Generalize the two-source-extractor recipe to arbitrary-bit outputs

Generalize the two-source extractor recipe used by the approach of Oh and Shaltiel to produce outputs of arbitrary length rather than only a single bit.

Background

The paper discusses seedless extractors for samplable sources and notes that the recent approach of Oh and Shaltiel is based on a two-source extractor construction. That approach currently produces only a single-bit output, and extending it to arbitrary output lengths is identified as unresolved.

References

Further, the recent approach of can currently only produce a single-bit output, as it uses the two-source extractor recipe where generalizing to arbitrary bits is an open problem.

— Certified Randomness with Optimal Rate  (2609.38945 - Jain et al., 30 Sep 2026) in Section 1, Related Work, paragraph “Other seedless extractors”