JPS62237548A - Ic card - Google Patents

Abstract

PURPOSE:To strengthen the security of a secret area in a semiconductor memory by dividing a command group into three groups consisting of a non- privileged command group, a privileged command group and a testing command group. CONSTITUTION:An IC card 1 is constituted of a microprocessor and an EEPROM semiconductor memory 3 consisting of a secret area 7 and a general area 8. After the success of collation of a private identity number (PIN), the non-privileged command group 4 can access only the general area 8. After the success of collation of a pass word, the privileged command group 5 can access all the areas of the semiconductor memory 3. Only when the PIN is the initial value, the testing command group 6 can erase all the areas of the memory 3 or check the operation. Since only a card issuing person using the privileged command knows the pass word, a card maker for inspecting the card can not know the contents of the secret area 7 at all.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an IC card used for cash cards, credit cards, and the like.

The configuration of a conventional IC card is as shown in FIG. 3, for example, and the command system for the conventional IC card is as shown in FIG. 2, for example. In FIG. 3, 11 is a microprocessor, 12 is a semiconductor memory consisting of ΣKFROM, 13 is an address signal line, 14 is a data signal line,
16 is a read/write control line, 16 is a serial data communication line with external equipment, 17 is a confidential area on the semiconductor memory 12, 18 is a general-purpose area, and in FIG. 2, 19 is an I
C card, 11 is a microprocessor, 12 is a semiconductor memory, 20 is a non-privileged command group, and 21 is a privileged command group.

The operation of the IC card configured as described above will be explained below.

The microprocessor 11 receives instructions such as reading or writing data from a specific address in a semiconductor memory 12 such as a PROM via an external device and a serial data communication line 16, and reports the status after completing a predetermined operation. Reply as a response. In addition, the command group for the IC card is divided into two groups, the non-privileged command group 2o and the privileged command group 21, and the non-privileged command group 20 can only access the general-purpose area 18 where transaction information etc. are stored. It is.

On the other hand, the privileged command group 21 includes a command to access the confidential area 17 containing information such as PIN and password, a command to erase information in the entire area of the semiconductor memory 12, etc. This privileged command group 21 includes password verification. After success, it became executable.

Problems to be Solved by the Invention In the conventional command system, the password is known to the card manufacturer who performs inspection work such as erasing information from the entire area of the semiconductor memory 12, so the password is known only to the card issuer. There is a security problem in that information in the confidential area 17, such as the PIN, can be known.

The present invention is intended to solve these problems, and aims to provide a command system that prevents a card manufacturer performing inspection work from knowing information in a confidential area of a semiconductor memory.

Means to Solve the Problem In order to solve this problem, the present invention divides the command group for IC cards into three groups: non-special commands, privileged commands, and inspection commands, and each command can be used. The conditions are different for each of the four groups IL. l: There are seven commands in the command system.

Effect In the case of this command system, for example, if the inspection command can be used only when the PIN is the initial value, the card manufacturer can freely use the inspection command during the inspection at the time of shipment because the PIN is the initial value, so the card issuer There is no need for you to know your password or PIN. Therefore, the card manufacturer cannot know the contents of the confidential area of the card on which the PIN has been written, and cannot use privileged commands, so the security of the card can be strengthened.

Embodiment FIG. 1 is a command system diagram of an IC card in an embodiment of the present invention. In FIG. 1, numeral 1 is an IC card, 2 is a microprocessor, and 3 is a semiconductor memory consisting of FROM, which is comprised of a confidential area 7 and a general-purpose area 8. 4 is non-privileged command group, 5 is special! 8+command group, 6 is an inspection command group. The structure of the IC card is the same as the conventional one, for example, as shown in FIG.

The operation of the IC card in this embodiment configured as described above will be described below. The non-privileged command group 4 can access only the general-purpose area 8, and can be used after successful PIN verification. The privileged command group 6 can access all areas of the semiconductor memory 3 including the confidential area 7, and can be executed after successful password verification. The inspection command group 6 includes a command to erase information in the entire area of the semiconductor memory 3 and a command to check the operation of the semiconductor memory 3.
Can only be executed when is the initial value. Under such a command system, only the card issuer using the privileged command knows the password, so the card manufacturer conducting the inspection cannot know the contents of the confidential area 7 at all. Also,
Since the inspection command group 6 can be executed only when the PIN is the initial value, there is no fear that the entire contents of the card that is used in the normal state will be accidentally or intentionally erased.

Effects of the Invention As described above, according to the present invention, a privilege command for an IC card is further added to a group of privilege commands that allow access to a confidential area only after successful password verification, and a group of privilege commands that allow access to the entire semiconductor memory only when the PIN is at the initial value. By dividing the IC card into inspection command groups that enable inspection operations such as erasing areas, the card manufacturer performing inspection operations will not be able to know information in confidential areas, thereby strengthening the security of the IC card. This is of great practical value.

[Brief explanation of drawings]

FIG. 1 is a command system diagram of an IC card according to an embodiment of the present invention, FIG. 2 is a command system diagram of a conventional IC card, and FIG. 3 is a block diagram of the IC card. 1...IC card, 2...Microprocessor, 3...Semiconductor memory, 4...
・Unprivileged command group, 5...Privileged command group, 6...
...Inspection command group, 7...Secret area, 8...
...General-purpose area. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure IC card Figure 3/l/2

Claims (2)

[Claims] (1) Equipped with a microprocessor and semiconductor memory,
An IC card characterized in that a command group is divided into three groups: non-privileged commands, privileged commands, and inspection commands, and conditions under which each command can be used are different for each group. (2) The conditions under which the inspection command can be used are set to the PIN (Private Identity) in the semiconductor memory.
The IC card according to claim 1, wherein the storage area (Number) is set to an initial value.