Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Perhaps I missed it somewhere, but I don't recall it ever being a goal of Bitcoin to act as a stable long-term store of value. - Jameson On 04/30/2014 01:06 PM, Troy Benjegerdes wrote: > On Wed, Apr 30, 2014 at 11:00:06PM +1000, Gareth Williams wrote: >> On 30/04/14 00:13, Mike Hearn wrote: >>>

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 30, 2014 at 11:00:06PM +1000, Gareth Williams wrote: > On 30/04/14 00:13, Mike Hearn wrote: > > I do think we need to move beyond this idea of Bitcoin being some kind > > of elegant embodiment of natural mathematical law. It just ain't so. > > I haven't seen anybody arguing that it is

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 30/04/14 23:55, Mike Hearn wrote: > If Bitcoin works correctly nobody should have to care if they consider > themselves attackers, defenders, or little green men from Mars. > > > One last time, I request that people read the white paper from 2008 > before making statements like this. I

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 30/04/14 00:13, Mike Hearn wrote: > Every time miners and nodes ignore a block that creates >formula() coins > that's a majority vote on a controversial political matter Actually, there's one more thing I'd like to add. Apologies to the list, but it bears repeating: * rejecting a block at vali

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

I think we're going around in circles here so this will be my last message on the thread unless someone comes up with something new. On Wed, Apr 30, 2014 at 3:12 PM, Gareth Williams wrote: > If Bitcoin works correctly nobody should have to care if they consider > themselves attackers, defenders,

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 30/04/14 00:13, Mike Hearn wrote: > I do think we need to move beyond this idea of Bitcoin being some kind > of elegant embodiment of natural mathematical law. It just ain't so. I haven't seen anybody arguing that it is. Bitcoin is the elegant embodiment of /artificially contrived/ mathematic

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 30/04/14 00:26, Mike Hearn wrote: > These parties wouldn't generally consider themselves attackers > > > Of course not, attackers rarely do :) If Bitcoin works correctly nobody should have to care if they consider themselves attackers, defenders, or little green men from Mars. There are s

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/29/2014 02:13 PM, Mike Hearn wrote: > I do think we need to move beyond this idea of Bitcoin being some > kind of elegant embodiment of natural mathematical law. It just > ain't so. > I think everybody understands that Bitcoin has a positive ne

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > These parties wouldn't generally consider themselves attackers > Of course not, attackers rarely do :) But they are miners who are taking part in malicious double spending. That makes them attackers. If miners don't exist to stop double spending, what do they exist for? I mean, this is funda

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Tue, Apr 29, 2014 at 7:13 AM, Mike Hearn wrote: > It only works if the majority of hashpower is controlled by attackers, in > which case Bitcoin is already doomed. So it doesn't matter at that point. These parties wouldn't generally consider themselves attackers— nor would many users (presumab

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

I do think we need to move beyond this idea of Bitcoin being some kind of elegant embodiment of natural mathematical law. It just ain't so. Every time miners and nodes ignore a block that creates >formula() coins that's a majority vote on a controversial political matter, as evidenced by the disag

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Sun, Apr 27, 2014 at 10:53:08PM +1000, Gareth Williams wrote: >Bitcoin is this perfect /trustless/ mathematical machine [...] > >2. the economic majority will not cooperate to reinterpret history > > [this proposal was...] replacing it with: > >2. the economic majority will not cooperate to rei

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Agreed. I'm a pragmatist, certainly not anti-change (or even anti-zero-conf.) Useful and non-controversial hard forks don't keep me awake at night :) I support your general position on zero-conf payments (that they're useful and we should make them as reliable as practical.) But the very essenc

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > That moves us away from a pure trustless system built upon a small > democratic foundation (as something of a necessary evil in an imperfect > world where humans run our computers and use our system) and toward a > "democratic system". > > You don't have to agree, but I hope you can understand

