JPH06161354A - Ic card terminal and system using the same - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To prevent unauthorized use of IC card terminals. [Structure] When the IC card 2 is inserted into the IC card terminal 1, the remaining amount V from the IC card, the number IDT of the terminal used last time, the number t indicating the number of times of updating the time stamp information st, the public key nT, and the signature of the time stamp ST (st) is transmitted to the terminal. Provide the service if V is higher than the service charge specified by the user unless there is a match with the stolen terminal number. After the service ends, the remaining V'after subtracting the usage charge from V, the IDT 'of the terminal, the update information t', the digital signature ST '(st') for the time stamp information st 'by the terminal keys pT', qT ', and the disclosure Send the key nT 'to the IC card. The IDT initial value in the terminal list is repeatedly calculated for the received t to update the time stamp information, and the validity of the signature ST is verified with this and the key nT.
Determine when the C card was used in the terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system using an IC card as a prepaid card, a credit card, a stamp card, etc., and an IC card terminal for the system.

[0002]

2. Description of the Related Art Conventionally, in this type of system, an IC card and an IC card terminal have the same encryption method and have the same secret key, and the amount information is encrypted by this secret key for communication, and each secret key is an IC. Even if the inside of the card or IC card terminal was opened, the private key could not be viewed or tampered with. Therefore, it is almost impossible to falsify the contents of the IC card unless the private key is leaked.

[0003]

However, it cannot be said that it is impossible to illegally rewrite the contents of the IC card by using the stolen IC card terminal, and once it is possible, a serious effect such as system down will occur. There is a risk of causing

[0004]

According to a first aspect of the present invention, a terminal number for identifying a terminal, time stamp information updated by a predetermined algorithm at appropriate intervals, and update information indicating the number of times the time stamp information is updated. To record the terminal key for creating the digital signature, the memory that stores the public key for verifying the digital signature, the terminal number received from the management center, the initial value of the time stamp information, and the update information as the terminal list. The terminal number received from the memory of the IC card and the terminal number recorded in the terminal list are compared, and when they match, the initial value of the time stamp information corresponding to the terminal number recorded in the terminal list is calculated. According to the update information received from the IC card, it is updated by the above predetermined algorithm, and the updated time stamp information and When the digital signature received is verified by the public key received from the C card and it is judged to be valid, the received update information is compared with the update information corresponding to the terminal number recorded in the terminal list, That I
It is an IC card terminal having means for judging the time when the C card is used by the IC card terminal having the received terminal number.

According to the invention of claim 2, the information including the IC card terminal of the invention of claim 1 and the terminal number of the IC card terminal, the update information, and the time stamp information after being used in the IC card terminal. , A means for receiving the public key and recording it in the memory, and means for transmitting the terminal number, update information, digital signature, and public key recorded in the memory to the IC card terminal at the next use. An IC card, a terminal number of each IC card terminal, a database that manages initial values and update information of time stamp information, and each time the IC card terminal updates its time stamp information, receives update information from the IC card terminal, The IC card system is operated by the management center having means for replacing the update information recorded corresponding to the terminal number with the received update information. Temu is configured.

[0006]

With this configuration, when the IC card is used, the terminal number of the IC card terminal used and the digital signature created by the IC card terminal are verified in a predetermined memory area in the IC card. A public key for recording, a digital signature created by the IC card terminal for time stamp information at the time of use, and update information of the time stamp information are recorded. Next, when the IC card is used in another IC card terminal, the IC card stores the information recorded in the memory in the IC.
The IC card terminal transmits to the card terminal, and the IC card terminal identifies the IC card terminal used last time from the received terminal number. When that terminal number is compared with the terminal number registered in the terminal list in the IC card terminal, and there is a match,
Read the initial value and update information of the time stamp information corresponding to the terminal number registered in the terminal list,
The initial value of the time stamp information is updated by a predetermined algorithm according to the update information received from the IC card, and the time stamp information of the IC card terminal at the time of the previous use is obtained. The validity of the digital signature for the time stamp information is verified by the obtained time stamp information and the public key received from the IC card, and it is checked that the update information received from the IC card has a correct value. When the update information is valid, the update information is compared with the update information recorded in the terminal list,
It is determined whether or not the IC card is used in the IC card terminal registered in the terminal list before or after the time when the terminal number is registered in the terminal list. When the authenticity cannot be verified in the verification of the digital signature, it is determined that the update information or the digital signature received from the IC card is not legitimate information and is processed as an abnormal card. Furthermore, by specifying the terminal number of the IC card terminal at the management center, the initial value of the time stamp information of the IC card terminal of that terminal number and the update information at that time can be known, and such information can be obtained from the IC card terminal. Can be registered in the terminal list of.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a case where one embodiment of the present invention is applied to a prepaid card system will be described with reference to the drawings.
FIG. 1 is an explanatory diagram of a system configuration of an embodiment of the invention of claim 2, in which an IC card terminal 1 carries out charge processing by an IC card 2 and provides various services such as a telephone call. The management center 3 manages the terminal number of the IC card terminal 1 and the like, and by calling the telephone number of the IC card terminal 1, the IC card terminal 1 and the management center 3 are connected via the communication network 4 and information is transmitted. Can be sent.

