Detection of blinding attack in quantum key distribution

TL;DR

This paper proposes a method using extended measurements, akin to Bell tests, to detect blinding attacks in quantum key distribution systems without modifying existing devices.

Contribution

It introduces a novel detection technique that identifies blinding attacks through extended measurements, eliminating the need for hardware modifications.

Findings

Extended measurement can detect blinding attacks

Detection method does not require device modifications

Enhances security of quantum key distribution systems

Abstract

Security of an ideal system for quantum key distribution can be formally proved. However, technological imperfections of real systems can be misused by an eavesdropper to get information about the key without causing a detectable change in the error rate. An example of this is the blinding attack where the eavesdropper manipulates detectors of the receiving party. To avoid such an attack, technical modifications of the device are usually required. In this paper we show that an extended measurement, similar to the Bell test measurement, can reveal the blinding attack without any modification of the device.