Double blinding-attack on entanglement-based quantum key distribution protocols

TL;DR

This paper introduces a double blinding-attack on entanglement-based quantum key distribution protocols, enabling eavesdroppers to fully learn the key undetected even with high detector efficiencies.

Contribution

It presents a novel double blinding-attack method that compromises entanglement-based QKD protocols more effectively than previous single-side attacks.

Findings

Eve can fully determine the key in BBM92 protocol undetected.

The attack remains effective with 100% detector efficiency.

Extends to Ekert protocol with up to 85.3% efficiency.

Abstract

We propose a double blinding-attack on entangled-based quantum key distribution protocols. The principle of the attack is the same as in existing blinding attack except that instead of blinding the detectors on one side only, Eve is blinding the detectors of both Alice and Bob. In the BBM92 protocol, the attack allows Eve to get a full knowledge of the key and remain undetected even if Alice and Bob are using 100% efficient detectors. The attack can be easily extended to Ekert protocol, with an efficiency as high as 85.3%.