Bitcoin Forum

http://hackingdistributed.com/2013/11/25/block-propagation-speeds/


Oh dear. Not only has it now be demonstrated that selfish mining is a feasible attack, but the rewards available are much greater than previously assumed. Still, not to worry, I'm sure the exchanges will keep pumping out false price data to keep the bubble going a bit longer before it is popped.

Nobody reply to this guy.

He's an established Troll.

Off course here a troll is anyone who dares to suggest Bitcoin is anything less than perfect.

no.

You're a troll because you make inflammatory posts to get a rise out of people.

Yo do it all over the forum.  You get people riled up, you make absurd statements on purpose, and then you walk away giggling like a little bitch because you got people upset.

that is the definition of a forum troll.

Jesus Bitcoiners, argue the paper not the person!

classic bitcoin cultist misdirection. Amazing how you've managed to avoid addressing the argument at hand.

"It takes 4.5 seconds for a block to reach 50% of the miners. That's approximately an eternity in computer terms. That's plenty of time for a selfish miner to push his own block and win some races, especially if he makes his block smaller than average."

But won't the 4.5 seconds apply equally to the selfish miner and honest miners?

What's the point about discussing a dead and deceased currency?
I really am curious about the motivation that keeps you coming back, sharing thoughts about an already buried shitty coin.
Really.

Why does winning a bunch of pointless races make any difference. Big pools control most of the hashrate and are only a handful of those nodes.

The attack vectors described in these "studies" have been discussed in the bitcoin community for years. It's also worth noting that despite a market-cap in the billions, these attacks have not been performed to any measurable degree. Nevermind the perverse incentives (the authors treat incentivization very myopically). These attacks are interesting to theorize about and should ultimately be insulated against for the long-term, but they're of little practical relevance.

Normally, yes.  However any mining pool acting in a 'selfish' manner can be identifed by predictable effects.  Once the offending pool is identified, honest miners who desire to punish the selfish pool may do so, by adding a delay to the propogation of any of their published blocks, or simply refusing to forward them at all.  There is nothing in the protocol that requires peers to treat each other equally.

You don't think the fact that Bitcoin is definitely not incentive compatible is an issue?

no worries , troll or not , i believe bitcoin community will mend this flaw

Because, as previously mentioned, he's a troll. 
He's not here for actual discussion.  He's here to agitate.
I'd be happy to argue the paper not the person, if the person was here to actually argue the paper.

Not all nodes are created equal. It doesn't matter if you reach 50% of the miners, if those 50% only have 1% of the hashrate.

I believe selfish-mining can be easily defeated (http://hackingdistributed.com/2013/11/09/no-you-dint/#comment-1136318528) by spying on the pool as a miner when told to generate shares for a new block. Propagation delay has no bearing on my proposed solution.

An incentive is a reward, and rewards are subjective.

We can argue all day about if miners make enough money or who gets the new coins and fees. None of that changes the fact that there will always be people out there who see things such as helping verify payments, having a fun hobby to play around with and generally contributing back to the web as an adequate incentive.

Even if you ignore all those things, and argue that there is absolutely no incentive, the conclusion of that is that it would be irrational to mine. There will always be people who behave irrationally.

The article is a bunch of nonsense. Support the ignore button of OP.

Explain why it is nonsense

Explain why your ignore button is in color.

Selfish mining doesn't break bitcoin at all. All this does is speed up the confirmation time, and increase the fees required to get your transaction in a block. In any case, bitcoin was meant from the beginning for miners to be incentivized, so of course the most profitable mining strategy will win out. It does not need "honest miners" who only mine for the good of the world.

if this will be a problem, they will solve it. trolls are welcome  :D

LOL!!!  Hey it actually is.   His ignore button is highlighted.  What does that mean?

Hmmmm. This gives me an idea.... Trollcoin!

Put you back on ignore.

It means that a number of forum members have put him on their personal ignore list.

Because Bitcoin cultists ignore people who disagree with them

bitcoin is software.

bugs can be fixed. i think we are beyond the point where even a major flaw would make it disappear. since there is so much money in the game, it will get handled ith care and common interest.

No, Bitcoin isn't software. Bitcoin is belief in the integrity of the block chain. Bitcoin survived a breach of that integrity early on in its development, but I doubt it would survive one now.

