QUANTUM KEY DISTRIBUTION METHOD (THREE OPTIONS) Russian patent published in 2023 - IPC H04L9/08 

FIELD: communications.

SUBSTANCE: quantum key distribution method includes the transmission of optical key signals in the form of single photons with basic polarization states corresponding to the selected protocol i from the sender to the recipient via a fibre optic channel and two-way exchange of information via an open channel, moreover, optical signals are transmitted via a fibre optic channel with modulation of outgoing polarization states on the sender side and their polarization detection by measuring the incoming polarization states on the receiver side, and the open channel is used to correct optical signal distortions in the fibre optic channel; preliminarily two to four test optical signals with modulation of polarization states mapped on the Poincaré sphere are transmitted via fibre-optic channel from the sender to the receiver so that the lines connecting the mentioned mappings do not cross the centre of the Poincaré sphere, measure the state of polarization of the test optical signals at the output of the fibre optic channel and the polarization states of the test optical signals modulated on the sender side and measured on the receiver side are used to determine the Muller matrix of the fibre optic channel M, and the outgoing polarization states of the optical signals of the key on the sender side are calculated according to the matrix product.

EFFECT: increase in the rate of transmission of quantum information.

4 cl, 8 dwg, 1 tbl