On the Secrecy Capacity of the Space-Division Multiplexed Fiber Optical Communication Systems
14 October 2013
Recent development in the field of space-division multiplexing (SDM) for fiber-optic communication systems suggests that the spatial diversity offered by SDM can be used not only to increase system bandwidth, but also to achieve provable security against physical layer attacks. Extending our previous work, we examine the information-theoretic security of SDMwith a focus on frequency-selective and rapidly-varying frequency-flat channels. We also analytically evaluate the outage-free secrecy capacity - the maximal data rate that guarantees perfect security within a class of channel realizations. Using both analysis and simulations, we evaluate extensively the impact of key system parameters on the secrecy capacity of SDM systems. Our results show that, with a proper code design that balances the trade-off between data rate and confidentiality, we can take full advantage of the SDM to offer a secure information rate that could be orders of magnitude higher than what can be achieved through known quantum key distribution (QKD) technique. In addition, the presence of mode-dependent loss (MDL) allows SDM systems to achieve fundamental security even if the eavesdropper's SNR is higher than that of the legitimate receiver
