OSA's Digital Library

Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 22, Iss. 4 — Feb. 24, 2014
  • pp: 4098–4107

QAM quantum stream cipher using digital coherent optical transmission

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka, and Keisuke Kasai  »View Author Affiliations

Optics Express, Vol. 22, Issue 4, pp. 4098-4107 (2014)

View Full Text Article

Enhanced HTML    Acrobat PDF (1107 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



A Quantum Stream Cipher (QSC) using Quadrature Amplitude Modulation (QAM) is presented to greatly increase the secure degree compared with ASK or PSK/QSC. We propose encoding multi-bit data in one symbol with a multi-bit basis state, resulting in QAM/QSC, which employs amplitude and phase encryption of the light beam simultaneously. A 16 QAM/QSC experiment at 10 Gbit/s was successfully carried out over 160 km using a digital coherent optical transmission technique, where 16 QAM data were encrypted in a constellation with 32 × 32~4096 × 4096 symbols. We show experimentally that the Number of Masked Signals (NMS) in the quantum noise ΓQAM for QAM/QSC becomes a square multiple larger than ΓASK for ASK/QSC. ΓQAM exceeds 10,000. This result indicates that the QSC technique is more robust against eavesdroppers than ASK or PSK/QSC.

© 2014 Optical Society of America

OCIS Codes
(060.1660) Fiber optics and optical communications : Coherent communications
(060.4080) Fiber optics and optical communications : Modulation
(060.4785) Fiber optics and optical communications : Optical security and encryption
(060.5565) Fiber optics and optical communications : Quantum communications

ToC Category:
Optical Communications

Original Manuscript: December 27, 2013
Revised Manuscript: February 10, 2014
Manuscript Accepted: February 11, 2014
Published: February 13, 2014

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka, and Keisuke Kasai, "QAM quantum stream cipher using digital coherent optical transmission," Opt. Express 22, 4098-4107 (2014)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. M. Nakazawa, K. Kikuchi, and T. Miyazaki, eds., High Spectral Density Optical Transmission Technologies, Springer (2010).
  2. A. J. Lowery, L. Du, and J. Armstrong, “Orthogonal frequency division multiplexing for adaptive dispersion compensation in long-haul WDM systems,” in Proceedings of OFC2006 (Anaheim, USA) PDP39.
  3. Q. Yang, Y. Ma, and W. Shieh, “107 Gb/s coherent optical OFDM reception using orthogonal band multiplexing,” in Proceedings of OFC2008 (San Diego, USA) PDP7.
  4. Y. Koizumi, K. Toyoda, M. Yoshida, M. Nakazawa, “1024 QAM (60 Gbit/s) single-carrier coherent optical transmission over 150 km,” Opt. Express 20(11), 12508–12514 (2012). [CrossRef] [PubMed]
  5. C. H. Bennett and G. Brassard, “Quantum cryptography: Public key distribution and coin tossing,” in Proc. Int. Conf. Comput., Syst., Signal Process. (Bangalore, India, 2011) 175–179. [CrossRef]
  6. A. K. Ekert, “Quantum cryptography based on Bell’s theorem,” Phys. Rev. Lett. 67(6), 661–663 (1991). [CrossRef] [PubMed]
  7. T. Jennewein, C. Simon, G. Weihs, H. Weinfurter, A. Zeilinger, “Quantum cryptography with entangled photons,” Phys. Rev. Lett. 84(20), 4729–4732 (2000). [CrossRef] [PubMed]
  8. G. A. Barbosa, E. Corndorf, P. Kumar, H. P. Yuen, “Secure communication using mesoscopic coherent states,” Phys. Rev. Lett. 90(22), 227901 (2003). [CrossRef] [PubMed]
  9. E. Corndorf, C. Liang, G. S. Kanter, P. Kumar, H. P. Yuen, “Quantum noise randomized data encryption for wavelength division multiplexed fiber optic network,” Phys. Rev. A 71(6), 062326 (2005). [CrossRef]
  10. C. Liang, G. S. Kanter, E. Corndorf, P. Kumar, “Quantum noise protected data encryption in a WDM network,” IEEE Photon. Technol. Lett. 17(7), 1573–1575 (2005). [CrossRef]
  11. O. Hirota, M. Sohma, M. Fuse, K. Kato, “Quantum stream cipher by Yuen 2000 protocol: Design and experiment by intensity modulation scheme,” Phys. Rev. A 72(2), 022335 (2005). [CrossRef]
  12. G. S. Kanter, D. Reilly, N. Smith, “Practical physical-layer encryption: The marriage of optical noise with traditional cryptography,” IEEE Commun. Mag. 47(11), 74–81 (2009). [CrossRef]
  13. K. Harasawa, O. Hirota, K. Yamashita, M. Honda, K. Ohhata, S. Akutsu, T. Hosoi, Y. Doi, “Quantum encryption communication over a 192-km 2.5-Gbit/s line with optical transceivers employing Yuen-2000 protocol based on intensity modulation,” J. Lightwave Technol. 29(3), 316–323 (2011). [CrossRef]
  14. F. Futami and O. Hirota, “40 Gbit/s (4 x 10 Gbit/s) Y-00 protocol for secure optical communication and its transmission over 120 km,” in Proceedings of OFC2012 (Los Angeles, USA) OTu1H.6.
  15. K. Kato and O. Hirota, “Quantum quadrature amplitude modulation system and its applicability to coherent state quantum cryptography,” SPIE 5893, Quantum Communications and Quantum Imaging III (Bellingham, USA, 2005) 589303.
  16. D. Reilly and G. S. Kanter, “Noise-enhanced encryption for physical layer security in an OFDM radio,” IEEE Radio and Wireless Symposium (RWS ’09), TU2P–28. [CrossRef]
  17. K. Kasai, A. Suzuki, M. Yoshida, M. Nakazawa, “Performance improvement of an acetylene (C2H2) frequency-stabilized fiber laser,” IEICE Electron. Express 3(22), 487–492 (2006). [CrossRef]
  18. H. Nyquist, “Certain topics in telegraph transmission theory,” Transact. Am. Inst. Elec. Eng. 47, 617–644 (1928).
  19. K. Kasai, J. Hongo, M. Yoshida, M. Nakazawa, “Optical phase-locked loop for coherent transmission over 500 km using heterodyne detection with fiber lasers,” IEICE Electron. Express 4(3), 77–81 (2007). [CrossRef]
  20. F. Futami and O. Hirota, “Masking of 4096-level intensity modulation signals by noises for secure communication employing Y-00 cipher protocol,” in Proceedings of ECOC2011 (Geneva, Switzerland) Tu.6.C.4.
  21. O. Hirota, “Practical security analysis of a quantum stream cipher by the Yuen 2000 protocol,” Phys. Rev. A 76(3), 032307 (2007). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited