Identification card and authentication system therefor

Claim 2

An identification card characterized by comprising: input means (2) for entering secret data unique to a card holder and transaction data; calculating means (13) for calculating encrypted data by using at least the secret and transaction data entered by said input means in accordance with a predetermined encryption algorithm; and output means (3, 9) for outputting the encrypted data calculated by said calculating means (13), wherein the card holder and a transaction with the card in a store are authenticated.

Claim 3

A card according to claim 1, characterized in that said input means comprises a keyboard (2).

Claim 4

A card according to claim 1, characterized in that said output means comprises display means (3) for visually displaying the encrypted data.

Claim 5

A card according to claim 1, characterized by further comprising: a first memory means (8) for storing the secret data entered at said input means (2); a second memory means (8) for storing transaction data; a third memory means (11) for storing key code data approved by an issuer upon issuance of said card; means (12) for detecting a coincidence between the secret data stored in said first memory means (8) and the key code data stored in said third memory means (11); and control means (4) for receiving an output from said detecting means and supplying an enable signal to said calculating means.

Claim 6

A card according to claim 1, characterized by further including time measuring means (10) for measuring a date, and wherein said calculating means (13) has the encryption algorithm for calculating the encrypted data in accordance with data representing the date as well as the secret data and the transaction data.

Claim 7

An identification card authentication system characterized by comprising: an identification card (1) having means (13) for calculating first encrypted data by using at least predetermined data entered by a card holder in accordance with a predetermined encryption algorithm and output means (3) for generating the first encrypted data; and an authentication device (40) having means (26) for calculating second encrypted data by using the predetermined data specified by said identification card (1) in accordance with a reference encryption algorithm and discriminating a coincidence between the second encrypted data calculated by said authentication device (40) and the first encrypted data calculated by said identification card (1); wherein the card holder and said card are authenticated in accordance with the coincidence detected by said authentication device (40).

Claim 8

An identification card authentication system characterized by comprising: an identification card (1) having means (13) for calculating first encrypted data by using at least predetermined data entered by a card holder in accordance with a predetermined encryption algorithm and output means (3) for generating the first encrypted data; and an authentication device (40) having means (26) for calculating second encrypted data by using the predetermined data specified by said identification card (1) in accordance with a reference encryption algorithm and discriminating a coincidence between the second encrypted data calculated by said authentication device (40) and the first encrypted data calculated by said identification card (1); wherein the card holder and said card are authenticated in accordance with the coincidence detected by said authentication device (40).

Claim 9

A system according to claim 6, characterized in that the predetermined data entered by the card holder includes secret data registered at a card issuer by the card holder.

Claim 10

A system according to claim 6, characterized in that said identification card (1) has a keyboard (2) for causing the card holder to enter the predetermined data and a display unit (3) for visually displaying the encrypted data.

Claim 11

A system according to claim 6, characterized in that the predetermined data specified by said identification card (1) includes secret data registered at a card issuer by the card holder, the secret data being specified in said authentication device (40) in accordance with a card identification code assigned to said identification card (1).

Claim 12

A system according to claim 6, characterized in that said authentication device (40) comprises: a first memory means (27) for storing the predetermined data; a second memory means (27) for storing the transaction data which are entered at said identification card (1); a third memory means (28) for storing the first encrypted data calculated by said identification card (1); means (29) for obtaining the secret data of the card holder which corresponds to the predetermined data; means for calculating (26) the second encrypted data by using the secret data, and the predetermined data stored in said first memory means (27) and the transaction data stored in said second memory means (27) in accordance with a predetermined encryption algorithm; a fourth memory means (30) for storing the second encrypted data; means (31) for detecting a coincidence of the first and second encrypted data stored in said third and fourth memory means (28, 31); and means (25) for generating a coincidence result.

Claim 13

A system according to claim 10, characterized in that said means for obtaining the secret data of the card holder includes a memory table (29) for storing secret data corresponding to the predetermined data.