Simple security proofs for continuous-variable quantum key distribution with intensity fluctuating sources

TL;DR

This paper presents straightforward security proofs for continuous-variable quantum key distribution systems with intensity fluctuations, addressing a key imperfection and enabling practical, secure implementations without hardware modifications.

Contribution

It introduces simple security proofs tailored for CV-QKD systems with intensity fluctuations, dividing cases based on device assumptions, and suggests compensation schemes for decoding flaws.

Findings

Security proofs applicable to systems with intensity fluctuations

No hardware adjustments needed for current CV-QKD implementations

Proposes compensation schemes for decoding flaws

Abstract

Quantum Key Distribution (QKD) in principle offers unconditional security based on the laws of physics. Continuous variable (CV) quantum key distribution has the potential for high-key-rate and low-cost implementations using standard telecom components. Despite tremendous theoretical and experimental progress in continuous-variable quantum key distribution, the security has not been rigorously established for most current continuous-variable quantum key distribution systems that have imperfections. Among the imperfections, intensity fluctuation is a significant principal problem affecting security. In this paper, we provide simple security proofs for continuous-variable quantum key distribution systems with an intensity fluctuating sources. Specifically, depending on device assumptions in the source, the imperfect systems are divided into two cases for security proofs. Our proofs are simple to implement without any hardware adjustment for the current continuous-variable quantum key distribution system. Besides, we show some compensation schemes for the decoding flaws for an outlook.