The cognitive dissonance here is astounding. I have the utmost faith in virtual currencies as a technology and Bitcoin as the best example of that technology, but why is it that any attack on Bitcoin is 'trolling'; technologies survive by mending their flaws. The fact that this level of theorization is going on around the protocol means it's getting somewhere.

It's an interesting article and brings up an important question to consider; whether it's implementable in practice is another question. I'll definitely respect a Cornell professor to know what he's talking about. The arrogant dismissiveness on these forums is stunning.

That wasn't much of a breach, it was more like a bug.  There wasn't any way that anyone could still funds, fake a bitcoin balance, or some such.  There was a bug that permitted a fairly effective DDOS attack on the network, thereby preventing transactions from processing.  The integrity of the blockchain, nor it's security model, was ever in peril.

Mostly we just get tired of repeatedly refuting the same crap.

Your button is also in color.  ::)

What color is mine?

I was referring to a client bug which allowed someone to credit themselves a few billion Bitcoins. There was another big which was discovered before it got exploited which would have allowed users to spend the balance of any other user.

You're going to have to prove those events happened, because as far as I know, that is still impossible.  There was a bug that permitted someone to create a custom transaction to credit themselves a negative balance, but why would anyone do that?

https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures


It's amongst this list

*edit* I realise you're a lazy douchebag so I'll actually paste the description here


"On August 15 2010, it was discovered that block 74638 contained a transaction that created over 184 billion bitcoins for two different addresses. This was possible because the code used for checking transactions before including them in a block didn't account for the case of outputs so large that they overflowed when summed. A new version was published within a few hours of the discovery. The block chain had to be forked. Although many unpatched nodes continued to build on the "bad" block chain, the "good" block chain overtook it at a block height of 74691. The bad transaction no longer exists for people using the longest chain."


and the other I mentioned

"On July 28 2010, two bugs were discovered and demonstrated on the test network. One exploited a bug in the transaction handling code and allowed an attacker to spend coins that they did not own. This was never exploited on the main network, and was fixed by Bitcoin version 0.3.5.
After these bugs were discovered, many currently-unused script words were disabled for safety."


If either of those happened again it could easily wipe Bitcoin out.

It is not fair to accuse Bitcoin of being insecure because of faults found in alt-coins.

Well, I stand corrected.  And yes, if either of those could ever happened again, it could wipe bitcoin out.  I'll give you that.  What are the odds that either of these expoits could be used agian, do you think?

Agreed.  It's rather shocking that such comments are dismissed outright.  Have you all even looked at the credentials of the person who wrote the article linked to by revan?  It's a professor who works at Cornell.  Not quite some no name guy with no credentials just randomly making comments about Bitcoin.

Is it fair for me to have to correct cretins all the time?

https://yourlogicalfallacyis.com/appeal-to-authority

It doesn't much matter who the author may be, only what the argument is.  Speaking for myself, I very rarely see actual arguments presented on this forum anymore.  And when that does happen, it's generally due to a misunderstanding of the protocol by the author.  I'm not saying that this article doesn't have merit, but it doesn't have merit because it was presented by a professor from Cornell.

The worst logical fallacy is the misuse of logical fallacies as a way of trying to win in argument. It was not an appeal to authority anyway, as it was not said that this guy is necessarily correct because he is a Cornell professor, rather it was stated that to summarily dismiss his work given his credentials and reputation would be stupid as it seems unlikely he would be making claims he could not defend with solid arguments.

Congratulations.  You have the honor of being one of the very few people on this forum that were able to tell me something about Bitcoin that I didn't already know.  Don't assume that because you knew this little factoid, that you really grok bitcoin on the same level as myself.  I'm not a programmer, but nor am I stupid.  I was here for years in the company of brilliant people who were actualy building the bitcoin economy; and was able to converse with these same founders before all of this useless noise infested the forum and most of those same brilliant people left the forums.  There are now more than 160K registered forum members.  I remember having these kinds of arguments with detractors when one of the arguments was, "not even 10K people have even heard of a bitcoin, it'll never even reach parity with the dollar!"  Seriously, this isn't even the same forum anymore.  It's filled with programmers who don't undertand economics, economists who don't understand human psychology, psycologists who don't understand cryptology, and laymen who don't understand any of it; while they all think they are f*cking polymaths!

It was implied, and you damn well know it.

The normal one. You aren't ignored. Luckily, mostly because you don't open threads like this one.

You're doing it wrong. It's like this.

https://yourlogicalfallacyis.com/the-fallacy-fallacy

Wow, Heinleinisms, you must be like some sort of sooperhackerd00dsavantmuthafukka.

