The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 25, 2004
Filed:
Jul. 26, 1999
Rohm Co., Ltd., Kyoto, JP;
Abstract
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.