Hitachi Ulsi Systems Co., Ltd.

Hitachi, Ltd.

Renesas Technology Corp.

Chiaki Tanimoto

Kunihiko Nakada

Yuuichirou Nariyoshi

Takashi Endo

Takashi Tsukamoto

Masahiro Kaminaga

Takashi Watanabe

Hiroshi Watase

Masatoshi Takahashi

Shigeo Hirabayashi

A malfunction detection system is provided that can continue or terminate processing appropriately even if a malfunction occurs in an information processing unit. In this regard, the information processing unit receives branch direction information, carries out a conditional branch depending on the branch direction information, and performs an applicable operation on data I. At this time, the information processing unit performs an applicable operation on data J, other than the operated data I, in the conditional branch path and outputs the result for examination, thereby enabling validation of the conditional branch.

Information processing unit having tamper-resistant system

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.

IC card and microprocessor

Growing community of inventors

Tsukuba, Japan

Chiaki Tanimoto