JP3246558B2 - IC card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card, and
The present invention relates to a technique for allocating a memory area of an IC card having a built-in PROM.

[0002]

2. Description of the Related Art As a new information storage medium replacing magnetic cards and optical cards, IC cards have attracted attention. A general IC card currently used has a built-in CPU, and has a ROM, a RAM, and an EEPROM as memories.
M is built in. Usually, a program for operating the CPU is written in the ROM, and the RAM is
Used as a work area. Also, EEPROM
Have the property that the stored contents are retained even after the power supply is stopped, and are rewritable. The memory space of the EEPROM has a user area for the IC card user and a manufacturing area for the IC card. System area for the publisher or issuer is defined. When an IC card is issued, system data such as a key (a password required to access the IC card) by a manufacturer or issuer is written in a system area. This system area is a dedicated area for the IC card manufacturer or issuer, and the user who has been issued the IC card has:
Only the user area is released.

[0003]

As described above, the user area and the system area are defined in the EEPROM in the IC card, and only the user area is opened to the user. For this reason, an address indicating the boundary between the user area and the system area is defined by a program in the ROM. Therefore, in the conventional general-purpose IC card, the boundary between the user area and the system area is determined in advance,
This cannot be changed by software.

[0004] However, the usage of the IC card varies depending on the user, and it is sometimes more efficient to secure a large system area with a small system area. However, in the conventional general-purpose IC card, since the boundary between the two areas is determined in advance, it is not possible to freely set each area according to the use mode of the user. Therefore, there is a problem that the use of the memory space of the EEPROM is wasted.

Accordingly, an object of the present invention is to provide an IC card which can freely set a memory area suitable for a user's use mode.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an EEPROM.
In an IC card that incorporates
In the memory space allocated to the PROM, a user area for IC card users to use, the IC card
The security code required to access the password
And a system area for storing a boundary address indicating a boundary of the area in a part of the system area.
The boundary address storage unit and the N
N passwords for storing all storage location addresses
And less storage unit, the address control area having provided, boundary
An address value indicating a boundary between the user area and the system area is written in the field address storage unit, and N passwords are stored.
Each storage has a corresponding PIN code
If it is written in the area, write its address value.
And the corresponding security code is written in the system area.
If not, the security code is not prepared.
This is to write a specific code indicating that the

[0007]

In the conventional IC card, the boundary between the user area and the system area is set to a predetermined address in advance, and this address value is defined in the ROM. On the other hand, in the IC card according to the present invention, the address value at the boundary is written in the system area on the EEPROM.
Therefore, the user area and the system area can be freely set by the address value written here.
The program in the ROM can recognize each area by referring to the boundary address value written in the system area.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a memory map of an EEPROM in a conventional general-purpose IC card. The IC card contains a ROM and a RAM as memories in addition to the EEPROM, and further exchanges data between a CPU for accessing these memories and an external reader / writer device. And a built-in I / O device. The CPU operates according to a program in the ROM, and the RAM is used as a work area at this time.

The EEPROM of this embodiment has a memory capacity of 256 bytes. In this memory map, the upper digit of the address is shown on the left side, and the lower digit is shown on the upper side. All the address values are displayed in hexadecimal. In this EEPROM, 176 bytes from address 00 to AF are a user area, and addresses B0 to FF
Up to 80 bytes are the system area. At each address of the system area, the following system data is stored. (1) F0 to FF (manufacturer area): data for the manufacturer such as the serial number and the date of manufacture of this IC card are stored. (2) E0 to EF (manufacturer KEY): a key for the manufacturer is stored. (3) D0-DF (Issuer KEY): The key for the issuer is stored. (4) C0 to CF (KEY1): other keys are stored. (5) B0-BF (KEY2): Other keys are stored. Here, each key is a password required for accessing the IC card. The CPU compares the keys given from the outside with the above-mentioned keys, and determines to what level access is permitted.

After all, in this general-purpose IC card, the user area of 176 bytes is open to the user, and the remaining 8 bytes are used.
0 bytes of system area not available to the user,
Is set. This setting is written in a program in the ROM, and this area setting cannot be changed by software. However, some users use this general-purpose IC card without using KEY1 and KEY2, and there are cases where the manufacturer does not need the manufacturer KEY. In such a case, there is no practical problem if the unnecessary keys written in the system area are ignored and used.
However, EEPROM with limited capacity
Memory space cannot be used efficiently.

