In practical quantum key distribution(QKD)systems,a single photon-detector(SPD)is one of the most vulnerable components.Faint after-gate attack is a universal attack against the detector.However,the original faint aft...In practical quantum key distribution(QKD)systems,a single photon-detector(SPD)is one of the most vulnerable components.Faint after-gate attack is a universal attack against the detector.However,the original faint after-gate attack can be discovered by monitoring the photocurrent.This paper presents a probabilistic generalization of the attack,which we refer to as probabilistic faint after-gate attack,by introducing probability control modules.Previous countermeasures for photocurrent monitoring may fail in detecting the eavesdropper under some specific probabilities.To mitigate this threat,we provide a method to determine the detectable boundary in the limitation of precision of photocurrent monitoring,and investigate the security of QKD systems under such boundaries using the weak randomness model.展开更多
文摘In practical quantum key distribution(QKD)systems,a single photon-detector(SPD)is one of the most vulnerable components.Faint after-gate attack is a universal attack against the detector.However,the original faint after-gate attack can be discovered by monitoring the photocurrent.This paper presents a probabilistic generalization of the attack,which we refer to as probabilistic faint after-gate attack,by introducing probability control modules.Previous countermeasures for photocurrent monitoring may fail in detecting the eavesdropper under some specific probabilities.To mitigate this threat,we provide a method to determine the detectable boundary in the limitation of precision of photocurrent monitoring,and investigate the security of QKD systems under such boundaries using the weak randomness model.
