JPH0416834B

PURPOSE:To secure protection of information by controlling writing and reading in specified areas and propriety of execution of specified function basing on the result of comparing input password code information with stored password code information. CONSTITUTION:An IC card has a built-in integrated circuit and user's password code numbers are stored in a memory 5 of the circuit 2 and business information is stored in a memory 6. When a read instruction signal R51 is given from a control circuit 4 to the memory 5, a read control signal R52 is generated to the memory 5 only when bit patterns of a temporary memory 11 and a permanent memory 12 coincide perfectly. When a read instruction signal R61 is outputted to the memory 6, a read control signal R62 to the memory 6 is generated only when more than one bit out of bit patterns of the memory 11 corresponding to the bit pattern of a permanent memory 13 coincide at ''1''.