Quantum nonlocality as the route for ever-lasting unconditionally secure bit commitment

TL;DR

This paper proposes a quantum nonlocality-based bit commitment protocol that aims for everlasting unconditional security by ensuring classical, uncorrelated proof data, overcoming previous impossibility results and enabling flexible, long-term secure commitments.

Contribution

It introduces a novel quantum nonlocality protocol that guarantees everlasting security and addresses limitations of prior relativistic quantum bit commitment schemes.

Findings

Supports security through physical arguments and simulations

Ensures proof data remains classical and uncorrelated

Allows the committer to choose reveal timing and guarantees long-term security

Abstract

We present a bit commitment protocol based on quantum nonlocality that seems to bring ever-lasting unconditional security. Although security is not rigorously proved, physical arguments and numerical simulations support this conclusion. The key point is that the proof of the commitment is forced to become classical data uncorrelated with anything else. This allows us to circumvent previous impossibility proofs in which it is assumed that classical data can be replaced by quantum data that may be entangled with the committer. The proposed protocol also recovers two features missing in recent "relativistic" quantum bit commitment protocols: (i) the committer can decide if and when she wants to reveal the commitment and (ii) the security of the commitment lasts for arbitrary long time.