JPS5977699A - Integrated circuit card - Google Patents

Abstract

PURPOSE:To utilize the merit of an erasable and an electric rewritable (EEP) ROM and to prevent incorrect data erasing securely by inhibiting the erasing on the basis of the contents stored in the specified area of the EEPROM. CONSTITUTION:An IC card is formed by an IC module 4 embedded with the EEPROM 43 together with a CPU40, etc. and the contents of the ROM43 are read out through a contact terminal 5. On the other hand, the contents stored in specified area A of the ROM43 are read out from the terminal 5 in accordance with the erasing instruction of the ROM43 to inhibit the erasing of the ROM43. In said constitution, the stored contents are easily rewritten, the merits of the EEPROM having high maintainability is utilized to prevent securely the incorrect data erasing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a card in which an integrated circuit (hereinafter referred to as an IC) containing an active element such as a microcomputer is embedded for holding various data such as identification, and in particular, a BE as a memory element.
FROM (Electricas Erase Pull and...
(abbreviation for grammatical read-only memory).

Identification cards such as identification cards, credit cards, or bank cards (referred to as ID cards)
Traditionally, data has been retained using the magnetic UN method.
Cards are mainly used.

This magnetic recording type card is advantageous for certain uses, such as when bank cards are used to record deposit balances, as data can be rewritten relatively easily. However, data cannot be prevented from being tampered with. There are problems in that it is difficult to protect data from magnetic contamination, which is easy to receive when carried, and reliability may not be obtained sufficiently.

Therefore, in consideration of these points, an electronic circuit consisting of an integrated circuit (IC) element or the like is embedded in the card, data is stored in the electronic circuit, and the data can be read out and used for identification as needed. Data cards based on this technology have been proposed and are beginning to be put into practical use.

A data card with a built-in IC-based electronic circuit is called an IC card, and as shown in the front view of Figure 1 and the cross-sectional view of Figure 2, it is made of a suitable plastic or the like. A four part 3 is formed in a part of the card base 2, and an IC module 4 is housed therein.The IC module 4 is provided with a contact terminal (electrode) 5, and is connected to an external circuit and the IC module 4. Electrical connections can be made between the included electronic circuits.

In addition, the surface of the card base 20 is often provided with a pattern 6 made of predetermined characters or figures drawn with ink or the like, and a protection layer 7 made of a suitable transparent plastic or the like is also provided to protect the surface of the card body 20. are provided, and together form the IC card 1.

Note that 8 is a magnetic stripe layer, which is provided so that it can also be used as a magnetic recording type data card, and is not particularly necessary for an IC card.

The electronic circuit provided in the IC module 4 is as follows:
L8. , various memory circuits based on large-scale integrated circuits (I), and data processing circuits such as microcomputers are used. Electrical connection between the electronic circuit and an external data processing circuit is made via the contact terminal 5, and data of if is output from the electronic circuit of the IC card 1 in accordance with data given from the external circuit, and identification is performed. It is designed to perform functions such as

This IC card is difficult to tamper with data, is resistant to changes in the magnetic environment, and can easily increase the amount of data that can be stored, so it can be used not only as an ID card but also for general data storage. It has become widely adopted.

By the way, the configuration of the IC module 4 in such a QIC card has conventionally been 1, for example, as shown in FIG.
(Programmable Read Write Only Memory) was often used. In the figure, 40 is cp
u (central processing unit), 41
is ROM (lead competition only tube memory), 42 is F R
OM, and these are the terminal pieces 51 to 56 of the contact terminal 5.
FROM, 4
However, in an IC card with a built-in IC module 4 as shown in FIG. Since it is generally impossible to rewrite the data, if the data to be read changes, the previous IC
Prepare a new IC card instead of the card, and use that FRO
Since new data must be written to the M42 before use, it is difficult and uneconomical to reuse an old IC card.

Therefore, in order to make it possible to reuse the IC card as it is even if the data is changed, an IC card that uses EBFROM 43 for storing transaction data is being used, as shown in Figure 4. It has become.

According to the IC card using this BFiPROM43,
If the data to be read changes, the previous data can be deleted and new data can be written, making it possible to reuse it any number of times, making it extremely economical. is obtained.

However, such E, B! ' IC cards using ROM k have the disadvantage that data can be easily erased, and there is a risk of accidentally erasing data that you want to keep. One drawback is that it is difficult to sufficiently increase the reliability of the IC card due to the loss of necessary data.

The object of the present invention is to eliminate the drawbacks of the existing prior art, and to
Easily provide an IC card that takes full advantage of the advantages of an IC card using tBP OM while sufficiently preventing the occurrence of a situation where even necessary data is accidentally deleted. There is something to do.

In order to achieve this object, the present invention provides a specific memory area in the memory area of the EEPROM built into the IC card, which is independent of the general transaction data write area, and eliminates manual data erasure from the EEPROM. is I
When the data is given to the C card, the data is first escaped from this specific area, and when the contents of this data are in a predetermined state, the data erasing operation to the EEPROM is prohibited, so that it is truly EEPII, OM. This is also because K requires rewriting data in a specific area of the EEPROM in advance in order to erase the data.

Hereinafter, embodiments of an IC card according to the present invention (ζ) will be described with reference to the drawings.

First, the IC module 4 provided in the IC card according to the embodiment of the present invention is the same as the conventional example shown in FIG. An area A is provided in which general data is not loaded and EgFROM4
Even if a data deletion command for 3 is input from an external device, instead of directly deleting KEgP 0M43, if the deletion command is input manually, first,
Data is read from the specific area A of the EDP ONi 43, and the EEP ROM is read out based on the contents of the successive data.
Determine whether data deletion for 43 is being produced or not, only if it is not prohibited.
This is different from the conventional example in that a program for executing a data erasing operation for the PI (OM 43) is stored in the OM 41 VC.

