Unconditionally Secure Quantum Bit Commitment

TL;DR

This paper challenges the established impossibility of unconditionally secure quantum bit commitment by introducing a protocol that leverages quantum and classical randomness, demonstrating its unconditional security.

Contribution

It presents a novel protocol that overcomes previous limitations by properly utilizing quantum and classical randomness, achieving unconditional security.

Findings

The protocol is unconditionally secure against entanglement cheating.

It addresses gaps in the impossibility proof by considering combined quantum and classical randomness.

The approach demonstrates a new direction for secure quantum cryptographic protocols.

Abstract

The ``impossibility proof'' on unconditionally secure quantum bit commitment is examined. It is shown that the possibility of juxtaposing quantum and classical randomness has not been properly taken into account. A specific protocol that beats entanglement cheating with entanglement is proven to be unconditionally secure.