Questions tagged [attack]
Relates to attempts to harm the Bitcoin network. In cryptography, an attack is a method/technique to break the code. Bitcoin also has to deal with other types of attack, such as double spends and denial of service.
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Can a malicious majority miner rewrite history?
Is it the case that a malicious miner with the majority of hash power (say, 99%) can perform a double-spending attack by rewriting history?
If so, I can't understand how. If not, under what ...
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Is the scriptPubKey of a previously unseen transaction in an incoming block checked? If so, where?
Today I was reading bitcoind src, and trying to find out where scriptPubKey is executed when a node received new block with transaction, for example transaction from new block may not be exist in ...
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What can be done about the no-transaction block relayer (currently 71.123.170.150)?
An unknown major solo miner (currently IP 71.123.170.150), most likely a botnet, is relaying blocks with zero transactions. Two weeks ago this miner constituted ~15% of the network, now it constitutes ...
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Flaw in Bitcoin protocol regarding incentives to share transactions
Once the 50BTC per block rewards have halved many times and the transaction fees start to become the primary reward for miners, it sound like there is incentive for miners to not pass on transactions ...
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How does namecoin and other merge-mined coins prevent pre-mine attacks?
So, namecoin supports merged mining against bitcoin. My understanding of the merged mining protocol is that basically miners can use the primary coin's POW solution to solve the aux coin's block. It's ...
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What is the risk of waiting for just one confirmation to validate a transaction, assuming the counterparty is not a miner?
I am trying to determine how many confirmations would be reasonably safe to wait before accepting a Bitcoin transaction from an attacker that is not a miner and hence cannot rely on Finney attacks, ...
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Probabilty of a Race Attack in time t with hashing power q
I read the original Satoshi's paper on bitcoin as well as Rosenfeld's paper on "Analysis of hashrate-based double-spending". However, they don't answer my question, which is as follows.
Let's assume ...
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What happens if I fork an older block chain and rejoin the network later?
Let's call it a "time machine attack".
Suppose I have an isolated network of n clients with a significant hash rate, install my client software on that and start mining on an older blockchain.
Since ...
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Which release fixed CVE-2010-5141 (attacker can spend any coin)
This post by Mike Hearn relates an interesting bit of history:
When Bitcoin was first released, it contained two completely fatal bugs that made the entire system worthless. Fortunately, they were ...
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Implicit/Tacit mechanisms in Bitcoin Core disclosing Selfish Mining
I'm referring to the selfish mine attack described by two researchers from Cornell University who describe a "possible" attack with lower than 51% hashing power.
Now it's interesting to know what ...
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DDoS on big mining pools: a quick way to 51%?
Slush's Pool, the second biggest mining pool around, is currently down, allegedly due to a DDoS attack:
News
16.04.2013
Pool is under DDoS attack. I'm working on recovering the service back to ...
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Would any of the current botnets be able to launch and sustain a 51% attack?
The "owners" of botnets probably runs them as businesses, meaning that they will always seek profit-optimization. Do you believe that it is a matter of time before they will seek to launch and sustain ...
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Developments to prevent 51% hack [duplicate]
How might Bitcoin be made impervious from attack by large monied interests that could atttack with a brute force majority hashrate hack?
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Is it possible to spam the bitcoin network with 'dust'?
Someone could buy or mine bitcoins, and send them in small transactions all day to spam the blockchain.
Is this possible? And could this mean the end of the trust people have in bitcoin?
edit:
And ...
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Simultaneously Solo and Pool Mining
It's possible to send shares both to a localhost GBT "pool" (e.g., Bitcoin Core's) and to a remote Stratum pool.* Now, if I discover a block, won't both my localhost GBT "pool" and the remote pool ...
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What is the story behind the "Linode problem"?
What is the story behind the "Linode problem"? How did the service become compromised and what has exactly happened because of it?
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How does bitcoin prevent this network splitting attack?
How are malicious nodes prevented from, after getting the nonce of a new block found by someone else, broadcast it to the other nodes claiming it to be its?
Also, how does the bitcoin system solve ...
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How can one simulate and analyze attacks on the Bitcoin network?
Are there any other platforms or tools beside TestNet where I can simulate and analyze various attacks like double spending (finney/block withholding attacks etc.)?
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Pseudo-Node and putative attack vectors on the network
Pseudo-Node is discussed here on Reddit's /r/Bitcoin
Essentially it functions to relay calls from connected nodes in a random fashion.
This was an experiment into how easily can full nodes be "...
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Is it possible to run a simple attack on a previous version of the client in testnet mode?
I need to simulate an attack locally or in testnet (if possible) for academic purpose, on an old and bugged version of the bitcoin core client. I am in posses of test BTC in the last version. I want ...
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How safe is bitcoin with regard to a random address generation attack? [duplicate]
Imagine an attacker implementing something like the following pseudocode on the fastest ASIC farm money can buy:
attack(blockchain, my_address)
addresses = generate_tree_of_all_nonempty_addresses(...
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When to worry about 1-confirmation payments
A customer sends me a payment for some digital good at my service, where delayed delivery is a deal-breaker, so I only wait for 1 confirmation by the network before releasing the links for the ...
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How did transaction malleability/DDOS attacks allow an exchange's internal accounting system to get "out of sync"?
This Coindesk article says that:
“So as transactions are being created, malformed/parallel transactions
are also being created so as to create a fog of confusion over the
entire network, which ...
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Is bitcoin vulnerable to a DOS/spam attack?
What happens if someone maliciously decides to make squillions of transactions on the Bitcoin network?
