Quote
You either dont understand what Bitcoin is Grin
I wrote my Bachelor Thesis about Bitcoin and developed a Paper Wallet site: moneyart.info
I know a lot about Bitcoin.
Topic: Cheap way to attack blockchain - page 3. (Read 28257 times)
I wrote my Bachelor Thesis about Bitcoin and developed a Paper Wallet site: moneyart.info
I know a lot about Bitcoin.
Each such transaction costs 0.00045 for dishonest attacker (can be even less)
88 transactions (attack one block) will cost only 0.0396 BTC
Daily attack 5.7024 BTC - not a big deal
Wanna hire me for this dirty job?
88 transactions (attack one block) will cost only 0.0396 BTC
Daily attack 5.7024 BTC - not a big deal
Wanna hire me for this dirty job?
Main "weakness" for this attack is that miners could easily just ignore those transactions, without involving any hard fork.
Only the pools that accept those transactions *and* that do not prioritize transactions in a block by total fee would be impacted, pools that build their blocks based on max fee they can rack in a block would automatically eliminate them, they may just need to take the SIGOPS limit into their block optimization code, but that's all.
In practice only the "faucet pools", those that accept zero-fee tx and do not prioritize tx would likely feel the attack.
So the practical spamming would be limited to relaying and the mempool, so no biggy.
You guys ought to be grateful for amaclin for doing security
testing and even paying for it out of his own pockets.
No, it is not your right to spam the blockchain, you simply have the ability.
Just because I have the ability to rob a store does not make it my right to do so. Same applies here.
There is no law, no punishment for doing this.Just because I have the ability to rob a store does not make it my right to do so. Same applies here.
There are only consensus rules and mining policy in bitcoin.
So, in this case right=ability. These are different apples.
Why would you want to spam the blockchain.
Because I have a rightWhy would you want to spam the blockchain.
Because I have a right 
Why would you want to spam the blockchain.
that kind of spamming will be really popular in future.
doubtQuote
If you add some text to each transaction and send it, it will works same as email spam
Are you sure that you really understand me? and the point of SIGOPs "block fulling" attack?Have a look:
https://bitcointalksearch.org/topic/storing-large-data-in-blockchain-1023190
http://webbtc.com/tx/300503d19fb80a083723ccfb43d54278f2555838595c3443907156bc9889aeec (stored today)
https://github.com/petertodd/python-bitcoinlib/blob/master/examples/publish-text.py
that kind of spamming will be really popular in future. If you add some text to each transaction and send it, it will works same as email spam
By the way, politicians still dont understand what Bitcoin is.
You either dont understand what Bitcoin is Quote
Governments do not need to "destroy" bitcoin.
Because there is no danger from it.
Because there is no danger from it.
Governments steal our money but because they have to pay so much interest on debt there is no money left for a bitcoin attack.
By the way, politicians still dont understand what Bitcoin is. Good for us, because when criminals dont understand something they dont want to steal it.
I changed my mind
At least the attack is proven to work in practice.
I thought this would be against your policy of not spending money on attacks?
I changed my mind Another attack, this time block #384831's sigOp limit was hit.
Is this you amaclin? I thought this would be against your policy of not spending money on attacks?
So are people actually trying to attack Blockchain? I thought it was fairly secure..
The crypto is till quantum computers. The design and economics not so much. The currency itself changes hundredths in seconds and has arbitrary fees.. It wasn't well thought out and anyone who learned programming two years ago are writing tools and solutions for it because it's marketable..
It's trivial to spam and fork the blockchain for anyone with little research..
Governments and botnet industry will eventually start looking for way to exploit things.
So are people actually trying to attack Blockchain? I thought it was fairly secure..
Worse case scenerio: Buffer Overflow->Code Execution in poorly coded clients.
This is a specific DoS attack vector that has nothing to do with buffer overflows.
The worse case scenario is that no transactions are confirmed for a while until centralized mining intervenes.
It depends on what controls the allocation in code. If it's secure it puts x bytes in a x bytes buffer after a verified pointer in meta data with no parsing except after allocation of said buffer. Otherwise it can likely be exploited for code execution through malicious hashing&encoding.
Even if it's not the case here with the reference implementation, that doesn't mean it's not the case with other full clients.
If we're going to raise alerts over dos and block spamming I could easily post a python script that fork-spams the block-chain and bloats it with orphan blocks. I'm more interested in programming flaws though and not the genius currency design that changes hundredths at second intervals and has arbitrary fees..
EDIT: I only mention it because it's obvious that the reference implementation and all the clients based on it just blindly allocate and mine on the block-chain.. At some point malicious people will exploit it..
Hi,
im not a technical guy, but i would fear to use a system, running on a not a self-devloped op. system. Since Snowden we know, how the US try to keep up his superiority above the net. It is possible to defect some of the major op.systems, so large part of the Bitcon system can be compromised on the next op.system update. The Bitcoin Core only a program running above the op. system.
im not a technical guy, but i would fear to use a system, running on a not a self-devloped op. system. Since Snowden we know, how the US try to keep up his superiority above the net. It is possible to defect some of the major op.systems, so large part of the Bitcon system can be compromised on the next op.system update. The Bitcoin Core only a program running above the op. system.
Jump to: