Quantum key distribution development for common optical networks

Wakako Maeda, Akihiro Tanaka, Seigo Takahashi +1 more

Evgeniy O. Kiktenko, N. O. Pozhar, Alexander Duplinskiy +11 more

We report the results of the implementation of a quantum key distribution (QKD) network using standard fibre communication lines in Moscow. The developed QKD network is based on the paradigm of trusted repeaters and allows a common secret key to be generated between users via an intermediate trusted node. The main feature of the network is the integration of the setups using two types of encoding, i.e. polarisation encoding and phase encoding. One of the possible applications of the developed QKD network is the continuous key renewal in existing symmetric encryption devices with a key refresh time of up to 14 s.

Sebstian Slaman

The field of quantum key distribution (QKD) has seen many advancements since its conception in 1984. Recently there have been developments towards establishing free space optical links between satellites and earth to enable global QKD networks. Polarization encoded photos are commonly utilized as qubits for these free space links, placing polarization distortion constrains on the optics used. \n \nTwo polarization distortion studies were conducted in this thesis. The first is a simulation of stress induced birefringence in the Window Observational Research Facility window on board the International Space Station (ISS). Atmospherics pressure inside the ISS elicits stress on window leading to optical birefringence, which in turn can distort the polarization of photons as they pass through the window. The model studies the birefringent effects for incoming optical beams over different polarizations, diameters and incoming angles. \n \nAs part of free space optical quantum links, it can be beneficial to utilize beam steering optics to manage the spatial positioning of various components in the system. Implementing beam steering optics can aid in achieving spatial and maneuverability requirements for ground stations and satellites as they track each other. However, these optics can have an adverse effect on incoming photon polarization states. Because of this, the effects of various different beam steering configurations were characterized experimentally, and compared to a corresponding simulated model. \n \nThe studies presented in this thesis have revealed that common optics such as windows and mirrors can distort polarization based quantum signals. The polarization distortion of the studied optics have shown high dependencies on the angular orientation of the incoming optical beam. However, the distortions measured can be noticeably reduced by implementing compensation optics. As a result, their distortions are not detrimental to a quantum link that utilizes them. The studies presented in this thesis are critical to the design of polarization based quantum receivers as they shed light on potential sources of link distortions. This work is part of a large collection of developments bringing the implementation of global quantum key distribution networks closer to reality.

张梓平 Zhang Ziping, 刘国军 Liu Guojun, 董凯 Dong Kai +3 more

Yufeng Wu, Zeshang Chen, Xiaohua Chen +6 more

With the development of optical networks integrated with quantum key distribution (QKD), the security of data transmission in virtual optical network has attracted increasing attention from researchers. In the existing security virtual optical network embedding (VONE) over elastic optical networks (EONs) integrated with QKD, the shortest path algorithm is used to reduce the consumption of security keys. In this paper, the concept and theory of computation and key distribution equilibrium (CKDE) is proposed. An integer linear programming model and a heuristic algorithm based on CKDE are presented for VONE over EONs integrated with QKD, where a node rank based on CKDE is introduced and the minimal element method is used to find a solution of VONE. Simulation experiments demonstrate that the proposed model and algorithm outperform existing approaches in terms of acceptance ratios, system revenues, and resource utilization. Specifically, the proposed algorithm achieves improvements of at least 35.1% in acceptance ratios and 49.6% in both system revenues and key resource utilizations compared to other heuristic algorithms.

Alberto Sebastián-Lombraña, Juan José Romero, Laura Ortíz +1 more