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 27/04/14 11:42, Christophe Biocca wrote:> This seems like splitting hairs, no? A block isn't a guarantee (it can > get orphaned). And as a user of bitcoin (as opposed to a miner), this > change cannot affect any payment you ever receive. Disagree. Maybe we just have a fundamental disagreement a

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

This seems like splitting hairs, no? A block isn't a guarantee (it can get orphaned). And as a user of bitcoin (as opposed to a miner), this change cannot affect any payment you ever receive. Some of the interpretation is already different for coinbase UTXO's (need a valid height, locked for 100 b

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 26/04/14 01:28, Mike Hearn wrote: > When you have a *bitcoin* TXn buried under 100 blocks you can be damn > > sure that money is yours - but only because the rules for interpreting > data in the blockchain are publicly documented and (hopefully) > immutable. If they're mutable t

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > When you have a *bitcoin* TXn buried under 100 blocks you can be damn > sure that money is yours - but only because the rules for interpreting > data in the blockchain are publicly documented and (hopefully) > immutable. If they're mutable then the PoW alone gives me no confidence > that the mo

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 25/04/14 20:17, Mike Hearn wrote: > Proving that you can convince the economic majority that the > > interpretation of existing blocks is in any way up for grabs would set a > dangerous precedent, and shake some people's faith in Bitcoin's overall > robustness and security (wel

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > Proving that you can convince the economic majority that the > interpretation of existing blocks is in any way up for grabs would set a > dangerous precedent, and shake some people's faith in Bitcoin's overall > robustness and security (well, mine anyway.) Hmm, then I think your faith needs t

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 25/04/14 00:28, Mike Hearn wrote: > Why are we here? We are here because we were brought together by shared > goals. > > What are those goals? They were defined at the start of the project by > the creator of the project. > > Why do we issue 21 million coins and not 42? Because 21 million is t

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/24/2014 03:37 PM, Jorge Timón wrote: The 21 million bitcoin limit is not important because of its exact value, nor is it important because Satoshi picked it. The 21 million limit is important because users hold bitcoin based on the promise tha

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > Casting that vote does them no harm. > Every time another pool joins the blacklist, there's no harm to them to > doing so. At some point they will reach a majority These statements do not follow from each other. -- S

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> Casting that vote does them no harm. > Every time another pool joins the blacklist, there's no harm to them to doing > so. I actually agree that this is a problem, but that's actually not inherent in the proposed enforcement mechanism (just the current voting rules). Here's an alternate: - To

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 4/24/14, Mike Hearn wrote: > You can't disentangle the two. Proof of work just makes a block chain hard > to tamper with. What it contains is arbitrary. Honest miners build a block > chain that's intended to stop double spending. Dishonest miners don't. > They're both engaging in proof of work,

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Thanks Sergio! On Thu, Apr 24, 2014 at 5:13 PM, Sergio Lerner wrote: > For more information you can check my post: > http://bitslog.wordpress.com/2014/02/17/5-sec-block-interval/ > Also NimbleCoin is a new alt-coin that uses 5-sec block intervals, allows > 100 tps and it's based on BitcoinJ

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 23/04/2014 05:51 p.m., Mike Hearn wrote: > On Wed, Apr 23, 2014 at 10:44 PM, Adam Ritter > wrote: > > Isn't a faster blockchain for transactions (maybe as a sidechain) > solving the problem? If there would be a safe way for > 0-confirmation transactions, t

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Thu, Apr 24, 2014 at 10:47:35AM -0400, Christophe Biocca wrote: > Actually Peter, coinbase confiscations are a much worse mechanism for > enforcement of widespread censorship rules than simple orphaning. They > lose their power when the transaction miners are punished for can > build up over tim

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Actually Peter, coinbase confiscations are a much worse mechanism for enforcement of widespread censorship rules than simple orphaning. They lose their power when the transaction miners are punished for can build up over time without losing their usefulness: Assume a world where 75% of the hashpow

