Research on Polarization Modulated QKD Through Overhead Transmission Lines

As the intelligence level of power grid growing, the power system relies more on information and communication infrastructure. As a result, the reliability and security of the electric power system have been exposed to threats like illegal hacking interception, tamper, etc., from the informatics field. Quantum Key Distribution (QKD) is considered as a promising technology for power communication network, which can realize One Time Pad (OTP) protocol and prevent key from eavesdropping by exploring the principles of quantum mechanics. In this paper, we study the nonideal characteristics of quantum channel when single photon transmitting over overhead transmission lines. We first present a field test system for BB84 QKD protocol based on polarization modulation, and reveal the relationship between nonideal characteristics of overhead transmission, such as attenuation, internal stress, and strong electromagnetic interference, and received single photons random polarization variation, and then address the above issues by the polarization compensation scheme.