According to the present invention, the boundary address between the user area and the system area is not defined in the ROM, but is defined by the EE.
By defining in the PROM, the area setting can be freely changed by software.
For example, in the memory map shown in FIG.
In the case where 1, KEY2 and manufacturer KEY are not required, according to the present invention, a memory map configuration as shown in FIG. 2 may be used. In this EEPROM, 208 bytes from address 00 to CF are a user area, and addresses D0 to FF
Up to 48 bytes are the system area. The issuer KEY is used for the addresses D0 to DF in the system area, and the addresses E0 to EF are used as the manufacturer area.
A new address control area is provided for 0 to FF.

FIG. 3 shows the details of the address control area. The following data is written to each address of this area. (1) Address F0: The start address of the manufacturer area is written. In the example of the address map shown in FIG. 2, the start address is “E0”. (2) Address F1: The start address of the manufacturer KEY is written. In the example of the address map shown in FIG. 2, since the manufacturer KEY is not used, “0” is added to the address F1.
"0" is written. (3) Address F2: The start address of the issuer KEY is written. In the example of the address map shown in FIG. 2, the start address is “D0”. (4) Address F3: The start address of KEY1 is written. In the example of the address map shown in FIG. 2, since KEY1 is not used, "00" is written in the address F3. (5) Address F4: The start address of KEY2 is written. In the example of the address map shown in FIG. 2, "00" is written in the address F4 because KEY2 is not used. (6) Address F5: The user area control address is written. The user area control address is an address indicating the upper limit value of the user area, and is an address indicating a boundary between the user area and the system area. In the example of the address map shown in FIG. 2, the user area control address is “CF”. (7) Addresses F6 to FF: Not used in this embodiment.

The programs in the ROM include the above (1) to
The address information of (7) is described. Therefore, for example, when the program requests the issuer KEY, the data in the address F2 of the address control area is first read (in this case, data "D0" is read), and the read data " The issuer KEY can be read using "D0" as the start address. Also,
When this program requests the manufacturer KEY, it is possible to recognize that the manufacturer KEY is not used by reading data "00" in the address F1 of the address control area.

In the memory map of FIG. 1, the user area is limited to 176 bytes, but in the memory map of FIG. 2, this is extended to 208 bytes. In other words, a useless portion in the system area in the memory map of FIG. 1 is effectively used as a user area in the memory map of FIG. That is, in the conventional general-purpose IC card, as shown in FIG. 1, it is necessary to secure an area in the system area for all the system data that may be used, but in the IC card of the present invention, As shown in FIG. 2, since it is sufficient to secure an area in the system area only for actually used system data, a useless area can be deleted and the memory area can be used effectively. . If various area settings are made for each IC card in this manner, the address at which each system data is written and the boundary address between the user area and the system area become
Although it differs for each IC card, a new address control area is provided and these address values are written therein, so that the program in the ROM can access a desired key without any trouble. it can.

As described above, the present invention has been described based on one embodiment shown in the drawings. However, the present invention is not limited to this embodiment, but can be implemented in various other modes.
For example, the configuration of the address control area shown in FIG. 3 is shown as an example, and any other configuration may be used.

[0016]

As described above, according to the IC card of the present invention, the boundary between the user area and the system area is set to an address having the highest memory efficiency, and the boundary address value and the address for accessing the system data are set. Since the value is written in a part of the system area, it is possible to freely set a memory area suitable for the usage mode of the user.

[Brief description of the drawings]

FIG. 1 is a general memory map of an EEPROM in a conventional general-purpose IC card.

FIG. 2 shows an EEPROM in an IC card according to the present invention.
3 is a memory map of FIG.

FIG. 3 is a detailed view of an address control area in the memory map shown in FIG. 2;

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-251990 (JP, A) JP-A-2-59940 (JP, A) JP-A-1-166279 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) G06K 19/07

Claims (1)

(57) [Claims] 1. An I / O device incorporating an EEPROM as a memory.
In the C card, a user area for the user of the IC card to use in the memory space allocated to the EEPROM and a user area for accessing the IC card are required.
A system area for writing a necessary personal identification code, and a boundary indicating a boundary of the area is provided in a part of the system area.
A boundary address storage unit for storing addresses, and a plurality of
Stores storage location addresses for N different security codes
And N PIN address storage unit for, provided the address control areas with, wherein the boundary address storage unit, the and address value indicating a boundary between the user area and the system area is written, the Each of the N password address storage units has a pair
The corresponding security code is written in the system area.
If there is, the address value is written and
Password is written in the system area
If not, make sure that the security code is not prepared.
An IC card in which a specific code shown is written.