Quantum key distribution (QKD) is a technology with the potential capability to achieve information-theoretic security. Phasecoding is an important approach to develop practical QKD systems in fiber channel. In order to improve the phase-coding modulation rate, we proposed a new digital-modulation method in this paper and constructed a compact and robust prototype of QKD system using currently available components in our lab to demonstrate the effectiveness of the method. The system was deployed in laboratory environment over a 50 km fiber and continuously operated during 87 h without manual interaction. The quantum bit error rate (QBER) of the system was stable with an average value of 3.22% and the secure key generation rate is 8.91 kbps. Although the modulation rate of the photon in the demo system was only 200 MHz, which was limited by the Faraday- Michelson interferometer (FMI) structure, the proposed method and the field programmable gate array (FPGA) based electronics scheme have a great potential for high speed QKD systems with Giga-bits/second modulation rate.
[1] Bennett C H, Brassard G. Quantum cryptography: Public key distribution and coin tossing. In: Proceedings of IEEE International Conference on Computers, Systems and Signal Processing. 1984. 175-179
[2] Vernam G S. Cipher printing telegraph systems for secret wire and radio telegraphic communications. Trans Am Inst Electr Eng, 1926, XLV: 295-301
[3] Zhang C M, Song X T, Treeviriyanupab P, et al. Delayed error verification in quantum key distribution. Chin Sci Bull, 2014, 59:2825-2828
[4] Wang C Z, Guo H, Ren J G, et al. Experimental validation of dynamic polarization compensation in ground-satellite quantum key distribution. Sci China-Phys Mech Astron, 2014, 57: 1233-1237
[5] Zhang C X, Guo B H, Cheng G M, et al. Spin-orbit hybrid entanglement quantum key distribution scheme. Sci China-Phys Mech Astron, 2014, 57: 2043-2048
[6] Su X L. Applying Gaussian quantum discord to quantum key distribution. Chin Sci Bull, 2014, 59: 1083-1090
[7] Chen S J, Liu D K, You L X, et al. Superconducting nanowire single-photon detection system and demonstration in quantum key distribution. Chin Sci Bull, 2013, 58: 1145-1149
[8] Xiao F Y, Chen H W, Xing M J, et al. Construction of punctured and extended quantum codes over GF(2). Sci China Inf Sci, 2013, 56:032113
[9] Shi J J, Shi R H, Guo Y, et al. Batch proxy quantum blind signature scheme. Sci China Inf Sci, 2013, 56: 052115
[10] Chen Y W, Lin Q. Optical quantum router with cross-phase modulation. Sci China Inf Sci, 2014, 57: 122304
[11] Sasaki M, Fujiwara M, Ishizuka H, et al. Field test of quantum key distribution in the Tokyo QKD Network. Opt Express, 2011, 19:10387-10409
[12] Clarke P J, Collins R J, Hiskett P A, et al. Robust gigahertz fiber quantum key distribution. Appl Phys Lett, 2011, 98: 131103
[13] Patel K A, Dynes J F, Choi I, et al. Coexistence of high-bit-rate quantum key distribution and data on optical fiber. Phys Rev X, 2012,2: 041010
[14] Wang J, Cui K, Luo C L, et al. Design of a high-repetition rate photon source in a quantum key distribution system. Sci China Inf Sci, 2013,56: 092305
[15] Jin W, Zheng L M, Wang F Q, et al. The influence of stochastic dispersion on quantum key distribution system. Sci China Inf Sci,2013, 56: 092304
[16] Lo H K, Chau H F. Unconditional security of quantum key distribution over arbitrarily long distances. Science, 1999, 283: 2050-2056
[17] Shor P W, Preskill J. Simple proof of security of the BB84 quantum key distribution protocol. Phys Rev Lett, 2000, 85: 441-444
[18] Dominic M. Unconditional security in quantum cryptography. J ACM,2001, 48: 351-406
[19] Dynes J F, Choi I, Sharpe A W, et al. Stability of high bit rate quantum key distribution on installed fiber. Opt Express, 2012, 20: 16339-16347
[20] Muller A, Herzog T, Huttner B, et al. “Plug and play” systems for quantum cryptography. Appl Phys Lett, 1997, 70: 793-795
[21] Mo X F, Zhu B, Han Z F, et al. Faraday-Michelson system for quantum cryptography. Opt Lett, 2005, 30: 2632-2634
[22] Nambu Y, Yoshino K, Tomita A. Quantum encoder and decoder for practical quantum key distribution using a planar lightwave circuit. J Mod Opt, 2008, 55: 1953-1970
[23] Yang Y. Research on Phase Encoding Quantum Key Distribution System. Dissertation for Doctoral Degree. Hefei: University of Sience and Technology of China, 2012
[24] Lu X M, Wang Y G, Yang Y. A high-speed quantum key distribution system based on Faraday-Michelson interferometers. In: Proceedings of IEEE 7th International Conference on Advanced Infocomm Technology, 2014. 148-154
[25] Lo H K, Ma X F, Chen K. Decoy state quantum key distribution. Phys Rev Lett, 2005, 94: 230504
[26] Lundskog A, Hsu C W, Karlsson K F, et al. Direct generation of linearly polarized photon emission with designated orientations from site-controlled InGaN quantum dots. Light-Sci Appl, 2014, 3: e139
[27] ChowWW, Jahnke F, Gies C. Emission properties of nanolasers during the transition to lasing. Light-Sci Appl, 2014, 3: e201
[28] Qi B, Fung C H F, Lo H K, et al. Time-shift attack in practical quantum cryptosystems. arXiv:quant-ph/0512080
[29] Pearson D. High-speed QKD reconciliation using forward error correction. AIP Conf Proc, 2004, 734: 299-302
[30] Martinez-Mateo J, Elkouss D, Martin V. Key reconciliation for high performance quantum key distribution. Sci Rep, 2013, 3: 1576
[31] Zhang C M, Li M, Huang J Z, et al. Fast implementation of lengthadaptive privacy amplification in quantum key distribution. Chin Phys B, 2014, 23: 90310
[32] Lucamarini M, Patel K A, Dynes J F, et al. Efficient decoy-state quantum key distribution with quantified security. Opt Express, 2013,21: 24550-24565
[33] Zhang L J, Wang Y G, Yin Z Q, et al. Real-time compensation of phase drift for phase-encoded quantum key distribution systems. Chin Sci Bull, 2011, 56: 2305-2311
Copyright 2019 Science China Press Co., Ltd. 科学大众杂志社有限责任公司 版权所有
京ICP备18024590号-1