JP3848994B2 - IC card system, card reader, IC card, and IC card system communication control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an IC card system that performs communication between a card reader and an IC card, a card reader used in the IC card system, an IC card, and a communication control method for the IC card system.
[0002]
[Problems to be solved by the invention]
Some IC cards are equipped with a processor (logic circuit) for performing cryptographic processing in addition to a CPU for controlling the IC card itself for the purpose of improving data security.
[0003]
The cryptographic process is performed by the following process, for example. Both the card reader and the IC card have a “key” for encryption. When the card reader sends an instruction to the IC card to perform encryption processing together with a multi-digit random number such as “1234”, the IC card encrypts the random number “1234” transmitted using the “key”. . Then, the IC card returns an encrypted random number such as “5678” to the card reader side. When the card reader compares the encrypted random number “5678” and recognizes that the IC card has the same “key” as itself, the card reader determines that the IC card is an appropriate communication partner, and Data communication starts.
[0004]
In this case, for example, if the cryptographic processor is configured to operate with a clock signal having the same frequency as the CPU of the IC card, the hardware that operates with the same clock signal temporarily increases during the period in which the cryptographic processor is operating. It becomes easy to generate noise.
[0005]
If the generated noise interferes with communication performed between the card reader and the IC card, the card reader side may mistakenly recognize that the signal on which the noise is superimposed is data transmitted from the IC card. is there. Then, the card reader ends communication at that time, and the IC card cannot transmit data that should have been originally transmitted.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an IC card system and an IC capable of preventing noise generated when an IC card operates a data processing unit from affecting communication. An object of the present invention is to provide a card reader used in a card system, an IC card, and a communication control method for the IC card system.
[0007]
[Means for Solving the Problems]
According to the IC card system of the first aspect, when the processing instruction is given from the card reader, the IC card operates the data processing unit and transmits the data processed by the data processing unit to the card reader. Then, the control unit of the card reader controls the reception of the signal to be stopped while the data processing unit of the IC card is operating by giving the processing command .
[0008]
In other words, since the IC card transmits the data processed by the data processing unit to the card reader, the card reader does not need to receive during the period when the data processing unit is processing. Therefore, even if the reception is stopped during the period, there is no hindrance to the original communication processing, and it is possible to appropriately avoid receiving a signal on which noise generated by the operation of the data processing unit is erroneously received.
[0009]
Specifically, when a processing command is given, the IC card notifies the card reader of the time required for data processing, and the control unit of the card reader stops receiving signals based on the notified time. The time for stopping the reception can be determined appropriately.
[0010]
According to the IC card system of claim 2 , the control unit of the card reader notifies the time when reception is stopped when giving a processing command to the IC card, and the IC card notifies the time notified from the card reader side. If the operation of the data processing unit has not ended even after the elapse of time, the operation of the data processing unit is interrupted, and the card reader is requested to extend the stop time. With this configuration, even if the stop time notified by the control unit of the card reader is shorter than the processing time of the data processing unit, if the stop time is extended in response to a request on the IC card side, the operation of the data processing unit Reception can be reliably stopped until the end.
[0011]
According to the IC card system of the third aspect , the control unit of the card reader sets itself to an operation mode in which power consumption is reduced during the period. That is, the control unit does not have to operate normally during the period in which reception is stopped. For example, the frequency of the clock signal supplied to the control unit is reduced or the supply is stopped. Thus, power consumption can be further reduced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment of the present invention will be described below with reference to FIGS. FIG. 3 is a functional block diagram showing an electrical configuration inside the non-contact type IC card 1. The IC card 1 includes a one-chip integrated circuit 2 and an antenna 3 connected to the integrated circuit 2. In the integrated circuit 2, the CPU 4 is operated by being supplied with an operating power supply of 3 V supplied from the constant voltage unit 5.
[0013]
The constant voltage unit 5 generates a power supply for operation in response to a direct-current voltage output by rectifying the radio signal received by the antenna 3 by the rectifying unit 6. The signal received via the rectifying unit 6 is demodulated and given to the CPU 4 as received data. The transmission data output by the CPU 4 is transmitted to the outside as a radio wave signal via the transmission unit 7 and the antenna 3. Further, the signal received via the rectifying unit 6 is also supplied to the clock generating unit 8, and the clock generating unit 8 generates a clock signal from the signal and supplies it to the CPU 4.
[0014]
Data used in accordance with various applications in which the IC card 1 is used is stored in a memory 9 connected to the CPU 4 so as to be writable and readable.
