Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 12:26:30PM +0100, Mike Hearn wrote: W.R.T. this paper and the oft-discussed miner backbone, http://arxiv.org/pdf/1311.0243v1.pdf I'm wondering about an alternative protocol change that perhaps has less subtle implications than their suggested change. Rather than

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Mike Hearn
On Mon, Nov 4, 2013 at 12:53 PM, Peter Todd p...@petertodd.org wrote: I proposed this as a means of giving a mechanism for wallets to get non-sybilled peers as well. Ah yes, good point. Doing so encourages pools to only bother connecting to other pools, which is a strong centralizing

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 01:03:50PM +0100, Mike Hearn wrote: The suggested change is actually very simple (minutes of coding) and elegant and addresses precisely the identified problem. Disagree. Unless I'm misunderstanding what they propose, their suggested change would mean anyone

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Michael Gronager
We propose a simple, backwards-compatible change to the Bitcoin protocol to address this problem and raise the threshold. Specifically, when a miner learns of competing branches of the same length, it should propagate all of them, and choose which one to mine on uniformly at random. So only in

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 12:26:30PM +0100, Mike Hearn wrote: W.R.T. this paper and the oft-discussed miner backbone, http://arxiv.org/pdf/1311.0243v1.pdf I'm wondering about an alternative protocol change that perhaps has less subtle implications than their suggested change. Rather than

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Pieter Wuille
On Mon, Nov 4, 2013 at 3:26 PM, Peter Todd p...@petertodd.org wrote: The correct, and rational, approach for a miner is to always mine to extend the block that the majority of hashing power is trying to extend. The current relay rules don't give you that information at all, but they can if we

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 03:34:35PM +0100, Pieter Wuille wrote: Mining strategy is now to mine to extend the first block you see, on the assumption that the earlier one probably propagated to a large portion of the total hashing power. But as you receive near-blocks that are under the PoW

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Mike Hearn
On Mon, Nov 4, 2013 at 3:26 PM, Peter Todd p...@petertodd.org wrote: The attacker now only needs to connect to every identified miner with especially fast nodes. With judicious use of DoS attacks and low latency . So you're back to a complicated sybil attack. I don't follow your thought

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 10:25:19AM -0500, Ittay wrote: Peter - how can you guarantee that the majority mines on the non-selfish block? Feedback basically. So suppose the hashing power is split exactly 50:50, with half the hashing power hearing about one block first, and half the other. Also

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Gregory Maxwell
On Mon, Nov 4, 2013 at 3:58 AM, Michael Gronager grona...@ceptacle.com wrote: The suggested change is actually very simple (minutes of coding) and elegant and addresses precisely the identified problem. It is actually a mental shortcut in the assumption of how probability works when mining a

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
(not sure if you meant this to go to the list, my apologies if not) On Mon, Nov 04, 2013 at 10:50:25AM -0500, Ittay wrote: On Mon, Nov 4, 2013 at 10:46 AM, Peter Todd p...@petertodd.org wrote: On Mon, Nov 04, 2013 at 10:25:19AM -0500, Ittay wrote: Peter - how can you guarantee that the

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 11:24:33AM -0500, Ittay wrote: Yes - this is for the mailing list. Regarding the algorithm - as we explain in the paper, as long as the attacker is way ahead - the others can mine on whatever they like. Doesn't really matter. Once they almost close the gap (and they

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 02:12:44PM -0500, Ittay wrote: On Mon, Nov 4, 2013 at 10:25 AM, Ittay ittay.e...@cornell.edu wrote: As for the rational motivation of the individual miners - that's a good point! Here is a solution we did not put in the paper due to space constraints that should

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Alan Reiner
Sorry guys, I'm a little late to the party here. I skimmed over the paper, and appreciated Peter Todd's recap of it. My first thought was that this seems profit-neutral at best, when you take into account all the races you lose by trying to beat the propagation of other miners' blocks. So given

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 04:45:24PM -0500, Alan Reiner wrote: So given the assumption that Alice is well-connected as Peter mentioned, it seems like this is a concern. But is this a realistic assumption? All miners have an incentive to be thoroughly connected to one another, to make sure they

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Gustaw Wieczorek
Mike Hearn wrote: how about if we wrote code to automatically build a miner backbone Yeah, let's build a backbone, or a cloud, and then we could have Google run it! Come on, Mike, your conflict-of-interest as an employee is hanging out in the open, flapping in the breeze here...  Don't you

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Peter Todd
On Mon, Nov 04, 2013 at 08:14:37PM -0800, Gustaw Wieczorek wrote: Mike Hearn wrote: how about if we wrote code to automatically build a miner backbone Yeah, let's build a backbone, or a cloud, and then we could have Google run it! Come on, Mike, your conflict-of-interest as an

Re: [Bitcoin-development] Auto-generated miner backbone

2013-11-04 Thread Gregory Maxwell
On Mon, Nov 4, 2013 at 8:39 PM, Peter Todd p...@petertodd.org wrote: I suggested the mechanism myself for slightly different reasons, and if you know me, you'd know I'm the first to jump on anyone pushing centralization. Likewise, I did too and am also not very tolerant with trusted or