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IC card having internal error checking capability

  • US 4,930,129 A
  • Filed: 03/11/1988
  • Issued: 05/29/1990
  • Est. Priority Date: 03/13/1987
  • Status: Expired due to Term
First Claim
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1. An IC card adapted to interface with at least one terminal for performing a plurality of applications, the IC card comprising in combination:

  • onboard memory means divided into a plurality of application blocks for storage of information related to the applications, some of the application blocks being of a size different from others, the memory means also having a protected block for storage of application block information including directory data and an error check code relating to each of the plurality of application blocks;

    an onboard microprocessor for controlling access to the memory in such a way as to prevent access to the protected block by the terminal and to selectively allow access to the application blocks by the terminal for selectively performing the applications; and

    program means for causing the microprocessor(a) to compute an error check code for a data group related to one of the plurality of applications, and to store the data group in a selected application block and the computed error check code in the protected block in the location associated with the selected application block when the data group is sent from the terminal,(b) to detect data error in the stored data group in an application block accessed from the terminal by using the data group and the error check code thereof when the data block is read out to the terminal.

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