High Speed Continuous Variable Source-Independent Quantum Random Number Generation

TL;DR

This paper introduces a high-speed, source-independent quantum random number generator that leverages quadrature fluctuations of quantum optical fields, providing provably secure, ultra-fast random numbers without assumptions on input states, and demonstrates its practical implementation.

Contribution

The paper presents a novel method for ultra-fast, source-independent quantum random number generation using continuous variables, with a comprehensive security analysis and experimental validation.

Findings

Achieved secure random number generation rates of 15.07 Gbits/s experimentally.

Developed a security framework based on the extremality of Gaussian states.

Potential to reach 6 Gbits/s with real-time post-processing.

Abstract

As a fundamental phenomenon in nature, randomness has a wide range of applications in the fields of science and engineering. Among different types of random number generators (RNG), quantum random number generator (QRNG) is a kind of promising RNG as it can provide provable true random numbers based on the inherent randomness of fundamental quantum processes. Nevertheless, the randomness from a QRNG can be diminished (or even destroyed) if the devices (especially the entropy source devices) are not perfect or ill-characterized. To eliminate the practical security loopholes from the source, source-independent QRNGs, which allow the source to have arbitrary and unknown dimensions, have been introduced and become one of the most important semi-device-independent QRNGs. Herein a method that enables ultra-fast unpredictable quantum random number generation from quadrature fluctuations of quantum optical field without any assumptions on the input states is proposed. Particularly, to estimate a lower bound on the extractable randomness that is independent from side information held by an eavesdropper, a new security analysis framework is established based on the extremality of Gaussian states, which can be easily extended to design and analyze new semi-device-independent continuous variable QRNG protocols. Moreover, the practical imperfections of the QRNG including the effects of excess noise, finite sampling range, finite resolution and asymmetric conjugate quadratures are taken into account and quantitatively analyzed. Finally, the proposed method is experimentally demonstrated to obtain high secure random number generation rates of 15.07 Gbits/s in off-line configuration and can potentially achieve 6 Gbits/s by real-time post-processing.