Bitcoin Forum

i read somewhere that somebody said its him doing the attack yet i cannot find this post.

so my questio nis - who did this attack and is it still running?

Anybody with a little bit of programming/bitcoin knowledge can easily perform this; hence there are many people doing it in an attempt to force improvement through the bitcoin network because it has already proven to be detrimental.
It is still occurring.

It is still ongoing as of this moment, and the certain user who performed it is this one: https://bitcointalk.org/index.php?action=profile;u=197593

You can find the thread regarding the attack here: https://bitcointalk.org/index.php?topic=1198032.0

I find it strange that all these technical loopholes have been found recently, and not a lot before that. I wonder how all of this fits into the Bitcoin Core vs Bitcoin XT debate.

It's pure speculation, but things has gone crazy, since this whole split has happened. The person doing this malleability attack has a lot of technical information of the inner

workings of Bitcoin, so it's probably a engineer or a developer? 

Check the user that I've just linked to here and also read the whole thread that I've just linked. The user claims that he doesn't use bitcoins and as I see it, is a pro-bankster. Cool, right? He seems to have a lot of knowledge regarding that certain attack vector on bitcoin.

Bitcoin has been growing extremely rapidly the past few years, and this brings a lot more pressure to any faults and flaws within the code.
More eyes and more incentive these days.

Isn't this the same old transaction malleability that has already happened last year? Markets have then reacted much wilder and we have seen major drops in price. I thought this is the same old problem.

As I know a BIP 62 is here to solve this problem but this BIP 62 still hasn't been finished and deployed successfully!

The attacker can't steal your money. All the attacker can do is change your transaction ID, then re-transmit it very quickly to send Bitcoins to the same address they were originally intended to be sent to. One of the transaction IDs has to be accepted by the network,and the other has to be discarded. Your Bitcoins still get sent to the address they were intended to go to, but sometimes they arrive with a different transaction ID than you were expecting if your transaction gets attacked.

Yes that's all they can do but it affects certain transaction which rely on the transaction ID, for example if you're live betting and you send in a bet, it gets accepted but then the other one is sent with different ID and the 2nd one gets confirmed and by that time the odds have changed, one other affect of it is, someone I know reloads his mobile using BTC, so he sended the BTC and waited but never received his reload because his transaction under original ID was never confirmed and the other one did but the website didn't recognize that as it relies on the Tx ID.

And OP it is still going on, I did many transactions today and couple of those were resent using different ID and thankfully it didn't affected anything, other than the Blockchain.info warning saying that this address has double spends.

From what I can see, it's somebody who is out to destroy bitcoin. What is there to gain by carrying out the attack only to cause inconvenience to the users. Obviously it is the trust and reputation factor that is at risk here because people see bitcoin as a reliable payment system. I'm also surprised that after so many years there is still loophole in the system that can be exploited.

The problem is that a known bug in the bitcoin protocol has festered for years.  If the "core" developers had been doing their job, this problem would have been fixed long ago.

1) I use bitcoins. But I do not hold them. Sorry for some misunderstanding. My English is not perfect.
Let me give an example:
I eat watermelons. But I do not buy watermelons for investing.
Because I do not think that I would be able to sell the watermelon tomorrow with profit.
And I advise to everyone not to invest and hodl watermelons.

2) I am not pro-bankster.
I just say, that keeping money in pockets is better than investing in watermelons

You can check if it's still running here (http://statoshi.info/dashboard/db/transactions), on the third graph

Some scam sites have taken advantage of this attack as an excuse to dissappear/lost deposits/lost withdrawals. Been a hard week for some.

Would there be a way for the attacker to use this explout to steal bitcoins from people? I am not an expert on this stuff.

There are a dozen different malleability vectors in the protocol as originally designed; some are quite useful and important intentional features-- others are not.  Though the harm from malleability is very moderate-- and because of the intentional features and the potential for ordinary double spends, wallets must have basically sane handling for it--, unwanted third party malleability is a nuisance. In Bitcoin Core's wallet the nuisance can be greatly mitigated by setting spendzeroconfchange=0.