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > And that's achieved through proof of work, not through "miner's honesty". > You can't disentangle the two. Proof of work just makes a block chain hard to tamper with. What it contains is arbitrary. Honest miners build a block chain that's intended to stop double spending. Dishonest miners don'

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > Like I said before, that leads to the obvious next step of > deleting/stealing their coinbases if they don't identify themselves. > And as I said before, that's a huge leap. A majority of miners deciding double spending needs tougher enforcement doesn't imply they also think all miners should

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 4/24/14, Mike Hearn wrote: > No! This is a misunderstanding. The mechanism they use to prevent double > spends is to *ignore double spends*. The blocks they created indicate the > ordering of transactions they saw and proof of work is used to arrive at a > shared consensus ordering given the po

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Thu, Apr 24, 2014 at 11:56:23AM +0200, Mike Hearn wrote: > > ... proposing the mechanism be used to claw back mining income from a > > hardware vendor accused of violating its agreements on the amount of > > self mining / mining on customers hardware. > > > > I think this would not be doable in

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Thu, Apr 24, 2014 at 1:22 PM, Jorge Timón wrote: > > I'm using it in the same sense Satoshi used it. Honest miners work to > > prevent double spends. That's the entire justification for their > existence. > > I thought the mechanism they used to prevent double-spends was proof of > work. > The

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 4/23/14, Mike Hearn wrote: >> I guess word "honest" might have different meanings, that can be a source >> of confusing. >> 1. Honest -- not trying to destroy bitcoin >> 2. Honest -- following rules which are not required by the protocol >> > > I'm using it in the same sense Satoshi used it. Ho

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > Yes, you can reorg out the blocks and actually remove them, but I > understood that you were _not_ proposing that quite specifically. But > instead proposed without reorging taking txouts that were previously > assigned to one party and simply assigning them to others. > Well, my original thou

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Thu, Apr 24, 2014 at 1:39 AM, Mike Hearn wrote: > It absolutely is! > https://bitcointalk.org/index.php?topic=60937.0 May I direct your attention to the third post in that thread? Luke attempting to ret-con the enforcement flag into a vote didn't make it one, and certantly wouldn't make it a

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wednesday 23 April 2014 15:31:38 Mike Hearn wrote: > > There _are_ consequences though: 95% of the time, you end up buying > > something and paying for it. > > Yeah, I was imagining a situation in which people who use Bitcoin regularly > do buy things they actually want, but wouldn't say no to

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Thu, Apr 24, 2014 at 10:19 AM, Gregory Maxwell wrote: > This is not voting. > It absolutely is! It was widely discussed as such at the time, here is a thread where people ask how to vote and the operator of Eclipse said he was removing his vote for P2SH: https://bitcointalk.org/index.php?topi

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Thu, Apr 24, 2014 at 12:58 AM, Mike Hearn wrote: > The complexity overhead is trivial - we already used coinbase scriptSigs for > voting on P2SH, I'm sure it'll be used for voting on other things in future > too. We use coinbase sigs to gauge the safety of enforcing a soft fork several times a

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Thu, Apr 24, 2014 at 12:06 AM, Alex Mizrahi wrote: > > Different approaches have different trade-offs, and thus different areas > of applicability. > > Proof-of-work's inherent disadvantage is that it takes some time until > transaction becomes practically irreversible. On the other hand, it has

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 4/23/2014 2:23 PM, Tier Nolan wrote: > An interesting experiment would be a transaction "proof of > publication" chain. What if a transaction could simply point back to an earlier transaction, forming a chain? Not a separately mined blockchain, just a way to establish an official publicati

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 10:39 PM, Gregory Maxwell wrote: > You can see me proposing this kind of thing in a number of places (e.g. > http://download.wpsoftware.net/bitcoin/wizards/2014-04-15.txt "p2pool > only forces the subsidy today, but the same mechnism could instead > force transactions.. I

