Integrated circuit protecting method for chip card, involves comparing data word before exiting circuit with respect to value stored in circuit, and generating error signal in case of identity between value and data in output standby

摘要

The method involves comparing a data word before exiting an integrated circuit (20) with respect to a prohibited value stored in the circuit. An error signal is generated in case of an identity between the value and the data in the output standby. The value is stored at several locations of the memory with the address not being requested by programs providing data outside the circuit.