Physical Layer Security in High-Speed Optical Communications

The capability to form a photonic shield by using a unique all-optical transmission scheme incorporating multi-THz coherent spreading, (SPE), and negative (OSNR) completely prevents offline deciphering of captured data-in-transit. This photonic shield scheme provides an ultimate solution to the "harvest-now, decrypt later"threat by eliminating unauthorised recording. Thus, no raw data is available for any post-processing, including by quantum computers. Both the full line rate payload and the asymmetric key exchange, are transmitted through the secured channel. This work presents an industry-level demonstration, including real-time client data transmission and seamlessly continuously changing SPE photonic keys. A 100 Gbps DP-QPSK signal and a 200 Gbps DP-16QAM link are established over 80 km of (SSMF).