Unconditionally Secure Bit Commitment by Transmitting Measurement Outcomes

TL;DR

This paper introduces a novel unconditionally secure bit commitment protocol leveraging Minkowski causality and quantum information principles, involving measurement outcomes transmitted at light speed to ensure security.

Contribution

It presents a new quantum bit commitment scheme that guarantees unconditional security based solely on relativistic causality and quantum properties, without relying on computational assumptions.

Findings

Security relies only on quantum information properties.

Protocol achieves unconditional security against superluminal attacks.

Uses BB84 states and relativistic constraints for security.

Abstract

We propose a new unconditionally secure bit commitment scheme based on Minkowski causality and the properties of quantum information. The receiving party sends a number of randomly chosen BB84 qubits to the committer at a given point in space-time. The committer carries out measurements in one of the two BB84 bases, depending on the committed bit value, and transmits the outcomes securely at light speed in opposite directions to remote agents. These agents unveil the bit by returning the outcomes to adjacent agents of the receiver. The security proofs rely only on simple properties of quantum information and the impossibility of superluminal signalling.