We present a quantum secure imaging(QSI) scheme based on the phase encoding and weak+vacuum decoy-state BB84 protocol of quantum key distribution(QKD). It allows us to implement a computational ghost imaging(CGI) syst...We present a quantum secure imaging(QSI) scheme based on the phase encoding and weak+vacuum decoy-state BB84 protocol of quantum key distribution(QKD). It allows us to implement a computational ghost imaging(CGI) system with more simplified equipment and reconstructed algorithm by using a digital micro-mirror device(DMD) to preset the specific spatial distribution of the light intensity. What is more, the quantum bit error rate(QBER) and the secure key rate analytical functions of QKD are used to see through the intercept-resend jamming attacks and ensure the authenticity of the imaging information. In the experiment, we obtained the image of the object quickly and efficiently by measuring the signal photon counts with a single-photon detector(SPD), and achieved a secure key rate of 571.0 bps and a secure QBER of 3.99%, which is well below the lower bound of QBER of 14.51%. Besides, our imaging system uses a laser with invisible wavelength of 1550 nm, whose intensity is as low as single-photon, that can realize weak-light imaging and is immune to the stray light or air turbulence, thus it will become a better choice for quantum security radar against intercept-resend jamming attacks.展开更多
Measurement-device-independent quantum key distribution （MDI-QKD） eliminates all loopholes on detection. 3 loss in the final key for the Previous experiments of time-bin phase-encoding MDI-QKD allow a factor of inc...Measurement-device-independent quantum key distribution （MDI-QKD） eliminates all loopholes on detection. 3 loss in the final key for the Previous experiments of time-bin phase-encoding MDI-QKD allow a factor of incapability of identifying two successive detection events by a single photon detector. Here we propose a new scheme to realize the time-bin phase-encoding MDI-QKD. The polarization states are used to generate the time bins and the phase-encoding states. The factor of loss in the final key is eliminated by using four single photon detectors at the measurement site. We show the feasibility of our scheme with a proof-of-principle experimental demonstration. The phase reference frame is rotated extremely slowly with only passive stabilization measures. The quantum bit error rate can reach 0.8% in the Z-basis and 26.2% in the X-basis.展开更多
In this communication, we report results of running tests on standard telecommunication metropolitan network 1550 nm fiber applied to a quantum channel to EPR S405 Quelle prototype systems installed in National Labora...In this communication, we report results of running tests on standard telecommunication metropolitan network 1550 nm fiber applied to a quantum channel to EPR S405 Quelle prototype systems installed in National Laboratory for Quantum Technologies WUT and in CompSecur Wroclaw. Testing was carried out by means of the original design by us and applied special data card collecting parameters of functioning system allowing for assessment of quality of quantum channel. We have performed several trials using various configurations of standard 1550 nm fiber patch-cord up to length of 6.5 km with additional usage of various patch-cords with weldings and connectors which typically present in already installed commercial metropolitan communication networks. The implementation of this testing indicated that the rigorous maintenance of photon polarization is required for quantum information exchange upon EPR S405 Quelle functioning. The polarization of optical signal turned out to be, however, very unstable for the tested connection which resulted in very rapid QBER rise precluding practical usefulness of this connection for secure quantum exchange of cryptographic key over practically significant distances. We have identified that the main obstacle was the polarization decoherence caused by weldings and connectors in standard patch-cords and accidental strains in fibers as well as generally poor transmitting properties of 1550 nm fiber for much shorter wave-length photons used by the Quelle system. To maintain the quantum channel active, very frequent manual corrections of polarization control were required. So we expect that by design and application of an automatic polarization control module, one would stabilize visibility ratio and lower QBER to an acceptable level conditioning possible future implementation of entangled QKD system in commercial networks.展开更多
文摘We present a quantum secure imaging(QSI) scheme based on the phase encoding and weak+vacuum decoy-state BB84 protocol of quantum key distribution(QKD). It allows us to implement a computational ghost imaging(CGI) system with more simplified equipment and reconstructed algorithm by using a digital micro-mirror device(DMD) to preset the specific spatial distribution of the light intensity. What is more, the quantum bit error rate(QBER) and the secure key rate analytical functions of QKD are used to see through the intercept-resend jamming attacks and ensure the authenticity of the imaging information. In the experiment, we obtained the image of the object quickly and efficiently by measuring the signal photon counts with a single-photon detector(SPD), and achieved a secure key rate of 571.0 bps and a secure QBER of 3.99%, which is well below the lower bound of QBER of 14.51%. Besides, our imaging system uses a laser with invisible wavelength of 1550 nm, whose intensity is as low as single-photon, that can realize weak-light imaging and is immune to the stray light or air turbulence, thus it will become a better choice for quantum security radar against intercept-resend jamming attacks.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11304391,11674397 and 61671455the Program for New Century Excellent Talents in University of China
文摘Measurement-device-independent quantum key distribution （MDI-QKD） eliminates all loopholes on detection. 3 loss in the final key for the Previous experiments of time-bin phase-encoding MDI-QKD allow a factor of incapability of identifying two successive detection events by a single photon detector. Here we propose a new scheme to realize the time-bin phase-encoding MDI-QKD. The polarization states are used to generate the time bins and the phase-encoding states. The factor of loss in the final key is eliminated by using four single photon detectors at the measurement site. We show the feasibility of our scheme with a proof-of-principle experimental demonstration. The phase reference frame is rotated extremely slowly with only passive stabilization measures. The quantum bit error rate can reach 0.8% in the Z-basis and 26.2% in the X-basis.
文摘In this communication, we report results of running tests on standard telecommunication metropolitan network 1550 nm fiber applied to a quantum channel to EPR S405 Quelle prototype systems installed in National Laboratory for Quantum Technologies WUT and in CompSecur Wroclaw. Testing was carried out by means of the original design by us and applied special data card collecting parameters of functioning system allowing for assessment of quality of quantum channel. We have performed several trials using various configurations of standard 1550 nm fiber patch-cord up to length of 6.5 km with additional usage of various patch-cords with weldings and connectors which typically present in already installed commercial metropolitan communication networks. The implementation of this testing indicated that the rigorous maintenance of photon polarization is required for quantum information exchange upon EPR S405 Quelle functioning. The polarization of optical signal turned out to be, however, very unstable for the tested connection which resulted in very rapid QBER rise precluding practical usefulness of this connection for secure quantum exchange of cryptographic key over practically significant distances. We have identified that the main obstacle was the polarization decoherence caused by weldings and connectors in standard patch-cords and accidental strains in fibers as well as generally poor transmitting properties of 1550 nm fiber for much shorter wave-length photons used by the Quelle system. To maintain the quantum channel active, very frequent manual corrections of polarization control were required. So we expect that by design and application of an automatic polarization control module, one would stabilize visibility ratio and lower QBER to an acceptable level conditioning possible future implementation of entangled QKD system in commercial networks.
