Higher rates for semi-device-independent randomness expansion by recycling input randomness

Quantum Physics [Submitted on 7 Apr 2026] Higher rates for semi-device-independent randomness expansion by recycling input randomness Rutvij Bhavsar, Hamid Tebyanian, Roger Colbeck Although quantum random number generators rely on the inherent indeterminism of quantum mechanics, ensuring that the numbers produced are secure remains a significant challenge. We introduce two semi-device-independent randomness expansion protocols in a prepare-and-measure setting, where the source and measurement devices are treated as uncharacterised and we assume trust only in testing device, which could be implemented using a photodiode. One protocol achieves expansion by recycling the input randomness, while the other uses a biased input distribution to achieve expansion in settings where recycling is not possible. The protocols are proven secure against quantum side information. Our results show that high randomness rates are achievable under experimentally realistic conditions, with expansion obtained in as few as 10^5 to 10^6 rounds with the recycling protocol. Comments: 34 pages, 6 figures. Comments are welcome Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2604.06457 [quant-ph]   (or arXiv:2604.06457v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2604.06457 Focus to learn more Submission history From: Rutvij Bhavsar Dr [view email] [v1] Tue, 7 Apr 2026 20:56:38 UTC (2,429 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-04 References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)