Maximization of Extractable Randomness in a Quantum Random-Number Generator

TL;DR

This paper presents a method to maximize the extractable quantum randomness in a QRNG by accounting for classical noise, demonstrating high-speed real-time generation and potential for even higher rates.

Contribution

We introduce a technique to maximize min-entropy in quantum random-number generators considering classical noise, with experimental validation and high-speed performance.

Findings

Achieved a real-time generation rate of 14 Mbit/s per MHz.

Potential to deliver over 70 Gbit/s of random numbers.

Method effectively safeguards against classical noise tampering.

Abstract

The generation of random numbers via quantum processes is an efficient and reliable method to obtain true indeterministic random numbers that are of vital importance to cryptographic communication and large-scale computer modeling. However, in realistic scenarios, the raw output of a quantum random-number generator is inevitably tainted by classical technical noise. The integrity of the device can be compromised if this noise is tampered with, or even controlled by some malicious party. To safeguard against this, we propose and experimentally demonstrate an approach that produces side-information independent randomness that is quantified by min-entropy conditioned on this classical noise. We present a method for maximizing the conditional min-entropy of the number sequence generated from a given quantum-to-classical-noise ratio. The detected photocurrent in our experiment is shown to have a real-time random-number generation rate of 14 (Mbit/s)/MHz. The spectral response of the detection system shows the potential to deliver more than 70 Gbit/s of random numbers in our experimental setup.