104 citations
3 papers
quant-ph2008★ 104 cited
Security proof for QKD systems with threshold detectors
Toyohiro Tsurumaru, Kiyoshi Tamaki
In this paper, we rigorously prove the intuition that in security proofs for BB84 one may regard an incoming signal to Bob as a qubit state. From this result, it follows that all s…
quant-ph2007★ 29 cited
Exact minimum and maximum of yield with a finite number of decoy light intensities
Toyohiro Tsurumaru, Alexandre Soujaeff, Shigeki Takeuchi
In this paper, for the decoy state method using a finite number of decoy light intensities, we present an improved upper and lower bounds for the asymptotic yield y_n for n-photon…
quant-ph2006★ 44 cited
Sequential Attack with Intensity Modulation on the Differential-Phase-Shift Quantum Key Distribution Protocol
Toyohiro Tsurumaru
In this paper, we discuss the security of the differential-phase-shift quantum key distribution (DPSQKD) protocol by introducing an improved version of the so-called sequential att…