JPS62232070A - Cipher calculation system for ic card system - Google Patents

Abstract

PURPOSE:To reduce the load of security processing at a terminal equipment by applying the security check of an IC card system to a security card loaded on the terminal equipment. CONSTITUTION:An IC card is loaded from an IC card port 4. In the side surface of a terminal equipment main body 1, a security card port 7 of a security card loading part is provided, from which the security card 8 is loaded. Such a security card 8 includes the cipher calculation parts necessary to execute all the security check in the IC card system. As a result, the load of security processing at the terminal equipment is reduced in comparison with a conventional IC card system in which all the security check is loaded on the terminal equipment.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a cryptographic calculation method for a tC card system using a dedicated card for security processing [Prior art and its problems] In recent years, the era has become known as the cashless era. By using a card issued by a credit card company, it is now possible to purchase products without having to handle cash.

Conventionally, the cards used include plastic cards, embossed cards, and magnetic striped cards, but these cards are structurally gAii! Since i is easy, unauthorized use has become a problem.

Therefore, in order to solve this problem, we have developed an information card that incorporates an IC circuit that stores a PIN number etc. inside the top of the car so that the PIN number cannot be easily read from the outside.
So-called IC cards are being considered, and such IC
An IC card system that combines a card and a terminal has been developed.

By the way, in conventional IC card systems, in order to prevent the terminal from being activated and used illegally by unauthorized persons, a terminal activation card is used, and this card is attached to the terminal when the terminal is activated. There is a concept of supplying data such as part of the software (or the encryption key itself) required for execution when the power is turned on. (For example, Japanese Patent Application No. 60-43386) However, when such a card finishes supplying data to the terminal, it is ejected from the terminal and does not take any part in subsequent terminal operations.

Therefore, various security checks (cryptographic calculations, etc.) for IC cards and the like during subsequent system operation all depend on the hardware and software algorithms built into the terminal in advance. However, in this case, the security processing method at the terminal becomes fixed, and the processing that the terminal must support requires advanced hardware and software to ensure stable security over the long term.

This means that such terminals and the IC cards used in combination with these terminals are required to have complex hardware, leading to an increase in costs and an increase in processing time. Ta.

Additionally, if the security processing method at the terminal becomes fixed, there will be no countermeasures against counterfeiting of the terminal due to election changes, etc., and unauthorized use of such devices will significantly reduce the security of the IC card system. There was a drawback.

εPurpose of the Invention This invention was made in view of the above circumstances, and it can reduce the burden of security processing on the terminal, simplify the hardware and shorten the processing time, and also ensure that the terminal is not counterfeited. An object of the present invention is to provide a cryptographic operation method for an IC card system that can prevent the above problems and improve the security of the system.

[Summary of the Invention] The cryptographic operation method of the IC card system according to the present invention is an IC card system having an IC card and a terminal to which the IC card is installed, and the terminal has calculation means for encrypting and decoding data. A security card is installed, and various security checks are performed using encrypted data or decrypted data obtained through the security card.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an external view of a terminal, an IC card and a security card attached to the terminal. In the figure, reference numeral 1 denotes a terminal body, and the surface of this body 1 has a keyboard 2 with numeric keys etc., a display part 3 for displaying messages, input data, etc., and an IC card insertion slot 4 in an IC card insertion part. have.

An IC card is inserted through this IC card insertion slot 4. This IC card 5 has an I
It incorporates a C circuit and has a connector 6 on its surface.

On the other hand, on the side of the terminal main body 1, there is a security card insertion lower part of the security card installation section. A security card 8 is attached to this security card insertion lower. This security card 8 has a cryptographic counter necessary for performing all security checks in the IC card system.

FIG. 2 shows the circuit configuration of such a terminal. In the figure, 11 is a system bus, and this system bus 11 includes a sound controller 12, a working RAM 13, a system program ROM 14, terminal attributes RO to 115, and initial parameters RA.
M16, main controller 17, display drive controller 18, key controller 19, reader/writer controller 20, comparison unit 21, input/output controller l-0-522
, an output buffer 24 via an output controller 23, and an input controller 26 via an input buffer 25.

A speaker 27 is connected to the sound controller 12 and outputs an alarm sound as necessary.

The working RAM 13 stores rPANJ, rcI-INJ, r, which will be described later, sent from the IC card side to the memory area.
EPDJ, etc. are stored, as well as various processing data within the terminal.

