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. 26, 2016
Filed:
Oct. 25, 2013
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Toshiba Solutions Corporation, Minato-ku, JP;
Ryotaro Hayashi, Kawasaki, JP;
Tatsuyuki Matsushita, Kawasaki, JP;
Yoshihiro Fujii, Tokyo, JP;
Takuya Yoshida, Inagi, JP;
Koji Okada, Tokyo, JP;
KABUSHIKI KAISHA TOSHIBA, Minato-ku, JP;
TOSHIBA SOLUTIONS CORPORATION, Minato-ku, JP;
Abstract
A re-encryption key generator according to an embodiment generates a re-encryption key required to re-encrypt, without decrypting, ciphertext data obtained by encrypting plaintext data by means of a first public key of a first user device to obtain re-encrypted text data which can be decrypted by a second private key of a second user device. The first storage device stores a first private key corresponding to the first public key. The second storage device stores a second public key corresponding to the second private key. The re-encryption key generation device generates the re-encryption key based on the first private key, the second public key, and the first random number.