Whilst you may be chagrined to learn this, I'm afraid I must inform you that brilliance is not communicable. You can hang from the coattails of luminaries, but your star shall shine no brighter as a result. Take heed little grasshopper: know thy limits, lest thy limits be known by all.

You inferred it.

I'm not threatened by others being aware that I have limits, and while brilliance may not be communicable, understanding most certainly is.  You could be every bit as brilliant as you seem to believe, but you still lack understanding.

Actually, no.

You can communicate information, but understanding require qualia

Link or citation please?  No such bug was ever exploited in the wild.

https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures


The latter was not exploited, I stated that clearly, but only because at the time the userbase was small. The former was exploited , and undoing the damage involved effectively rebooting Bitcoin; again, this was possible because it was nascent at this stage, if it happened now it would be the end of Bitcoin.

They have not been dismissed outright.  They have been argued against and shown not to be a major issue.

The attack in the article is a block withholding attack. It is well argued but ignores the COST of block withholding. When you factor in the cost the attack is much less profitable. When you further factor in the possible backlash against a pool operator it rules out pools doing it.  Basically you would need a lone miner with more than 20% or so of the network.

Now anyone with 20% of the network and therefore a substantial investment in Bitcoin would be ON CRACK to do this.  They could potentially devalue Bitcoin more than the extra profit they make. In summary... The attack is not worth it for the people who could actually do it.  

The writer of the article ignores these points.

This page on the wiki should be renamed.

https://en.bitcoin.it/wiki/Common_Non_Working_Vulnerabilities_and_Exposures

Anyone got a better name?

Billions of Bitcoins were credited to 2 wallets. That attack worked. ubdoing it involved breaking Bitcoin's own rules, and if it happened now it would destroy Bitcoin.

You rule out nefarious intent (state actors for example, established corporations with business interests hurt by Bitcoin) and you also ignore the fact that just like the forger creating dollars does not consider himself to be damaging the viability of the dollar, so the selfish miner would not necessarily deem their actions as harming Bitcoin.

This comes to mind: Low-latency strategies (http://en.wikipedia.org/wiki/High-frequency_trading#Low-latency_strategies)

I do not rule out nefarious intent.   The attack is silly for nefarious intent.  If you want to hurt Bitcoin, set up a similar amount of power AND DON'T INCLUDE ANY TRANSACTIONS.  An attacker would not hurt Bitcoin all that much by taking other miners rewards, maybe just a slight hit in price.  In many ways if it was know it was an attacker was doing selfish mining it would instill MORE confidence in Bitcoin as transactions would work as normal.

The selfish miner IS BEING PAID IN BITCOINS so even a slight hit in price causes the attack to be not worth it.  It is quite simple, and that paper works only if you ignore that reality.  

Sado-mining, on the other hand...
http://www.eorc.jaxa.jp/en/imgdata/topics/2010/tp101129.html

Going right back to ancient Rome, the best way to destroy a currency is to undermine confidence in it. Selfish mining incentives malign behaviour, it puts fair players at a disadvantage, and a dynamic like that always ends the same way: Rome burns.

You have not countered my argument at all. 

The incentives are not there for real world miners, and for nefarious miners (trying to break the network itself) the effects on the network are not great enough for the effort. 

I have countered on both points.

The forger never believes their forgeries will diminish the value of that which they forge. Selfish miners would behave likewise. As to the latter, prove it. Prove that altering the mining dynamic such that rewards are no longer proportional would not cause havok.

Not at all the same.  A forger (of money, art etc) gains 95% + so they do not care if they devalue what they forge.  They take paper worth pennies and turn it into hundreds.

A selfish miner would not have such a profit by the attack AND they have a vested position in Bitcoin.   Blocks are NOT being forged in any of these attacks.  The selfish miner only makes a SMALL gain.  That is the difference and why in the real world this does not play out. 

Who said it was a small gain?

You will have to figure this one out for yourself.  It seems like you know how to respond to something quickly with a response that looks right but contains no real information and adds nothing to the conversation.   You don't get it, just like the 'professor' who wrote that article. 

Absolutely this. It's possible to see why, because bitcoin is such a disruptive technology, there are certain actors who would be willing to absorb great cost to damage the credibility of the technology.

I hate popular thread based on crapy argument, I just ignore him, next time, I'll pass by !