JPS60205689A - Portable medium - Google Patents

Abstract

PURPOSE:To protect information safely against alteration of content of memory, improper reading etc. by providing a control device that changes acceptable instruction signal. CONSTITUTION:An IC card has a built-in integrated circuit 2 and the circuit 2 makes exchange of information between external equipment through a terminal section 3. When a write instruction signal W51 or a read instruction signal R51 is given from a control circuit 4 to a memory 5, a write control signal W52 or read control signal R52 is generated only when the content of a memory circuit 11 is ''0'' or ''1'' signal. When a write instruction signal W61 or a read instruction signal R61 is given from the circuit 4 to a memory 6, a write control signal W62 or a read control signal R62 is generated to the memory 6 only when the content of the circuit 11 is ''1'' signal. Accordingly, executable instruction signal can be changed according to the content of the circuit 11.

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 microcomputer (hereinafter simply referred to as microcomputer) that performs calculations, etc., and a data memory (FROM) that stores personal identification numbers, transaction information, etc.
It has a built-in integrated circuit consisting of a , interface circuit, etc. that exchanges information with the outside of the card, and information is exchanged with external equipment outside the card via the interface circuit and terminal section. ing. 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.

By the way, 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 there are cases where it is used incorrectly in other application systems due to incorrect operation or malfunction of related equipment. In this case, it is not guaranteed that the above selection will be made appropriately. Therefore, there is a problem in that information cannot be safely protected from 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, reference numeral 1 denotes an IC card, which has an integrated circuit 2 built therein. Further, a terminal portion 3 is provided at a predetermined portion on the surface of the IC card 1, and this terminal portion 3 is electrically connected to the internal integrated circuit 2, and the card is externally connected via this terminal portion 3. Information is exchanged with external 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, PROM) as an information storage means connected to the control circuit 4. ) 5, a second memory (for example, PROM) 6°, and an interface circuit 7, and when exchanging information with the outside of the card, either the first or second memory 5.6 is selected by the control circuit 4. Information is written or read via the interface circuit 7 and 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, and this switching control circuit is provided within the control circuit 4, for example. In the figure, a storage circuit 11 stores switching control information, and in this embodiment, for example, a non-volatile memory is used, and the initial value is a "0'' signal. That is, the first and second
In the initial state where no information is written in the memory 5゜6, a 0°° signal is written, and when fixed information 1 is written into the first memory 5, the control circuit 4 is activated after the writing is completed. This is to write a "1" signal into the memory circuit 11.

The inverter circuit 12 is a circuit that inverts the output of the memory circuit 11. The AND circuit 13 outputs a write command signal Ws! to the first memory 5 which is output from the inverter circuit 12 and the control circuit 4. A write control signal Ws2 for the first memory 5 is output. AND circuit 1
4 performs an AND operation between the output of the storage circuit 11 and the write command signal Ws1 for the second memory 6 output from the control circuit 4, and outputs a write control signal W62 for the second memory 6. The AND circuit 15 performs a logical product of the output of the storage circuit 11 and the read command signal R5I for the first memory 5 output from the control circuit 4, and outputs a read control signal RIi2 for the first memory 5.

The AND circuit 16 combines the output of the storage circuit 11 with a successive instruction signal Rs1 for the second memory 6 output from the control circuit 4.
Which AND is taken and the read control signal R62 for the second memory 6 is output.

In such a configuration, the first memory 5 is connected to the control circuit 4.
When the write command signal Ws s for the first memory 5 is output, the write control signal Ws 2 for the first memory 5 can be generated only when the content of the storage circuit 11 is the "0" signal.Similarly, Read command signal R for first memory 5
When ss is output, the contents of the memory circuit 11 become ``1''
Only in the case of a signal, the read control signal R52 for the first memory 5 can be generated. In addition, the control circuit 4
When the write command signal Ws1 or the read command signal Rss for the second memory 6 is output from the storage circuit 11
It is possible to generate the write control signal W62 or the read control signal R62 for the second memory 6 only when the content of the above-mentioned write command signal Wl is the "1" signal.
i1゜Ws l or read command signal Rs t, R
61 is configured so that, for example, when writing or continuously writing information, by inputting a write command signal or a read command signal from outside the card via the terminal section 3, the control circuit 4 receives and outputs the signal. There is.

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. Further, it is possible to prevent information from being written to or read from the second memory 6 unless information is written to the first memory 5.

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.

In the above embodiment, the instruction signal for writing or reading information to the first and second memories has been described, but in addition to this, it is also possible to include an instruction signal for calculation to the control circuit. Further, the above-mentioned command signal switching control can also be performed by software using a microcomputer within the control circuit. Furthermore, in order to safely protect information, the switching control described above can be selected as either reversible or irreversible as necessary. Further, the switching control circuit shown in FIG. 9 may be provided outside the integrated circuit.

Further, in the above embodiment, the case where the IC card is applied to the IC card used as the IC card of the currency transaction device has been described, but the application is not limited to this, and the application can be applied to other memory cards such as shopping cards, cash cards, telephone bill cards, etc. It can also be applied to IC cards, etc.

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

[Brief explanation of drawings]

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 part, 4... Control circuit, 5.6... Memory, 7...
Interface circuit, 11... Memory circuit, 12...
Inverter circuit, 13-16...AND circuit. Applicant's representative Patent attorney Takehiko Suzue Figure 1 1 Figure 2 2) Figure 3 1

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, which can receive command signals. 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.