Because of it being a nuisance all of vectors for malleability except for one were blocked as non-standard transactions in Bitcoin Core years ago.  The remaining one could not be simply blocked because it requires transactions to confine their signatures to a particular form-- low-S-- and all software was violating before the issue was known.  Because of this applying that final constraint would have blocked almost all transactions on the network-- something not justified for a nuisance level attack. Bitcoin Core changed constrain its own transactions to this form in 2013 but it has taken a long time for other software to update themselves. Fortunately, the final remaining type of malleability was ever so slightly trickier to exploit, so people haven't been doing so at scale. In the meantime a proposal was made, as part of BIP62, for a v3 transaction type where parties creating transactions could opt into the protective behavior if they were recent enough to support it. Unfortunately BIP62 is fairly complex and no one outside of a small group of contributors to Bitcoin Core have cared at all about advancing it.  So we've been breaking up parts of them and applying them to the consensus incrementally (e.g. BIP66).

Current git master Bitcoin Core enforces (https://github.com/bitcoin/bitcoin/commit/b196b685c9089b74fd4ff3d9a28ea847ab36179b) the requirement for all transactions it relays or mines, once this is in a release and widely deployed it will end this irritation; but it will also block most transactions from small portion of the network on software which is out of date or hasn't been updated to produces anti-malleability-friendly low-S signatures (on the order of 5% of all transactions now; due to ongoing efforts to harass parties to fix their wallet software).

I've called (https://bitcointalk.org/index.php?topic=1198032.msg12604527#msg12604527) for assistance several times in identifying the origin of a list of lowS violating transactions in order to help speed deployment of this, but it seems that the Bitcoin community is a lot more interested in whining and throwing blame then stepping up and doing a little bit of the non-development work needed to get this deployed. :(

No I don't think so. Only a great danger of double spending as far as I know!

Please explain (or reference an explanation) as to why malleability features would be quite useful.

Also, I would like to understand why people care about old implementations that aren't being actively maintained by people who are following bitcoin.  Please explain why it matters what happens to these old implementations?  Why should you or anyone else waste effort to dig up these issues?

Those attack can be anyone from credit cards companys ,google or any person with huge skills trying to get into the team of bitcoin,we will never know why and who are attacking it,to destroy well if there is a hole to attack the team should be working in something to close it before too late,i cant imagine bitcoin being hacked and controlled by some hacker..... destroying all crypto instantly.

never say never.
it was me behind this particular stress-test
i am not from bank company and do not work for google

I understand you are a developer, but which industry do you serve as an employee or an employer ?

I am a code developer, but my main work is not bitcoin-related. I am employee in small it-company.
Bitcoin technolodgy is a hobby.

When malleability attack is running you will see this:

https://bitcoinnewsmagazine.com/wp-content/uploads/2015/10/transaction-malleability.png

Attack ended 10/5 about 10:00 and is not ongoing right now.

Why is the mempool increasing in size so quickly if the attack is now stopped? It's now 909.7 MB which is the largest size I've ever seen, not that I regularly keep a track of it. It's the largest size in the lat seven days according to tradeblock. Something must be causing it, and it's not unconfirmed transactions this time. I thought its size would reduce after the attack stopped.

http://s3.postimg.org/cx2h806sj/mem.jpg

For example, anyonecanpay sighash flag allows arbitrary parties to add funds to a transaction. It's what makes lighthouse possible, but every time someone updates the transaction the txid changes.

Because they are widely used (or had been historically-- we're getting to the point where .this is less true). Just blocking the transactions for non-trivial amounts of users does not yield a good experience, to say the least. Forcing people to constantly rev their software reduces decentralization-- and who precisely has the authority to go decide what is "old" or "actively maintained"?--if people are happy happy with what they're running, I am not eager to disrupt that.  I am also not eager to try to dictate how often authors of wallet software must revise their software (again, something that would reduce decentralization-- by pushing out development teams with less resources).  As to why you should care and go help move them along: it's cheap to do, and the failure to do so holds the ecosystem back.--- the same reason I've done so.

