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. 25, 2022
Filed:
Dec. 28, 2018
Mitsubishi Electric Corporation, Tokyo, JP;
MITSUBISHI ELECTRIC CORPORATION, Tokyo, JP;
Abstract
A registration apparatus generates a data random number tuple R that is a tuple of random numbers whose quantity is the same as a level quantity L of a hierarchy that a user attribute forms, and that is also a tuple of uniformly random numbers. Also, the registration apparatus accepts a plaintext M and attribute information B. The registration apparatus executes a function F_2 by taking as input a concatenated value of an attribute value of each level j in the attribute information B and a number of each level j, executes a function F_3 by taking as input a function value of the function F_2, calculates an attribute element C_{j, 0, 0} that is an exclusive-or of a function value of the function F_3 and a jth random number of the data random number tuple R, executes a function F_4 by taking as input the plaintext M and an exclusive-or of the data random number tuple R, and generates encrypted data C that includes the attribute element C_{j, 0, 0} and a ciphertext C_{L+1} which is a function value of the function F_4. Then, the registration apparatus registers the encrypted data C in a data management apparatus.