Disclosed herein are an IC card and a microcomputer which have implemented
the strengthening of security and the speeding up and enhancement of signal processing
for the security. In an IC card, which is supplied with an operating voltage by
an electrical connection between each of external terminals and a read/write device,
and includes an input-output operation of data with an encoding process or a decoding
process, a disturbance-aimed processing operation is included in the encoding process
or decoding process to uniformalize timings provided to operate an internal circuit
and its operating current. In a microcomputer having a module configuration including
an input-output operation of data with an encoding process or a decoding process,
a disturbance-aimed processing operation is included in the encoding process or
decoding process to uniformalize timings provided to operate an internal circuit
and its operating current.
