Patent ID: 6028935
Filing Date: 2000-02-22
Classification: H04L

Abstract:
A cryptographic receiver for receiving individual information carrying photons comprising:a first photon channel and a second photon channel;distributing means for distributing received photons between the first photon channel and the second photon channel;means in the first photon channel for imposing a first measurement basis on photons within the first photon channel;means in the second photon channel for imposing a second measurement basis on photons within the second photon channel, the first and second measurement bases being non-orthogonal;photon detecting means for detecting received photons and for providing output signals upon detection of such photons; andsignal processing means for receiving said output signals and signals from an external source and for generating a cryptographic key-code from a combination of said output signals and said signals from an external source such that the receiver and the external source share an identical key-code,whereinthe distributing means distributes received photons randomly between the first and second photon channels without the requirement for a control signal, andthe output signals from the photon detecting means are indicative of the respective measurement basis imposed on each received photon.