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:
Jan. 21, 2014
Filed:
Oct. 28, 2011
Yoichi Hata, Yokohama, JP;
Toshiaki Kakii, Yokohama, JP;
Yasuhito Fujita, Yokohama, JP;
Yoshimitsu Goto, Yokohama, JP;
Hitoshi Kiya, Hino, JP;
Kiyoshi Nishikawa, Hino, JP;
Masaaki Fujiyoshi, Hino, JP;
Shoko Imaizumi, Hino, JP;
Yoichi Hata, Yokohama, JP;
Toshiaki Kakii, Yokohama, JP;
Yasuhito Fujita, Yokohama, JP;
Yoshimitsu Goto, Yokohama, JP;
Hitoshi Kiya, Hino, JP;
Kiyoshi Nishikawa, Hino, JP;
Masaaki Fujiyoshi, Hino, JP;
Shoko Imaizumi, Hino, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Tokyo Metropolitan University, Tokyo, JP;
Abstract
A master key (K) inputted by an input unit is stored in a storage unit. A matrix generating unit generates key element matrices (M-M) with respect to each of split keys (e, e, e) obtained by a key dividing unit dividing the master key (K). To each coordinate entry of the key element matrices (M-M), operation data that successively obtained by repeating a hash operation with a one-way hash function is assigned, so as to maintain hierarchical nature of scalability (L). A key generating unit generates partial keys (K-K) corresponding to respective hierarchies of the scalabilities (R, L), on the basis of the key element matrices (M-M). These partial keys (K-K) are outputted to a coding unit or a decoding unit by an output unit.