JPS6387296A - Portable medium - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a portable medium, for example, a so-called IC card, which has a built-in integrated circuit.

[Technical background of the invention and its problems] Generally, so-called ID cards are used as transaction media in currency transaction devices, etc., but recently,
As this type of ID card, a so-called IC card has been developed and is being put into practical use. This IC card consists of a microcombi card that performs calculations, a data memory (CPROM) that stores personal identification numbers, transaction information, etc., and an interface that sends and receives information from outside the card. It has a built-in integrated circuit consisting of a face circuit, etc., and information is exchanged with external equipment outside the card via an interface circuit and a terminal section. Each function such as inputting, outputting, storing, and calculating information provided by the integrated circuit can be selectively executed by applying a command signal from outside the card via the terminal section.

Inputting information on such an IC card,
Functions such as output, storage, and computation must be appropriately selected and executed to protect information. However, in an IC card application system that is properly designed and operated, the above selection can be made appropriately, but due to incorrect operation or malfunction of related equipment, it may be used incorrectly in other application systems. etc., it is not guaranteed that the above selection will be made appropriately. As a result, there is a problem in that information cannot be safely protected against tampering or unauthorized reading of stored contents due to erroneous operation or malfunction of the application system.

[Purpose of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to safely protect information from falsification of memory contents due to erroneous operation or malfunction of an application system, unauthorized reading, etc. The objective is to provide a portable medium that can

[Summary of the Invention] In order to achieve the above object, the present invention provides a switching control means for switching the command signals that can be accepted, so that only the command signals that can be accepted are accepted.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is an IC card, which has an integrated circuit 2 built therein. Further, a terminal section 3 is provided at a predetermined portion on the surface of the IC card 1, and this terminal section 3 is electrically connected to the internal integrated circuit 2, and is connected to an external device outside the card via this terminal section 3. Information is exchanged with devices.

Each function such as input, output, storage, and calculation of information provided by the integrated circuit 2 is performed by giving a command signal in the form of a message from outside the card via the terminal section 3, or by giving a command signal to a specific terminal. This makes it possible to execute it selectively.

FIG. 2 shows the configuration of the integrated circuit 2, which includes a control circuit 4 mainly composed of a microcomputer that performs calculations, etc., and a first memory (for example, FROM) connected to the control circuit 4 as an information storage means. ) j, second memory (
For example, it consists of a FROM (FROM) 6 and an interface circuit 1, and when exchanging information with outside the card,
Either one of the first and second memories 5.6 is selected by the control circuit 4, and information is written or read via the interface circuit 2 and the control circuit 4.

For example, the first memory 5 writes fixed information (for example, the card issuer's issuer PIN number, the card user's user PIN number, etc.) when the card is issued, and after the writing is completed, only reading can be accepted. Further, the second memory 6 is set so that information (for example, transaction information) can be written or read after the fixed information has been written to the first memory 5 described above.

FIG. 3 shows a switching control circuit for switching command signals that can be accepted under the above conditions.The switching control circuit shown in FIG. In the figure, a storage circuit 11 stores switching control information, and in this embodiment, a non-volatile memory is used as an example, and the initial value is set to an @0'' signal. That is, the first and second In the initial state when no information is written in the memory 5.6, the @0'' signal is written, and when fixed information is written in the first memory 5, the control circuit 4 stores it after the writing is completed. circuit 1
It writes the @1" signal to 1.

The inverter circuit 12 is a circuit that inverts the output of the memory circuit 11. The AND circuit 13 calculates the logical product of the output of the inverter circuit 12 and the write command signal WS1 for the first memory 5 output from the control circuit 4), and the write control signal Ws! for the first memory 5! Output. The AND circuit 14 combines the output of the memory circuit 1z and the second output from the control circuit 4.
The AND with the write command signal W61 for the memory 6 is
, outputs a write control signal W4t to the second memory 6. The AND circuit 15 connects the output of the memory circuit 11 and the control circuit 4.
Read command signal R5 for the first memory 5 output from
1 and outputs a read control signal RSS to the first memory 5. The AND circuit 16 is the memory circuit 11
and the read command signal alll for the second memory 6 output from the control circuit 4, and output the read control signal R@z for the second memory 6.

