> Most things I've seen working in this space are attempting to minimize > the data transfered. At least for the miner-interested case the round > complexity is much more important because a single RTT is enough to > basically send the whole block on a lot of very relevant paths. Agreed. Yaron's scheme is magical because it is non-interactive. I send you a packet of O(expected-delta) and you immediately figure out the delta without further back and forth communication, each requiring an RTT. > I know much better is possible (see up-thread where I linked to an old > proposal to use forward error correction to transfer with low data > transfer (but not optimal) and negligible probability of needing a > round-trip, with a tradeoff for more overhead for lower roundtrip > probability). FEC schemes are both fairly complex, because the set is constantly changing, and (if i understand your suggestion correctly) they add additional metadata overhead (albeit mostly during tx propagation). Set reconciliation is near optimal. In any case, I have no horse here (I think changing the client so it's multithreaded is the best way to go), but Yaron's work is pretty cool and may be applicable. - egs