Physical layer security in space-division multiplexed fiber optic communications

Recent developments in the field of space-division multiplexing (SDM) for fiber-optic communication systems suggest that the spatial diversity offered by SDMcan be used not only to increase system capacity, but also to achieve provable security against physical layer attacks. In this work, we outline some of the mathematical framework necessary to assess the security benefits of the SDM. We substantiate our conjecture that allocating the maximal allowable power to each mode is optimal in terms of physical layer security. Further more, we expand the scope of our security analyses to include distortion as a quantitative metric for secrecy and study how the rate of reliable communication between the legitimate transmitter-receiver pair can be chosen to maximize reconstruction (decoding) errors of the eavesdropper.