Polarization tracking method, system and medium of continuous variable quantum key distribution system

Abstract

The present invention provides a polarization tracking method, system and medium for a continuous variable quantum key distribution system, including: step A: realizing synchronous transmission of quantum signals and phase reference signals by means of polarization multiplexing; Detect the quantum signal and the phase reference signal; Step B: Track the polarization state through the Kalman filter algorithm, so as to demultiplex the polarization of the aliased quantum signal and the phase reference signal, and finally restore the quantum signal accurately at the receiving end. The present invention can accurately recover quantum signals under bad channels, expands the applicable scenarios of the quantum key distribution system, encrypts the transmitted voice or image data, and ensures the safety of information transmission.

Description

technical field [0001] The present invention relates to the technical field of quantum key distribution, in particular to a polarization tracking method, system and medium of a continuous variable quantum key distribution system. In particular, it relates to a continuous variable quantum key distribution system, and uses a Kalman filter algorithm to track the deviation of the polarization state, and realizes a solution for polarization demultiplexing of quantum signals and phase reference signals. Background technique [0002] In the context of the rapid development of communication technology, people pay more and more attention to the security of transmitted information. Although the traditional classic security scheme provides a relatively secure security method at the data link layer, its security is based on the security of mathematical calculations. With the rapid development of quantum computers, the computational security that classical cryptography relies on will fa...

AI Technical Summary

Problems solved by technology

The coherent detection technology requires that the polarization state of the local oscillator light and the quantum signal are consistent, otherwise a large part of the signal power will be lost.

On the other hand, more and more practical scenarios require the security protection of quantum key distribution systems, but the polarization state changes will be more rapid and irregular, which will limit the use scenarios of quantum key distribution systems

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