Portable data carrier i.e. smart card, protecting method, involves changing faulty operation counter such that counter indicates additional faulty execution of command when indicator is in condition indicating faulty execution of command

摘要

The method involves testing whether an indicator is in a condition that indicates faulty execution of a command and in another condition indicating successful execution of the command, before execution of the command. A faulty operation counter is changed such that the faulty operation counter indicates additional faulty execution of the command when the testing results that the indicator is in the former condition, and the faulty operation counter is unchanged when the testing results that the indicator is in the latter condition. An independent claim is also included for a portable data carrier comprising a storage area.