In such a configuration, the first memo I) from the control circuit 4
When the write command signal Ws1 for 5'IC is output,
Only when the content of the memory circuit 11 is a '0' signal, the first
Write control signal Ws for memory 5! can be generated. Similarly, when the read command signal RSt for the first memory 5 is output, the successive reading control signal Rat for the first memory 5 can be generated only when the content of the storage circuit z1 is a 1'' signal. , when the write command signal W61 or the read command signal R81 to the second memory 6 is output from the control circuit 4, the write control to the second memory 6 is performed only when the content of the storage circuit 11 is a "1" signal. The signal W6z or the read control signal Ram can be generated.
*Wet or read command signal R8l5R411 is
For example, when writing or reading information, a write command signal or a read command signal is input from outside the card via the terminal section 3, and the control circuit 4 accepts and outputs it.

With the configuration described above, executable command signals can be switched depending on the contents of the memory circuit 11, and thereby additional writing or content modification can be performed after writing the stored contents of the first memory 5. can be prevented and information can be safely protected. Furthermore, unless information is written to the first memory 5, writing or continuous output of information to the second memory 6 can be prevented. Therefore, it is possible to safely protect information from tampering or unauthorized reading of stored contents due to erroneous operation or malfunction of the application system.

Furthermore, in IC card application systems, information important for security can only be written when the card is issued, assuming that the command signals that can be accepted are switched as described above between when the IC card is issued and when it is operated. It becomes like this.

Note that in the above embodiment, the first. Although the command signal for writing or reading information to the second memory has been described, it is also possible to include an operation p command signal for the control circuit. Further, the above-mentioned command signal switching control can also be performed by software using a microcomputer within the control circuit. Further, in order to safely protect information, the above switching control 'C1 can select either reversible or irreversible depending on each requirement. Further, the switching control circuit shown in FIG. 3 may be provided outside the integrated circuit.

In addition, in the above embodiment, the case where the application is applied to an IC card used as an ID card of a currency transaction device (C was described, but it is not limited to this, for example, a transaction card,
The present invention can also be applied to other IC cards used as memory cards, such as cash cards and telephone bill cards.

[Effects of the Invention] As detailed above, the present invention provides a portable medium that can safely protect information from falsification of stored contents or unauthorized reading due to erroneous operation or malfunction of an application system. can.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention; FIG. 1 is an external perspective view of an IC card, FIG. 2 is a configuration diagram of an integrated circuit, and FIG. 3 is a configuration diagram of a switching control circuit. DESCRIPTION OF SYMBOLS 1... IC card, 2... Integrated circuit, 3... Terminal section, 4... Control circuit, 5, 6... Memory, 7...
Inter 7 chair circuit, 11... memory circuit, 12...
Inverter circuit, 13-16...AND circuit.

Claims (6)

[Claims] (1) A portable medium comprising an integrated circuit having at least an information storage means and an information exchange means with the outside, each of said means being able to be selectively operated by a command signal given from the outside; A portable medium characterized in that it is provided with a switching control means for switching. (2) The portable medium according to claim 1, wherein the switching control means switches the command signals that can be accepted based on switching control information stored in the integrated circuit. (3) The portable medium according to claim 1, wherein the switching control means is provided within the integrated circuit. (4) The portable medium according to claim 1, wherein the switching control means is provided outside the integrated circuit. (5) The portable medium according to claim 1, wherein the switching of command signals that can be accepted by the switching control means is reversible. (6) The portable medium according to claim 1, wherein the switching of command signals that can be accepted by the switching control means is irreversible.