FIG. 2 shows an IC card terminal 1 according to the first aspect of the invention.
FIG. 9 is a diagram showing the internal configuration of the control unit 11 including a CPU, and programs such as a processing procedure, an algorithm for updating time stamp information, and an algorithm for creating a digital signature are recorded in an internal ROM. In addition, the terminal number, time stamp information, update information of time stamp information, terminal key for creating digital signature, public key for verifying digital signature, etc.
It is recorded in AM. As an algorithm for updating the time stamp information, for example, "The Institute of Electronics, Information and Communication Engineers, Journal D Volume, J70-D, No. 7, p.
3 (1987) ”, and the digital signature algorithm is, for example,“ NTT ”.
R & D Vol. 40, No. 5, p. 687-696
(1991) ”described in ESIGN can be used. Terminal number, initial value of time stamp information, terminal key,
The public key may be connected to a management center 3 (not shown) via a communication network when the IC card terminal is installed, received from the management center 3 and recorded in a memory. May be. For the update information, for example, 0 is set as the initial value, and 1 is set every time the time stamp information is updated.
2, ... will increase. In addition, a specific I
A terminal list area for registering the terminal number of the C card terminal, the initial value of the time stamp information, and the update information is provided. I exchange data with IC card 2
The C card reader / writer section 12, the operation input section 13 including operation buttons and dial buttons, the display section 14 including a liquid crystal display, the call circuit 15 are connected to the control section 11, and the handset 16 is connected to the call circuit 15. A communication processing unit 17 that performs processing with a communication network is connected to the control unit 11.

FIG. 3 is a diagram showing the internal structure of the IC card 2. A program such as an IC card processing procedure and an algorithm for verifying a digital signature is recorded in the ROM 61, and the CPU 63 uses the RAM 62 as a work area. 2 to perform all control, and communication with the IC card reader / writer unit 12 of the IC card terminal 1 shown in FIG.
5 via contact 66. The money amount information is written by the IC card issuing machine (not shown) when the IC card 2 is issued, and recorded in the EEPROM 64.

1 to 3, the terminal number set in the IC card terminal 1, the initial value of the time stamp information, and the update information are registered in the management center 3. The time stamp information (initial value) set in the IC card terminal 1 is updated by an internal clock function, for example, by a predetermined algorithm every day, and replaced with new time stamp information such as s0 → s1 → s2 → ... st. The previous time stamp information disappears. The update of the time stamp information does not have to be performed every fixed period, that is, it may be aperiodic. Every time the time stamp information is updated, the number of updates is replaced with the update information as long as the time stamp information corresponds to the update information. In other words, the time stamp information is a mere symbol, and even if it is not a quantity, each update number The time stamp information and the time stamp information have a one-to-one correspondence. When the update information is updated, the IC card terminal 1 automatically makes a call to the management center 3 and transmits the terminal number and the updated update information. The management center 3 replaces the update information of the registered corresponding terminal number with the received update information. The predetermined algorithm for updating the time stamp information needs to be an algorithm such that the previous time stamp information cannot be obtained from the current time stamp information. Further, the initial value of the time stamp information registered in the management center 3 is not updated. In such a state, when the IC card terminal is stolen, the management center 3 starts from the terminal number of the stolen IC card terminal to the initial value of the time stamp information of the IC card terminal and the time stamp at the time of the theft. The information update information can be known, and the information is registered in the terminal list of all IC card terminals 1 by downloading from the management center 3.

In FIG. 4, the user uses the IC card 2 to IC
It is a figure explaining the process at the time of receiving a service from the card terminal 1. The money amount information V is recorded in a predetermined area of the EEPROM 64 of the IC card 2, and the terminal number IDT of the IC card terminal used last time, the public key nT, the update information t, and the digital signature ST for the time stamp information are recorded in other predetermined areas. (St) is recorded. Further, a terminal number IDT 'and a digital signature terminal key pT', q are provided in a predetermined area of the RAM in the control unit 11 of the IC card terminal 1.
T'and public key nT 'are recorded, and time stamp information sT' and update information t'are recorded in other predetermined areas. Furthermore, the terminal number IDT _i (i = 1, 2, ...) Of the specific terminal, the initial value s _i 0 of the time stamp information, and the update information t _i are recorded in the terminal list of the IC card terminal 1.