The system program ROM14 is an ENQ for matching with IC cards as well as various system programs.
It has codes etc.

The terminal ROM 15 stores terminal codes TC (for example, manufacturing code, issue code, store code, etc.) depending on the application.

Initial parameter RAM 16 stores answer-to-reset data from IC card 5 all at once. This initial parameter RAM 16 contains the transmission line 16.
Output controller 23, input controller 2 via a
6, a vpp level latch section 28, a pp timer latch section 29, and an Ipp level latch section 30.
, Vpp timer 32, It) I) limiter 33 are connected.

Here, the Vppff1 source 31 is for securing the voltage Vpp used for writing data into the data memory of the IC card. Further, the Vpp timer 32 is for securing the maximum unit processing time specified by the IC card. Furthermore, the lpp limiter 33 determines the permissible value of the data write current.

In this case, the maximum data write voltage by the Vpp power supply 31, the ■pp application time by the Vpp timer 32, the maximum allowable data write current by the Ipp limiter 33, etc. are based on the answer-to-reset data stored in the initial parameter RAM 16. Set.

An IC card operating frequency selector 34 is connected to the data transmission line 16a. An oscillation signal from an oscillator 35 is supplied to this selector 34 via a frequency divider 36.
It is output from the C1ockl element as a signal with the operating frequency set.

A timer 37 is connected to the initial parameter RAM 16. This timer 37 is the initial parameter RA
Based on the answer-to-reset data stored in M16, the maximum response time is counted from the time when an ENQ signal or other command signal is sent to the IC card, and within this waiting time If there is no response signal from the card side, main controller 1
7 again instructs the transmission of these signals, or the reader/writer controller 2
0 to instruct disconnection with the IC card.

A comparator 21 and an input/output controller 22 are connected to the system control line 17a of the main controller 17.
Control commands are distributed from the main controller 17 to each circuit depending on the operating state of the system. Furthermore, the main controller 17 is provided with a random number generator 17b.

The display driver 1 roller 18 controls the display on the display section 3 of the terminal 1 shown above.

The key controller 19 provides a key sampling signal to the keyboard 2 of the terminal 1 described above so as to detect a key input signal.

The reader/writer controller 20 drives and controls the reader/writer wire groove 81138. Here, the separate section 38 is equipped with a motor for transporting the card, and transports the IC card inserted from the card insertion slot of the terminal to a predetermined position and electrically connects the card to the terminal, thereby completing the predetermined processing. Then, the IC card is returned to the card insertion slot.

The output buffer 24, reset controller 39, lpp level latch section 30, operating frequency selector 34, and vCC power supply 40 are connected to such a reader/writer tim section 38. These output buffer 24, reset controller 39, II) I) level latch section 30,
Operating frequency selector 34, I10 and R connected to the above-mentioned IC card 5 side in correspondence with VCC voltage [40]
e5et terminal, Vpp terminal, (:, lock terminal, v
It has a CC terminal, among which I10 terminal, Re5et terminal, Cl0Ck terminal, and Vcc terminal can be connected to the security card 8 side. In this case, I10
The terminal is connected to the IC card 5 or security card 8 via a transfer gate 41 controlled by the main controller 17.

The input controller 26 and the output controller 23 control data exchange with the IC card in accordance with commands from the main controller 17 via the initial parameter RAM 16. Of these, the input controller 26 outputs the data sent from the IC card to the working RAfv 113 etc. via the input buffer 25 and also provides it to the comparison section 21, and provides the comparison output here to the main controller 17. Further, the output controller 23 sends data provided from the terminal attribute ROM 15 or the like to the IC card 5 or security card 8 side via the output buffer 24.

The input/output controller 22 is used to exchange data encoded in [18] when a database, that is, a host computer is connected online.

Next, Figure 3 shows the IC that can be seen in such a terminal.
This shows the circuit configuration of the card.

In the figure, 51 is a system bus, and this system bus 51 includes a data ROM 52 and an application ROM 5.
3. System program ROM54, working RAM
55, system controller 56, encoder 57, read/write controller 58, card status buffer 5
an input controller 61 via an input buffer 60;
Output controllers 63 are connected through output buffers 62, respectively. Further, a data input/output terminal I10 is connected to the input controller 61 and the output controller 63.

