Semi-device-independent randomness certification on discretized continuous-variable platforms

TL;DR

This paper introduces a semi-device-independent method for certifying quantum randomness in continuous-variable optical systems, using simple measurements and a two-level subspace assumption to ensure security.

Contribution

It proposes a practical scheme for randomness certification in continuous-variable platforms with minimal experimental complexity and robustness against losses.

Findings

Achieves dimension-witness violations certifying positive min-entropy

Uses standard homodyne and displacement measurements in simple setups

Demonstrates robustness to realistic losses and misalignments

Abstract

Randomness is fundamental for secure communication and information processing. While continuous-variable optical systems offer an attractive platform for this task, certifying genuine quantum randomness in such setups remains challenging. We present a semi-device-independent scheme for randomness certification tailored to continuous-variable implementations, where the dimension assumption is operationally implemented by restricting state preparations to the two-level Fock subspace. Using standard homodyne and displacement-based measurements, we show that simple optical setups can achieve dimension-witness violations that certify positive min-entropy, even in the presence of realistic losses and misaligned reference frames. These results demonstrate that practical and scalable quantum randomness generation is achievable with minimal experimental complexity on continuous-variable platforms.