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. 21, 2023
Filed:
Oct. 04, 2021
Mitsubishi Electric Corporation, Tokyo, JP;
Yutaka Kawai, Tokyo, JP;
Yoshihiro Koseki, Tokyo, JP;
MITSUBISHI ELECTRIC CORPORATION, Tokyo, JP;
Abstract
A cryptographic system comprising an encryption device to generate a ciphertext; a master re-encryption key generation device to generate a master re-encryption key that cannot decrypt a ciphertext generated by the encryption device, but can generate a re-encryption key for changing an access range for a ciphertext generated by the encryption device; re-encryption device to generate a re-encryption key for re-encrypting a target ciphertext generated by the encryption device, using the master re-encryption key, and re-encrypts the target ciphertext to generate a re-encrypted ciphertext, using the generated re-encryption key; and a decryption device to decrypt at least one of the ciphertext generated by the encryption device and the re-encrypted ciphertext generated by the re-encryption device.