Continuous variable quantum key distribution method based on coherent optical communication system

Abstract

The invention relates to a continuous variable quantum key distribution method based on a coherent optical communication system in the technical field of quantum key distribution, which includes the following steps: S1, superimposing a quantum signal on a coherent optical communication signal to achieve synchronous transmission of the coherent optical communication signal and the quantum signal; and S2, for the problem of carrier phase shift in the receiving process, carrying out carrier recovery through a digital signal processing technology to separate the coherent optical communication signal from the quantum signal. A quantum signal is superimposed on an original coherent optical communication signal so that a coherent optical system carries quantum signal information in the communication process. The carrier phase is recovered and classical and quantum signals are separated by the digital signal processing technology at the receiving end, and classical communication and quantum communication can be carried out simultaneously on the same set of equipment. The method not only can meet the needs of quantum key distribution, but also can reduce the cost of actual implementation and improve the channel utilization rate in communication.

Description

technical field [0001] The present invention relates to the technical field of quantum key distribution, in particular to a continuous variable quantum key distribution method based on a coherent optical communication system. Background technique [0002] With the rapid development of information technology, people's demand for information security is increasing day by day. Although the traditional classical encryption scheme provides a relatively safe encryption method, its security is based on the security of mathematical calculations. With the rapid development of quantum computers, its calculation security will be threatened. [0003] On the one hand, the quantum key distribution scheme based on the basic principles of quantum mechanics has physical unconditional security, which has attracted extensive attention in recent years. Continuous variable quantum key distribution is a kind of quantum key distribution scheme. It is based on the uncertainty principle of the orth...

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Problems solved by technology

The invention adopts passive preparation, the cost is low, and the single-mode heat source is not strictly required. The multi-mode heat source also completes the preparation of the quantum state, but the patent application introduces an additional over-noise in the preparation process, by increasing the average number of photons in the thermal state also cannot effectively suppress this additional over-noise

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