TTD-based detecting and locating scheme for multi-branch tapping attacks in optical access networks

To address the security problem of multi-branch tapping attacks in optical access networks, we propose a terminal thermal distribution (TTD)-based detecting and locating scheme. A TTD control module (TCM) including parts of attack detection, branch distinction, and location via effective thermal distribution product (ETDP) is set at the optical line terminal, can detect and locate the tapping attacks simultaneously occurring on multi-branch drop fiber links according to the feedback signals uploaded by each optical network units, and has the advantage of saving a lot of communication and computing resources for the physical layer. Meanwhile, what we believe to be a novel ETDP model is established to improve the efficiency of TTD image processing and judging. An experimental platform with two-branch drop fiber links and the corresponding measurements are set up in the laboratory, in which the single-wavelength OTDR analyzer is combined to verify and evaluate the experimental results of the scheme proposed in this paper. By comparing the experimental results of the TTD-based scheme with that of the OTDR, the detection success rate and location spatial resolution for multi-branch tapping attacks in the TTD-based detecting and locating scheme are around 98% and 0.006 km on average, respectively.