If you note the patch I linked to, my change was only a few characters--- why? because the code was already written a long time ago... but not activated due to waiting for the ecosystem to catch up; we're ready.

This has been delaying all the transactions and been the cause for many vendors and other service providers to increase the tx fee.

Does anyone knows or at least has a suspicion on who's responsible for this bug exploit?

There is at least one poster on this forum who is claiming credit for this, FWIW.

At this point, years after the bug has been identified, there really isn't much of an excuse for not having plugged this hole.  But then, the philosophy of the so called leaders is not to make and execute any decisions that might inconvenience anyone. In other words, abdicate leadership.  A strong leader has to make decisions and take responsibility for the consequences, including the possibility that people won't follow him and he may have to find a new job or even a new career.

The problem in your example is not changing some code.  It's an architectural question.  What is the meaning of a "transaction", in other words what is the object that a transaction id references?  Binding time issue.  if there is lack of clarity here, then there is no hope for a clean software design or bug free operation.

Reasonable people running old software have no problem switching to new software.  Anyone who has used computers for more than a few years understands that technology changes and people have to keep up.  It's the way the industry works.  The most these people have a right to expect is a migration path from old software to new software that enables them to keep their coins.

Attack seems to be back on and seems to have been predicted by mempool increase:

https://bitcoinnewsmagazine.com/wp-content/uploads/2015/06/malleability-attack.png

increasing tx fee right, well there must be only one responsable, a miners, it's in their interest to increase the fee at all cost

so i'll not be surprised if they are again the one to blame for this

http://statoshi.info/dashboard/db/transactions
right now there is some sort of "turbulence" there.
the reason of "turbulence" is https://bitcointalk.org/index.php?topic=1175321.msg12623681#msg12623681

Yeah, something is definitely up, my transactions have been stuck for 2+ hours, they were medium priority which usually takes upto 6 blocks and there have been 10 blocks since then and they still haven't moved, I think they might get stuck for infinity. :( If only I knew that there's another stress test I would have added extra fee.

Thanks for the link.

What if there is another wave of malleability attack whilst the spam attack is underway, it could really turn things upside down.  :-\

Should we test this case?
I can resume malleability stress-test in any moment

Well according to this article (http://motherboard.vice.com/read/i-broke-bitcoin), a fix might get pushed soon.


And until then, you can do whatever you want to do.

On the brighter side of things, all of my transactions just got confirmed. :)

Bitcoin is decentralized. Nobody can "push a fix soon".
Yes, I do understand, that today we have a very small number of miner pools.
And it is quite possible to developer team to communicate with admins and ask them to implement a "small and very good patch" in code.
What does it mean?
This means, that all words about the "real decentralization" have been forgotten.
And the community is under the control by core devs and pool owners.

Would be an interesting experiment... in the name of science of course  :)

Soo why not to join the team of bitcoin to clear the bugs and the hole that you looks like you are taking advantage to explore ,would be better clear it instead use it .

Bitcoin developers are already planning to block the malleability attack with an update that will enforce lowS according to the chat in bitcoin-dev (http://bitcoinstats.com/irc/bitcoin-dev/logs/2015/10/08#l1444332212.0).

you are right, seems BTC is loosing decentralization

but that just means... nothing can be decentralised for real

marcotheminer said something about maleability issues with the bot that affected some users from the bit-x campaign.

I thought the problem has been solved long ago after the Gox thing ???

I am not sure if he is out to destroy Bitcoin. If anything there is benefit out of all this - many noobs who did not understand what the malleability attack was prior to this now do. For most systems it is not too difficult to build countermeasures against this. Of course, if someone's system depends on the abitlity to react instantly to unconfirmed transactions the moment it sees them ... well then it is their stupidity.

Only primitive organisms. Worms for example.
Ants have primitive centralization. They can build an anthill.
People can work in fully centralized community. They are launching rockets to Mars.

