JP2748252B2 - IC card command identification method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an IC card, and more specifically, to a command identification method in an IC card.

BACKGROUND ART For example, as a half-duplex start-stop synchronous block transmission protocol between an IC card and an interface device, there is a Japanese block transmission protocol (protocol type T = 14) used in Japan. IC using this protocol
In the exchange of commands between the card and the interface device, initially, a different code identifier was set for each command. However, in such a method in which a different identifier is set for each command, a command type is required for each execution function, so that the types of commands increase,
This caused the program efficiency inside the IC card to decrease. For this reason, the latest ISO (International Stnda
rds Organization),
By identifying the function implemented in each command by the parameters of the command part, it is being unified in the direction of giving many functions to few commands.

However, such a command standardization plan is for basic operation commands such as, for example, job selection, key collation, and record read / write, and commands other than those are not standardized. For this reason, each company adopts its own format for commands that are not subject to the standardization plan, and in practice, types of commands are provided for each implemented function. That is, for example, when initializing a desired area in an IC card, different commands are used for each access right and depending on the contents of the initialization, for example, whether the entire area is initialized or a part of the area is initialized. .

As described above, the conventional technology has a drawback in that since each company uses a different command even if the processing content is the same for commands that are not subject to the standardization proposal, identification on the user side becomes complicated. Was. In addition, the increase in the number of commands causes the processing on the IC card to become complicated and delays the processing speed. In addition, the mask program capacity increases and internal resources such as memory cannot be used effectively and efficiently. There was a point.

Objective The present invention solves the drawbacks of the prior art and simplifies the command configuration to provide an IC card command identification signal that enhances operability and functionality and improves utilization of internal resources. Aim.

DISCLOSURE OF THE INVENTION According to the present invention, in an IC card connected to an interface device, receiving an information block including an instruction code from the device, and executing a process specified by the instruction code, an IC card command identification method in the IC card is The IC card has an instruction code including a plurality of instruction contents for one instruction code, and when the IC card identifies the instruction content indicated in the information block received from the interface device, the IC card indicates the instruction code of the information block. The transmitted command content is identified based on the transmitted content and a predetermined field length of the information block, and the command content is processed.

DESCRIPTION OF THE EMBODIMENTS Next, an embodiment of an IC card command identification system according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a functional block diagram of an IC card 1 to which an embodiment of an IC card command identification system according to the present invention is applied. The IC card 1 is connected to an interface device (not shown) such as a reader / writer, for example, as necessary, and incorporates a microprocessor for performing various processes by exchanging information with the interface device. Card. As a protocol of information exchanged between them, a protocol type T = 14 or the like is used.

Information is exchanged between the interface device and the IC card 1 according to the frame structure of the block defined by the protocol type T = 14. FIG. 2 shows a frame configuration of the information block 200. As shown in the figure, an information block 200 includes a prologue section (PROLOG) 210 and an information section (INFORMATIO
N) 220 and an epilogue section (EPILOG) 230.

The prologue section 210 is a field of the introduction section of the information block 200. The prologue section 210 includes a node address NAD (Node Aderess) in which the node address is stored, and a protocol control PCB (Protocol Controller) in which information for protocol control and control specific to the IC card 1 is stored.
ol Byte) and a length LEN (Length) in which the information length of the information section 220 is stored, each of which is indicated by 1 byte.

The information section 220 is a field in which information relating to processing of the application layer independent of protocol control or information relating to protocol control is stored. The information section 220 has a function class CLS (Functio
n Class), command code C in which command information is stored
It is a command information section composed of an OD (Command Code) and a data section. Each of the function class CLS and the command code COD is 1 byte, and the data portion has a variable length of 0 to n bytes.

In the present embodiment, the command code COD indicates a basic command, and the command code is added to the data section as necessary.
The processing contents related to COD are described. Therefore, the content of the processing to be executed differs depending on the length of the information section 220. Therefore, when identifying the command sent from the interface device, the IC card 1 identifies the processing content of the command based on the content of the command code COD and the length of the information section 220.

