A tunable quantum random number generator based on a fiber-optical Sagnac interferometer

TL;DR

This paper presents a fiber-optical Sagnac interferometer-based quantum random number generator with tunable splitting ratio, capable of producing over 2 gigabytes of certified random data with high entropy, suitable for real-time performance testing.

Contribution

It introduces a novel, tunable photonic QRNG design using a Sagnac interferometer, enhancing entropy maximization and component tolerance compensation.

Findings

Generated over 2 GB of random data with high entropy

Sequence passes NIST and Dieharder randomness tests

Demonstrates real-time adjustable entropy for improved QRNG performance

Abstract

Quantum random number generators (QRNG) are based on the naturally random measurement results performed on individual quantum systems. Here, we demonstrate a branching-path photonic QRNG implemented with a Sagnac interferometer with a tunable splitting ratio. The fine-tuning of the splitting ratio allows us to maximize the entropy of the generated sequence of random numbers and effectively compensate for tolerances in the components. By producing single-photons from attenuated telecom laser pulses, and employing commercially-available components we are able to generate a sequence of more than 2 gigabytes of random numbers with an average entropy of 7.99 bits/byte directly from the raw measured data. Furthermore, our sequence passes randomness tests from both the NIST and Dieharder statistical test suites, thus certifying its randomness. Our scheme shows an alternative design of QRNGs based on the dynamic adjustment of the uniformity of the produced random sequence, which is relevant for the construction of modern generators that rely on independent real-time testing of its performance.