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > These sorts of proposals are all just ways of saying block chains kind of > suck and we should go back to using trusted third parties. > No. Different approaches have different trade-offs, and thus different areas of applicability. Proof-of-work's inherent disadvantage is that it takes some t

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 2:23 PM, Tier Nolan wrote: > An interesting experiment would be a transaction "proof of publication" > chain. > > Each transaction would be added to that chain when it is received. It could > be merge mined with the main chain. > > If the size was limited, then it doesn't

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

An interesting experiment would be a transaction "proof of publication" chain. Each transaction would be added to that chain when it is received. It could be merge mined with the main chain. If the size was limited, then it doesn't even require spam protection. Blocks could be "discouraged" if

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

The memory pool is just talk. There is no expectation that the memory pool has to satisfy some standard as to what will eventually exist in the block chain, and there are any number of ways that people could communicate transactions to one another without putting them in the memory pool. The memory

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 1:44 PM, Adam Ritter wrote: > Isn't a faster blockchain for transactions (maybe as a sidechain) solving > the problem? If there would be a safe way for 0-confirmation transactions, > the Bitcoin blockchain wouldn't even be needed. Large scale consensus can't generally prov

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 10:44 PM, Adam Ritter wrote: > Isn't a faster blockchain for transactions (maybe as a sidechain) solving > the problem? If there would be a safe way for 0-confirmation transactions, > the Bitcoin blockchain wouldn't even be needed. > The 10 minute average comes from a des

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Isn't a faster blockchain for transactions (maybe as a sidechain) solving the problem? If there would be a safe way for 0-confirmation transactions, the Bitcoin blockchain wouldn't even be needed. On Wed, Apr 23, 2014 at 10:37 PM, Mike Hearn wrote: > On Wed, Apr 23, 2014 at 10:24 PM, Gregory Ma

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 10:24 PM, Gregory Maxwell wrote: > Right, this works in the Bitcoin network today absent any collusion by > the miners. You give one miner a transaction and you give every other > node you can reach another transaction. > Yes, but that can be fixed with double spend alerts

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 12:59 PM, Mike Hearn wrote: >> What you're talking about is just disagreement about the content of >> the memory pool > That's the same thing. Whilst you're mining your double spend tx, it's in > your mempool but you don't broadcast it as per normal. Then when you find > th

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > What you're talking about is just disagreement about the content of > the memory pool > That's the same thing. Whilst you're mining your double spend tx, it's in your mempool but you don't broadcast it as per normal. Then when you find the block you broadcast it to override everyone elses memp

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 12:19 PM, Mike Hearn wrote: > That's the definition of a Finney attack, right? A finney attack is where you attempt to mine a block with a transaction paying you, and as soon as you are successful you quickly make a transaction spending that coin to someone else, then rele

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks]

(this e-mail is cc to the bitcoin-research list) Hi everyone from the bitcoin-development mailing list! I decided to join this legendary list because it seems that all the research fun is taking place in here, and I don't want to miss the research party. Regarding the discussion about BitUndo, a

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 8:57 PM, Gregory Maxwell wrote: > Hm? I didn't think this is at all what they did. What they claim to > do is to prioritize transactions in their mempool from people who pay > them > That's the definition of a Finney attack, right? A tx is broadcast and nodes normally ta

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Cut it out with the ad hominem attacks please. If you cant be civil, please go away until you learn some manners. I think the issue being discussed is do you orphan an entire block causing distress to users as well, or try to just cause distress just to the evil miner? This discussion is about exp

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Bitcoin has various checks and balances that help keep everything honest. Even if a pool had 60% of the hashing power, they couldn't reverse 6 blocks without anyone noticing that it had happened. There are sites which monitor the blocks and estimate the percentage of the blocks found by each pool

