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. 17, 2025
Filed:
Aug. 18, 2020
British Telecommunications Public Limited Company, London, GB;
Marco Menchetti, London, GB;
British Telecommunications Public Limited Company, London, GB;
Abstract
There is herein disclosed a method of establishing at least a portion of an encryption key, the method including transmitting a first photon along a channel, determining the length of time the first photon takes to propagate along the channel, making a modification to the channel so as to change the length of time it takes a photon to propagate along the channel, transmitting a second photon along the modified channel, determining the length of time the second photon takes to propagate along the modified channel, using the determined lengths of time to determine the at least a portion of an encryption key, and, separately, using the fact that a modification has been made to the channel to determine the at least a portion of an encryption key.