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. 26, 2013
Filed:
Apr. 29, 2011
Fukio Handa, Tokyo, JP;
Yoshihiro Yano, Tokyo, JP;
Takayuki Chikada, Tokyo, JP;
Syouzou Niwata, Tokyo, JP;
Fukio Handa, Tokyo, JP;
Yoshihiro Yano, Tokyo, JP;
Takayuki Chikada, Tokyo, JP;
Syouzou Niwata, Tokyo, JP;
Dai Nippon Printing Co., Ltd., Tokyo, JP;
Abstract
It is possible to perform encrypted communication between members of a group while assuring a sufficient security compatible with a change of the members. An IC card having the same fixed code F(a) is distributed to all the staffs of company A. When communication is performed between a staff α and a staff β belonging to the same project group, α of the transmission side writes an arbitrary variable code V() in the IC card () so as to generate encryption key information K(a) according to F(a) and V() in the IC card and encrypt data Dby using K(a). β of the reception side writes the variable code V() received from α in the IC card () so as to generate encryption key information K(a). By using this K(a), the encrypted data Dreceived is decrypted to obtain data D. The fixed code F(a) is different for each of the companies and rewrite-disabled so as to assure security.