Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which woul...Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.展开更多
For a compact quantum key distribution (QKD) sender for the polarization encoding BB84 protocol, an eavesdropper could take a side-channel attack by measuring the spatial information of photons to infer their polariza...For a compact quantum key distribution (QKD) sender for the polarization encoding BB84 protocol, an eavesdropper could take a side-channel attack by measuring the spatial information of photons to infer their polarizations. The possibility of this attack can be reduced by introducing an aperture in the QKD sender, however, the effect of the aperture on the QKD security lacks of quantitative analysis. In this paper, we analyze the mutual information between the actual keys encoded at this QKD sender and the inferred keys at the eavesdropper (Eve), demonstrating the effect of the aperture to eliminate the spatial side-channel information quantitatively. It shows that Eve’s potential on eavesdropping spatial side-channel information is totally dependent on the optical design of the QKD sender, including the source arrangement and the aperture. The height of compact QKD senders with integrated light-emitting diode (LED) arrays could be controlled under several millimeters, showing great potential on applications in portable equipment.展开更多
A silicon quantum photonic circuit was proposed and realized for the generation and the dynamic manipulation of telecom-band frequency-degenerate polarization entangled Bell states.Frequency degenerate biphoton states...A silicon quantum photonic circuit was proposed and realized for the generation and the dynamic manipulation of telecom-band frequency-degenerate polarization entangled Bell states.Frequency degenerate biphoton states were generated in four silicon waveguides by spontaneous four wave mixing.They were transformed to polar-ization entangled Bell states through on-chip quantum interference and quantum superposition,and then coupled to optical fibers.The property of polarization entanglement in generated photon pairs was demonstrated by two-photon interference under two non-orthogonal polarization bases.The output state could be dynamically switched between two Bell states,which was demonstrated by the simplified Bell state measurement.The experiment results indicated that the manipulation speed supported a modulation rate of several tens kHz,showing its potential on applications of quantum communication and quantum information processing requiring Bell state encoding and dynamic control.展开更多
基金the National Key R&D Program of China under Grants No.2017YFA0303704 and No.2018YFB2200400Natural Science Foundation of Beijing under Grant No.Z180012National Natural Science Foundation of China under Grants No.61875101 and No.91750206.
文摘Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.
基金supported by the National Key Research and Development Program of China under Grant No.2017YFA0303704National Natural Science Foundation of China under Grants No.61575102,No.61671438,No.61875101,and No.61621064+1 种基金Beijing Natural Science Foundation under Grant No.Z180012Beijing Academy of Quantum Information Sciences under Grant No.Y18G26
文摘For a compact quantum key distribution (QKD) sender for the polarization encoding BB84 protocol, an eavesdropper could take a side-channel attack by measuring the spatial information of photons to infer their polarizations. The possibility of this attack can be reduced by introducing an aperture in the QKD sender, however, the effect of the aperture on the QKD security lacks of quantitative analysis. In this paper, we analyze the mutual information between the actual keys encoded at this QKD sender and the inferred keys at the eavesdropper (Eve), demonstrating the effect of the aperture to eliminate the spatial side-channel information quantitatively. It shows that Eve’s potential on eavesdropping spatial side-channel information is totally dependent on the optical design of the QKD sender, including the source arrangement and the aperture. The height of compact QKD senders with integrated light-emitting diode (LED) arrays could be controlled under several millimeters, showing great potential on applications in portable equipment.
基金National Key R&D Program of China(2017YFA0303704)Natural Science Foundation of Beijing(Z180012)+2 种基金National Natural Science Founda-tion of China(61875101,91750206)Beijing Academy of Quantum Informa-tion Science(Y18G26)Tsinghua Initiative Scientific Research Program.
文摘A silicon quantum photonic circuit was proposed and realized for the generation and the dynamic manipulation of telecom-band frequency-degenerate polarization entangled Bell states.Frequency degenerate biphoton states were generated in four silicon waveguides by spontaneous four wave mixing.They were transformed to polar-ization entangled Bell states through on-chip quantum interference and quantum superposition,and then coupled to optical fibers.The property of polarization entanglement in generated photon pairs was demonstrated by two-photon interference under two non-orthogonal polarization bases.The output state could be dynamically switched between two Bell states,which was demonstrated by the simplified Bell state measurement.The experiment results indicated that the manipulation speed supported a modulation rate of several tens kHz,showing its potential on applications of quantum communication and quantum information processing requiring Bell state encoding and dynamic control.