[gizmo686]

I haven't read either of the papers yet, but can anyone comment on what makes it difficult to output multiple bits. Naively, couldn't you gather weak random data from the two sources, get a single bit, then gather more weak data, and run the extractor again to get a second bit?

[henrytcs]

Hi gizmo686. Yes, what you propose is correct. But this requires that every time you iterate this process, you're required to find additional sources of weak data that is completely independent of the sources of weak data you used in the previous iterations. In that case, you're describing an extractor that requires multiple independent sources.

What the challenge was (and it looks like there was some progress a couple weeks ago), was that you'd like to produce multiple bits using only two independent sources, and no more than that!