'J5 and B represent general data storage areas required for IC cards, such as for product classification, and M represents EE PIL OM.
4 ::; Represents the entire memory area.

Next, the operation of this practical example will be explained with reference to the flow chart shown in Figure 6.

After a data erasing command is input from the external device in step (2), the specific area A of the EEPROM 43 is accessed in step (2) and the data stored there is read. Next, proceed to step ■, and in step ■, examine the data issued by the gun and determine whether the content indicates erasure prohibition.0 If the result in step ■ is NO, proceed to step 1, and the data can be erased. Output the code, then step ■ to HE
After erasing the data in the PROM 43, this flow exits.

On the other hand, if the result in step (2) is YB8, the process proceeds to step (2), an erasure prohibition code is output, and after seven steps, the process exits from this flow.

Therefore, in this embodiment, if the error is caused by an external device or the like,
When the PROM 43 is accessed and a command to erase the data stored therein is input, the data in the EEPROM 43 is not erased immediately in response, but first a specific memory in the EEPROM 43 is erased. The data stored in area A is read, and the contents of this read data are EEPRO
M43 f7) This does not indicate that data erasure is prohibited.
If the data transferred to the C card is data that requires storage, the corresponding B HP H, OM 43
Data representing a specific storage area AK that cannot be erased? All you have to do is memorize it, and even if a data deletion command is given manually with the intention of doing so, the data will not be deleted.
It is possible to completely prevent necessary data from being accidentally erased and lost.

It should be noted that the information written on the IC card according to this embodiment. If the data is no longer needed, then write new data (7) overnight.
All you have to do is access the specific area A of 1%0M43, input the operation command for the data indicating prohibition of erasing the data stored there, and then input the data erasing command.

Konotame, E E P R Oh + 43 no special 54 sparrow,
i area A p(l G-1 as data representing the frequency of data deletion to be stored.

It must be rewritable when accessed by an external device.

For example, the EEFROM 43 is generally in hexadecimal code, and its initial state is often set to (FF)16 in hexadecimal code. The binary code corresponding to (FF) 16 & hood when writing data (
11111111) Value of 2 (1) 2 Data is written by setting the arbitrary value of each bit to binary code (0), so in order to make it possible to rewrite the data, , the original data must be a hexadecimal code other than (OO)+e.

Therefore, in the case of hexadecimal code, the data indicating the prohibition of erasing data to be stored in the above-mentioned specific area A is (ooL
It is necessary to set it to something other than a.

Therefore, the data whose result is YB2 in step 2 in FIG. 6 is expressed as (FO)t in hexadecimal code.

Suppose that it is configured so that

Then, if this data (FO)+s is written in the specific area A of EgPROM43, the IC can be accessed from the external device.
Even if a data loss command is input to the card 1, at this time the IC card 1 only outputs a signal representing the erasure prohibition code, and the data is not erased.Therefore, there is a risk that the data that should be saved may be lost. It is possible to eliminate this problem.

Then, when the data stored in the IC card IK is no longer needed, the data (FO) + a stored in the special electric area AIC of the EEPROM 43 is transferred to (EO) t6.
etc., the data stored in the EEPROM 43 will be rewritten according to the manual effort of the subsequent data deletion command.
Since all data including the specific area A data can be erased and returned to the initial state ()'F)t6, the IC card 1 can be reused for new data.

By the way, the data that is stored in this specific area and indicates that erasure of data is prohibited, that is, IJ6! As the data for which the result is YES in step (2) of A, the data expressed in the initial state of the BEF ROM 43 may be used as is. For example, in the above example, (FF)+a is set.

If this is done, the IC card 1 will be in a state where data loss is prohibited at the beginning of its use and immediately after the data is erased, and no special processing is required for the specific area A. It is possible to obtain an IC card with no risk of data loss due to erroneous operation.

In addition, in this case, the data to be written to the specific area A in order to cancel the data erasure prohibition may be writable data, etc.
Processing becomes easier.

As explained above, according to the present invention, even in an IC card that is equipped with BI3FROM for data storage and can be used repeatedly, there is less risk of necessary data being accidentally erased and lost. Since data can be erased whenever necessary, it is possible to eliminate the drawbacks of the prior art and easily provide a highly reliable and economical IC card.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an example of an IC card, Fig. 2 is a sectional view thereof, Fig. 3 is a circuit diagram showing an example of an IC module in a conventional IC card, and Fig. 4 is an E g P ROM.
FIG. 5 is a conceptual diagram showing an example of a storage area in the B E P it OM of an IC card according to the present invention, and FIG. 6 is a circuit diagram showing an example of an IC module using the present invention. 3 is a flowchart showing the operation of FIG. 1...IC card, 2...card base, 3...recess, 4...IC module, 5...contact terminal, 40 ...CPU
(Central Processing Unit), 41...
...ROM (read-only-1 memory), 43
・・・・・・(Electric urn eraseable and e-programmable, ROM). Figure 5 Figure 6

Claims (2)

[Claims] (1) In an IC card that is equipped with an active element having an electrical signal processing function and uses an EEPROM as a storage element, the IC card is activated by inputting a command to erase stored data from the outside to the EEFROM, and the BEFROM
An IC card characterized in that the IC card is configured to prohibit erasure of data in the BEPROM by inputting the erasure command according to data stored in a specific storage area of the IC card. (2) In claim (1), the above E
1. An IC card characterized in that data to be stored in the specific storage area in order to prevent data loss in the KFROM is data represented in the initial state of the EEFROM.