AT507882A2 - CHIP CARD WITH REPLACEMENT INDICATION - Google Patents

Description

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Chip card with exchange indication

The largest limitation on the life of a smart card follows from the maximum number of write / erase cycles of the EEPROM. The minimum number of write / erase cycles guaranteed by most semiconductor manufacturers for each EEPROM memory page is a minimum of 100,000. In practice, however, at room temperature and with small power supply deviations, the EEPROM will only fail for 2 million to 5 million cycles. The failure of an EEPROM page is not 10 abrupt, but gradually. An indication of the incipient failure is that the EEPROM can not be set to the desired value on the first attempt at writing and the written data is no longer available in memory after a few hours. 15 If you continue to use such a memory page, after a few more thousand cycles you will no longer be able to save any data in the EEPROM because it immediately loses the contents. Affected is but only one memory page (usual size: 4 bytes or 32 bytes) of the EEPROM. 20 Other pages are unaffected or unaffected by a page outage. This can be used as part of the memory organization for fault-bridging strategies. Such fault-bridging strategies have become known, for example, from DE 102006001873A1 or EP015665821B1. However, these 25 do not take account of an indication for the complete replacement of the chip card.

Data storage in the EEPROM works on the basis of storing electrical charges in tiny capacitors. Like all 30 capacitors, these also have a leakage current. This causes the charge contained in the capacitor to drain off over time and the stored information is no longer available.

The invention is therefore based on the object, a reliable

To obtain information about the necessary exchange of a chip card due to a defective EEPROM.

According to the invention, this information is used via 5 memory cells that are becoming corrupted in order to derive an indication that the chip card is nearing the end of its service life and should therefore be replaced.

The invention therefore relates to a smart card, consisting u. a. from chip hardware and software that is embedded in a data processing system 10, to which it transmits the information about memory cells becoming corrupted, and which then generates a reorder of a follower card.

The benefit to the cardholder is that he is likely to get a new card before the card he is using now reaches the end of his life. This is also a benefit for the card issuer. In particular, if the card is a payment card according to the EMC specification, this information can be transmitted to the card issuer via the existing data processing system of the EMV transactions. The invention is not limited to the determination of defective memory cells in an EEPROM, but also relates to the detection of defective memory cells in a ROM or a RAM as well.

The invention is based on the assumption that the user automatically receives a card from the card issuer without his or her own intervention, if, in a transaction with the defective chip card, the software application stored on the chip card informs after a memory check that so many memory cells are defective a secure re-use of the chip card is no longer guaranteed. • • • • • • • • • • • • • • · • · · · ·

A message is automatically generated, so to speak, at the user's next transaction with the smart card, and a data about the necessary exchange of the chip card is generated via the data connection to a banking system existing during the transaction. This is particularly simple and secure, because in this exchange anyway such data of the chip card to the card issuer and the banking system are transmitted, which allow a conclusion on the identity of the user (name, address, etc.). Without the user himself 10 noticing something of his faulty chip card, he will then receive after a certain time a new chip card delivered, in which defective memory cells are no longer available. This is always ensured for an automatic replacement of faulty chip cards, so that with the transmission of the transaction data also information about the 15 memory state and the presence of faulty memory cells are transmitted.

The invention is not limited to the fact that when making a decision as to whether the card is to be replaced, it is not necessary to adhere to a threshold to be preset. This is one option of several.

Depending on what information the hardware provides, other decision paths are also provided. The hardware can also communicate other parameters instead of the number of defective memory cells, eg. For example, calculate itself a probability that will result in a memory error not covered by the error correction mechanism.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with one another.

All information and features disclosed in the documents, including the abstract, in particular the spatial education shown in the drawings, are claimed to be essential to the invention, as far as they are concerned individually or in combination with the prior art are new.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment 5. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Show: 10

Figure 1: schematically a block diagram of a conventional chip card

Figure 2: the procedure in the determination of faulty

Memory cells of the chip card according to FIG. 1 15

1 shows a conventional chip card 1 is shown, which consists in a conventional manner of an interface 2, which accesses a memory 4 with an address and safety logic 3, for example, from the 3 memory areas EEPROM 5, ROM 6 and RAM. 7 consists. 20

It is not shown with which communication interface the chip card interacts with the environment. In this case, a contactless or contact-based transfer of data to an assigned terminal can take place. 25

For this purpose, a microcontroller 8 is used, which includes the operating system and one or more data applications and

Managed software applications. It is not shown that and in what form the chip card communicates with the environment. In this case, contactless or contact-type communication with the environment may take place.