I see there being two vulnerabilities. Firstly - computation resources used, though this doesn'...
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Specifics on "Race Double Spending Attacks"?
Hi guys I am doing some research on double spending in the bitcoin network several ideas have been confusing me:
In prevention of Race attacks, merchants are advised to "connect to a large random ...
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Have network DDoS attacks ever been successful on any coin?
Has a cryptocurrency network ever been fully DDoSed so that the blockchain did not advance during the attack?
If so, which one and how?
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How did Ripple handle DoS/DDoS during the ripplescam.com days?
I'm going to assume that during the days where Ripple was irrationally hated by some sub-population, a la the ripplescam.com site which used to be the first result on Google for "ripple coin" until ...
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Isn't bribe smearing possible because no payee signature is required?
The Bitcoin protocol does not require the payee to sign for a payment; only the payer signs (the payer signs a hash of the payee and payer's public keys). In other words, a payee signature is not ...
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Is there a real threat of so called ">50% attack"?
According to Bitcoin Wiki attacked who has majority of computing power of the bitcoin network can successfully do some nasty things such as potentially book double-spending or prevent transactions ...
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Why do pools get so often DDoS attacked?
In other words: who has incentives for attacking pools?
Do you think it's the government?
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What attacks are possible with a malicious bootstrap.dat?
The standard Bitcoin client normally needs to download the entire blockchain from the p2p network when first installed, but a shortcut is to provide it with a snapshot of the blockchain (at some point ...
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How much would it cost for a government to undermine Bitcoins?
Articles by for example the Economist stating that Bitcoins are being used for drug trading (Silk Road), I believe that the biggest risk to Bitcoins is that a government will pull a stunt similar to ...
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Would it be feasible to attack the bitcoin network by buying and deleting large amounts of bitcoin?
Could a government, determined to stop bitcoins, just buy a lot of bitcoins and delete the wallet afterwards? Are the bitcoins gone then?
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What happens if Bitcoin itself is obsoleted by another digital currency?
Unless Bitcoin is replaced with a Bitcoin-compatible currency, I believe that all holders of Bitcoin will be out of luck when the day comes that it is obsoleted by a superior system, as inevitably ...
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Attack on bitcoin network with modified client?
Scenario:
Mallory, Alice and Bob found block on their farm.
They disconnect from internet, simulating split and change all of nodes in their segment to malicious.
Malicious nodes decrease ...
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Government disrupting reception of bitcoins. Is it possible?
I was thinking of a very specific scenario: Suppose we have a new organization, let's call it "WikiLeaks2", which receives donnations mostly in the form of Bitcoins. Suppose a national government ...
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Could the target become unreachable? [duplicate]
As far as I understand it, the target T is a floating point number that is adjusted based on the moving average of the difficulty of some previous transactions. Mining a block happens when somebody is ...
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Could a mining pool attack Satoshi Dice?
Is it possibile for a mining pool to attack Satoshi Dice? A strategy might be: bet on Satoshi Dice and if the bet wins, do nothing, if it looses, don't put the transaction in the block (try to double ...
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DDOS Safety Electrum?
How hard would it be to successfully attack (all) the Electrum backend servers? I think there is about a handful of them.
I would consider an attack successful that stops Electrum from working for a ...
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I'm developing on the Test network. Are there any "rules" or communication methods I should adopt?
I'm testing a C# port of the client on the Test network and need to test for a variety of conditions.
Should I communicate to others regarding my actions on the network? If so, what method of ...
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What stops miners/nodes lying about what time a block was mined?
From what I understand, the difficulty required by the proof-of-work in bitcoin is a function of block history, specifically the average time between last ~2000 blocks, with the intention that its ...
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How do mining pool payout methods affect the cost of executing a block withholding attack?
I'm wondering how each payout method (PPS, DGM, PPLNS, Proportional, etc) influences the cost of executing a block withholding attack.
Does it matter how the payout method places variance between ...
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How can I assure my consumers they are actually paying the correct person? (prevent MITM attacks)
There are many network level attacks that give someone Man in the Middle ability to replace my Bitcoin address with their own.
Since there is no way to cancel a transaction, and the best practice ...
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What nodes are best for lessening the risk of loss from a race attack
A successful race attack is one where the payment recipient's node receives a spend transaction yet the next block that is mined has a different transaction that spends the same coin. Thus the ...
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Does the protocol ensures that private keys are unique?
There is a very very low chance for the same private key to be generated. (source)
However, what happens when my generated private key matches a private key that is already used?
Does the protocol ...
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What does a double spend look like?
What does a double spend look like? Can anyone link to an example on blockchain.info?
Will invalid half of the double spend simply remain at 0-confirmations, or might it ever reach 1 or 2? Will the ...
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What is the story behind MyBitcoin?
The name of MyBitcoin eWallet comes up quite often here and there. What is the story behind it and the attack on it they claimed occurred?
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Is an attack on a local bitcoind via an img or embedded flash viable?
In this thread on the Bitcoin forums it was suggested that a local attack on bitcoind might be possible through malformed img tags or (more likely in my opinion) through embedded flash. This also ...
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How would one inject a blockchain fork to the Bitcoin network?
For theoretical purposes, how would one inject a blockchain fork in to the Bitcoin network? For example, lets say we have a small chain of blocks prepared in a program that is not a standard client / ...
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Current block vs whole block chain attack
If an evil computer network wanted to attack Bitcoin, would they need to have more computing power than the present Bitcoin network and then attack a current block, or would they need even more to go ...
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