Comment on "A short impossibility proof of quantum bit commitment"

TL;DR

This paper critiques a recent proof claiming quantum bit commitment impossibility, identifying errors that undermine its claim to cover all possible protocols involving quantum and classical information.

Contribution

It exposes errors in a recent impossibility proof, demonstrating that it does not comprehensively address all quantum bit commitment protocols.

Findings

The proof contains significant errors.

Not all protocols are covered by the original proof.

Quantum bit commitment may still be feasible under some conditions.

Abstract

In a recent letter (Phys. Lett. A 377 (2013) 1076, arXiv:0905.3801), the authors presented an impossibility proof of quantum bit commitment, which attempted to cover all possible protocols that involve both quantum and classical information. Here we show that there are many errors in the proof, thus it fails to exhaust all conceivable protocols.