Here, the data ROM 52 stores all operating conditions for the IC card itself (for example, data writing).

applied voltage, current permissible value, maximum applied voltage, maximum data transmission amount, maximum response waiting time, etc.), and these condition data are stored in a predetermined format after the card's internal initialization is completed. It is sent to the terminal side as answer-to-reset data.

The data ROM 52 also stores key data used for data encryption or decryption by an encoder 57, which will be described later.

The application ROM 53 stores card type data rAPNJ indicating what type of IC card this card is, and this card type data is the attribute of the terminal side after initial parameter setting based on the above answer-to-reset data. At the time of exchange, it is placed in a predetermined format and sent.

The system program ROM 54 contains various system programs as well as code signals rAcKJ or rNAc indicating whether the signals transmitted and supplied from the terminal side are correct or not.
Equipped with J.

The working RAM 55 stores various processing data within the card.

The system controller 56 outputs operation commands to each circuit according to the data reception signal transmitted and supplied via the input cover sofa 60 and the operation state.

The read/write controller 58 controls the writing and reading of data in the data memory 64 in response to commands from the system controller 56.

For example, an EEP-ROM is used as the data memory 64. In this case, such data memory 64 has a storage area for transactions and r l P I
It stores information such as codes N, J, IPANJ, rcHNJ, and rEPDJ, status data rsTJ, and the like. Here, rlPINJ(lnitialzatio
n Personal Identity
on Number) is a random code of, for example, 6 bits, and is a number until the own verification number rPINJ is used. [PANJ (Primary AC
COUNT Number) represents the account number. fcHNJ (Card holder-sN
ame) represents the cardholder's name.

rEPDJ (Exp i ration Dat
e) represents the expiration date. rsTJ is used to represent the current card status, and is sent to the terminal side using data formats 1 to 1.

The encoder 57 performs encryption based on a predetermined algorithm using key data stored in the data ROM 52, and also decrypts the encrypted data.

The status buffer 59 is used to set a flag when the card is invalid and to disable the card from being used thereafter.

The contents of the data memory read by the read/write controller 58 are sent to one input terminal of the comparator 65 and the system bus 5.
1 or the card status buffer 59.

The comparator 65 receives data encrypted or decoded by the encoder 57 or a specific code stored in the data ROM 52 at the other input terminal. The comparison output of this comparison section 65 is supplied to the system controller 56 via the system control line 56a.

Note that while the IC card thus constructed is attached to a terminal (not shown), a reset signal, C!, is sent from the terminal side to the Re5et terminal. A system clock is supplied to the ock terminal, and Vc is supplied to the VCC and Vpp terminals.
c power supply, vpp? ! source is connected. Here, Vcc!
1 is system drive II, Vpp power supply is data memory 6
The power supply voltage is set on the terminal side based on the answer-to-reset data stored in the data ROM 52. on the other hand.

A system operation signal from the C1ock terminal is supplied to each circuit via a frequency divider 66.

Next, FIG. 4 shows the circuit arrangement of the security card installed in the terminal.

In the figure, 71 is a system bus, and this system bus 71 includes an input control circuit 72, an output control circuit 73,')
--Teng RAM 74.7'', ROM 75, and main controller 76 are connected.

Here, the input control circuit 72 and the output control circuit 73 are I10
This is for exchanging data with the above-mentioned terminal 1 via the terminal.

The working RAM 74 stores various processing data within the card.

The data ROM 75 stores key data for encryption or decoding.

The main controller 76 operates according to the operating state of the system.
Control commands are generated to each circuit via the control bus 76a.

One input terminal of each of three arithmetic units 77, 78, and 79 is connected to the system bus 71. These computing units 77.
A distributor 80 is connected to the other input terminal of 78 and 79. Further, the outputs of these computing units 77, 78, and 79 are sent to the system bus 71 via the selector 81.

Here, the arithmetic units 77, 78, and 79 are independent cryptographic circuits, and each performs arithmetic operations based on mutually different algorithms.
1. I am able to do things.

Plain text data to be encrypted or cipher text data to be decoded is given to the input terminals connected to the system bus 71 of the computing units 77, 78, 79, and the other input terminals connected to the distributor 80 , key data for encryption or decryption is given by the distributor 8o to the specific arithmetic unit that is currently about to start calculation.

Note that here, the computing unit 77 is used for encryption or decoding for IC card authentication or terminal authentication, the computing unit 78 is used for encryption or decoding in transactions, and the computing unit 7 is used for IIIJT when online. used respectively.

