Patent ID: 8189966

Claim:
A QKD (quantum key distribution) arrangement comprising: a photon source for generating pairs of entangled idler photons and signal photons during use, wherein the photon source is adapted for a pulsed delivery of the pairs of photons; two measuring units, the idler photons being fed to one of the two measuring units and the signal photons being fed to the other one of the two measuring units during use, each of the two measuring units comprising: an optical module having several photon channels, a photon passing only one of the photon channels as a function of its polarization during use, wherein photon delay units with different pre-fixed delaying periods are comprised in the photon channels in the optical module; and a detection device for detecting such a photon in association with its respective photon channel, wherein each detection device being one single photon detector and the respective passed-through photon being associated to its respective photon channel on the basis of a time pattern; a first interrupting unit upstream of the other measuring unit for pulse-wise supplying the signal photons to the optical module during use; and a time controller which adjusts the detection devices of the two measuring units with a view to the correlated detection of the photons of each such pair.