Information synchronization method and apparatus

Abstract

The invention discloses an information synchronization method. The information synchronization method is applied to a quantum key distribution system and comprises three steps: first step, delay calculation: calculating the delay of transmitting signal light from a transmitting end to a receiving end; second step, frame synchronization: performing frame synchronization, that is, determining a frame, through a classical channel; and third step, intra-frame position synchronization: performing intra-frame position synchronization on quantum signal light in a quantum channel, that is, determiningwhich number of the pulse in the frame is, according to the transmission delay calculated in the first step. The invention further discloses an information synchronization apparatus. Compared with the prior art, the information synchronization method and apparatus disclosed by the invention have the following advantages: 1. no additional synchronization light needs to be transmitted, and only oneoptical signal of one wavelength is transmitted in an optical fiber at both ends of a connection system, that is, only one channel is occupied. 2. The receiving end of the system does not need to usea wavelength division multiplexing device and directly uses a single photon detector for detection, thereby saving devices. 3. The synchronization scheme of the two ends of the system is completed bythree steps, so that the implementation efficiency is high.

Description

technical field [0001] The invention relates to the field of quantum secret communication, and in particular provides a synchronization method suitable for a quantum key distribution system. Background technique [0002] The fundamental difference between Quantum Key Distribution (QKD) and the classical key system is that it uses a single photon or entangled photon pair as the carrier of the key, and the basic principles of quantum mechanics guarantee that the process cannot be eavesdropped or deciphered , thus providing a more secure key system. At present, the technology of using entangled photon pairs to realize quantum key distribution is still far from commercialization and practicality, so the existing commercial QKD systems mostly use quantum key distribution technology based on single photon realization. [0003] Taking polarization coding as an example, the basic process of quantum key distribution based on single photon is: [0004] 1) Alice at the transmitter ra...

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Problems solved by technology

[0005] 2) Bob at the receiving end randomly selects the measurement base vector to receive. Due to the efficiency of the detector and the path attenuation problem, Bob cannot detect all the photon signals, and can only detect photons at some positions randomly;

The disadvantages of this scheme: First, the internal deviation of Bob (the misalignment between the measurement base vector recorded by Bob and the measurement result) can be completely avoided, so our proposal does not consider the internal deviation of Bob.

[0016] In the existing technology, the synchronization scheme can be completed without using synchronous light, and the implementation efficiency is very low, which is not practical for high-speed QKD systems

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