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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What are the advantages to attackers of different styles of replacement cycle attacks?
In Antoine Riard's
original description of replacement cycle attacks against HTLCs, a replacement cycle looks like this:
Bob broadcasts an HTLC-timeout (input A, input B for fees, output X)
Mallory ...
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Miners setting timestamps up to 2h into the Future
When a miner adds the Timestamp to a block template, it must satisfy two conditions:
Timestamp must be greater than the Median Timestamp of the previous 11 blocks
Timestamp must be less than its ...
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Public key factors - but what's next?
Let's say I found (I know, impossible) public key factors. What to do with them next to compute original private key for that public key?
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Is OP_CODESEPARATOR disabled in Bitcoin and if so why?
OP_CODESEPARATOR is used in the Bitcoin script language to mark the beginning of signature-checked data. However, the given operator never found its real practical use case. So, is the given operator ...
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Why are OP_MUL and OP_DIV disabled in Bitcoin?
What is the reason why OP_MUL and OP_DIV operators were removed from Bitcoin? Is this because someone could maliciously create a script that multiplies large numbers and thus blows the stack, or is ...
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Theoretical attack on the network by companies
I've thought about how powerful companies can change the protocol in pretty much any way they want. I'm pretty sure and hope there's some kind of way the network is resilient to this but I'm not sure ...
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DDOS attack via BRC-20 & ordinals on Bitcoin
Do we currently see a DDoS attack on Bitcoin as the mempool is flooded with low value transactions incl. BRC-20, ordinals etc. (where the transaction fee exceeds the transferred value)?
What can / ...
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Can the claim that "Bitcoin has a fee model that can be easily manipulated" be proven? If so are there any proposed solutions?
phillipma1957 claims:
Bottom line is the fee setup is subject to attack at little or no cost if any major pool gets involved in the attack.
I am a small commercial miner maybe 160kwatts of gear ...
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Is there any known 80-bit collision attack?
Regarding [bitcoin-dev] Time to worry about 80-bit collision attacks or not?
considering that it is from July 2016, is there any known instance of this attack in practice?
Also what addresses are ...
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Why would someone create a transaction where the fee is bigger than the sum of the outputs?
At the moment I am writing this question, the network is extremely bloated with, more than 60k transaction in the mempool. Inspecting the recent transactions, I found 4 very weird examples, at least ...
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DoS attack and MAX_BLOCKS_IN_TRANSIT_PER_PEER
I was reading Mastering Bitcoin and I found, in the section Exchanging "Inventory", this:
"The node keeps track of how many blocks are "in transit" per peer connection, ...
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Is Bitcoin fee attack preventable?
A block on Bitcoin blockchain contains about 4000 transactions.
Since a block is added approximately every 10 minutes, in 3 months, about 51 million transactions can be added (4000 x 6 x 24 x 90 = ~51 ...
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What can an attacker do if they compromise a DNS seeder?
Recently Bitcoin Core developer Luke-jr was hacked and has stated that we should consider anything owned by him to be compromised. This would include his DNS seeder at dnsseed.bitcoin.dashjr.org. If ...
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Attack in bitcoin network [duplicate]
I am new to blockchain and quite curious about some attack in bitcoin network. So, assume there is already an existing block which has content A and address B. Let's say if an attacker changes the ...
Mirage
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Why does an attacker need 51% mining power to overtake the blockchain?
I am really struggling to understand this thing about the 51% attack.
Usually whoever mines a block first wins.
My understanding is that mining is like a race. In a race, an athlete does not need to ...
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How can an attacker change the address to receive someone's reward
At the end of my lecture, my lecturer asked a question that we never had time to cover:
A miner creates a block A, which contains address b, on which they want to receive their rewards. An attacker ...
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Convert raw values to Int
how do I convert the given raw values in RSZ and Hash to integer?
Is there an online convertor or a script I can use?
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How does bitcoin prevent DDoS amplification via the `addr` p2p message type?
If I am not mistaken the mainline bitcoind will accept unsolicited addr messages, and upon receiving this message - the struct is deserialized, and then verify each address from the unsolicited ...
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Revealing chain earlier when private attack
Private attack is to violate the safety of a block B by creating another chain of length equal to or longer than the longest chain containing B, after B has been confirmed.
As in my reference
If the ...
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Mining stale low-difficulty blocks as a DoS attack
A DoS attack vector against a bitcoin node I haven't really seen mentioned anywhere is mining a stale chain in a low-difficulty era (say right after the genesis block), ideally with a lot of expensive ...
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What is the main purpose of the idea PASSPHRASE (25th word)?
I understand that the 25th word is to protect your assets when your 24 seed phrases are compromised. But I have some questions:
If I use a simple word as the 25th word, it will be easily brute force ...
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what kind of a double spend attack is a career attack?
there is an article that name different type of double spent attach like "Several variations of attacks could allow miners with bad intentions to double spend. Included are the Finney attack, ...
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What is a block-relay-only connection? What is it used for?
Modern versions of bitcoin core establish a fixed number of outbound connections: 8 outbound-full-relay connections and 2 block-relay-only connections. What is the purpose of block-relay-only ...
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Can you get the longest chain by keeping a constant low difficulty?
I'm struggling with this question that should be easy to answer.
If the truth is the longest chain,
what if I redo all the work from Block 1
until I have the longest chain by keeping a constant low ...
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What is a Feeler Connection? When is it used?
The bitcoin client hard codes a limit of 8 outbound connections and 2 block-only connections. Your node will try to always maintain these 10 outbound connections with reliable peers as a defense ...
