Questions tagged [security]
This tag should be used for questions regarding security issues with the design or implementation of Bitcoin and related cryptocurrencies.
904
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Is the 'real barrier' to attack bitcoin's consensus 33.34%, rather than 51%?
Saw a random tweet thread that claimed that the "51" in "51% attack" was misinformation, and that in reality only 33.34% of hash power would be needed for a bad actor to attack the ...
- 195
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1
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64
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12 or 24 words for menomonic?
I do not have reference, but I have heard that there is no use in using more than 12 word for mnemonic, because ECDSA secp256k1 only have 128 bit strength.
Is this correct ?
If it is, does then ...
- 111
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First Question from New User to Bitcoin [duplicate]
What is Bitcoin?
I received a "congratulations" message from George Green saying I have a new Bitcoin transaction and to click a link to "get it."
Payout is: $29,970.07 and ...
0
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1
answer
43
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Does key derivation make (or help to make) Bitcoin "quantum safe"?
We have these two other questions that touch on the same subject of how safe is Bitcoin from quantum computing attacks, but I believe mine is specific enough to be a separate question:
What effects ...
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74
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What are the risks of OP_VAULT?
In the past it has been argued that some covenant schemes could be risky. However AFAIK OP_VAULT is a very specific and limited construction.
What are the risks associated with it, if any?
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1
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82
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Is spitting a BIP39 seed phrase in half meaningly less secure than splitting the entropy in half?
One way to create a distribution, 2-of-3 backup of your seed phrase ABC is to store the following in three separate places:
AB
BC
CA
Any two of these lists is sufficient to reconstructed the entire ...
- 21
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45
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Are bitcoins with more confirmations more valuable?
Are bitcoins with more confirmations more valuable, or does the number of confirmations not add a sort of "time value of money (TVM)"?
- 4,449
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52
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If Multisig Xpub is compromised, but not the seeds or wallets
I have a multisig set up.
My seeds and hardware wallets are secure.
However, what would happen if someone got a hold of my Xpub file only?
Am I correct they could view my holdings and transactions, ...
- 21
1
vote
1
answer
65
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does connecting to full node via rpc over the public internet reveal your credentials?
While trying to connect to my full node, I accidentally entered my public ip address in the rpcconnect field of bitcoin.conf. Should I be worried that my password is now out there and anyone can ...
- 13
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1
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71
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What were any supply chain attacks against Bitcoin, if any?
Was there ever a case were Bitcoin or Bitcoin-Core itself was compromised? For example, did it ever happen that a malware hacker could insert code that compromised Bitcoin at the protocol level? For ...
0
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2
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59
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What is the correct way to make crypto payments except the escrow intermediate?
For small payments, bitcoin does not require any way to guarantee the exchange of coins for goods. But how do you make a big purchase (such as houses), especially when buyer and seller do not meet in ...
- 103
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48
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Security issues and theft of money from the wallet
A transaction was sent from my node night
CTransaction(hash=27aac94405, ver=2, vin.size=7, vout.size=1, nLockTime=762357)
CTxIn(COutPoint(85d4e6a81c, 0), scriptSig=, nSequence=4294967294)
...
2
votes
2
answers
51
views
What is the difference between a push-based transaction model and a pull-based transaction model?
What is a pull-based transaction model? What is a push-based transaction model?
I've heard people describe bitcoin as a push-based transaction model.
I've heard people describe traditional financial ...
- 152
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1
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66
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Has money ever been stolen in bitcoin due to a design flaw in the protocol?
Is there an example of a single historical case of theft of bitcoin due to a flaw in the design of the bitcoin protocol?
When googling "is bitcoin secure?" it's easy to get confused because ...
- 152
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1
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135
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What is the November 2022 bug in LND, what caused it and what would prevent a similar bug in future?
LND users are being asked as of November 2022 (as they were in October 2022) to urgently update their Lightning node software due to a bug in LND/btcd (alternative Bitcoin implementation in Go). What ...
- 12.7k
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Block Transaction if it is over a certain amount
Is there a way to block a transaction if the transaction exceeds a certain amount of BTC. I am running bitcoind.