BTC lost  its decentralization when some smart guy decided to mine on his video card and another clever guy organized a pool.

Altruism is centralized - who knew?

If I may use an unfortunate term (or two), the decentralization of space exploration is literally exploding.

The development of bitcoin was never decentralised, looking at it from a wider angle, the blockchain itself is a centralised system(the blockchain) on which we entrust the bitcoin economy. The meaning of decentralisation is that there is not a single entity but the blockchain itself, until there is someone who can make and overtake a mining rig so powerfull it will mine all the remaining blocks and will not share the technology.

This will however result in a non trustworthy blockchain and the whole thing crumbles before the one investing so hard to gain control will have the biggest loss. "Now you're king of the mountain, but it's all garbage!"

Now i did a payment to myself by Mycelium 2.5.2
After transaction was made, after 1 minute i tried to send new transaction (parent transaction had 0-confirmation). Mycelium allows to send transaction based on 0-confirmed.
But Mycelium could not send a new transaction - "transaction was declined by network"

I think for 1 minute (because blockchain.info & tradeblock.com shows to me different cashes of my first (parent) transaction) while i did new payment in this time anybody changed my transaction and some miners got other and inputs of second transaction after this referered to invalid TxID.

I think this type of attack affects user wallets too - if wallet software can spend unconfirmed outputs (Mycelium, Breadwallet, Electrum and etc.). And user can think that payment was not sent but some peers got normal valid transsacion, other got invalid... It's not good news for bitcoin users.

I think anybody monitors only transactions which have only 0-confirmed parent transactions, and then they change its and rebroadcast.
After many wallets affected to this when user try to send new transaction based on 0-confirmed old transactions - a wallet software make new transaction from itself TxIDs, but network knows about other TxIDs...
:(

And by this attack affected mining pools - some pools got transactions outputs of which valid but other ones. So after this attack all chains of 0-confirmed transaction very very slowly propogated through bitcoin network :( I send valid fine fee transactions but they are not confirmed a long time :( - somebody changed iut and rebroadcasted with other TxID :(
As i understand should BIP62 help?

I disagree with how he expressed his opinion (doing an attack) about the whole Bitcoin getting centralized but I do agree to some extent that he is right, maybe right now it's not the case but in future the bigger pools will completely take control of the mining operation and then they'll make their own rules and that will again result in a non trustworthy blockchain and maybe these stress test are done by them to increase the miner's fee. I don't think this is how Satoshi envisioned the mining to be, I think it was meant to be completely decentralized and people mining from different parts of the world and not just from few mining farms.

Thanks for explaining your view on the things gmaxwell. I think this attack can only help bitcoin. Showing if the attack vector is really a problem, pushing the funding of code to go against.

I think the influence on the network is rather small anyway.

The "test" did a number on my bitcoind + electrum server machine, saturating the CPU completely, with the node falling behind the block chain.  Fortunately, this was easily fixed by changing the config file. I deliberately run a slow processor, so I get a preview of "coming attractions".  Based on ealier "tests" I had surmised that my little Atom based machine would be (barely) able to handle 8 MB blocks running bitcoind. (Electrum server code is hopelessly inefficient and would require a faster processor or more efficient code.)  However, for some reason this new "test" was more effective at consuming my CPU cycles than previous tests.

It strikes me that the developers do not have node performance under control.  Software that runs real-time transaction critical software needs characterization of its performance and how this relates to transaction load, not just average transaction load but also "worst case" transaction load.  This is one of the reasons that I disagree with gmaxwell's response to my earlier post in this thread.  Perhaps there are models, measurements and benchmarks for node performance as a function of a number of parameters, but I haven't seen them.

malleability attack can only work in a tiers payment processor ... NOT with connected wallet to Bitcoin network.

Do you say that this attack pattern became possible because of changes that were implemented into bitcoin to make the lightning network possible?

You mean the big mining companies. The pools that exist are practically only big companies that allow some small miners to take part. But they control the majority of the hashrate anyway.