It should be noted that when the security card thus configured is attached to the terminal, a reset signal is supplied from the terminal side to the Re5et terminal, a system clock is supplied to the Clock terminal, and a VCC power supply is connected to the VCC terminal. Here, the VCC power supply is a system driving power supply. On the other hand, the clock signal from C1ocki is passed through frequency divider 8.
2 to the timing bus 76b as a timing signal.

Next, the operation of the embodiment configured as described above will be explained.

First, in FIG. 1, the IC card 5 is inserted through the card insertion slot 4 of the terminal body 1, and then the security card 8 is inserted through the security card insertion lower.

The case where the IC card 5 is authenticated in this state will be explained according to the flowchart of FIG.

First, in the terminal, in step A1, any RAN is selected from the random number generator 17b of the main controller 17.
(Random number) data is generated and sent to the IC card. In this case, in the terminal, main controller 1
RAN data is created by the command 7, and is sent to the IC card side from the I10 terminal via the output controller 23 and output buffer 24. In this case, the output buffer 24 is connected to the I10 terminal on the IC card side by the transfer gate 41 according to a command from the main controller 17.

The IC card receives RAN data in step B1. That is, the RAN data input to the I10 terminal is temporarily stored in the working RAM 55 via the input controller 61 and the input buffer 60.

Next, proceed to step B2. In step B2, the RAN data stored in the working RAM 55 is read out and provided to the encoder 57. Then, encryption is performed in this encoder 57 based on a predetermined algorithm using the key data stored in the data ROM 52, and the RAN
The data is converted to RAN' data. Then, in step B3, this encrypted RAN-data is sent to I1 via the output buffer 762 and the output controller 63.
It is sent from the 0 terminal to the terminal side.

In the terminal, the RAN-data inputted to the I10 terminal in step A2 is received via the input controller 26 and input buffer 725, and is stored in the working RAM 13.
is memorized. Then, the process advances to step A3. In this step A3, the RA is
N” data is read from the working RAM 13 and I
An identification code indicating C card authentication is added, and the I/ODa is sent via the output controller 23 and output buffer 724.
The child then sends it to the security card side.

In this case, the output buffer 24 is connected to the I10 terminal on the security card side by the transfer gate 41 according to a command from the main commil roller 17.

In the security card, the RAN is
=Receive data. That is, the RAN-data input to the I10 terminal is normalized by the input control circuit 72 and temporarily stored in the working RAM 74.

In this state, the process proceeds to step C2. In step C2, the main controller 76 analyzes the contents of the working RAM 74 and determines the arithmetic unit and key data to be used. In this case, since it is IC card authentication, calculation 2377
is specified. In this state, predetermined key data for decoding is read from the data ROM 75, and is provided to the arithmetic unit 77 via the distributor 80. Also, at the same time, RAN stored in the working RAM 74 =
The data is read out and sent to the arithmetic unit 7 via the system bus 71.
7 is given. As a result, the arithmetic unit 77 performs an arithmetic operation using predetermined key data, and the RAN' data is decoded and converted into [RAN-] data. This [RAN'] data is then written to the buffer area of the working RAM 74.

In this state, the process proceeds to step C3, where the decrypted [RAN
-] Data is sent back to the terminal side from the I10 terminal via the output control circuit 73.

On the terminal side, input is made to the I and '0 terminals in step A4. [RANi data is input to controller 26]
, received via the input buffer 25 and working RA
It is stored in M13. Then, the process advances to step A5.

In this step A5, the RAN sent to the IC card in step A1 according to a command from the main controller 17 is
[RAN] stored in the data and working RAM 13
”] The data is given to the comparator 21 and compared there. Then, the process proceeds to step 86, and the authenticity of the IC card is determined from the comparison result of the comparator 21.

In this case, if the RAN data and [RAN'] data match, the IC card at this time is determined to be genuine, and this fact is displayed on the display unit 3 via the display drive controller 18, and the next processing is performed. is permitted to migrate to. On the other hand, if the RAN data and [RAN=] data do not match, the IC card is considered to be counterfeit, and a message to that effect is sent to the display unit 3 via the display drive controller 18.
will be displayed to alert you.