The user inserts the IC card 2 into the IC card terminal 1
When it is inserted into the IC card reader / writer unit 12 of the above, V, IDT, t, nT, S from the IC card 2 to the IC card terminal 1
T (st) is transmitted. The IC card terminal 1 compares the received IDT with the data IDT _i in the terminal list, and if there is no match, displays V and guidance on the display unit. When the user refers to the guidance displayed on the display unit 14 and designates a service from the operation input unit 13 by dialing or the like, the IC card terminal 1 stores the fee for the designated service in the memory in the control unit 11. Read from the list, or communication network 4
The service charge is received from a service center (not shown) via the, and the required service charge is compared with the remaining amount V, and if V is large, the service provision is started. For example, in the case of a telephone service, if the remaining amount of money is 10 yen or more, a dial instruction is displayed on the display unit 14, and the user is dialed to make a call. When the user receives the service and, for example, the service ends when the call with the other party ends, the IC card terminal 1 displays the service charge result stored in the memory in the control unit 11 or the service charge result transmitted from the service center. A new remaining amount V'is obtained by subtracting from the remaining amount V, and the digital signature ST 'is added to the time stamp information st'.
(St ') is created with the terminal keys pT' and qT ', and the ID
T ', V', t ', nT'ST' (st ') are transmitted to the IC card 2. The IC card 2 is I together with the remaining amount V '.
The information received from the C card terminal 1 is recorded in the EEPROM 64.

In the above processing, when the data matching the IDT received by the IC card terminal 1 is in the data IDT _i in the terminal list, the following processing is performed. When IDT ₁ is the matched terminal number, the initial value s ₁₀ of the time stamp information corresponding to the matched terminal number in the terminal list is used by the predetermined algorithm recorded as the program of the IC card terminal 1 in the IC card. Two
According to the update information t received from, the calculation is repeated for the number of times of update, and the time stamp information s, t corresponding to this t is obtained.

S ₁ 0 → s ₁ 1 → s ₁ 2 ………… → s ₁ t The time stamp information st ₁ obtained by this calculation,
The validity of the digital signature ST (st) is verified with the public key nT received from the IC card 2. If the validity cannot be verified, the processing is stopped as an abnormal card, and the IC card 2 is returned. When the validity can be verified, the update information t ₁ corresponding to the matching terminal number IDT ₁ in the terminal list is compared with the update information t received from the IC card 2. If t ≦ t ₁ , then t is IDT ₁ , s ₁ 0, t
_{If 1} is update information before being registered in the terminal list, that is, the IC card has data (terminal number, update information, public key) at the IC card terminal before the IC card terminal of IDT ₁ is stolen. , The digital signature time stamp information) is determined to be an updated IC card, and the subsequent processing is performed as a valid IC card. If t> t ₁ , the t ₁ is IDT ₁ , s
_{If 10} and t ₁ are update information after being registered in the terminal list, that is, the IC card is the IC of the IDT ₁ .
After the card terminal is stolen, the IC card terminal determines that the IC card has the updated data, the processing is stopped as an illegal card, and the card is returned or detained in the IC card terminal.

FIG. 5 is a diagram for explaining another embodiment of the present invention. In the ROM 61 of the IC card 2, an algorithm for creating a digital signature and an algorithm for generating a random number are recorded. In the EEPROM 64 of the IC card 2, a card number IDU, card keys pU and qU for creating a digital signature, and a public key nU for verifying the digital signature are recorded. EEPR
In the predetermined area of the OM 64, the terminal number IDT of the IC card terminal used last time, the public key nT, the update information t, the random numbers R and X generated at the time of the last use, together with the random number R, X, the amount information V, the card. The first digital signature ST (R * X * V * IDU) created by the IC card terminal used last for the number IDU, and the IC card terminal used last for the digital signature and time stamp information st Second digital signature ST (st * ST
(R * X * V * IDU)) is recorded. Also, I
An algorithm for generating random numbers is recorded in the ROM in the control unit 11 of the C card terminal 1.

The user inserts the IC card 2 into the IC card terminal 1
When it is inserted into the IC card reader / writer unit 12 of the above, the R, which is the last use information, from the IC card 2 to the IC card terminal 1,
X, V, IDU, first digital signature, IDT, t, n
T, the second digital signature is transmitted. The IC card terminal 1 verifies the validity of the first digital signature by the received nT. If it is valid, the received terminal number IDT is compared with the data in the terminal list, and if there is no match, a random number R'is generated and transmitted to the IC card. I
In the C card, a random number X'is generated and R ', X',
A digital signature SU (R '
* X '* V) is created and X', SU (R '* X' *
V) and nU are transmitted to the IC card terminal 1. The IC card terminal 1 receives the digital signature SU using the received public key nU.
Verify the correctness of (R '* X' * V). If it is valid, V is displayed on the display unit to provide a predetermined service. After the service ends, a new remaining amount V'is obtained and R ', X',
A first digital signature ST '(R' * X '* V' * IDU) is created for the V'and IDU using the keys pT 'and qT', and the time stamp information st 'and the first digital signature are added. On the other hand, the second digital signature ST ′ (st ′ *
ST (R ′ * X ′ * V ′ * IDU)) is created, and V ′,
The IDT ′, nT, t ′, the first digital signature and the second digital signature are transmitted to the IC card 2. The IC card 2 verifies the received first digital signature by the received nT ′, and if it is valid, records the received information in a predetermined area. If the validity of the digital signature cannot be verified by the above procedure, the process is stopped at that point and the IC card 2 is returned.

