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:
Mar. 01, 2016
Filed:
Sep. 27, 2011
Ken Naganuma, Tokyo, JP;
Ken Naganuma, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A client executes processing for data encryption by adding an error vector to plaintext, the error vector being not larger than a predetermined criterion and processing for sending limitation information to a server, the limitation information being formed from a sublattice basis of a lattice generated by a secret key. The server executes processing for receiving the limitation information and storing it in a storage device and in the homomorphic computation processing on the encrypted data received from the client, processing for, when a bit length of ciphertext which is a result of the homomorphic computation processing is equal to or larger than a predetermined value, reducing the bit length of the ciphertext to a value not larger than a predetermined threshold by translating a vector of the ciphertext to an inside of a region formed from the sublattice basis corresponding to the stored limitation information.