25 MHz clock continuous-variable quantum key distribution system over 50 km fiber channel

In this paper, a practical continuous-variable quantum key distribution system is developed and it runs in the real-world conditions with 25 MHz clock rate. To reach high-rate, we have employed a homodyne detector with maximal bandwidth to 300 MHz and an optimal high-efficiency error reconciliation algorithm with processing speed up to 25 Mbps. To optimize the stability of the system, several key techniques are developed, which include a novel phase compensation algorithm, a polarization feedback algorithm, and related stability method on the modulators. Practically, our system is tested for more than 12 hours with a final secret key rate of 52 kbps over 50 km transmission distance, which is the highest rate so far in such distance. Our system may pave the road for practical broadband secure quantum communication with continuous variables in the commercial conditions.

[1]  Gilles Brassard,et al.  Experimental Quantum Cryptography , 1990, EUROCRYPT.

[2]  N. Cerf,et al.  Quantum key distribution using gaussian-modulated coherent states , 2003, Nature.

[3]  P. Grangier,et al.  Finite-size analysis of a continuous-variable quantum key distribution , 2010, 1005.0339.

[4]  G. Guo,et al.  Quantum hacking of a continuous-variable quantum-key-distribution system using a wavelength attack , 2013, 1302.0090.

[5]  N. Cerf,et al.  Unconditional optimality of Gaussian attacks against continuous-variable quantum key distribution. , 2006, Physical Review Letters.

[6]  R. Penty,et al.  Quantum key distribution for 10 Gb/s dense wavelength division multiplexing networks , 2014, 1402.1508.

[7]  L. Liang,et al.  Local oscillator fluctuation opens a loophole for Eve in practical continuous-variable quantum-key-distribution systems , 2013, 1303.6043.

[8]  Jun Zhu,et al.  An integrated quantum secure communication system , 2011, Science China Information Sciences.

[9]  Daniel J. Rogers.  Broadband Quantum Cryptography , 2010, Broadband Quantum Cryptography.

[10]  E. Diamanti,et al.  Preventing Calibration Attacks on the Local Oscillator in Continuous-Variable Quantum Key Distribution , 2013, 1304.7024.

[11]  S. Braunstein,et al.  Quantum Information with Continuous Variables , 2004, quant-ph/0410100.

[12]  Mu-Sheng Jiang,et al.  Wavelength attack on practical continuous-variable quantum-key-distribution system with a heterodyne protocol , 2013 .

[13]  E. Diamanti,et al.  Field test of classical symmetric encryption with continuous variables quantum key distribution. , 2012, Optics express.

[14]  Jian-Wei Pan,et al.  Quantum teleportation and entanglement distribution over 100-kilometre free-space channels , 2012, Nature.

[15]  Seth Lloyd,et al.  Gaussian quantum information , 2011, 1110.3234.

[16]  Vaidman.  Teleportation of quantum states. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[17]  Gilles Brassard,et al.  Quantum cryptography: Public key distribution and coin tossing , 2014, Theor. Comput. Sci..

[18]  J. Dynes,et al.  Gigahertz decoy quantum key distribution with 1 Mbit/s secure key rate. , 2008, Optics express.

[19]  H. Bechmann-Pasquinucci,et al.  Quantum cryptography , 2001, quant-ph/0101098.

[20]  T Franz,et al.  Continuous variable quantum key distribution: finite-key analysis of composable security against coherent attacks. , 2011, Physical review letters.

[21]  Huang Duan,et al.  A 300-MHz Bandwidth Balanced Homodyne Detector for Continuous Variable Quantum Key Distribution , 2013 .

[22]  E. Diamanti,et al.  Field test of a continuous-variable quantum key distribution prototype , 2008, 0812.3292.

[23]  M. Curty,et al.  Secure quantum key distribution , 2014, Nature Photonics.

[24]  Xiaosong Ma,et al.  Quantum teleportation over 143 kilometres using active feed-forward , 2012, Nature.

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

[26]  P. Grangier,et al.  Continuous variable quantum cryptography using coherent states. , 2001, Physical review letters.

[27]  Zheshen Zhang,et al.  A 24 km fiber-based discretely signaled continuous variable quantum key distribution system. , 2009, Optics express.

[28]  Miguel Navascués,et al.  Optimality of Gaussian attacks in continuous-variable quantum cryptography. , 2006, Physical review letters.

[29]  Christian Weedbrook,et al.  Security of continuous-variable quantum key distribution with coarse-grained detector , 2016 .

[30]  N. Gisin,et al.  High rate, long-distance quantum key distribution over 250 km of ultra low loss fibres , 2009, 0903.3907.

[31]  Romain Alléaume,et al.  Multidimensional reconciliation for continuous-variable quantum key distribution , 2007, 2008 IEEE International Symposium on Information Theory.

[32]  Eleni Diamanti,et al.  Experimental demonstration of long-distance continuous-variable quantum key distribution , 2012, Nature Photonics.

[33]  J. Cirac,et al.  De Finetti representation theorem for infinite-dimensional quantum systems and applications to quantum cryptography. , 2008, Physical review letters.

[34]  Timothy C. Ralph,et al.  Quantum information with continuous variables , 2000, Conference Digest. 2000 International Quantum Electronics Conference (Cat. No.00TH8504).

[35]  P. Grangier,et al.  Reverse reconciliation protocols for quantum cryptography with continuous variables , 2002, quant-ph/0204127.

[36]  Guihua Zeng,et al.  Quantum Private Communication , 2010 .

[37]  Renato Renner,et al.  Security of continuous-variable quantum key distribution against general attacks. , 2012, Physical review letters.

[38]  Fibirova Jana,et al.  Profit-Sharing – A Tool for Improving Productivity, Profitability and Competitiveness of Firms? , 2013 .

[39]  H. Lo,et al.  Experimental study on the Gaussian-modulated coherent-state quantum key distribution over standard telecommunication fibers , 2007, 0709.3666.