Rohm Co., Ltd.

Toyokazu Komuro

Yoshihiro Ikefuji

Junichi Hikita

Shigemi Chimura

A private key write control unit ( ) permits writing of a private key just once into a private key storage unit ( ) after initialization. Similarly, a particular data write control unit ( ) permits writing of particular data only once into a data storage unit ( ) after initialization. Since a person other than the IC card manufacturer can write in a private key or particular data after the fabrication stage of the IC card, flexibility in the application of IC cards can be ensured. Also, improper usage of a card can be prevented since the written data is inhibited of being rewritten. The IC card manufacturer can initialize the data storage unit ( ) and the private key storage unit ( ) by a data initialization unit ( ) and a private key initialization unit ( ). Therefore, the cost of an IC card can be reduced by allowing reusage of IC cards.

IC card and method of using IC card

A highly rigid ceramic frame ( ) is embedded in a layer of a core member ( ). An IC chip ( ) is held inside ( ) via an elastic member ( ). IC chip arranged inside ( ) will not be greatly deformed even when a strong bending, torsional, or pressing force is applied to the IC card ( ). An impact, when exerted on the IC card ( ), will not be directly conveyed to the IC chip ( ). A coil ( ) formed by printing and the like is provided at an upper end face ( ) of the ceramic frame ( ). The coil ( ) is connected to the IC chip ( ) by a wire ( ). By forming the IC chip ( ), the ceramic frame ( ) and the coil ( ) integrally in advance, the workability in fabrication is improved. Therefore, a circuit chip mounted card of high reliability and low fabrication cost can be provided.

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Kyoto, Japan

Toyokazu Komuro