FIG. 2 shows in general that the memory 4 consists of a memory

Matrix 9 may consist of columns 10 and rows 11, wherein a plurality of memory cells 12 are arranged in the memory matrix 9. 5 With a corresponding memory check of the microcontroller 8 on the chip card 1, for example, the faulty memory cells in the coordinates A1, C3, D5 and C6 are detected.

This takes place, for example, under the action of the operating system 13, to which an application software 14 is loaded, which performs the said memory check of the memory matrix 9.

If faulty memory cells 12 are detected in the memory matrix 9, an error table 21 (arrow direction 22) is created, and the content of the error table is forwarded in the direction of the arrow 23 to a query block 24. This determines how many memory cells are defective and decides with a corresponding threshold detector whether an exchange of the chip card is required (arrow direction 26). In the local decision block 29, the decision of the exchange 20 (arrow 19) or the non-exchange (arrow 25) is made.

In the decision of the non-exchange is queried back from the query block 24 in the direction of arrow 25 to the query of the error table 21. The software 9 requesting the memory matrix 9 generates an error report 20, which is forwarded to the terminal 16 via an interface 15 when the chip card is exchanged (arrow direction 19).

Such a terminal is any terminal that the user uses with his smart card and this includes, for example, a screen 17 and a keyboard 18.

As an application, it is described here that the user carries out a payment transaction at the terminal 16 with his chip card. ·· ·· • · · · · · · · · · · · ·

For this purpose, a data connection 26 is established in a manner known per se to a banking and payment system 28, in which, inter alia, the card issuer 27 of the smart card 1 is integrated. 5 Via the data connection 26, the card issuer 27 thus receives the message from the faulty chip card and initiates the issuing of a new chip card using the data of the user, which can thus be sent to him directly. 10

The present invention thus prevents defective chip cards from interfering with or even preventing use, interfering with payment transactions and other transactions with the chip card, and of all of this the user does not notice because he automatically receives a new chip card 15 if too many memory cells 12 are damaged. τ::

Diagram of communication 1 Chip card 2 Interface 5 3 Address and safety logic 4 Memory 5 EEPROM 6 ROM 7 RAM 10 8 Microcontroller 9 Memory matrix 10 Column 11 Row 12 Memory cell 15 13 Operating system 14 Application software 15 Interface 16 Terminal 17 Screen 20 18 Keyboard 19 Arrow direction 20 Error report 21 Error table 22 Arrow direction 25 23 Arrow direction 24 Query block 25 Arrow direction 26 Arrow direction 27 Data connection 30 28 Card issuer 29 Bank and payment system 30 Decision block

Claims (10)

1. A method for operating a chip card consisting of a chip hardware 5 with at least one memory (4-7) with a plurality of memory cells (12) and chip software (14) embedded in a data processing system (16, 17, 18, 27, 28), characterized in that the chip software (14) detects defective memory cells (12) and sends information to the data processing system (14). 16, 17, 18, 27, 28) generates over the 10 necessary replacement of the chip card (1) in the exceeding of a predetermined threshold and via an already existing when using the chip card data connection (26) with the transaction receiver information about the necessary exchange the card issuer (27) passes on. 15 2. The method according to claim 1, characterized in that the threshold value is calculated from the number of defective memory cells (12). 3. The method according to claim 1 or 2, characterized in that the threshold value calculates a probability with which there is a memory error not covered by the error correction mechanism. 4. The method according to any one of claims 1 to 3, characterized in that in the detection of a certain number of defective memory cells in the next transaction, the card issuer (27) is informed and thus the reordering of a follow-up or replacement card is effected. 5. The method according to any one of claims 1 to 4, characterized in that the operating system (15) in the examination of the function of the memory cells (12) of a memory (4-7), the nature and distribution of the defective memory cells (12) in an error table (21) writes a query (24) is followed by a threshold decision that decides on the output • · ♦ · information for the necessary replacement of the smart card (1). 6. Chip card for performing the method according to one or more of 5 claims 1 to 5, characterized in that the chip card (1) is a payment transaction card or a public transport card or a general customer card or general eCard with insurance card function and / or citizen card function. 7. Chip card according to claim 6, characterized in that the chip card is a payment transaction card with EMC specification. 8. Chip card according to claim 6 or 7, characterized in that the chip card is a contact-type or contactless or dual-interface chip card 15. 9. Chip card according to one of claims 4-8, characterized in that the memory cells are EEPROM cells. 10. Application of a chip card (1) consisting of a chip hardware with at least one memory (4-7) with a plurality of memory cells (12) and a chip software embedded in a data processing system, wherein the chip software recognizes defective memory cells and at Achieving the end of the life information to the data processing system (16, 17, 18, 27, 28) passes and generates the order of a replacement or subsequent chip card.