Next, the case of authenticating the terminal 1 will be explained according to the flowchart of FIG. First, in the terminal, in step A11, the terminal-specific TCN code (
It can be any random number. ) is generated and sent to the security card. In this case, the terminal uses the terminal-specific TC according to the instructions from the main controller 17.
The N code is taken out and this is the output controller 23, output buffer? The signal is sent from the I10 terminal to the security card side via 24. In this case, main controller 1
7, the output buffer 24 is connected to the I10 terminal on the security card side by the transfer gate 41.

In the security card, TCN is sent in step C11.
Receive code. In other words, the T input to the I10 terminal
The CN code is normalized by input control circuit 72 and stored in working RAM 74.

In this state, the process advances to step C12. This step C12
Then, the main controller 76 controls the working RAM 7.
The contents of 4 are analyzed and the arithmetic unit and key data to be used are determined. In this case, the arithmetic unit 77 is specified because it is a terminal-specific certificate. In this state, data ROM7
Predetermined key data for encryption is read out from 5, and is given to arithmetic unit 77 via distributor 80. At the same time, the TC stored in the working RAM 74
The N code is read out and applied to the arithmetic unit 77 via the system bus 71. As a result, the arithmetic unit 77 performs an arithmetic operation using predetermined key data, and the TCN code is encrypted and converted into a TCN-code. And this T
The CN' code is written to the buffer 1 area of working RAM 74.

In this state, the process proceeds to step C13, where the encrypted TCN
``The code is sent back to the terminal side from the I/'O terminal via the output control circuit 73.

On the terminal side, the TCN-code input to the I10 terminal in step A12 is received via the input controller 26 and input buffer 725, and is stored in the working RAM1.
3 is temporarily stored. Then, the process advances to step A13.

In this step A13, the TCN code sent to the security card and the TCN = code stored in the working RAM 13 are retrieved according to the command from the main controller 17, and these are sent to the IC card from the I10 terminal via the output controller 23 and output buffer 24. sent to the side.

For IC cards, enter the TCN code and TC in step B11.
Receive N-code. In other words, the TCN code and TCN- code input to the I10 terminal are input to the input controller 6.
1. Working RA lvl via input buffer 60
55 is temporarily stored.

Next, the process advances to step 812. In this step 812, the TCN=code stored in the working RAM 55 is read out and given to the encoder 57. This encoder 57
is given predetermined key data from the data ROM 52, and in this state the TCN = code is decoded and [T
CN-] code.

Then, the process proceeds to step B13, where the TCN code stored in the working RAM 55 and the [TC
The Ni code is given to the comparing section 65, where it is compared. Then, the comparison result in this comparison section 65 is determined in step B1.
4, it is sent to the terminal side from the I10 terminal via the output buffer 62 and output controller 63.

In the terminal, the comparison result inputted to the I10 terminal in step A14 is received via the input controller 26 and input buffer 25, and is temporarily stored in the working RAM 13.

The contents of this working RAM 13 are then read out by the main controller 17, but here, T
If a result in which the CN code and [TCNN code match] is obtained, the terminal at this time is determined to be legitimate, and this fact is displayed on the display unit 3 via the display drive controller 18, and the next Allowed to proceed to processing.

On the other hand, if a result is obtained in which the TCN code and [TCNi code] do not match, the terminal is considered to be a counterfeit, and a message to that effect is displayed on the display unit 3 via the display drive controller 18, so that caution is advised. Become encouraged.

Next, an actual transaction, that is, a case of 1 to 1 run will be explained. First, data related to the transaction is
The case of writing to the C card will be explained according to the flowchart shown in FIG. First, in the terminal, step A
At step 21, data relating to the actual transaction, such as AMT (transaction amount) data, is input using the numerical keys of the keyboard 2.

Then, in step A22, the AMT data is sent to the security card from the I10 terminal via the output controller 23 and output buffer 24. In this case, the output buffer 24 is
is connected to the I/OM child on the security card side by a transfer gate 41.

In the security card, in step C21, AMT
Receive data. In other words, the A input to the I10 terminal
The MT data is normalized by the input ff1l control circuit 72 and stored in the working RAM 74.

In this state, the process advances to step C22. This step C22
Then, the main controller 76 controls the working RAM 7.
The contents of 4 are analyzed and the arithmetic unit and key data to be used are determined. In this case, since it is a transaction, the arithmetic unit 78 is specified.

