Quantum key distribution based on orthogonal states allows secure quantum bit commitment

Abstract

For more than a decade, it was believed that unconditionally secure quantum bit commitment (QBC) is impossible. But basing on a previously proposed quantum key distribution scheme using orthogonal states, here we build a QBC protocol in which the density matrices of the quantum states encoding the commitment do not satisfy a crucial condition on which the no-go proofs of QBC are based. Thus the no-go proofs could be evaded. Our protocol is fault-tolerant and very feasible with currently available technology. It reopens the venue for other "post-cold-war" multi-party cryptographic protocols, e.g., quantum bit string commitment and quantum strong coin tossing with an arbitrarily small bias. This result also has a strong influence on the Clifton-Bub-Halvorson theorem which suggests that quantum theory could be characterized in terms of information-theoretic constraints.

Published version plus an appendix showing how to defeat the counterfactual attack, more references [76,77,90,118-120] cited, and other minor changes

References in corpus (11)

• Probabilistic theories with purification
• Characterizing quantum theory in terms of information-theoretic constraints
• Implications of Superstrong Nonlocality for Cryptography
• Implementation of two-party protocols in the noisy-storage model
• Fully Distrustful Quantum Cryptography
• Experimental quantum cryptography scheme based on orthogonal states
• Security of quantum bit string commitment depends on the information measure
• Strong no-go theorem for Gaussian quantum bit commitment
• Remote preparation of arbitrary ensembles and quantum bit commitment
• The cryptographic power of misaligned reference frames
• Dilemma that cannot be resolved by biased quantum coin flipping

Cited by in corpus (13)

• A Simple Voting Protocol on Quantum Blockchain
• An Efficient Routing Protocol for Quantum Key Distribution Networks
• Local Distinguishability of Generic Unentangled Orthonormal Bases
• Security bound of cheat sensitive quantum bit commitment
• Simplified quantum bit commitment using single photon nonlocality
• Secure quantum weak oblivious transfer against individual measurements
• Quantum key distribution based on orthogonal state encoding
• Quantum bit commitment and the reality of the quantum state
• Can relativistic bit commitment lead to secure quantum oblivious transfer?
• Unconditionally secure quantum bit commitment based on the uncertainty principle
• An optical implementation of quantum bit commitment using infinite-dimensional systems
• Unconditionally secure quantum coin flipping
• Insecurity of a relativistic quantum commitment scheme