Epilogue section 230 is a field in which an error detection code is stored. That is, the information block 20
Error detection code EDC (Errrr Detection Cod) for 0
e) is set.

Returning to FIG. 1, the information block 200 sent from the interface device side is a serial input / output line (SIO) 10
2 and transmitted to the IC card 1.

The reception byte number counter 12 is connected to the input / output line 102, and receives the information block 200 therefrom. The byte number counter 12 is a counting circuit that counts the number of bytes of the information section 220 of the received information block 200 as a reception length value. The counter 12 is connected to the comparator 14 via the output 120, and outputs the counted number of bytes of the received length value to the comparator 14.

The control circuit 16 is connected to the input / output line 102 similarly to the counter 12, and receives the information block 200 therefrom. When the command code COD is included in the information section 220 of the information block 200, the control circuit 16 sends the information length (the number of bytes) of the command to the comparator 14 via the output 160. As described above, in the present embodiment, basic commands are shown in the command card COD of the information block 200. If this command requires command information such as parameters and identifiers, the information content is appropriately added to the data portion. Therefore, the basic instruction length differs depending on the instruction. Therefore, the control circuit 16 identifies the instruction indicated by the command code COD, reads the instruction length from the random access memory 18 described later, and outputs the instruction length to the comparator 14.

The comparator 14 is a comparator that receives the length value of the information section 200 from the reception byte number counter 12 and the basic instruction length from the control circuit 16 and compares these values. Comparator 14 compares these values and notifies control circuit 16 of the result via output 140.

The control circuit 16 refers to the contents of the data part as necessary based on the comparison result from the comparator 14 to identify and execute an instruction from the interface device. At this time, the control circuit 16 determines whether or not the instructor of the command has an access right, and if so, executes the process. Control circuit 16
A random access memory (RAM) 1 via bus 100
8. Connected to a read only memory (ROM) 20 and an electrically erasable / writable memory (EEPROM) 22, and controls the components in the IC card 1 according to the received command.

The random access memory 18 stores information on each command sent from the interface device. Specifically, command information including the command length of the command described in the command code COD of the information section 220 is recorded. The command information stored in the memory 18 is referred to by the control circuit 16 when receiving an instruction from the interface device.

The read-only memory 20 stores a processing program for the IC card 1. That is, here, for example, an operation program of the control circuit 16 and the like are stored. The electrical erasable / writable memory 22 stores data 4 relating to the user of the IC card 1 and the like. The timing control circuit 10 is a circuit that supplies a timing signal to each circuit in the IC card 1.

In the same figure, the IC card 1 not directly related to the present embodiment is shown.
, And the function of transmitting information to the interface device are not described in abbreviated form.

FIG. 3 shows an example of an operation flow in this embodiment. The operation of this embodiment will be described with reference to FIG. 1, FIG. 1 and FIG. The information block 200 transmitted from the interface device is received by the reception byte number counter 12 and the control circuit 16 via the input / output line 102. When receiving the information block 200, the control circuit 16 identifies the instruction indicated by the command code COD (300). That is, when the command code COD is “01”, the control circuit 16 refers to the corresponding command content from the random access memory 18 via the bus 100 (302). Then, the instruction length “X1” of the command code 01 is read, and the X1 byte is sent to the comparator 14 via the output 160.

On the other hand, the received byte number counter 12
Is received, the number of bytes of the information section 220 is sent to the comparator 14 via the output 120. Upon receiving these, the comparator 14 determines whether or not the values match, and outputs the result to the output 140.
To the control circuit via. Information section 220
If the number of bytes is X1 bytes, the control circuit 16 executes the command processing A (306). Otherwise, the control circuit 16 refers to the contents of the data part to execute the command processing B.
(308).

If command code 01 is an area initialization instruction, the fourth
As shown in the figure, in addition to the erase command indicated by the function class CLS and the command code COD, a parameter for initializing the area is indicated by one byte. Therefore, the length (LEN) of the command information section 220 is 3 bytes. Therefore, when the information section 220 has 3 bytes, the instruction is to initialize the area (delete all records), and the control circuit 16 executes the processing A (306). However, when the information section 220 is 3 bytes or more (5 bytes in this case), it means that the initialization of the area is an erase command of the designated record number indicated by 2 bytes. Therefore, the control circuit
16 executes command processing B, that is, deletes the designated record indicated by the record number (308).

