Round robin differential phase shift quantum key distribution with yes-no detectors only

TL;DR

This paper introduces a practical RRDPS quantum key distribution protocol using only yes-no detectors, providing security bounds and demonstrating comparable key rates to photon-number-resolving detector setups.

Contribution

The authors develop a RRDPS protocol utilizing only yes-no detectors, simplifying implementation while maintaining security and performance.

Findings

Key rate close to that of photon-number-resolving detector RRDPS.

Security bounds derived for yes-no detector-based RRDPS.

Protocol remains robust against source flaws and side-channel attacks.

Abstract

In the original round-robin differential-phase-shift (RRDPS) quantum key distribution and its improved method, the photon-number-resolving detectors are must for the security. We present a RRDPS protocol with yes-no detectors only. We get the upper bounds of mutual information of Alice and Eve, and Bob and Eve, and the formula of key rate. Our main idea is to divide all counts into two classes, the counts due to the odd number photons of incident detectors and the counts due to the even number photons of incident detectors. The fact that the bit-flip error rate of the later class is certainly $50\%$ makes it possible for us to perform a tightened estimation of the upper bound of the leakage information. The robustness of original RRDPS against source flaws such as side-channel attacks still holds for the RRDPS with yes-no detectors. The simulation results show that the key rate of RRDPS with yes-no detectors is close to that of RRDPS with photon-number-resolving detectors. Our results make the RRDPS protocol much more practical.