Eur. Phys. J. D (2016) 70: 5
https://doi.org/10.1140/epjd/e2015-60469-8

Regular Article

The countermeasures against the blinding attack in quantum key distribution

¹ Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, P.R. China
² State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, P.R. China
³ Department of Engineering Technology, Guangdong Polytechnic Institute, Guangzhou 510091, P.R. China

^a e-mail: Wangjd@scnu.edu.cn

Received: 13 August 2015
Received in final form: 7 November 2015
Published online: 12 January 2016

Abstract

It has been shown that the single photon detectors (SPDs) based on the avalanche photodiode (APD) can be blinded and controlled by the bright light and short trigger pulses. Eavesdropper can get the full information without causing additional quantum bit error rate. Hence, in order to guarantee the security of the quantum key distribution (QKD) systems, some countermeasures, by changing the characteristic of the SPD or monitoring the parameters of the detector, are presented by some research groups. In this paper, we provide a new and effective countermeasure against the blinding attack based on improving the optical scheme of the decoding unit in the QKD system rather than only considering the characteristic of the SPD. In our proposal we use a coupler with asymmetric splitting ratio to distinguish the detection characteristic of the SPD with blinding attack from that without blinding attack. The detailed analysis shows that the proposed scheme is feasible to defense the blinding attack.