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62
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Is it possible to sign a transaction programmatically via a connected cold storage wallet?
Lets say I want to generate my own transactions and sign them myself via my computer. Signing them in the computer would require me to input my private key, which would compromise the key. Is it ...
- 181
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97
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Security of Vanity Addresses
I found a vanity address with this verified tool: https://github.com/JeanLucPons/VanitySearch
And now I hold my private key, with BTC I am used to only the recovery seed and I don't know what position ...
- 1
2
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1
answer
198
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What is the current status of watchtower implementations in October 2022? Are they mature, widely in use?
One way of protecting yourself against losing money as a result of bugs and crashes in your Lightning node implementation software (e.g. the recent LND bug) is to run a watchtower yourself or employ ...
- 12.7k
2
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1
answer
330
views
What is the October 2022 bug in LND, what caused it and what would prevent a similar bug in future?
LND users are being asked as of October 2022 to urgently update their Lightning node software due to a bug in LND/btcd (alternative Bitcoin implementation in Go). What is the bug and what caused it? ...
- 12.7k
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0
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246
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How to recover from forgotten password for Bitcoin Wallet for Android backup?
Back in 2016, I had a Bitcoin wallet with a couple of euros worth of Bitcoin. I used the Android app "bitcoin wallet" to backup my wallet but I had to use a password.
This week, I found the ...
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1
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45
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Exploiting the use of signature?
I've just learned signatures and why they're used in blockchain.
As I understand there is a key pair that consist of one public key and one private key:
Private keys are used to sign a message(...
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47
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What prevent users from cheating in an HTLC contract
I was reading about HTLC and how Charlie have to create a random number and generates its SHA256 hash that is supposed to be used by Bob in the end to finalize the payment he has received from Alice.
...
- 2,550
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Application security of Bitcoin Core
Is there any information about how Bitcoin Core has applied secure development or application security in the past and currently? For example, the inclusion of third-party dependencies must be checked ...
0
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1
answer
121
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What's the difference between the anti klepto protocol and anti exfil?
What is the difference between the anti-klepto protocol (also here) and Anti-Exfil? Is it the same thing just with different names or are there differences? It seems they are both addressing the nonce ...
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2
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832
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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 ...
- 333
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2
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83
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can MITM read my metamask seed phrase when I click "Reveal Secret Recovery Phrase" in the wallet? [closed]
I worry someone is leaching my WiFi and potentially trying to do a MITM attack. If I click "Reveal Secret Recovery Phrase" in my metamask wallet extension, will they be able to read it via ...
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1
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83
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The true reason bitcoin needs merkle proof for SPV wallet?
I know exactly what merkle tree is, and I know it is used to verify a transaction is in a block with just a hundred of bytes flowing through my network cable (btw do I really lack that megabytes ...
- 151
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40
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Is there any privacy issue in doing this hard-to-summarize thing with Bitcoin Core?
I have a "hot" wallet.dat with no password, with a small amount of satoshis.
Recently, I transferred them all over to my Bisq wallet temporarily to make trades. So the hot wallet.dat has 0 ...
- 13
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1
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101
views
Shasum output of signature keys not matching
My shasum output does not match ANY keys listed on https://github.com/bitcoin/bitcoin/blob/master/contrib/builder-keys/keys.txt ?
shasum -a 256 bitcoin-22.0-osx-signed.dmg
...
- 11
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1
answer
171
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Why is the Generator Point G for secp256k1 curve typically indicated in (y,-x) quadrant?
Generator Point G for the secp256k1 curve is typically indicated below where the curve intersects the y-axis. At x=0, y=sqrt(7) and -sqrt(7), which are both small numbers less than 3, but G is an ...
- 33
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167
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Which offers more privacy, coinjoin-whirlpool or non-KYC online exchanges?
After buying crypto with fiat on a KYC exchange, instead of just moving the crypto to a wallet, I understand that I should get more anonymity from tracking by putting the coin through coinjoin or ...
1
vote
1
answer
124
views
Is it feasible to calculate EC private key k from public key K for very low values of k?