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 12:55 AM, Mike Hearn wrote: > Lately someone launched Finney attacks as a service (BitUndo). As a reminder > for newcomers, Finney attacks are where a miner secretly works on a block > containing a double spend. Hm? I didn't think this is at all what they did. What they c

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/23/2014 06:37 PM, Mike Hearn wrote: > If you want to try and argue that the development list is the wrong > place to discuss development, please do so on another thread (or > your blog). Let's keep this thread for discussion of the original > pro

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

If you want to try and argue that the development list is the wrong place to discuss development, please do so on another thread (or your blog). Let's keep this thread for discussion of the original proposal - ideally, discussed with the dryness that a topic as nerdy as distributed consensus algori

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/23/2014 06:15 PM, Peter Todd wrote: > But I also agree with Gavin that the bitcoin-development email list > is a perfectly good place to have these types of discussions. I > myself have used it repeatedly to publish ideas specifically due to > w

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 06:04:49PM +, Justus Ranvier wrote: > The integrity of Bitcoin is more important than you and your personal > preferences. > > > You don't have the right to decide which valid scripts in the > blockchain will be disregarded, and neither does anyone else. > > > If you

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/23/2014 05:57 PM, Mike Hearn wrote: > I'm not going to bother arguing in replies to a blog post. Suffice > it to say, miners are already handsomely compensated via both > inflation and fees for doing their job of preventing double spends. > Your

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > Non-developers are more comfortable using social media tools. Blog > posts can be shared, Tweeted, and commented upon using nothing more > than a web browser. > I don't think Twitter is an appropriate medium for discussing the details of byzantine consensus algorithms. I'm not going to bother

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/23/2014 05:47 PM, Gavin Andresen wrote: > And why do you think your blog is more public than this open, > publicly archived mailing list??? > Non-developers are more comfortable using social media tools. Blog posts can be shared, Tweeted, and c

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > > I've formulated my replies to you and this proposal in a more public > venue, where such discussions of existential changes to the protocol > more rightfully belong > > I strongly disagree. It makes perfect sense to discuss changes here, first, where there are lots of people who understand h

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/23/2014 03:07 PM, Mike Hearn wrote: > On Wed, Apr 23, 2014 at 4:52 PM, Justus Ranvier > wrote: > >> If enough miners don't like a block that has been mined, they can >> all work to orphan it without any change to the protocol >> whatsoever. >>

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 4/23/2014 12:04 PM, Christophe Biocca wrote: > It's not necessary that this "coinbase retribution" be either > profitable or risk-free for this scheme to work. I think we should > separate out the different layers of the proposal: > > 1. Attacking the coinbase instead of orphaning allows for 100

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

I think the cost to mines is the same as what's possible today, actually. Consider a group of miners who wish to do this with no changes to the rule set. They can coordinate out of band and figure out if they have a majority of hashpower behind the decision to orphan a block, e.g. by signing a non

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

What is the advantage of this proposal over just orphaning the block with double spends? There's currently a set of rules which government what constitutes a valid block. Miners don't build on blocks that don't accord with those rules out of fear that a major won't follow and they will waste hashi

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

It's not necessary that this "coinbase retribution" be either profitable or risk-free for this scheme to work. I think we should separate out the different layers of the proposal: 1. Attacking the coinbase instead of orphaning allows for 100 blocks' time for a consensus to be reached, rather than

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 05:41:26PM +0200, Pieter Wuille wrote: > On Wed, Apr 23, 2014 at 5:34 PM, Kevin wrote: > > I have some questions: > > 1. How can we work towards solving the double-spending problem? > > We have this awesome technology that solves the double-spending > problem. It's called

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 5:34 PM, Kevin wrote: > I have some questions: > 1. How can we work towards solving the double-spending problem? We have this awesome technology that solves the double-spending problem. It's called a blockchain. Of course, it only works when transactions are actually in a

