Skip to Main content Skip to Navigation
Preprints, Working Papers, ...

Quantum weak coin flipping with a single photon

Abstract : Weak coin flipping is among the fundamental cryptographic primitives which ensure the security of modern communication networks. It allows two mistrustful parties to remotely agree on a random bit when they favor opposite outcomes. Unlike other two-party computations, one can achieve information-theoretic security using quantum mechanics only: both parties are prevented from biasing the flip with probability higher than $1/2+\epsilon$, where $\epsilon$ is arbitrarily low. Classically, the dishonest party can always cheat with probability $1$ unless computational assumptions are used. Despite its importance, no physical implementation has been proposed for quantum weak coin flipping. Here, we present a practical protocol that requires a single photon and linear optics only. We show that it is fair and balanced even when threshold single-photon detectors are used, and reaches a bias as low as $\epsilon=1/\sqrt{2}-1/2\approx 0.207$. We further show that the protocol may display quantum advantage over a few hundred meters with state-of-the-art technology.
Document type :
Preprints, Working Papers, ...
Complete list of metadatas
Contributor : Ulysse Chabaud <>
Submitted on : Monday, March 2, 2020 - 8:22:24 AM
Last modification on : Tuesday, August 4, 2020 - 9:02:51 AM

Links full text


  • HAL Id : hal-02495409, version 1
  • ARXIV : 2002.09005


Mathieu Bozzio, Ulysse Chabaud, Iordanis Kerenidis, Eleni Diamanti. Quantum weak coin flipping with a single photon. 2020. ⟨hal-02495409⟩



Record views