In this case, the control circuit 16 checks the access right of the commander before executing the command. In other words, if the access right for initializing the area is limited to the issuer,
Even if this command is sent from other than the issuer, the control circuit 16 does not execute the processing. Similarly, when the access right of the erasure command of the designated record number is restricted to a person who can write in the area, the process is executed when this command is sent from a person who corresponds to this.

If the command code is not "01", the control circuit 16 determines whether this is "02" (310). In the case of the command code 02, the command information section 220
Instruction length read from memory 18 is "X2"
Is compared (312), and command processing C or command processing D is executed according to the result (314, 316). If the command code 02 is a data file forced stop command as shown in FIG. 5, the control circuit 16 reads the instruction length from the memory 18. If the read instruction length is 2 bytes, the information section 2 of the received information block 200
If 20 is 2 bytes, the control circuit 16 forcibly stops the data file currently specified and used by the job selection command (314).

If the information section 220 has three bytes, the control circuit 16 forcibly stops the data file specified by the third byte (316). Also in the case of this command, a determination is made as to who can access the command, and the command is executed if it is determined that the user is accessible. The control circuit 16 similarly identifies the command content indicated in the command information section 220 and executes the processing (318, 32).
0).

As described above, according to the present embodiment, the command processing is identified by the length of the command information section 220 on the transmission protocol. That is, after identifying the command code COD, the control circuit 16 compares the received length values using the comparator 14, thereby identifying the subdivided command execution function and executing the processing. Therefore, it is possible to configure a system command that is not subject to the ISO standard proposal with a minimum command code and parameters, and the operability and functionality of the IC card 1 can be improved. In this embodiment, since the service is performed after the access right is checked, different command systems can be defined by the same instruction code according to the user level.

It should be noted that the embodiments described herein are intended to explain the present invention, and the present invention is not necessarily limited thereto. Variations and modifications that can be made by those skilled in the art without departing from the spirit of the present invention are described below. Included in the category of the present invention. That is, the reception byte number counter 12 in the present embodiment counts the number of bytes of the information section 220. You may ask. Of course, in this case, the control circuit 16
Is output to the comparator 14 in consideration of the number of these bytes. In the description of the operation in this embodiment, one of the two command processes is selected based on the reception length value of the information section 220. However, the number of the selected command processes is not particularly limited to two, but may be more than two. Of course, it is good.

Effects As described above, according to the present invention, the command configuration can be simplified. Therefore, simplification of processing, reduction of the number of commands, and increase in processing speed can be realized, and internal resources such as mask program capacity can be effectively used. Furthermore, according to the present invention, different command systems can be defined by the same code according to the user level, so that different services can be implemented for each level and confidentiality of each other can be maintained.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an IC card to which an embodiment of an IC card command identification method according to the present invention is applied, and FIG. 2 is a frame configuration showing a frame configuration of an information block transmitted to the IC card of FIG. FIG. 3 is a flowchart showing an example of the processing operation of the IC card shown in FIG. 1, and FIGS. 4 and 5 are specific examples of the information section in the processing operation shown in FIG. FIG. Description of Signs of Main Parts 1 IC card 10 Timing control circuit 12 Received byte number counter 14 Comparator 16 Control circuit 18 Random access memory 20 Read-only memory 22 Electrically erasable / writable memory

Claims (1)

(57) [Claims] 1. An IC card connected to an interface device, receiving an information block including an instruction code from the device, and executing a process specified by the instruction code, wherein an IC card command identification method in the IC card is: The IC card has an instruction code including a plurality of instruction contents for one instruction code, and the IC card identifies the instruction contents indicated in the information block received from the interface device,
An IC card command identification method characterized by identifying the content of an instruction transmitted by a content indicated by an instruction code of the information block and a predetermined field length of the information block, and executing the processing of the instruction content.