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

Abstract

The present 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, comprising: step 1: superimposing a quantum signal on a coherent optical communication signal to realize the communication between the coherent optical communication signal and the quantum signal Synchronous transmission; Step 2: For the carrier phase drift problem in the receiving process, the carrier recovery is carried out through digital signal processing technology to realize the separation of coherent optical communication signals and quantum signals. The invention superimposes the quantum signal on the original coherent optical communication signal, so that the coherent optical system carries quantum signal information during the communication process, and uses digital signal processing technology at the receiving end to recover the carrier phase and separate the classical and quantum signals, realizing In order to carry out both classical communication and quantum communication on a set of equipment, this method can not only meet the requirements of quantum key distribution, but also reduce the cost of its actual implementation, and at the same time improve the channel utilization 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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