Long-distance entanglement-based quantum key distribution experiment using practical detectors.

We report an entanglement-based quantum key distribution experiment that we performed over 100 km of optical fiber using a practical source and detectors. We used a silicon-based photon-pair source that generated high-purity time-bin entangled photons, and high-speed single photon detectors based on InGaAs/InP avalanche photodiodes with the sinusoidal gating technique. To calculate the secure key rate, we employed a security proof that validated the use of practical detectors. As a result, we confirmed the successful generation of sifted keys over 100 km of optical fiber with a key rate of 4.8 bit/s and an error rate of 9.1%, with which we can distill secure keys with a key rate of 0.15 bit/s.

[1]  N. Namekata,et al.  800 MHz single-photon detection at 1550-nm using an InGaAs/InP avalanche photodiode operated with a sine wave gating. , 2006, Optics express.

[2]  M. Fejer,et al.  Differential phase shift quantum key distribution experiment over 105 km fibre , 2005, quant-ph/0507110.

[3]  Gisin,et al.  Quantum cryptography using entangled photons in energy-time bell states , 1999, Physical review letters.

[4]  Nicolas Gisin,et al.  Quantum key distribution over 30 km of standard fiber using energy-time entangled photon pairs: a comparison of two chromatic dispersion reduction methods , 2004 .

[5]  T. Tsuchizawa,et al.  Low loss mode size converter from 0.3 /spl mu/m square Si wire waveguides to singlemode fibres , 2002 .

[6]  T Honjo,et al.  Long-distance entanglement-based quantum key distribution over optical fiber. , 2008, Optics express.

[7]  Kyo Inoue,et al.  Differential-phase quantum key distribution experiment using a series of quantum entangled photon pairs. , 2007, Optics letters.

[8]  Kyo Inoue,et al.  Generation of 1.5-μm band time-bin entanglement using spontaneous fiber four-wave mixing and planar light-wave circuit interferometers , 2005 .

[9]  Shor,et al.  Simple proof of security of the BB84 quantum key distribution protocol , 2000, Physical review letters.

[10]  Hiroki Takesue,et al.  Effects of multiple pairs on visibility measurements of entangled photons generated by spontaneous parametric processes , 2009, 0907.4535.

[11]  V. Scarani,et al.  Two independent photon pairs versus four-photon entangled states in parametric down conversion , 2003, quant-ph/0310167.

[12]  M. Peev,et al.  Practical quantum key distribution with polarization entangled photons , 2005, EQEC '05. European Quantum Electronics Conference, 2005..

[13]  Normand J. Beaudry,et al.  Squashing models for optical measurements in quantum communication. , 2008, Physical review letters.

[14]  T. Shoji,et al.  Microphotonics devices based on silicon microfabrication technology , 2005, IEEE Journal of Selected Topics in Quantum Electronics.

[15]  Sae Woo Nam,et al.  Quantum key distribution over a 40-dB channel loss using superconducting single-photon detectors , 2007, 0706.0397.

[16]  H. Takesue,et al.  Entanglement generation using silicon wire waveguide , 2008, 2008 5th IEEE International Conference on Group IV Photonics.

[17]  T. Tsurumaru.  Squash operator and symmetry , 2009, 0910.2326.

[18]  Ekert,et al.  Quantum cryptography based on Bell's theorem. , 1991, Physical review letters.

[19]  Edo Waks,et al.  Security of quantum key distribution with entangled photons against individual attacks , 2000, quant-ph/0012078.

[20]  A. R. Dixon,et al.  Gigahertz quantum key distribution with InGaAs avalanche photodiodes , 2008 .

[21]  H. Takesue,et al.  Frequency and Polarization Characteristics of Correlated Photon-Pair Generation Using a Silicon Wire Waveguide , 2010, IEEE Journal of Selected Topics in Quantum Electronics.

[22]  Charles H. Bennett,et al.  Quantum cryptography without Bell's theorem. , 1992, Physical review letters.

[23]  Masato Koashi,et al.  Security of entanglement-based quantum key distribution with practical detectors , 2008 .

[24]  A. Uchida,et al.  Fast physical random bit generation with chaotic semiconductor lasers , 2008 .

[25]  H. Lo,et al.  High-speed quantum random number generation by measuring phase noise of a single-mode laser. , 2010, Optics letters.

[26]  Lo,et al.  Unconditional security of quantum key distribution over arbitrarily long distances , 1999, Science.

[27]  H. Takesue,et al.  Observation of 1.5 μm band entanglement using single photon detectors based on sinusoidally gated InGaAs/InP avalanche photodiodes , 2009 .

[28]  N. Gisin,et al.  Pulsed Energy-Time Entangled Twin-Photon Source for Quantum Communication , 1999 .

[29]  Hiroshi Fukuda,et al.  Generation of high-purity entangled photon pairs using silicon wire waveguide. , 2008, Optics express.

[30]  Wolfgang Tittel,et al.  Tailoring photonic entanglement in high-dimensional Hilbert spaces , 2003, quant-ph/0309058.

[31]  White,et al.  Entangled state quantum cryptography: eavesdropping on the ekert protocol , 1999, Physical review letters.

[32]  N. Gisin,et al.  Long-distance entanglement-based quantum key distribution , 2000, quant-ph/0008039.

[33]  Weinfurter,et al.  Quantum cryptography with entangled photons , 1999, Physical review letters.

[34]  N. Gisin,et al.  Low jitter up-conversion detectors for telecom wavelength GHz QKD , 2006 .

[35]  A. W. Sharpe,et al.  A High Speed, Post-Processing Free, Quantum Random Number Generator , 2008, ArXiv.