[0015]
The cryptographic processor (data processing unit) 10 is used for performing an authentication process when communicating with a card reader 11 (see FIG. 4) described later. That is, the cryptographic processor 10 stores a “key” common to the card reader 11. When a random number transmitted from the card reader 11 to the IC card 1 is passed through the CPU 4, the cryptographic processor 10 encrypts using the “key”. This is a logic circuit configured to perform an operation for converting to a logic circuit.
[0016]
When the CPU 4 receives the encrypted data from the cryptographic processor 10, the CPU 4 sends it back to the card reader 11 side. If the card reader 11 collates the encrypted random number and recognizes that the IC card 1 has the same “key” as itself, the card reader 11 determines that the IC card 1 is an appropriate communication partner and substantially Data communication starts.
[0017]
FIG. 4 is a functional block diagram showing an electrical configuration on the card reader 11 side. The card reader 11 includes a control unit 12, a carrier generation unit 13, a modulation unit 14, a demodulation unit 15, an antenna 16, a sleep timer 17, a power supply unit 18, and the like. The control unit 12 is configured by a microcomputer or the like. The carrier generation unit 13 outputs a 13.56 MHz carrier signal to the modulation unit 14 when performing communication, and ON / OFF of the carrier generation unit 13 is controlled by the control unit 12.
[0018]
The modulation unit 14 modulates the carrier given from the carrier generation unit 13 with the transmission data output from the control unit 12 and outputs the modulated data to the antenna 16. In addition, when the radio wave signal transmitted from the IC card 1 is received via the antenna 16, it is given to the demodulator 15 and the demodulated data is output to the controller 12 as received data.
[0019]
The sleep timer 17 is a timer for setting the control unit 12 to a sleep mode, which is a mode in which power consumption is reduced for a set time. That is, the control unit 12 also includes a circuit for generating an operation clock signal therein, and when the sleep input terminal becomes active (sleep ON), the output of the clock signal by the clock generation circuit is stopped, and the internal register Thus, the sleep mode can be set to temporarily stop the operation while maintaining the above state.
[0020]
When the control unit 12 sets the set time of the sleep mode for the sleep timer 17, the sleep timer 17 is driven so as to be active only for the time when the sleep input terminal of the control unit 12 is set, and the time is set. After a lapse, the sleep input terminal is made inactive (sleep OFF).
[0021]
The power supply unit 18 supplies operation power to each unit of the card reader 11.
[0022]
Next, the operation of this embodiment will be described with reference to FIGS. FIG. 1 is a sequence showing a portion related to encryption processing in the contents of communication performed between the card reader 11 and the IC card 1. First, the control unit 12 of the card reader 11 transmits a random number to the IC card 1 side together with an encryption processing command ((1)). Then, the CPU 4 of the IC card 1 sets the estimated time required for the cryptographic processing (data processing) performed by the cryptographic processor 10 as a waiting time ((2)), and notifies the waiting time to the IC card 1 side. (3). Then, the random number transmitted from the card reader 11 is passed to the cryptographic processor 10 to start the cryptographic process (4).
[0023]
On the other hand, when the control unit 12 of the card reader 11 receives the notification of the waiting time, it performs a reception prohibiting process ((5)). That is, the demodulation processing in the demodulator 15 and the output of received data are prohibited. Then, the control unit 12 waits for the notified waiting time to elapse ((6)). That is, during the standby in (6), the cryptographic processor 10 performs cryptographic processing on the IC card 1 side, and there is a possibility that noise from the IC card 1 may be generated due to the processing operation.
[0024]
Then, when the waiting time has elapsed (<6>, "YES"), the control unit 12 permits the reception processing by the demodulation unit 15 (<7>). Even during the reception processing prohibition period from (5) to (7), the carrier continues to be transmitted to the IC card 1 by the modulation unit 14, and the power for operation of the IC card 1 is supplied.
[0025]
FIG. 2 shows detailed processing during standby in (5) to (7) of FIG. That is, after (5), the control unit 12 sets a count value corresponding to the notified waiting time in the sleep timer 17 (A), and then sets sleep ON (B). Then, the sleep timer 17 activates the sleep input terminal of the control unit 12 to place the control unit 12 in the sleep ON state, and down-counts the set count value.
[0026]
That is, (6) corresponds to a state in which the down count is performed by the sleep timer 17. When the count value of the sleep timer 17 becomes “0” (6, “YES”), the sleep timer 17 inactivates the sleep input terminal of the control unit 12 and puts the control unit 12 in the sleep OFF state. Return (C). Then, the process proceeds to (7).