In the above processing, when the data matching the IDT received by the IC card terminal 1 is in the data IDT _i in the terminal list, the same processing as the above-mentioned processing is performed. In this embodiment, since the mutually generated random numbers are used for transmitting and receiving the information, the contents of the signals are not the same, and it is possible to prevent the illegal use of the intercepted signals. In addition, since digital signatures are mutually created and mutual authentication is performed, security can be further enhanced. It should be noted that the greater the number of information, the higher the security, but even if the card number IDU is omitted, it becomes considerably better than in the case of FIG.

In the above description, it has been explained that the IC card terminal 1 and the IC card 2 respectively record only the terminal number and the card number in the memory, but the digital signature in the case of the terminal number and the card is specified by the specific key information. Create a digital signature, record the digital signature in each memory together with the verification key, send the digital signature and verification key together with the terminal number or card number, and verify the digital signature with the verification key to obtain the terminal number. Alternatively, the security can be further enhanced by configuring to verify the validity of the card number.

Further, the IC card 2 and the IC card terminal 1 store an algorithm for encryption / decryption of transmission information and a common key for encryption / decryption in a memory so that they can be mutually exchanged. Communication can be performed by cipher communication, and security can be further enhanced.

[0020]

According to the present invention, the update information indicating the elapsed time since the IC card terminal was installed and the time stamp information for verifying the validity of the update information are recorded in the IC card terminal, When a card is used, the digital signature of the IC card terminal for verifying the correctness of the time stamp information together with the update information is recorded on the IC card. Therefore, the contents of the IC card are analyzed and the update information is tampered with. In this case, however, the digital signature of the IC card terminal cannot be created for the time stamp information corresponding to the falsified update information, so that the illegal operation cannot be performed. Further, even if the contents of the IC card terminal are analyzed and tampered with so that the update information is returned, the time stamp information corresponding to the returned update information cannot be obtained,
You can't cheat. What can be done by analyzing the IC card terminal is the time stamp information after that point,
If the contents with the update information are tampered with and used in another IC card terminal, it is possible to prevent fraud by checking the terminal list.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of an embodiment of the invention of claim 2;

FIG. 2 is a block diagram showing a configuration example of an IC card terminal according to the first aspect of the invention.

FIG. 3 is a block diagram showing a configuration example of an IC card.

FIG. 4 is a diagram showing an example of an information processing procedure of the present invention.

FIG. 5 is a diagram showing another information processing procedure of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoji Miyaguchi 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Tatsuaki Okamoto 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Corp. (72) Inventor Jun Fujioka 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp.

Claims (2)

[Claims] 1. A means for updating time stamp information at a proper interval by a predetermined algorithm, a means for transmitting update information indicating the number of times of updating each time stamp information is updated to a management center, and a terminal is specified. For storing the terminal number, the time stamp information, the update information, the terminal key for creating the digital signature, the public key for verifying the digital signature, and the terminal number received from the management center, The initial value of the time stamp information and the memory in which the update information is recorded as a terminal list are compared with the terminal number received from the IC card and the terminal number in the above terminal list. If they match, the time stamp of the terminal list is compared. The initial value of the information is updated by the predetermined algorithm according to the update information received from the IC card, The digital signature received from the IC card is verified with the new time stamp information and the received public key, and when it is determined to be valid, the received update information and the update information of the terminal list having the same terminal number as the received update information. Means for determining when the IC card has been used in the IC card terminal having the received terminal number, means for digitally signing the updated time stamp information using the terminal key, and An IC card terminal comprising: a terminal number for identifying a terminal, the update information, the public key, and means for transmitting the digital signature to the IC card. 2. The IC card terminal according to claim 1, a memory for recording a digital signature for the terminal number, update information, public key and time stamp information received from the IC card terminal, and inserted in the IC card terminal Then the terminal number in the above memory,
An IC card having update information, a public key, and means for transmitting a digital signature to the IC card terminal to the IC card terminal, and a database for managing the terminal number of each IC card terminal, the initial value of the time stamp information, and the update information. And means for replacing the update information of the corresponding terminal number in the database with the update information received from the IC card terminal, and selecting one set of the terminal number in the database, the initial value of the time stamp information and the update information. And an IC card system comprising a management center having means for transmitting to all IC card terminals.