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:
Nov. 14, 2017
Filed:
Feb. 06, 2015
Re-encryption key generator, re-encryption device, encryption device, decryption device, and program
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Toshiba Solutions Corporation, Kawasaki-shi, JP;
Yoshihiro Fujii, Tokyo, JP;
Koji Okada, Tokyo, JP;
Tatsuyuki Matsushita, Tokyo, JP;
Ryotaro Hayashi, Hiratsuka, JP;
KABUSHIKI KAISHA TOSHIBA, Minato-ku, JP;
TOSHIBA SOLUTIONS CORPORATION, Kawasaki-shi, JP;
Abstract
A re-encryption key generator according to an embodiment generates a re-encryption key to obtain re-encrypted data that can be decrypted by a second private key of a second user device by re-encrypting ciphertext obtained by encrypting plaintext by a first public key of a first user device without decryption. The re-encryption key generator stores a first private key corresponding to the first public key. The re-encryption key generator stores a second re-encryption key generation key of the second user device that is different from a second public key corresponding to the second private key. The re-encryption key generator generates the re-encryption key based on the first private key and the second re-encryption key generation key.