Measurement-Device-Independent Quantum Coin Tossing

TL;DR

This paper introduces a measurement-device-independent quantum coin tossing protocol that enhances security against detector attacks, maintains loss tolerance, and can be implemented with current quantum communication technology.

Contribution

It proposes a novel MDI-QCT protocol that removes detector side channels, is loss tolerant, and can be adapted for practical quantum sources, improving security and distance.

Findings

MDI-QCT removes detector side channel vulnerabilities.

The protocol is loss tolerant with single-photon sources.

Potential to double secure communication distance.

Abstract

Quantum coin tossing (QCT) is an important primitive of quantum cryptography and has received continuous interest. However, in practical QCT, Bob's detectors can be subjected to detector-side channel attacks launched by dishonest Alice, which will possibly make the protocol completely insecure. Here, we report a simple strategy of a detector-blinding attack based on a recent experiment. To remove all the detector side channels, we present a solution of measurement-device-independent QCT (MDI-QCT). This method is similar to the idea of MDI quantum key distribution (QKD). MDI-QCT is loss tolerant with single-photon sources and has the same bias as the original loss-tolerant QCT under a coherent attack. Moreover, it provides the potential advantage of doubling the secure distance for some special cases. Finally, MDI-QCT can also be modified to fit the weak coherent-state sources. Thus, based on the rapid development of practical MDI-QKD, our proposal can be implemented easily.