Practical Decoy State for Quantum Key Distribution

Decoy states have recently been proposed as a useful method for substantially improving the performance of quantum key distribution (QKD). Here, we present a general theory of the decoy state protocol based on only two decoy states and one signal state. We perform optimization on the choice of intensities of the two decoy states and the signal state. Our result shows that a decoy state protocol with only two types of decoy states---the vacuum and a weak decoy state---asymptotically approaches the theoretical limit of the most general type of decoy state protocol (with an infinite number of decoy states). We also present a one-decoy-state protocol. Moreover, we provide estimations on the effects of statistical fluctuations and suggest that, even for long-distance (larger than 100 km) QKD, our two-decoy-state protocol can be implemented with only a few hours of experimental data. In conclusion, decoy state quantum key distribution is highly practical.

[1]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[2]  Giovanni Mastrobuoni,et al.  Preliminary Version , 1994 .

[3]  N. Lütkenhaus.  Security against individual attacks for realistic quantum key distribution , 2000 .

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

[5]  David P. DiVincenzo,et al.  Quantum information and computation , 2000, Nature.

[6]  Tor Helleseth,et al.  Advances in Cryptology — EUROCRYPT ’93 , 2001, Lecture Notes in Computer Science.

[7]  Won-Young Hwang.  Quantum key distribution with high loss: toward global secure communication. , 2003, Physical review letters.

[8]  Z. Yuan,et al.  Quantum key distribution over 122 km of standard telecom fiber , 2004, quant-ph/0412171.

[9]  John Preskill,et al.  Security of quantum key distribution with imperfect devices , 2002, International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings..

[10]  Hoi-Kwong Lo,et al.  Efficient Quantum Key Distribution Scheme and a Proof of Its Unconditional Security , 2004, Journal of Cryptology.

[11]  2004b, A decoy-state protocol for quantum cryptography with 4 intensities of coherent light, Los Alamos e-print archive: quant-ph/0411047 , .

[12]  Yi Zhao,et al.  Experimental Decoy State Quantum Key Distribution Over 15km , 2005 .

[13]  Xiongfeng Ma.  Security of Quantum Key Distribution with Realistic Devices , 2005, quant-ph/0503057.

[14]  J. M. Ettinger,et al.  Enhancing practical security of quantum key distribution with a few decoy states , 2005, quant-ph/0503002.

[15]  Xiongfeng Ma,et al.  Decoy state quantum key distribution. , 2004, Physical review letters.

[16]  Xiang‐Bin Wang,et al.  Beating the PNS attack in practical quantum cryptography , 2004 .