Source-independent quantum key distribution without pre-sending entanglement

TL;DR

This paper introduces a source-independent quantum key distribution protocol that enhances security against source-side attacks and doubles transmission distance without needing pre-sent entanglement.

Contribution

The proposed protocol achieves source-independence and improved distance robustness, addressing vulnerabilities in existing QKD systems without relying on entanglement pre-sending.

Findings

Protocol doubles transmission distance

Provides security against all known source-side attacks

Utilizes non-classical light sources for practical security

Abstract

Quantum key distribution (QKD) theoretically offers information-theoretic security. The prevailing approach is the prepare-and-measure BB84 protocol, which implements QKD using conventional laser rather than single-photon source via the decoy-state method. However, side-channel attacks targeting sources severely threaten system security. Despite extensive efforts, including fully passive scheme, this vulnerability persists even with perfect single-photon source. Here, we propose a source-independent (SI) QKD protocol that resolves all known and unknown source-side attacks without pre-sending entanglement source. Aligning with advances in quantum light sources, our protocol simultaneously doubles the transmission distance while remaining robustness against imperfection of source. Theoretical analysis shows that non-classical light source provides practical security advantages unattainable with conventional laser.