[0027]
Referring again to FIG. 1, during the standby on the card reader 11 side, the cryptographic processing is completed by the cryptographic processor 10 ((8)). Then, the control unit 12 of the card reader 11 that has permitted the reception process in (7) gives an instruction to respond to the result of the encryption process to the IC card 1 ((9)). Then, the CPU 4 of the IC card 1 returns the cryptographic processing result received from the cryptographic processor 10 to the card reader 11 side (10).
[0028]
Thereafter, as described above, if the control unit 12 that has received the cryptographic processing result collates the result and recognizes that the IC card 1 has the same “key”, data communication with the IC card 1 is performed. If the “key” does not match, communication is prohibited.
[0029]
As described above, according to the present embodiment, the CPU 4 of the IC card 1 operates the cryptographic processor 10 when the cryptographic processing instruction is given from the card reader 11, and the data processed by the cryptographic processor 10 is sent to the card reader 11. Send. Then, the control unit 12 of the card reader 11 performs control so that signal reception is stopped while the cryptographic processor 10 of the IC card 1 is operating. Specifically, when an encryption processing command is given, the IC card 1 notifies the card reader 11 of the time required for encryption processing, and the control unit 12 of the card reader 11 performs a signal based on the notified time. The reception of was stopped.
[0030]
That is, since the IC card 1 transmits the data processed by the cryptographic processor 10 to the card reader 11, the card reader 11 does not need to receive during the period when the cryptographic processor 10 is processing. Therefore, even if the reception is stopped during the period, there is no problem in the original communication processing, and it is possible to appropriately avoid erroneous reception of a signal on which noise generated by the operation of the cryptographic processor 10 is superimposed.
[0031]
Furthermore, since the control unit 12 of the card reader 11 sets itself to the sleep mode and stops supplying the operation clock signal during the encryption process, it is possible to further reduce wasteful power consumption.
[0032]
(Second embodiment)
FIG. 5 shows a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. Only different parts will be described below. The configuration of the second embodiment is basically the same as that of the first embodiment, and the communication processing sequence shown in FIG. 5 is slightly different.
[0033]
That is, the processes (1) to (8) are performed in the same manner as in FIG. In the first embodiment, the card reader 11 then transmits a result response command to the IC card 1, but in the second embodiment, the waiting time set in the process (2) by the CPU 4 of the IC card 1 is used instead. It is determined whether or not the time has elapsed (9). When the waiting time elapses (“YES”), the IC card 1 notifies the card reader 11 of the processing result as in the first embodiment (10).
In the case of the second embodiment configured as described above, the same effect as that of the first embodiment can be obtained.
[0034]
(Third embodiment)
FIG. 6 shows a third embodiment of the present invention, and only different portions from the first embodiment will be described. The configuration of the third embodiment is basically the same as that of the first embodiment, and the communication processing sequence shown in FIG. 6 is different.
[0035]
That is, the control unit 12 of the card reader 11 first sets the time estimated to be required for the encryption processing on the IC card 1 side as a waiting time (that is, the reception processing stop time) ((1)), and then the encryption The waiting time set together with the processing command (and random number) is notified to the IC card 1 ((2)). Then, when the reception process is prohibited ((3)), the process waits until the waiting time set in the process (1) elapses ((4)).
[0036]
On the other hand, when the CPU 4 of the IC card 1 that has received the notification in the process (2) causes the cryptographic processor 10 to start cryptographic processing ((5)), the notified waiting time elapses in the same manner as the card reader 11 side. Wait ((6)). When the waiting time elapses ((6), “YES”), the CPU 4 determines whether or not the cryptographic processing by the cryptographic processor 10 is actually finished at that time ((7)).
[0037]
On the card reader 11 side, when the waiting time has elapsed ((4), “YES”), the receiving process is permitted ((8)). Therefore, if the cryptographic process is actually finished in the process (7) (“YES”), the CPU 4 of the IC card 1 finishes the cryptographic process as it is ((9)) and sends the processing result to the card reader 11 side. Notify (10).
[0038]
If the time required for the actual cryptographic process is longer than the notified waiting time on the IC card 1 side (7, “NO”), the CPU 4 performs the cryptographic process by the cryptographic processor 10 at that time. Suspend (11). Then, a request for processing extension (that is, extension of the reception processing stop time) is transmitted to the card reader 11 (12), and the process returns to the step (5).
