Experimental implementation of bit commitment in the noisy-storage model

TL;DR

This paper demonstrates a practical quantum bit commitment protocol secure under the noisy-storage model, using real-world quantum devices and accounting for experimental imperfections and finite-size effects.

Contribution

It provides the first experimental implementation of a secure bit commitment protocol based on the noisy-storage model, including comprehensive security analysis.

Findings

Protocol is secure with imperfect quantum memory

Experimental implementation using polarization-entangled photons

Security holds under realistic experimental conditions

Abstract

Fundamental primitives such as bit commitment and oblivious transfer serve as building blocks for many other two-party protocols. Hence, the secure implementation of such primitives are important in modern cryptography. In this work, we present a bit commitment protocol which is secure as long as the attacker's quantum memory device is imperfect. The latter assumption is known as the noisy-storage model. We experimentally executed this protocol by performing measurements on polarization-entangled photon pairs. Our work includes a full security analysis, accounting for all experimental error rates and finite size effects. This demonstrates the feasibility of two-party protocols in this model using real-world quantum devices. Finally, we provide a general analysis of our bit commitment protocol for a range of experimental parameters.