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:
Dec. 24, 2024
Filed:
Oct. 19, 2022
Mitsubishi Electric Corporation, Tokyo, JP;
Yutaka Kawai, Tokyo, JP;
MITSUBISHI ELECTRIC CORPORATION, Tokyo, JP;
Abstract
An encryption device () generates a session key K and a ciphertext ctin which the session key K is encrypted that are generated by an encryption algorithm using as input attribute information S. A re-encryption key generation device () generates a re-encryption key rk including a converted decryption key skgenerated by setting a random number r in a decryption key skwith which the ciphertext ctcan be decrypted, a session key K' and a ciphertext ctthat are generated by the encryption algorithm using as input attribute information S′, and conversion information generated from the random number r. A re-encryption device () outputs a re-encrypted ciphertext rctincluding the ciphertext ctand a cipher element Kgenerated by deleting an element related to the random number r by the conversion information from decryption information K{circumflex over ( )} obtained by decrypting the ciphertext ctwith the converted decryption key skand setting the session key K′.