On 6 November 2013 06:33, kjj wrote: > One of the things that really gets me going is when someone devises a > model, tests it against itself, and then pretends that they've learned > something about the real world. > > Naturally, the Selfish Mining paper is exactly this sort of nonsense. > Their model is one with no latency, and one where the attacker has total > visibility across the network. An iterated FSM is not a suitable > simulation of the bitcoin system. The bitcoin network does not have > states, and to the extent that you can pretend that we do, you can't > simulate transitions between them with static probabilities. > > The authors understand this deep down inside, even though they didn't > work out the implications. They handwave the issue by assuming a total > sybil attack, and in true academic spirit, they don't realize that the > condition necessary for the attack is far, far worse than the attack > itself. > > Greg said he'd like to run some simulations, and I'm thinking about it > too. Unfortunately, he is busy all week, and I'm lazy (and also busy > for most of tomorrow). > > If neither of us get to it first, I'm willing to pitch in 1 BTC as a > bounty for building a general bitcoin network simulator framework. The > simulator should be able to account for latency between nodes, and > ideally within a node. It needs to be able to simulate an attacker that > owns varying fractions of the network, and make decisions based only on > what the attacker actually knows. It needs to be able to simulate this > "attack" and should be generic enough to be easily modified for other > crazy schemes. > > (Bounty offer is serious, but expires in one year [based on the earliest > timestamp that my mail server puts on this email], and /may/ be subject > to change if the price on any reputable exchange breaks 1000 USD per BTC > in that period.) > > Basically, the lack of a decent network simulator is what allowed this > paper to get press. If the author had been able to see the importance > of the stuff he was ignoring, we wouldn't be wasting so much time > correcting him (and sadly the reporters that have no way to check his > claims). > > https://bitcointalk.org/index.php?topic=324413.msg3495663#msg3495663 > Thanks for posting this bounty. I'm interested in working on it, and will give it a try. I also have some other commitments, so I suspect you guys will finish it first tho... but if not, I'll post details of the simulator. > > > > > ------------------------------------------------------------------------------ > November Webinars for C, C++, Fortran Developers > Accelerate application performance with scalable programming models. > Explore > techniques for threading, error checking, porting, and tuning. Get the most > from the latest Intel processors and coprocessors. See abstracts and > register > http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development >