In this state, predetermined key data for 01 encoding is read from the data ROM 75, and is provided to the arithmetic unit 78 via the distributor 8o. At the same time, the AMT data stored in the working RAM 74 is read out.
It is applied to the σ operator 78 via the system bus 71. With this, performance T! An operation using predetermined key data is performed in the unit 78, the AMT data is encrypted, and AMT=
converted to data. This AMT-data is then written to the buffer 1 area of the working RAM 74.

In this state, the process proceeds to step C23, where the encrypted AMT
- The data is added with a cryptographic identification code to the output control circuit 7
3 is sent back to the terminal side via the I10 terminal.

On the terminal side, the AMT-data input to the 17'O terminal in step A23 and the cryptographic identification code added thereto are received via the input controller 1-roller 26 and the input buffer 25, and are stored in the working RAM 13. Memorized temporarily. Then, the process advances to step A24.

In this step A24, AMT stored in the working RAM 13 according to a command from the main controller 17
- The data and encrypted identification code are extracted and sent to the IC card side from the I10 terminal via the output controller 23 and output buffer 24.

The IC card receives AMT-data and a cryptographic identification code in step B21. In other words, the AMT-data and cryptographic identification code input to the terminal 110 are transferred to the working RAM 5 via the input controller 61 and the input buffer 760.
5 is temporarily stored.

Next, the process advances to step B22. In step B22, the working RA is
The AMT-data and code identification code stored in the M55 are read out, and these are sent to the read/write controller 5.
8 to the transaction area of the data memory 64 as transaction data.

Next, the case where data related to a transaction is read from an IC card will be explained according to the flowchart shown in FIG. First, in step B31, the IC card performs read/write operations according to a command from the system controller 56.
Predetermined AMT' data is read out from the transaction area of the data memory 64 via the write controller 58 with the cryptographic identification code added. Then these A
M”M data and cryptographic identification code are temporary working R
It is stored in AM55. In this state, the process advances to step 832.

In this step 832, the AMT=data and cryptographic identification code stored in the working RAM 55 are taken out and sent from the ■/'O window to the terminal side via the output buffer 62 and output controller 63.

On the terminal side, the AMI data and code identification code input to the I10 terminal in step A31 are transferred to the input controller 26 and the input buffer. 25 and temporarily stored in the working RAM 13. and,
Proceed to step A32.

In this step A32, the △MT' data and the [lIi identification code] stored in the working RAM 13 are taken out according to a command from the main controller 17, and these are sent to the I1 via the output controller 23 and the output buffer 24.
It is sent from the 0 terminal to the security card side. In this case, the output buffer 24 is connected to the I10 terminal on the security card side by the transfer gate 41 according to a command from the main controller 17.

For the security card, go to step C31.
- Receive data and cryptographic identification codes. In other words, 1
The AMT' data and abbreviation identification code input to the /'0 terminal are sent to the working RAM 7 via the input control circuit 72.
4 is stored.

In this state, the process advances to step C32. This step C32
Then, the main controller 76 controls the working RAM 7.
The contents of 4 are analyzed and the arithmetic unit to be used is determined.

In this case, since it is a transaction, the arithmetic unit 78 is specified. From this state, first work RAM7
The encrypted identification code is read out from 4 and given to the arithmetic unit 78 via the distributor 80, and at the same time, the working R
The AMT" data stored in the AM74 is read out and given to the arithmetic unit 78 via the system bus 71. As a result, the arithmetic unit 78 performs an arithmetic operation using the encrypted identification code, and the AMT=data is decoded. Then, this [AMT-] data is occupied in the buffer area of the working RAM 74.

In this state, the process advances to step C33, where the decrypted [AMT
The i data is sent back to the terminal side from the I10 terminal via the output control circuit 73.

On the terminal side, the [AMT''] data input to the I10 terminal in step A33 is input to the input controller 2.
6, received via input buffer 725 and working R
It is temporarily stored in Alv113.

Then, the process advances to step A34.

In this step A34, the [AMTi
Data is retrieved and used as transaction data during the transaction.

Next, the case of transmitting data online will be explained according to the flowchart of FIG. 9.

First, in the IC card, predetermined data is read from the data memory 64 via the read/write controller 58 in accordance with a command from the system controller 56 in step B41. Then, this data is temporarily stored in the working RA.
Stored in M55.

In this state, the process advances to step B42.