[0039]
When the control unit 12 of the card reader 11 receives the request for extending the processing in the process (12), the control unit 12 returns to the process (1), sets the waiting time once again, and repeats the above-described processing. Then, if the encryption processing is completed when the waiting time notified again by the IC card 1 has elapsed (7, “YES”), processes 9 and 10 are executed.
[0040]
As described above, according to the third embodiment, the control unit 12 of the card reader 11 notifies the IC card 1 of the waiting time for stopping reception when giving the encryption processing command, and the CPU 4 of the IC card 1 If the operation of the cryptographic processor 10 is not finished even after the time notified from the reader 11 side, the card reader 11 is requested to extend the processing time. Therefore, even when the waiting time notified by the control unit 12 is shorter than the processing time of the cryptographic processor 10, if the waiting time is extended in response to a request on the IC card 1 side, it is reliably received until the operation of the cryptographic processor 10 is completed. Can be stopped.
[0041]
The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following modifications or expansions are possible.
A configuration for setting the control unit to the sleep mode while reception is stopped may be provided as necessary.
The operation mode for reducing power consumption is not limited to the one for stopping the supply of the clock signal, and may be an operation mode for reducing the frequency of the clock signal or stopping a part of the functions.
You may apply to a contact-type IC card.
Data processing unit is not limited to the cryptographic processor 10, the data to be transmitted when the processing command is given to the outside as long as it performs a predetermined processing.
[Brief description of the drawings]
FIG. 1 is a first embodiment when the present invention is applied to a non-contact type IC card system, and is a sequence diagram showing a portion related to encryption processing in communication contents performed between a card reader and an IC card. 2] Sequence diagram showing detailed processing during standby in steps (5) to (7) of FIG. 1 by the control unit of the card reader. FIG. 3 is a functional block diagram showing the electrical configuration inside the non-contact type IC card. 4 is a diagram corresponding to FIG. 3 on the card reader side. FIG. 5 is a diagram corresponding to FIG. 1 illustrating a second embodiment of the present invention. FIG. 6 is a diagram corresponding to FIG. 1 illustrating a third embodiment of the present invention.
Reference numeral 1 denotes an IC card, 11 a card reader, 10 a cryptographic processor (data processing unit), and 12 a control unit.

Claims (8)

An IC card for operating the data processing unit when a processing command is given from the outside, and transmitting the data processed by the data processing unit to the outside;
During the period in which the data processing unit is operating by giving the processing command to the IC card, the IC card is configured with a card reader including a control unit that controls to stop signal reception ,
When the IC card is given the processing command, the IC card notifies the card reader of the time required for the data processing,
The controller of the card reader, the IC card system characterized that you stop receiving signal based on the time notified by the IC card. An IC card for operating the data processing unit when a processing command is given from the outside, and transmitting the data processed by the data processing unit to the outside;
During the period in which the data processing unit is operating by giving the processing command to the IC card, the IC card is configured with a card reader including a control unit that controls to stop signal reception,
The control unit of the card reader notifies the time to stop reception when giving the processing command to the IC card,
The IC card interrupts the operation of the data processing unit when the operation of the data processing unit has not ended even after the time notified from the card reader has elapsed, and stops the operation time of the card reader. IC card system which is characterized that you request the extension. 3. The IC card system according to claim 1, wherein the control unit of the card reader sets itself to an operation mode in which power consumption decreases during the period . A card reader used in the IC card system according to any one of claims 1 to 3. IC card characterized in that it is used in the IC card system according to any one of claims 1 to 3. When the card reader gives a processing command to the IC card, the IC card operates the data processing unit, and the card reader gives a signal during the period when the data processing unit is operating by giving the processing command. In the communication control method of the IC card system, the IC card transmits the data processed by the data processing unit to the card reader.
The IC card notifies the time required for the data processing to the card reader when the processing command is given,
The IC card system communication control method, wherein the control unit of the card reader stops signal reception based on a time notified by the IC card. When the card reader gives a processing command to the IC card, the IC card operates the data processing unit, and the card reader gives a signal during the period when the data processing unit is operating by giving the processing command. controls reception to stop the IC card, the communication control method I C card system that sends data processed by the data processing unit to the card reader,
The control unit of the card reader notifies the time to stop reception when giving the processing command to the IC card,
The IC card interrupts the operation of the data processing unit when the operation of the data processing unit has not ended even after the time notified from the card reader has elapsed, and stops the operation time of the card reader. A communication control method for an IC card system, characterized by requesting an extension of the card. 8. The communication control method for an IC card system according to claim 6, wherein the control unit of the card reader sets itself to an operation mode in which power consumption decreases during the period .

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