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:
Jul. 12, 2011
Filed:
Mar. 31, 2008
Ikuko Osajima, Yokohama, JP;
Nobuyuki Ikeda, Fuchu, JP;
Akira Suzuki, Fuchu, JP;
Shinji Ogishima, Yokohama, JP;
Ikuko Osajima, Yokohama, JP;
Nobuyuki Ikeda, Fuchu, JP;
Akira Suzuki, Fuchu, JP;
Shinji Ogishima, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A network communication system has terminal devices belonging to a group, the terminal devices generating, if there is a leaving terminal device leaving from the group, an updated group encryption key corresponding to a new group encryption key, from a deletion key corresponding to the leaving terminal device and a group encryption key, and, after the leaving terminal device leaves the group, communicating by using the updated group encryption key; and a group management server generating the updated group encryption key corresponding to the new group encryption key from the deletion key corresponding to the leaving terminal device and the group encryption key, and, after the leaving terminal device leaves the group, communicating by using the updated group encryption key.