> > On Sat, Jul 11, 2015 at 11:24:48AM +0200, Jorge Timón wrote: > > All miners should validate transactions precisely because of the latest > > attack you've described. Full miners can gain a lot from this attack to > > leverage their full validation against spv miners who blindly spend > energy > > hashing on top of something that may be worthless crap. SPV mining makes > no > > sense, but some miners claim they're doind it for very short periods of > > time, which shouldn't be as bad as doing it all the time. > > > > I think it would be more rational for them to keep mining on top of the > old > > block until they've fully validated the new block (which shouldn't take > so > > long anyway), even if this slightly increases the orphan rate. > > You're missing something really critical about what F2Pool/AntPool were > (are?) doing: They're finding out about new blocks not by getting block > headers from just anywhere, but by connecting to other pools' via > stratum anonymously and determining what block hash they're telling the > hashers at the pool to work on. (e.g. what prevblockhash is in the block > header of shares being generated) > > If other pools try to fake this information they're immediately and > directly losing money, because they're telling their own hashers to make > invalid blocks. This of course has a high chance of being detected, and > can easily be FUDed into "STOP MINING AT FOO POOL!" reardless of what > the ivory tower game theory might say. The only hope the pools have is > to somehow identify which connections correspond to other pools with > high reliability and target just those connections - good luck on that. > > > Anyway, all this concern about SPV mining is misguided: relying purely > on SPV w/ low #'s of confirmations just isn't very smart. What SPV can > do - at least while the inflation subsidy is still high - is give > reasonable protection against your third-party-run trusted full nodes > from lying to you, simply because doing so has well-defined costs in > terms of energy to create fake blocks. Targetting enough people at once > to make a fake block a worthwhile investment is difficult, particularly > when you take into account how timing works in the defenders favor - the > attacker probably only has a small % of hashing power, so they're going > to wait a long time to find their fake block. Between that and a trusted > third party-run full node you're probably reasonably safe, for now. > > -- > 'peter'[:-1]@petertodd.org > 0000000000000000086007e31decd6eb80e07f77271ef50c69e1e6342161f4e5 > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > >