reading/writing only when the ciphers match; and a cipher designation means that determines a cipher to be used for the next read/write during reading/writing to the IC card and writes this cipher to the IC card. 2. The IC card system according to claim 1, wherein the IC card is provided with read/write means for reading/writing predetermined data including the code in response to a command signal transmitted from the CPU. (3) Electromagnetic coils for signal exchange are provided on the IC card and terminal in correspondence with each other, and signals are exchanged between the IC card and the terminal without contact through electromagnetic coupling between the card side coil and the terminal side coil. 3. The IC card system according to claim 1 or 2, wherein the IC card system is configured to carry out the processing. (4) The IC card and the terminal device are each provided with four electromagnetic coils for transmitting and receiving signals: a power supply and clock signal, a data write signal, a data read signal, and a command signal. IC card system described. (5) The IC card system according to claim 3 or 4, wherein the electromagnetic coils for transmitting and receiving signals provided in the IC card and the terminal device are each formed by a printed circuit board pattern formed by etching. (6) A command signal generating means for outputting a command signal to be transmitted to the IC card in the form of a serial signal is provided in the CPU of the computer or terminal, and this command signal generating means generates a reset command when all bits are 0, write commands and address set commands are bit combinations in which any two bits are 1, and read commands are output by combinations of bits other than the above reset command, write commands, and address set commands. 6. The IC card system according to claim 3, wherein the IC card system is configured as follows.