Abstract

This article proposes a redundancy-free multiple phase-offset based key distribution (MPO-KD) scheme for solving the physical-layer session key agreement in optical data center interconnections (DCIs). High-dimensional chaotic encryption is a promising technology expected to provide better security for massive-scale data transmission in DCIs. Considering the huge key space introduced by hyper-chaos, the proposed scheme converts digital keys into the phase of quadrature amplitude modulation (QAM) symbols by actively introducing controllable offsets. The solution of offset factor space is modeled as a multi-objective optimization problem for improving the key distribution performance. The Pareto optimal set is obtained using the non-dominated sorting moth-flame optimization (NS-MFO) algorithm. The two-channel 140 Gb/s 16-QAM, 176 Gb/s 32-QAM and 210 Gb/s 64-QAM orthogonal frequency division multiplexing (OFDM) signal transmissions are successfully demonstrated. The results indicate that this scheme achieves error-free key distribution without degrading system performance, which supports an expandable large key space and has good compatibility with various encryption algorithms.