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:
Nov. 27, 2007
Filed:
Mar. 12, 2002
Tetsuo Shinriki, Tokyo, JP;
Kazuyoshi Irisawa, Tokyo, JP;
Naoto Shibata, Tokyo, JP;
Dai Nippon Printing Co., Ltd, Tokyo, JP;
Abstract
Authentification data (R) comprising random numbers generated by a reader/writer () is given to an IC card (), encrypted by utilizing a secret key (a), and returned as encryption data (C). This encryption data (C) is decoded by utilizing an open key (β) to authentify the IC card. A set of past given authentification data (R) is stored in an authentification data storage section (): if another set of given authentification data (R) is the same as the set of past data, an encryption operating section () is prevented from executing an illegal statistical analysis technique by repeatedly giving encrypting operation the same set of authentiification data (R).