Continuous-Variable Source-Independent Quantum Random Number Generator with a Single Phase-Insensitive Detector

TL;DR

This paper introduces a practical continuous-variable source-independent quantum random number generator using a single phase-insensitive detector, with a security proof and a dimension reduction technique for efficient computation.

Contribution

It proposes a novel CV-SI-QRNG scheme with a single detector and a dimension reduction method for security analysis, advancing practical quantum randomness generation.

Findings

Feasibility demonstrated through simulations

Efficient SDP-based security proof developed

Single detector design simplifies implementation

Abstract

Quantum random number generators (QRNGs) harness quantum mechanical unpredictability to produce true randomness, which is crucial for cryptography and secure communications. Among various QRNGs, source-independent QRNGs (SI-QRNGs) relax the trust on the quantum source, allowing for flexible use of advanced detectors to achieve high randomness generation rates. Continuous-variable (CV) SI-QRNGs, in particular, hold promise for practical deployment due to their simplicity and randomness generation rates comparable to trusted-device QRNGs. In this work, we propose a novel CV-SI-QRNG scheme with a single phase-insensitive detector, and provide security proof based on semi-definite programming (SDP). We introduce a dimension reduction technique, which rigorously reduces an infinite-dimensional SDP problem to a finite-dimensional one, enabling efficient computation while maintaining valid randomness lower bound. We further validate our method through simulations. These results demonstrate the feasibility of our framework, paving the way for practical and simple SI-QRNG implementations.