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> And it still would. Non-collusive miners cast votes based on the outcome > of their own attempts to double spend. > Individually rational strategy is to vote for coinbase reallocation on every block. Yes, in that case nobody will get reward. It is similar to prisoner's dilemma: equilibrium has

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On 4/23/2014 3:55 AM, Mike Hearn wrote: Lately someone launched Finney attacks as a service (BitUndo). As a reminder for newcomers, Finney attacks are where a miner secretly works on a block containing a double spend. When they eventually find a block, they run to the merchant and pay, then bro

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 06:04:00PM +0300, Alex Mizrahi wrote: > This is outright ridiculous. > > Zero-confirmation double-spending is a small problem, and possible > solutions are known. (E.g. trusted third party + multi-sig addresses for > small-value transactions.) Also replace-by-fee scorched

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > No. Bitcoin should work if miners are merely individually rational, i.e. > they try to maximize their pay-offs without colluding with others. > And it still would. Non-collusive miners cast votes based on the outcome of their own attempts to double spend. If enough agree then they all agree th

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 4:52 PM, Justus Ranvier wrote: > If enough miners don't like a block that has been mined, they can all > work to orphan it without any change to the protocol whatsoever. > As was already pointed out, yes. However this requires them to immediate establish a majority consens

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

This is outright ridiculous. Zero-confirmation double-spending is a small problem, and possible solutions are known. (E.g. trusted third party + multi-sig addresses for small-value transactions.) On the other hand, protocol changes like described above might have game-theoretical implications whi

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 04/23/2014 07:55 AM, Mike Hearn wrote: > 2. Miners can vote to reallocate the coinbase value of bad blocks > before they mature. If a majority of blocks leading up to maturity > vote for reallocation, the value goes into a pot that subsequent > blo

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > There _are_ consequences though: 95% of the time, you end up buying > something and paying for it. Yeah, I was imagining a situation in which people who use Bitcoin regularly do buy things they actually want, but wouldn't say no to occasionally getting them for free (think coffees at starbuck

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wednesday 23 Apr 2014 12:45:34 Mike Hearn wrote: > OK, sure, let's say most Bitcoin users will be honest (we hope). But > unfortunately in a situation where fraud is possible users wouldn't > necessarily distribute evenly over transactions. That's true, but even in the worst that that 5% hashi

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wed, Apr 23, 2014 at 2:43 PM, Christophe Biocca < christophe.bio...@gmail.com> wrote: > 1. This provides a very strong incentive to always vote for > reallocating a block if it isn't yours If everyone votes to reallocate everyone elses blocks all the time, then you'd end up losing your own co

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

Just a few issues with the idea as it currently stands: 1. This provides a very strong incentive to always vote for reallocating a block if it isn't yours, regardless of whether it's bad or not (there's a positive expected return to voting to reallocate coinbases from other miners). The incentive

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wednesday 23 Apr 2014 12:07:25 Mike Hearn wrote: > > Just pedantry: 100% of credit card transactions _can_ be fradulantly > > charged > > back but arent. > > If you do a chargeback the bank double checks this, investigates it and > people who repeatedly try and do fraudulent chargebacks get the

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > You're still being unfair to bitcoin. Not everyone who uses bitcoins will > be dishonest. The dishonest 5% hashing power is not going to be used in > 100% of any given merchants transactions. > OK, sure, let's say most Bitcoin users will be honest (we hope). But unfortunately in a situation

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

> > Just pedantry: 100% of credit card transactions _can_ be fradulantly > charged > back but arent. > If you do a chargeback the bank double checks this, investigates it and people who repeatedly try and do fraudulent chargebacks get their accounts terminated. It's not like your bank offers you a

Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

On Wednesday 23 Apr 2014 08:55:30 Mike Hearn wrote: > Even with their woeful security many merchants see <1-2% credit card > chargeback rates, and chargebacks can be disputed. In fact merchants win > about 40% of chargeback disputes. So if N was only, say, 5%, and there > was a large enough popula