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.

arXiv comment23 pages, 14 figures

References in corpus (11)

• Sending-or-Not-Sending with Independent Lasers: Secure Twin-Field Quantum Key Distribution Over 509 km
• Experimental quantum key distribution beyond the repeaterless secret key capacity
• Spontaneous parametric down-conversion
• Experimental Quantum Coin Tossing
• A quantum protocol for cheat-sensitive weak coin flipping
• Experimental plug&play quantum coin flipping
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Cited by in corpus (11)

• Enhancing quantum cryptography with quantum dot single-photon sources
• Multiphoton and side-channel attacks in mistrustful quantum cryptography
• Quantum cryptography beyond key distribution: theory and experiment
• Composable Security for Multipartite Entanglement Verification
• Direct and Efficient Detection of Quantum Superposition
• Experimentally Certified Transmission of a Quantum Message through an Untrusted and Lossy Quantum Channel via Bell's Theorem
• Single-Photon Advantage in Quantum Cryptography Beyond QKD
• Continuous Variable Quantum Advantages and Applications in Quantum Optics
• Quantum Universally Composable Oblivious Linear Evaluation
• Testing Single Photon Entanglement using Self-Referential Measurements
• Experimental cheat-sensitive quantum weak coin flipping