DSP-Based Physical Layer Security for Coherent Optical Communication Systems

A novel digital signal processing (DSP)-based scheme for physical layer security in coherent optical communication systems is proposed and numerically investigated. The encryption accomplished by two dispersive elements one phase modulator (PM) driven a DSP-generated key, whilst decryption uses similar components but with inverted dispersion values keys. critical aspect of the DSP-based that keys, driving PMs to hide/recover data signals, must be highly unpredictable noise-like, thus orthogonal frequency division multiplexing (OFDM) signals are employed as they possess these characteristics, can also easily generated cover suitably wide range unique Numerical simulations conducted determine optimum system parameters achieving high level security, key requiring optimization bandwidth Using determined parameters, in-depth investigations undertaken encryption/decryption induced transmission performance penalties, sensitives various parameter offsets operation over distances. To observe any dependencies, metrics investigated different combinations modulation formats (DQPSK 16QAM) baud rates (40 Gbaud 100 Gbaud) transmitted signals. shown have potential achieve, low-cost effective manner, acceptable penalties existing systems.