METHODS FOR QUANTUM KEY DISTRIBUTION AND RELATED DEVICES

摘要

A method for distributing a quantum digital key is described. The method comprises the use of an optical broadband source to generate an optical broadband signal. The optical broadband signal may be transmitted from a first party to a second party through an optical communication channel. The optical broadband signal may be transmitted with a low brightness, such as less than one photon/(sec-Hz), so as to be immune from passive attacks. Furthermore, a method for detecting the presence of active attackers is described. The method may comprise a coincidence measurement configured to measure the level of entanglement between an optical detection signal and an optical idler signal.

主权项

1. A method for distributing a quantum digital key comprising:
generating an optical broadband signal with an optical broadband source; transmitting a first portion of the optical broadband signal with less than one photon/(sec-Hz) through a first optical communication channel; time-delaying a second portion of the optical broadband signal with an optical delay element; receiving a modulated optical broadband signal encoded with the quantum digital key through a second optical communication channel; and obtaining the quantum digital key by mixing the modulated optical broadband signal with the delayed second portion of the optical broadband signal.