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What is the prior work or inspiration for the new/tried table design?
In Eclipse Attacks on Bitcoin’s Peer-to-Peer Network section 8 Related Work, the authors describe how some of the countermeasures to eclipse attacks were inspired by botnets. What inspired the design ...
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Is it possible to realize MitM attack between bitcoin full node and listener of this node?
I have the appication listening bitcoin full node and receiving tx messages. Is it possible to change TxOut value by man in the middle, so I don't detect this changes?
Node I connect is public node, ...
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What are the various denial of service vectors on the Lightning Network?
What are the various denial of service (DoS) vectors on the Lightning Network?
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Is there a distinction between an attack and an exploit?
I'm writing up lecture notes and attempting to put the language on the most logical footing. I'm hoping to distinguish attacks on the consensus itself from exploits of the protocol, as these seem to ...
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can the network stagnate if the difficulty grows too big?
So im mainly thinking in the very early days of bitcoin when the networks compute power was minimal.
What would happen if say a big organization with exponentially more compute power than the network, ...
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Selfish mining attack: Probability of block being mined - CS251 exam question
I am currently studying for the CS251 Cryptocurrencies and Blockchain Technologies exam. In a past exam, there is this question without an answer and I would really appreciate your help so that I can ...
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What happens if a miner deliberately ignores a transaction, and "wins"?
Suppose a miner decides to solve the nonce for a particular block, where the miner deliberately excluded a particular transaction from this block. The miner "wins", i.e. they found the nonce ...
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Can an attacker flood the Bitcoin network with fake transactions?
We are in 2050. People show an ever-growing distrust in the global banking system and start transitioning to only using Bitcoin: most companies accept it as a form of payment, and people settle their ...
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Known cases of block-withholding attacks
At the moment I am doing a course about Bitcoin. The topic of the last session was the block-withholding attack and the course (being from 2014) claimed that there are no known attacks so far.
Is ...
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Forced fork of older, low difficulty blocks
Let’s assume main chain (A) height is 1000 and the difficulty adjustment is 50 blocks. At height 450, the difficulty is very small. By modifying timestamp of blocks 450-500, I mine a fork (B) such ...
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Transaction Denial of Service
If the BTC network can only only handle on average 2,759 transactions per block.
During a period where whales attempt a mass dump, could they essentially perform a DoS attack where they make a large ...
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How does the bitcoin core protect against initial DNS seed changes?
While the bitcoin network is essentially P2P, one still needs to identify an initial node to connect to. I understand that a method for such initial connections is connecting to known DNS seeds, e.g ...
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What stops an attacker from crippling the Bitcoin network?
An individual (or government) who wants to bring down the Bitcoin network could conceivably broadcast a ton of junk/illegitimate transactions to the network thereby consuming the bandwidth and ...
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Attacker Changing Address to Receive Block Reward [duplicate]
A miner creates a block B which contains address α, on which he wants to receive his rewards. An attacker changes block B, such that instead of α it defines a new address α’, which is controlled by ...
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Two threats to Bitcoin: Quantum Computing and Mining farm seizures - what new BIPs are needed before it is too late? [closed]
How resistant is bitcoin blockchain against physical attacks? Contrary to other consensus mechanisms, Bitcoin's PoW model is dependent on massive Mining Farms with tons of ASIIC hardware. These farms ...
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Which opcodes where disabled by Satoshi Nakamoto for cve 2010 5137
Lot of opcodes where disabled over the years.
But which opcodes where disabled Satoshi himself and specifically for the any one can spend any coin bug?
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Name of attack where you pay a high fee to block others
Is there a name for an attack where someone with a lot of capital makes loads of transactions with a high fee, just to prevent other transactions from taking place?
This seems like a moderately cheap ...
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Is history reversal a concern if the absence of attackers is assumed?
As described in the Bitcoin paper, the Bitcoin network may temporarily diverge, or "fork," as nodes may work on different blockchains.
The network reconverges, however, as a node will always ...
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Exchange Confirmation Requirements
What does the minimum confirmations required for a deposit mean for the security of exchanges? For example, Coinbase requires 3 confirmations for Bitcoin deposits. Suppose an adversary deposits 10 ...
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What are the potential attacks against ECDSA that would be possible if we used raw public keys as addresses?
According to this answer about why addresses are hashes rather than public keys there are potential attacks that are possible if you have the public key rather than the address, what are these attacks?...
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If I were executing a 51% attack, would I be broadcasting my state of the network to nodes?
In the scenario where an entity has control of greater than 51% of the hash power and wishes to build a longer chain where they double-spend previously confirmed transactions, do they broadcast the ...
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What is the SPV Mining Exploit?
Can anyone explain this simply? I am not finding enough explanation exactly on this type of attack. If possible, add some additional reading to your answer so that I can understand more.
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What are some potential scenarios that a state actor can harm bitcoin if they control more than 51% of the hashing power?
As reported recently, China controls more than 51% of the hashing power and just in one province in China controls 54%. Assuming China has bad intentions and forces all these mining operators to ...
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Bitcoin 51% majority miner attack - question on the role of user activated soft forks as defense tactic
If one mining entity has alone 52% hash power of the overall network, then this party can block transactions for example and try to "build" up a forked, longer chain while time passes, right?. As I ...
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Is OP_RETURN dangerous for Bitcoin?
Please explain something about OP_RETURN to me?
https://bitcointalk.org/index.php?topic=1166928.0
I saw a discussion that the contents of OP_RETURN can open the value of access to the private key. I ...
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