Method for Dealing with Double Click Events for Guaranteeing Security of Quantum Key Distribution System

The present embodiment relates to a quantum key distribution (Quantum Key distribution, QKD) methods and systems. More particularly, the present invention relates to a method and a QKD system using this to process the double click event (Event Double Click) generated upon detection of both signals in order to ensure the safety of the QKD system. According to one embodiment in the aspect of this embodiment, by no use of the TRNG detect the attacker's behavior, and reflect the occurrence of an event, double-click on the length of the final key to ensuring the safety of the QKD system.