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:
Apr. 16, 2013
Filed:
Mar. 05, 2009
Nori Matsuda, Tokyo, JP;
Mitsuhiro Hattori, Tokyo, JP;
Takeshi Yoneda, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
Secret key backup is safely implemented even if a role base access structure in which the access structure is specified using roles is used. An all combination generating unitobtains a backup participating user listwhich is a list of backup participating users and a list of validated roles validated by the users, and a role base access structurewhich is a combination of specified roles by which a secret keycan be restored, and generates an all combination extracted result which is all combinations of restoration enabling users of the secret key by applying users described in the backup participating user listto the specified role. A same user/role deleting unit, etc. deletes a combination showing the same user redundantly, etc. from the all combination extracted result, a general access structure secret distributing unitgenerates fragments of secret key from the secret key, and distributes the fragments of secret key to the combinations of users from which the redundancy is removed.