Method and system for improving the integrity of data on a smartcard

• US 5,869,823 A
• Filed: 01/03/1997
• Issued: 02/09/1999
• Est. Priority Date: 01/03/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bublitz, Hermann R., Hanel, Walter, Rindtorff, Klaus
• Primary Examiner(s): Gross, Anita Pellman
• Assistant Examiner(s): Dunn, Drew A.
• Application Number:
  US08/778,801
• Time in Patent Office: 767 Days
• Field of Search: 235/380, 235/382, 235/382.5, 235/379
• US Class Current: 235/380
• CPC Class Codes: G06F 11/004 Error avoidance G06F11/07 and subgroups take precedence
• CPC Class Codes: G06F 11/1433 during software upgrading
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G07F 7/082 Features insuring the integrity of the data on or in the card
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system

Abstract

A method and a system are proposed for increasing the data integrity on smartcards. In accordance with the invention a sequence of write processes on a smartcard is defined as a unit for which the integrity of the data to be written is ensured. The write process may involve the writing of data to one or more files. The data of an integrity unit i.e. a unit of data for which the integrity is to be ensured is preferably written to shadow memory. The method in accordance with the invention decreases considerably the likelihood that data will be corrupted through an error in writing the data on the smartcard. Data can be restored or completed through the interface of read-write units. The method in accordance with the invention can serve as a basis for maintaining data files external to the smartcard consistent with data on the smartcard.

Claims

1. Method for improving the integrity of data during communication between a terminal and a smartcard having an EEPROM memory so that the data on the smartcard remains consistent with data in the terminal comprising the steps of:

defining an integrity unit of data to be communicated by opening old data on the smartcard to preserve the old data on the smartcard comprising the steps of;

creating from an original copy of the old data another copy of the old data;

storing the another copy of the old data in another page of EEPROM memory on the smartcard;

communicating data between the terminal and the smartcard for preparing new data from one copy of the old data comprising the steps of;

amending the one copy of the old data with data received from the terminal;

completing storage of the new data in place of the one copy of the old data;

committing the stored amended copy as the valid copy when the storage of the new data has been completed; and

indicating that transfer of the integrity unit of data has been successfully completed.

2. Method of claim 1 wherein the step of storing stores the another copy in a shadow memory.

3. Method of claim 1 wherein the step of amending the one copy of the old data amends the original copy.

4. Method of claim 3 wherein the step of completing storage stores the new data in memory where the original copy of the old data had been stored.

5. Method of claim 1 wherein the step of amending the one copy of the old data amends the another copy.

6. Method of claim 3 wherein the step of completing storage stores the new data in memory where the another copy of the old data had been stored.

7. Method for improving the integrity of data on a card having a memory during communication between the card and a card read-write terminal so that the data on the card remains consistent with data in the card read-write terminal comprising the steps of:

defining an integrity unit of data by opening a file of old data on the card to preserve the old data on the card comprising the steps of;

creating from an original copy of the old data another copy of the old data;

storing the another copy of the old data in a shadow memory on the card;

changing a status table to indicate that the file of old data has been opened;

communicating data between the card read-write terminal and the card for preparing new data from one copy of the old data comprising the steps of;

amending the one copy of the old data with data received from the card read-write terminal;

completing storage of the new data in place of the one copy of the old data;

changing a status table to indicate that the file of new data has been prepared;

committing the new data as the valid copy when the storage has been completed;

indicating successful transfer of the integrity unit by changing a status table to indicate that the file of new data has been committed and the other copy of the old data can be erased.

8. Method of claim 7 wherein the step of amending the one copy of the old data amends the original copy.

9. Method of claim 8 wherein the step of completing storage stores the new data in memory where the original copy of the old data had been stored.

10. Method of claim 7 wherein the step of amending the one copy of the old data amends the another copy.

11. Method of claim 10 wherein the step of completing storage stores the new data in shadow memory where the another copy of the old data had been stored.

12. Method for improving the integrity of data on a card having a memory so that during communication between the card and a card read-write terminal the data on the card remains consistent with data in the card read-write terminal comprising the steps of:

defining an integrity unit of data by opening a file of old data on the card to preserve the old data on the card comprising the steps of;

creating from an original copy of the old data, another copy of the old data;

storing the another copy of the old data in a shadow memory on the card;

changing a status table to indicate that the file of old data has been opened;

communicating data between the terminal and the card for preparing new data from the another copy of the old data comprising the steps of;

amending the another copy of the old data with data received from the terminal;

completing storage of the new data in place of the another copy of the old data in shadow memory;

changing a status table to indicate that the file of new data has been prepared;

unrolling the new data as the valid copy when one of the steps of amending and of completing storage has been incomplete;

indicating unsuccessful completion of transfer of the integrity unit by changing a status table to indicate that the file of new data has been unrolled and that the original copy of the old data remains valid.