US 11,743,037 B2
Quantum key distribution system and method for performing differential phase shift in a quantum network
Anindita Banerjee, Bengaluru (IN); and Rajesh Kumar Krishnan, Bengaluru (IN)
Assigned to QuNu Labs Private Ltd
Filed by QuNu Labs Pvt Ltd, Bengaluru (IN)
Filed on Jul. 29, 2021, as Appl. No. 17/388,705.
Prior Publication US 2023/0035266 A1, Feb. 2, 2023
Int. Cl. H04L 9/08 (2006.01); G06N 10/00 (2022.01)
CPC H04L 9/0852 (2013.01) [G06N 10/00 (2019.01); H04L 9/0819 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A quantum key distribution system for performing differential phase shift in a network, the quantum key distribution system comprising: a hardware processor; and a memory coupled to the hardware processor, wherein the memory comprises a set of program instructions in the form of a plurality of subsystems, executed by the hardware processor, wherein the plurality of subsystems comprises: a configuration selection subsystem determining a quantum key distribution (QKD) configuration for a quantum signal comprising a series of pulses based on signal amplitude, signal pulse width and block length; a compartment generation subsystem grouping one or more pulses to generate one or more quantum signal blocks based on determined QKD configuration, wherein the one or more quantum signal blocks comprises grouped sequence of one or more pulses; a label generation subsystem assigning a random label to each of the one or more quantum signal blocks based on the determined quantum key distribution configuration; a hybrid phase modulation subsystem performing hybrid phase modulation to each of the one or more pulses individually and to each of the one or more quantum signal blocks with a defined phase difference between the each of the one or more pulses individually and each of the one or more quantum signal blocks, wherein the hybrid phase modulation is performed based on the assigned random label; and a communication interface transmitting the hybrid phase modulated quantum signal blocks to one or more receiving units using a quantum communication link; and
demodulating the hybrid phase modulated quantum signal blocks using an interferometer upon receiving the hybrid phase modulated quantum signal blocks from a transmitter node; extracting one or more monitoring parameters associated with the demodulated quantum signal blocks; evaluating security level of the quantum communication link by analyzing the extracted one or more monitoring parameters, monitoring signals and coincident measurement; and post processing the demodulated quantum signal blocks to generate quantum secure keys based on difference of phase of consecutive quantum signals.