Centrosymmetric QKD ring-type multi-user system and key distribution method thereof

Abstract

According to the centrosymmetric QKD ring type multi-user system and the key distribution method thereof, the system is realized based on a Sagnac ring, the network structure is relatively simple, and the technology is relatively mature; meanwhile, each user stabilizes the light polarization state through the polarization controller, so that the system has better stability; the number of network users can be expanded by the two multi-user terminals according to actual conditions, and quantum key distribution between the users and a plurality of receiving users of the receiving terminal can be controlled through a wavelength division multiplexing / demultiplexing device. Each multi-user side shares one multi-wavelength laser generating device, and shares one group of detectors through the arrangement of the adjustable light delay line, so that the network structure is simplified, and the network cost is saved; the multi-wavelength laser generating device selectively generates multi-wavelength light pulses with certain wavelength intervals, signal crosstalk caused by the four-wave mixing effect can be reduced, and the bit error rate is reduced.

Description

technical field [0001] The present invention relates to the technical fields of quantum secure communication and optical communication, and more specifically, relates to a centrosymmetric QKD ring multi-user system and a key distribution method thereof. Background technique [0002] Quantum secure communication is different from classical communication. It does not rely on the complexity of mathematical calculations to increase the difficulty of eavesdroppers in a limited time, but to discover the existence of eavesdropping based on the basic principles and characteristics of quantum mechanics, so that the legitimate communication parties Encrypted information is theoretically unconditionally secure. With the development of information technology and the popularization of Internet applications, quantum secure communication has become a research hotspot in the interdisciplinary field of quantum physics and information science at home and abroad. [0003] The research directi...

AI Technical Summary

Problems solved by technology

The photon utilization rate of the passive star network is low, and as the number of users increases, the uncertainty of each user receiving the photon signal will also increase

Other multi-user QKD schemes have improved, but one optical pulse can only be used by one user at a time. In fact, it is still a one-to-one multi-user QKD scheme, and there is only one user at the control end, which can easily lead to network crashes

These problems not only limit the expansion of the number of users, but also lead to problems such as low utilization of optical pulses.

In addition, in the above scheme, the sending and receiving parties are fixed, and only one direction of quantum key distribution can be performed.

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