JPH0632099B2 - Card writing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a card writing device, and more particularly to a data writing device for a card with an arithmetic function used for trading money data.

(Prior Art and Problems) Conventional data writing devices use magnetic cards or punch cards for exchanging monetary data, but these cards have the drawback of being easily duplicated. A card with a calculation function (hereinafter referred to as an IC card) has been developed for a recent data writing device.
A card authentication method using it has been proposed. For example, I E E Spectrum
m) In February 1984, pages 43 to 49, there is a method of storing a personal identification number in an area that cannot be accessed from the outside and determining whether or not the user inputs the personal identification number and agrees. It is listed. However, the card writing device using these methods has a drawback in that if the input information is recorded on the IC card and is reproduced later, fraud cannot be prevented.

(Object of the Invention) It is an object of the present invention to eliminate such drawbacks in the conventional card writing device and to provide a card writing device which is not capable of copying a card or writing illegal data to the card.

(Structure of the Invention) According to the present invention, in the card writing device for detecting the unauthorized access to the card, the first predetermined
Storage means for storing the code and the second code, and pattern generation means for sending the first authentication pattern to the card,
First to the first authentication pattern from the card
Of the response pattern, the first code, and the first authentication pattern have a predetermined relationship, and the second authentication pattern sent from the card is the second authentication pattern. A card writing device is obtained which comprises pattern conversion means for converting a pattern returned to the card depending on a code.

(Example) Next, the Example of this invention is described with reference to drawings.

FIG. 1 shows an embodiment of the present invention. Referring to FIG. 1, an embodiment of the present invention is a card writing device for detecting unauthorized access to a card, which includes a microprocessor 101 for controlling each part and a bus 1 for the microprocessor 101.
Keyboard interface 1 connected via 20
05, display 106, read only memory (RO
M) 108, random access memory (RAM) 109,
A keyboard 1 connected to the random number generator 110, the encryption / decryption device 111, and the keyboard interface 105.
05, and a card interface 107 connected to the bus 120 and to the IC card 104.

The microprocessor 101 controls the entire apparatus, and the keyboard 102 and the keyboard interface 105 are for inputting data to be written in the IC card. The display 106 is for displaying input data and a notification when the IC card is illegal. IC card 1
Reference numeral 04 denotes a counterpart card to which the apparatus according to the present embodiment is about to write data, and is configured to send and receive data through the card interface 107. The ROM 108 stores a program for the microprocessor 101 and codes K ₁ and K ₂ for encryption / decryption (hereinafter referred to as a key K ₁ and a key K ₂₎ and constitutes a storage means. The RAM 109 is a work area, The random number generator 110 is for generating a random number used for the authentication pattern and constitutes a pattern generating means, and the encryption / decryption device 111 is for encryption / decryption used in the authentication process and is a pattern for converting into a response pattern to be returned to the card. Included in the conversion means, the microprocessor 101 further includes means for determining whether the first response pattern and the first authentication pattern have a predetermined relationship.

FIG. 2 shows a flowchart of the work to be performed by the microprocessor 101 in this embodiment. In FIG. 2 (a), in this embodiment, when the IC card 104 is inserted and contacted, the random number generator 110 generates a random number and sends it to the IC card as the first authentication pattern. Also, the random number is the key K
It is encrypted in ₁ and stored in the RAM 109 as a verification pattern. The IC card 104 encrypts this first authentication pattern with the key K ₁ and sends it back to the microprocessor 101 as a first response pattern. Microprocessor 101
Then, as shown in FIG. 2B, it is determined whether or not the IC card is a correct card by determining whether the first response pattern from the IC card 104 is equal to the verification pattern stored in the RAM 109. If correct, microprocessor 101
Requests the IC card 104 to write the data, and if it is incorrect, displays the notification on the display 106.

On the other hand, with regard to the IC card, it is not allowed to write data into an unauthorized card terminal (card writing device) without permission, so the terminal will be authenticated. That is, the IC card 104 creates and sends a second authentication pattern with a random number as shown in FIG. 2C, but the microprocessor 101 encrypts it with the key K ₂ and sends it back as a second response pattern. .
The IC card 104 uses this second authentication pattern as the key K ₂
It is determined whether the card terminal is a correct terminal or not depending on whether or not the pattern encrypted in step 2 and this second response pattern match. The key K ₁ ,
K ₂ needs to be kept secret.

As described above, according to the present embodiment, even if the communication between the previous IC card and the card writing device is recorded and the card is used again, the authentication pattern is changed every time the card is used, so that the illegal use is prevented. it can.

The encryption / decryption device 111 is, for example, an American data encryption standard.
(DES) can be used. The random number generator 110 preferably generates a natural random number, but may be a pseudo random number generator.
Further, both or one of the encryption / decryption unit and the random number generator can be implemented by software by the microprocessor 101.

(Effects of the Invention) As described above, the present invention makes it difficult to illegally write data on a card or to write data on a card, and the effect is extremely large when applied to financial data transactions and the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flow chart showing the work to be performed by the microprocessor 101 in this embodiment. 101 ... Microprocessor, 102 ... Keyboard, 104 ... IC card, 105 ... Keyboard interface, 106 ... Display, 107 ... Card interface, 108 ... ROM, 109 ... R
AM, 110 ... Random number generator, 111 ... Encryption / decryption device.

Claims (1)

[Claims] 1. A card writing device for detecting an unauthorized access to a card, a storage means for storing a predetermined first code and a second code, and a first authentication pattern for the card. And a first pattern for the first authentication pattern from the card.
Of the response pattern, the first code, and the first authentication pattern in a predetermined relationship, and a second authentication pattern sent from the card. Second
A card writing device comprising: a pattern converting means for converting into a pattern to be returned to the card, depending on the code.