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:
Jun. 30, 2009
Filed:
Feb. 21, 2003
Applicants:
Yoshihiro Nambu, Tokyo, JP;
Toshiyuki Kambe, Tokyo, JP;
Inventors:
Yoshihiro Nambu, Tokyo, JP;
Toshiyuki Kambe, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04K 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a quantum cryptography key distribution system for sharing a secret key between a transmitter and a receiver site, an unbalanced interferometer system in the transmitter site has a Mach-Zehnder interferometer switch with a phase modulator while the receiver site records photon arrival time slots. The system utilizes a whole of arrival photons in the receiver site and dispenses with any phase modulator in the receiver site. This system serves to improve a photon utilization efficiency.