Practical random number generation protocol for entanglement-based quantum key distribution

TL;DR

This paper introduces a practical quantum random number generation protocol leveraging inherent detection randomness in entanglement-based QKD, requiring minimal hardware modifications and demonstrated through a proof-of-principle experiment.

Contribution

The paper presents a novel, hardware-efficient random number generation method for QKD that uses existing detectors and detection times, avoiding the need for dedicated quantum random number generators.

Findings

The protocol is feasible with current QKD setups.

Generated sequences pass standard randomness tests.

Experimental demonstration confirms practical applicability.

Abstract

A simple protocol which takes advantage of the inherent random times of detections in single photon counting modules is presented for random active basis choices when using entanglement-based protocols for Quantum Key Distribution (QKD). It may also be applicable to the BB84 protocol in certain cases. The scheme presented uses the single photon detectors already present on a QKD setup, working on the same rate as the system is capable of detecting, and is, therefore, not limited by the output rates of quantum random number generators. This protocol only requires small hardware modifications making it an attractive solution. We perform a proof-of-principle experiment employing a spontaneous parametric down-conversion process in a $\chi^{(2)}$ non-linear crystal to demonstrate the feasibility of our scheme, and show that the generated sequence passes randomness tests.