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:
Aug. 24, 2021
Filed:
Jun. 29, 2016
Applicant:
Massachusetts Institute of Technology, Cambridge, MA (US);
Inventor:
Vincent W. S. Chan, Lincoln, MA (US);
Assignee:
Massachusetts Institute of Technology, Cambridge, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L 9/06 (2006.01); H04B 10/61 (2013.01); H04B 10/27 (2013.01); H04B 10/50 (2013.01); H04B 10/85 (2013.01);
U.S. Cl.
CPC ...
H04B 10/61 (2013.01); H04B 10/27 (2013.01); H04B 10/50 (2013.01); H04B 10/85 (2013.01); H04L 9/0656 (2013.01);
Abstract
A pseudo-random cipher stream is used to band-spread an optical carrier signal with coded data. A legitimate receiver uses an agreed-upon key to modulate its local oscillator and a resulting beat signal uncovers the band-spread signal. An eavesdropper who does not have the key finds the spread signal with too low signal-to-noise ratio to perform any useful determination of the message sequence. Theoretical bounds based on Shannon's Theory of Secrecy are used to show strength of the encoding scheme and predict it to be superior to the prior art.