ALL-OPTICAL CRYPTOGRAPHY THROUGH SPECTRAL AMPLITUDE AND DELAY ENCODING
Keywords:Transparent Optical Networks, Optical Cryptography, Spectral Slicing, Spectral Amplitude Encoding
All-optical data encryption is a promising technology that could lead communication systems to an unprecedented degree of security. In this paper we use computer simulations to systematically investigate a new all-optical cryptography technique that is bit-rate independent and transparent to modulation formats. Encryption encompasses signal spectral slicing followed by two encoding stages that impose different attenuations and delays to each of the spectral slices. We analyze the quality of the encoded signal by evaluating its bit error rate (BER) performance. Results indicate that such BER may achieve 45 and 28%, respectively, for input non-return-to-zero on-off keying (NRZ-OOK) and differential quadrature phase-shift keying (DQPSK) signals. At the receiver side, results suggest that signals may be properly decoded after propagation distances that are compatible with those utilized in metropolitan area networks. The robustness of the technique against waveform analysis and brute force attacks is also approached.
Photonic Networks: Threats and Security Enhancement," IEEE/OSA Journal of Lightwave Technology, vol. 29, pp. 3210-3222,
 K. Shaneman, and S. Gray, "Optical network security: technical analysis of fiber tapping mechanisms and methods for detection &
prevention," IEEE Military Communications Conference, vol. 2, pp. 711-716, 2004.
 N. Skorin-Kapov, J. Chen, and L. Wosinska, "A New Approach to Optical Networks Security: Attack-Aware Routing and Wavelength
Assignment," IEEE/ACM Transactions on Networking, vol. 18, pp. 750-760, June 2010.
 L. Zhang, X. Xin, B. Liu, and Y. Wang, "Secure OFDM-PON Based on Chaos Scrambling," IEEE Photonics Technology Letters, vol.
23, pp. 998-1000, July 2011.
 P. Juleang, R. Putthacharoen, S. Mitatha, and P.P. Yupapin, “Highly secured optical communication by optical key and identification
address,” Elsevier Optik - International Journal for Light and Electron Optics, vol. 124, pp. 834-839, May 2013.
 A. Argyris, D. Syvridis, L. Larger, V. Annovazzi-Lodi, P. Colet, I. Fischer, J. García-Ojalvo, C.R. Mirasso, L. Pesquera, and K.A.
Shore, "Chaos-based communications at high bit rates using commercial fibre-optic links," Nature 438, pp. 343-346, 2005.
 Y. Hong, M.W. Lee, J. Paul, P.S. Spencer, and K.A. Shore, “GHz Bandwidth Message Transmission Using Chaotic Vertical-Cavity
Surface-Emitting Lasers,” IEEE/OSA Journal of Lightwave Technology, vol. 27, pp. 5099-5105, november 2009.
 J-P. Goedgebuer, P. Levy, L. Larger, C-C. Chen, and W.T. Rhodes, "Optical communication with synchronized hyperchaos generated
electrooptically," IEEE Journal of Quantum Electronics, vol. 38, pp. 1178-1183, September 2002.
 N. Kostinski, K. Kravtsov, and P.R. Prucnal, "Demonstration of an All-Optical OCDMA Encryption and Decryption System With
Variable Two-Code Keying," IEEE Photonics Technology Letters, vol. 20, pp. 2045-2047, December 2008.
 T.H. Shake, "Security performance of optical CDMA Against eavesdropping," IEEE/OSA Journal of Lightwave Technology, vol. 23,
pp. 655-670, February 2005.
 C-C. Yang, “Hybrid Wavelength-Division-Multiplexing/Spectral-Amplitude-Coding Optical CDMA System,” IEEE Photonics
Technology Letters, vol. 17, pp. 1343-1345, june 2005.
 K. Kitayama, X. Wang, and N. Wada, “OCDMA Over WDM PON—Solution Path to Gigabit-Symmetric FTTH,” IEEE/OSA Journal
of Lightwave Technology, vol. 24, pp. 1654-1662, 2006.
 J.A. Cornejo, C.E. Perez, and J-L. B. Tocnaye, “Non-invasive WDM channel scrambling for secure high data rate optical
transmissions,” IEEE/OSA Journal of Lightwave Technology, vol. 25, pp. 2081-2089, 2007.
 L. Yi, T. Zhang, Z. Li, J. Zhou, Y. Dong, W. Hu, “Secure optical communication using stimulated Brillouin scattering in optical fiber,”
Elsevier Optics Communications, vol. 290, pp. 146-151, March 2013.
 S. Singh, Lovkesh, X. Ye, and R.S. Kaler, “Design of Ultrafast Encryption and Decryption Circuits for Secured Optical Networks,”
IEEE Journal of Quantum Electronics, vol. 48, pp. 1547-1553, 2012.
 K. Mukherjee, “A method of implementation of frequency encoded all optical encryption decryption using four wave mixing,”
Elsevier Optik - International Journal for Light and Electron Optics, vol. 122, pp. 1407-1411, 2011.
 M.L.F. Abbade, L.A. Fossaluzza Jr., R.F. Silva, and E.A.M. Fagotto, “Criptografia Óptica Mediante Controle Analógico da Amplitude
e do Atraso de Fatias Espectrais: Análise para Sinais NRZ,” (in Portuguese) MOMAG , 2012.
 M. Kavehrad, Fellow, and D. Zaccarh, “Optical Code-Division-Multiplexed Systems Based on Spectral Encoding of Noncoherent
Sources,” Journal of Lightwave Technology, vol. 13, pp. 534-545, 1995. B.P. Lathi, "Modern Digital and Analog Communication
Systems," 3rd Edition, Oxford Press, 1998.
 B.P. Lathi, "Modern Digital and Analog Communication Systems," 3rd Edition, Oxford Press, 1998.
 R.F. Silva, "Análise de criptografia óptica realizada mediante controle da amplitude e do atraso de fatias espectrais geradas com perfil
de filtros ópticos comerciais," (in Portuguese) Master Dissertation, PUC-Campinas, 2012.