On Wed, May 11, 2016 at 3:47 AM, Jannes Faber wrote: > On 11 May 2016 at 12:36, Henning Kopp wrote: > >> On Wed, May 11, 2016 at 11:21:10AM +0200, Jannes Faber via bitcoin-dev >> wrote: >> > On 11 May 2016 at 05:14, Timo Hanke via bitcoin-dev < >> > bitcoin-dev@lists.linuxfoundation.org> wrote: >> > >> > > There is no way to tell from a block if it was mined with AsicBoost or >> > > not. So you don’t know what percentage of the hashrate uses AsicBoost >> at >> > > any point in time. How can you risk forking that percentage out? Note >> that >> > > this would be a GUARANTEED chain fork. Meaning that after you change >> the >> > > block mining algorithm some percentage of hardware will no longer be >> able >> > > to produce valid blocks. That hardware cannot “switch over” to the >> majority >> > > chain even if it wanted to. Hence you are guaranteed to have two >> > > co-existing bitcoin blockchains afterwards. >> > > >> > > Again: this is unlike the hypothetical persistence of two chains >> after a >> > > hardfork that is only contentious but doesn’t change the mining >> algorithm, >> > > the kind of hardfork you are proposing would guarantee the >> persistence of >> > > two chains. >> > > >> > >> > Assuming AsicBoost miners are in the minority, their chain will >> constantly >> > get overtaken. So it will not be one endless hard fork as you claim, but >> > rather AsicBoost blocks will continue to be ignored (orphaned) until >> they >> > stop making them. >> >> At least until a difficulty adjustment on the AsicBoost chain takes >> place. From that point on, both chains, the AsicBoost one and the >> forked one will grow approximately at the same speed. >> >> > No: you are still assuming AsicBoost miners would reject normal blocks. > They don't now and they would have to specifically code for that as a reply > to AsicBoost being banned. So there won't be two chains at all, only the > main chain with a lot (more than usual) of short (few blocks) forks. Each > forks starts anew, it's not one long fork. Therefore there is no > "difficulty adjustment on the AiscBoost chain". > > Now if they do decide to ban non-AsicBoost blocks as a response to being > banned themselves, they're just another altcoin with a different PoW and no > one would have a reason to use them over Bitcoin (apart from maybe selling > those forked coins asap). > This is what I meant. If existing hardware gets forked-out it will inevitably lead to the creation of an altcoin. Simply because the hardware exists and can't be used for anything else both chains will survive. I was only comparing the situation to a contentious hardfork that does not fork out any hardware. If the latter one is suspected to lead to the permanent existence of two chains then a hardfork that forks out hardware is even more likely to do so (I claim it's guaranteed). > You're confused about what "longest" means as well: it's not just the > number of blocks, it's the aggregate difficulty that counts: so AsicBoost > would never become "longer" (more total work) either. > > Hope this helps clear things up. > > -- > Jannes >