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:
Jul. 09, 2024
Filed:
Jun. 29, 2022
Nippon Telegraph and Telephone Corporation, Chiyoda-ku, JP;
Reo Yoshida, Musashino, JP;
Tetsutaro Kobayashi, Musashino, JP;
Yuto Kawahara, Musashino, JP;
Hitoshi Fuji, Musashino, JP;
Kazuki Yoneyama, Hitachi, JP;
NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Chiyoda-ku, JP;
Abstract
A key exchange technique of performing a key exchange among N (≥2) parties, which can conceal metadata on communication, is provided. A key exchange method includes: a first key generation step in which a communication device Ugenerates a first key; a first anonymous broadcast step in which the communication device Uanonymously broadcasts the first key with a set R-{U} being designated for i∈{1, . . . , n} and the communication device Uanonymously broadcasts the first key with φ being designated for i∈{n+1, . . . , N}; a second key generation step in which the communication device Ugenerates a second key; a second anonymous broadcast step in which the communication device Uanonymously broadcasts the second key with the set R-{U} being designated for i∈{1, . . . , n} and the communication device Uanonymously broadcasts the second key with φ being designated for i∈{n+1, . . . , N}; and a session key generation step in which the communication device Ugenerates a session key SK for i∈{1, . . . , n} if a predetermined condition is satisfied.