title: Countermeasure against tailored bright illumination attack for DPS-QKD.
abstract: We propose a countermeasure against the so-called tailored bright illumination attack for differential-phase-shift QKD (DPS-QKD). By monitoring a rate of coincidence detection at a pair of superconducting nanowire single-photon detectors (SSPDs) which is connected at each of the output ports of Bob's Mach-Zehnder interferometer, Alice and Bob can detect and defeat this kind of attack. We also experimentally confirmed the feasibility of this countermeasure using our 1 GHz-clocked DPS-QKD system. In the emulation of the attack, we achieved much lower power of the bright illumination light compared with the original demonstration by using a pulse stream instead of broad pulses.
authors.affiliation: NTT Secure Platform Laboratories, NTT Corporation, 3-9-11 Midori-cho, Musashino, Tokyo 180-8585, Japan. honjo.toshimori@lab.ntt.co.jp
authors.forename: Toshimori
authors.initials: T
authors.lastname: Honjo
authors.forename: Mikio
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Kaoru
authors.initials: K
authors.lastname: Shimizu
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Tamaki
authors.forename: Shigehito
authors.initials: S
authors.lastname: Miki
authors.forename: Taro
authors.initials: T
authors.lastname: Yamashita
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Terai
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Masahide
authors.initials: M
authors.lastname: Sasaki
mesh_terms: D008029:Lighting / Q000379:methods*; D012637:Security Measures; D012815:Signal Processing, Computer-Assisted; D013685:Telecommunications