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:
Apr. 26, 2011
Filed:
Jul. 07, 2006
Akihiro Tanaka, Tokyo, JP;
Akio Tajima, Tokyo, JP;
Seigo Takahashi, Tokyo, JP;
Wakako Maeda, Tokyo, JP;
Akihiro Tanaka, Tokyo, JP;
Akio Tajima, Tokyo, JP;
Seigo Takahashi, Tokyo, JP;
Wakako Maeda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
For an error rate QBER, threshold values are preset, including a threshold value Qfor frame synchronization processing, a threshold value Qfor phase correction processing, and a threshold value Qfor eavesdropping detection. Upon the distribution of a quantum key from a sender to a receiver, when the measurement value of QBER is deteriorated more than Q, frame synchronization processing is performed. When the measurement value of QBER is deteriorated more than Q, phase correction processing and frame synchronization processing are performed. When QBER does not become better than Qeven after these recovery-processing steps are repeated N times, it is determined that there is a possibility of eavesdropping, and the processing is stopped.