If an EC private key k is very small, say "1", is it feasible to calculate the private key k from its public key K, since there would only be one step back to generator point G and therefore ...
- 33
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2
answers
792
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How much entropy is lost alphabetising your mnemonics?
Yes I know this is a horrible idea and not BIP39 compliant, but please help satisfy my curiosity with this "thought experiment" and applied maths exercise.
Two questions, one for 12 words, ...
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1
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45
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Hello, I'm not new to crypto, but I am quite new to Mining, can someone give me some tips on the best BTC miner as of today?
I am quite afraid of all the things I read on the internet, in seems that there are quite a bit of scams going on and the whole space, specifically crypto mining is quite uncertain.
Anyway, I was ...
2
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1
answer
68
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Can hot wallets be secure?
Hot wallets are generally considered the least secure because their online nature creates an opportunity for hackers to crack them. but is there a way to cryptographically secure the seed generation ...
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1
answer
80
views
Is it safer to send bitcoin to multiple addresses when moving to another wallet?
If I decide to move all of my bitcoins from one wallet to another, are there any theoretical benefits to generate multiple addresses in a new wallet and split the bitcoins between them?
It will still ...
- 23
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0
answers
190
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In what ways does BGP hijacking affect Bitcoin?
Based on this answer from 2014, bitcoin nodes are vulnerable to BGP hijacking although I am looking for more details about how BGP hijacking attack could affect Bitcoin p2p network.
What could be ...
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1
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77
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Is bitcoin core secure?
Amir Taaki says Bitcoin Core is not secure because of undefined behaviour in this video https://youtu.be/EPpDpULPhHc after 30:00
Is this true and how can we fix this? What are the risks of using ...
- 11
1
vote
1
answer
625
views
Bitcoin private key, key range calculation?
I saw a Bitcoin puzzle on https://privatekeys.pw, on which there are different private key spaces with addresses and then you need to somehow find out the right private key?
Is there a way to ...
- 45
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0
answers
48
views
How secure are the decentralized nodes?
I colloquially understand the inherent security provided by the decentralized distribution of the nodes that host the bitcoin network. However, is the distribution of the devices which run the nodes ...
- 195
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1
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174
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Bitcoin.org gpg keys expired?
I was trying to add the keys to a keyring to verify the bitcoin core download, but it looks like the gpg keys are all expired.
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1
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75
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Exploit vulnerable projects using RBF policy
If a project is vulnerable to some type of RBF policies, how could an attacker exploit this project?
user103136
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1
answer
146
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What is a security model, security assumption, and security guarantee?
I often hear bitcoiners talk about
security models
security assumptions
security guarantees
but I can't find definitions of these terms.
What do these terms mean and how do they relate to each other?...
- 350
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1
answer
39
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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, ...
0
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1
answer
45
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Methods to find BTC addresses collisions with less complexity approaches/attemps
I have one question. I'm trying to lower complexity when breaking private keys for BTC.
If we have that an address is a hash160 from priv key, then we can assume that we have 2^96 per each address.
If ...
- 101
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1
answer
78
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How does PoW ensure that all the transactions are recorded and that all the transactions are valid?
I just started to study blockchain and bitcoin yesterday and came up with some questions.
If miners can select transactions when creating a block, how is it ensured that all the transactions over ...
- 111
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2
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544
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Does a 12 word recovery phrase offer the same security as 24 words?
Watching this Q&A with andreas he states that a 12 word recovery phrase offers the same amount of security as a 24 word seed phrase as the output is 128 bits either way.
If this is the case, why ...
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65
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If someone cuts a standard Bitcoin private key into two (or more) equal parts, would another person be able to spend the coins after finding one part?
Someone has a standard (non-compressed) bitcoin private key (256 bits) and wishes to store it on paper. Being paranoid about someone finding the sheet of paper, he/she cuts the private key up and ...
- 152
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0
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227
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How many words are enough to confirm user backed up all words for seed phrase?
If there are 12 words in the seed phrase, is confirming random 3 words enough to ensure user has backed up all words?
Or is it necessary to confirm all words and in the correct order?
If I create a ...
user103136