US 12,463,791 B2
Method for detecting blinding attacks on photodetectors in a quantum cryptography system
Lijiong Shen, Singapore (SG); and Christian Kurtsiefer, Singapore (SG)
Assigned to NATIONAL UNIVERSITY OF SINGAPORE, Singapore (SG)
Appl. No. 18/556,249
Filed by NATIONAL UNIVERSITY OF SINGAPORE, Singapore (SG)
PCT Filed Feb. 8, 2022, PCT No. PCT/SG2022/050062
§ 371(c)(1), (2) Date Oct. 19, 2023,
PCT Pub. No. WO2022/225448, PCT Pub. Date Oct. 27, 2022.
Claims priority of application No. 10202103968W (SG), filed on Apr. 19, 2021.
Prior Publication US 2024/0187207 A1, Jun. 6, 2024
Int. Cl. H04L 9/00 (2022.01); H04L 9/08 (2006.01)
CPC H04L 9/005 (2013.01) [H04L 9/0852 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of identifying occurrence of a blinding attack in a quantum cryptography system, the method comprising the steps of:
providing a light emitter at a receiver of the quantum cryptography system, wherein the light emitter is different from a transmitter of a quantum cryptography signal to be received by the receiver, wherein the light emitter is different from a transmitter of a blinding attack signal directed at the receiver, and wherein at least a portion of light emitted from the light emitter is detectable by a single photon detector of the receiver;
switching the light emitter off during a normal operation mode of the single photon detector;
measuring a first number of detection events registered in the single photon detector in a first time period, T1, with the light emitter switched on; and
identifying the occurrence of the blinding attack based on the first number of detection events.