And yes, they have all the might. Which sounds pretty bad. Some years ago we had a lot of private miners. That is not the case anymore.

Surprisingly satoshi foresaw that. I wonder why he did not see a problem in that. Decentralization is something different of a miner corporation, which we will see for sure.

lighthouse

 Explanation you can find in link below,looks like it is kind of hobby for guys who are doing that or mission of his life

http://webonanza.com/2015/10/08/no-you-did-not-break-bitcoin-today/ (http://webonanza.com/2015/10/08/no-you-did-not-break-bitcoin-today/)

Thanks for the correction...

It would have been better if mining would be non-profit in any other any way than just the sheer joy of running your own decentralised mining rig in your basement, as a hobby and as a means to keep the blockchain alive. You could make it break even, so no profit, but no loss, but it is still the market at work here.
The incentive is money, and that is one that feeds greed, greed is a very mighty thing and hard to control. We always want more, eat all the cake till nothing is left and then franticly search for the last crumbs...

Mining without profit would increase the decentralisation, because it would only interest those who want to invest without any earthly rewards other than recognition and being part of it. But where do you put the coins? How to distribute those? It is stil about the blockchain and the coins. To distribute them evenly around to all wallets available? That would make running the most wallets profitable and take the whole thing askew again.

Trying to manipulate the bitcoin value to keep it non-profitable for miners, but how?

Wat?

Dat!

It is the profit that is centralising the mining towards pools and mega mining rigs. Thus undermining the decentralised nature of the blockchain.

But what is the incentive to mine?
Where does the value of the bitcoin come from if it is not from profit?

It is a flaw(or asset) in human nature to be greedy, so how could we overcome this problem to keep the blockchain decentralised?

It wouldn't work.

There was an altcoin with a dev who thought people would mine his coin for no reward whatsoever, apart from knowing they were keeping the network alive. It didn't work out. A few people mined it to begin with, but soon there were only a few hours a day when anyone was mining, and it became difficult to send coins to another wallet. Then the network was attacked, and the dev had to do a coin swap to a wallet with a different system that rewarded miners.

It would be reasonable to doublespend by reorganizing the blockchain.

The mining happened because people saw that they could mine and make some money otherwise bitcoin and crypto world would happen,sure bitcoin must keep developing and raising their security and cleaning any hall anywher to avoid any kind of attack.On the begining they just tested the concept of mining and made some deals till it grow .

I thought he was just a Lithuanian bumpkin who happened to see "Visit Bitcoin" (written in mother tongue) advertised on a roof of a barn next to a major thoroughfare while on his way to the annual Kugelis Fest.

I think most things would be better off as non-profit but money makes the world go round not altruism. It really wouldn't be feasible for people to mine for free currently just as it wouldn't be feasible for all doctors and fire fighters around the world to work for free as great as that would be. People need money at the end of the day and most people cant afford to work for free.

1) I have never been in Lithuania
2) What is "Visit Bitcoin"?

For free we give smiles and friendship some try to take advantage of it,at bitcoin world there is someone hidden trying to take advantage of the hall that bitcoin has and the team should know about it but not focus into block it or reforece the system protection but well it needs to close halls to be able to grow.

Freak Show ?

Are we still under attack?  I have a transaction that is unconfirmed for over 2 hours .  Miners fee is 0.00014659.

Well the information you wanna i dont know sometimes the transfers takes a bit more then usual even without attacks, sometime ago i had waited 3 hours to my transaction get confirmed (3 confirmations) and the other time tooked less then 30 minutes soo just wait it will credit soon,the transaction is instant but most places ask for the confirmations before credit anything.

No.

The phrase was inspired by ...

https://s-media-cache-ak0.pinimg.com/originals/65/cf/d9/65cfd9179b1678e9834fd9988f828e5d.jpg

https://en.wikipedia.org/wiki/Rock_City


https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTRqwu8B5cfEJsE9k2dBErqSEdlelKJf3iulH4-0br3a9J7SRMG