Patent ID: 8949300
Filing Date: 2015-02-03
Classification: G06F,H04L,Y04S

Abstract:
1. A receiver of a quantum key distribution system in which a sender and the receiver are connected to each other through a transmission line, the receiver comprising: a photodetecting section which receives optical pulses to detect random numbers and separately outputs a plurality of values of the random numbers, wherein the photodetecting section varies in reception efficiency depending on applied bias voltage, wherein the detected random numbers are used for the generation of a quantum key, wherein the photodetecting section comprises a plurality of photodetectors corresponding to the plurality of values; a calculating section which calculates a proportion of count of each of the plurality of values of the random numbers detected by the photodetecting section; and a controller which controls a reception efficiency of the photodetecting section so as to bring the proportion closer to a desired value, wherein the controller controls the reception efficiency by independently adjusting respective bias voltages applied to the plurality of photodetectors.