JPS63301389A - Ic card - Google Patents

Abstract

PURPOSE:To disable data with secrecy to be read out after a prescribed time and to erase it, by providing a discrimination information storing area to decide the lapse of the prescribed time from the storage of data in a memory. CONSTITUTION:The data storing area 1 of an IC card is divided into an ordinary data storing area 1a and an erase data storing area 1b. In the area 1b, the data are stored in the form of (Ak.Ak+1) which form the pairs of addresses (An.An+1), (An+2.An+3),...(Am-1.Am), and erase data SDl is recorded in the address Ak, and a time Tl to be erased is recorded in the address Ak+1. At the time of reading out the card 1 by an external device, readout is disabled if an area is the area 1b and the time Tl of the Ak+1 is before the present time, and furthermore, the data is erased. Such processing procedure is performed by a CPU in the card by using an application program stored in a ROM, etc., in the card.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC card having a function of disabling reading of data stored for a predetermined period of time and further erasing this data.

[Conventional technology]

Recently, I
C cards have been proposed and are becoming popular. This IC card generally has a nonvolatile programmable memory, and by storing various information as data in this memory, long-term data storage can be performed. Furthermore, progress has been made in the development of rewritable memory, making it easier to update the data stored in memory, making it possible for IC cards themselves to be used for recycling.

Access to data stored in the memory of such an IC card is generally controlled by a CPU or an external device based on a built-in or external program. Also, depending on the application program stored in the ROM of this IC card, the CPU in the IC card specifies and manages the logical or physical recording position in the memory of the IC card according to a predetermined interpretation on the program. There are many configurations. Therefore, in order to record the necessary information as data, a data storage area 1 according to the information content is defined in advance in the memory of the IC card.
In the application system, the data storage area 2 is specified to read and write information.

[Problem that the invention seeks to solve]

However, in conventional IC cards with the above configuration, data written to a data storage area in a non-luminous read/write memory is stored until it is erased or overridden with other data after the data is recorded. . Therefore, confidential information is stored on the IC card, and this
If you lose your C card, confidential information will be permanently stored in the IC card, and there is a high possibility that the confidential information will be stolen by a third party who finds this IC card. There was a problem.

This invention was made in order to solve the above-mentioned problems, and provides an IC that, when storing highly confidential information, prevents the information from being read out after it has been stored for a predetermined period of time, and further erases the information. The aim is to get cards.

(Means for Solving the Problems) The IC card according to the present invention has a time determination information storage area in the memory for determining after a predetermined period of time has elapsed from the data storage time in the memory, When reading the data in this IC card, when it is confirmed that the predetermined time has elapsed based on the time discrimination information, the data is made unreadable and further erased.

(Operation) By checking whether or not a predetermined time has elapsed after data storage using the time discrimination information of the present invention, the data stored in the memory of the IC card after the predetermined time is made unreadable and further erased. be able to.

〔Example〕

FIG. 1 is a memory configuration diagram of a nonvolatile programmable memory in an IC card according to an embodiment of the present invention. In the figure, 1 is a data storage area, 1a is a normal data storage area, 1b is an erased data storage area, and normal data storage area 1ii! 1a is assigned to address AA, and the erase data storage area is assigned to address 1n-1Ao-AIll.

The normal data storage area 1a stores data D1-D, -1 corresponding to each address A1-An-1. On the other hand, in the erased data storage area 1b, (A, A), (A
,A),...(nn÷I n+
2 n+3A, 1. A) paired with (Ak, Ak
, 1), and the address Ak records the erase data SD, and the address A1,1 records the time TI at which the erase data SD should be erased.

FIG. 2 is a flowchart showing the processing procedure when writing data to the IC card having the memory configuration shown in FIG. 1, and the write operation will be explained below with reference to the same figure.

In step S1, the inputting person specifies whether the data inputted by the input device or the like is erased data or normal data, and if it is specified as erased data, then in step S2 data SD is stored in the empty address Ak of erased data storage area VJ, 1b. Then, in step S3, the erase time T, which is the current time plus a predetermined storage time, is written to the address Ak+1. On the other hand, if normal data is specified in step S1, free address A of the normal data storage area 1a is determined in step S4.
- Insert data into (i=1 to n-1) as data Di.

FIG. 3 is a flowchart showing the processing procedure when reading data from the IC card having the memory configuration shown in FIG. 1, and the reading operation will be explained below with reference to the same figure. In step S11, it is determined whether the address Aj on the memory of the IC card 1 accessed by the CPU in the IC card is the normal data storage area 1a or the erased data storage area 1b, and this address A is the normal data storage area 1a. If so, the contents of this address A are read out in step 812, and the process ends. On the other hand, this address Aj
If is the erase data storage area 1b, the erase time written to address Aj+1 is compared with the current time in step S13, and if the current time has not passed the erase time, the contents of address A are read out in step S12, Finish the process.

However, if the current time exceeds the erasing time in step 813, the process moves to the next step S14, making it impossible to read the contents of address Δj, and in step 815, the contents of address Aj are erased, and the process ends.

In this way, if confidential data, etc. is stored as erase data in the erase data storage area 1b with the erase time as a pair, when the read time exceeds the erase time, the data is made unreadable and further erased. It has become. Therefore, even if the tC card is handed over to a third party, as long as the erasure time has passed, there is no possibility that the third party will steal the confidential data.

The processing shown in FIGS. 2 and 3 can be performed by the CPU in the IC card based on an application program stored in a ROM or the like in the IC card. Furthermore, time management can be achieved by incorporating a clock function into the IC card, or by allowing time information to be obtained from an external clock into the IC card.

In addition, in this embodiment, the erasure time is set to the erasure data storage area 1.
Although the write time is stored in the erase data storage area 1b, the write time may be stored in the erase data storage area 1b. In this case, by comparing the current time and the self-write time + storage time, it is possible to determine whether or not the erase data needs to be erased. Able to judge and process. Also, the storage time can be made variable. Furthermore, a method may be considered in which information indicating whether data is erased data is added to the data and stored in the data storage area 1 without dividing the data storage area 1 into the normal data storage area 1a and the erased data storage area 1b.

[Effects of the Invention] As described above, according to the present invention, it is possible to confirm whether or not the data to be read has passed a predetermined period of time after the data was stored, based on time determination information such as erasure time, for example.
Data can be made unreadable after a predetermined period of time, and the data can also be erased, so even if highly confidential information is stored as data in an IC card, after a predetermined period of time has elapsed, it is possible to make the data unreadable and erase the data. be able to.

[Brief explanation of the drawing]

FIG. 1 is a memory configuration diagram of a non-volatile programmable memory in an IC card which is an embodiment of the present invention, and FIGS. It is a flowchart which shows a processing procedure. In the figure, 1 is a data storage area, 1a is a normal data storage area, and 1b is an erased data storage area. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (3)

[Claims] (1) In an IC card having a CPU and a non-luminous read/write memory, a time determination information storage area is provided in the memory for determination after a predetermined period of time has elapsed from the time data is stored in the memory. and when it is confirmed that the predetermined time has elapsed based on the time discrimination information when reading the data stored in the memory, the data is made unreadable and further erased. IC card. (2) Claim 1 further comprising a data discrimination information storage area in the memory for determining whether or not to erase the data after a predetermined period of time from when the data is stored.
IC card listed in section. (3) A data storage area to be erased and other data storage areas are separately provided in the memory, and only data in the data storage area to be erased is erased. IC card.