In this step B42, the data stored in the working RAM 55 is taken out and sent to the terminal side from the I10 terminal via the output buffer 62 and the output controller 63.

On the terminal side, data input to the I10 terminal in step A41 is received via the input controller 2G and input buffer 25, and is temporarily stored in the working RAM 13. Then, the process advances to step A42.

In this step A42, the data stored in the working RAM 13 is taken out according to a command from the main controller 17, and sent to the security card side from the I/O terminal via the output controller i-roller 23 and the output buffer 24. In this case, the output buffer 24 is connected to the I10 terminal on the transfer gate side according to a command from the main controller I roller 17.

The security card receives data from the terminal in step C41. That is, 1, -' O
The data input to the terminal is normalized by the input control circuit 72 and stored in the working RAM 74.

In this state, the process advances to step C42. This step C42
Then, the main controller 76 controls the working R A
The contents of M74 are analyzed, and the arithmetic unit and key data to be used are determined. In this case, since it is online, seven computing units are specified. From this state, data RO
Predetermined key data for encryption is read from the M75 and is given to the arithmetic unit 79 via the distributor 80.

At the same time, the data stored in the working RAM 74 is read out and sent to the arithmetic unit 7 via the system bus 71.
given to. As a result, the arithmetic unit 77 performs an arithmetic operation using the predetermined key data, and the data is converted into v3 code. This encrypted data is then sent to the working RA
3 is stored in the buffer area of M74.

In this state, the process proceeds to step C43, and the encrypted data is sent back to the terminal side from the I/O terminal via the output control Ut+ circuit 73.

On the terminal side, the Oa encoded data input to the I10 terminal in step A43 is received via the input controller 26 and input buffer 725, and is stored in the working RAM1.
3 is temporarily stored. Then, the process advances to step A44.

In step A44, the encrypted data stored in the working RAM 13 is read out according to a command from the main controller 17, and is sent online to the outside.

Therefore, by doing this, a security card having calculation means for encrypting and decoding data is installed in the terminal, and various security checks are performed using the 88-encrypted data or decrypted data obtained through the security card. I decided to do it, so
Compared to conventional IC card systems in which all security checks are carried out on the terminal, the burden of security processing on the terminal can be reduced. This eliminates the need for sophisticated hardware and software to ensure security, making it possible to simplify the terminal for security processing and the hardware of the IC card used in combination, thereby reducing costs. At the same time, processing time can also be shortened. Furthermore, since the security card is replaceable, unauthorized use due to forgery of the security check terminal for IC card authentication can be prevented, and the security of the entire system can be improved.

It should be noted that the present invention is not limited only to the above embodiments, but can be implemented with appropriate modifications within the scope without changing the gist.

[Effects of the Invention] According to the present invention, the security check for the IC card system is carried out on the security card attached to the terminal, so the burden of security processing on the terminal can be reduced. The hardware related to security processing in the system, such as the terminal and the IC card combined with the terminal, can be simplified, and costs can be reduced accordingly, as well as processing time. Furthermore, since the algorithm for security checks can be changed as appropriate by simply replacing the security card, unauthorized use due to forgery of terminals can be prevented, and the safety of the entire system can be improved.

[Brief explanation of drawings]

FIG. 1 is an external view showing an embodiment of the present invention, FIG. 2 is a block diagram showing the circuit configuration of the terminal of the same embodiment, and FIG.
The figure is a block diagram showing the circuit configuration of the IC card of the same embodiment, FIG. 4 is a block diagram showing the circuit configuration of the security card of the same embodiment, and FIGS. 5 to 9 explain the operation of the same embodiment. This is the flowchart i- for. 1... Terminal body, 2... Keyboard, 3...
-Display unit, 5...IC card, 8...Security card, 13...Working RAM, 17...Main controller, 21...Comparator, 52-Data R
OM, 55... Working RAM, 56... System controller, 57... Encryptor, 64... Data memory, 65... Comparison unit, 74... Working RA
M, 75...Data RO~1.76...Main controller, 77-79...Arithmetic unit, 80...Distributor, 81...Selector.

Claims (1)

[Claims] In an IC card system having an IC card and a terminal to which the IC card is installed, a security card having a calculation means for encrypting and decoding data is installed in the terminal, and encrypted data obtained through the security card is installed. Alternatively, a cryptographic calculation method for an IC card system is characterized in that various security checks are performed using decrypted data.