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.