Questions tagged [transaction-verification]
Refers to the process of checking the validity of transactions.
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questions
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How to verify if a transaction is signed correctly?
Given an arbitrary signed raw transaction, how can we easily verify if all inputs are correctly signed (assuming all inputs are existent/unspent and the fee is higher than zero)? Bitcoin core's RPC ...
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3answers
67 views
Basic question about transaction verification
I am fairly new to crypto and had some questions about how transactions are verified by the nodes
Would it be correct to say that the full nodes check to see if the sender(Alice’s) signature is valid. ...
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1answer
42 views
What can I do with “unspent” transactions? Can I transmit them to a chain?
I withdrew some bitcoin from a service's account I maintain. The transaction shows up in my wallet, but it has been marked as "unspent" ever since. What does this mean?
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38 views
Why is 'script' used in a transaction instead of the output address?
I see transactions contain script for each output, but this "script" seems to be deterministically derived from the address associated with the output.
Why does the bitcoin protocol opt for the use ...
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0answers
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Unspent bitcoin transaction
So about two weeks ago i sent bitcoin to a friend, and it was confirmed but in the summary it was listed unspent, he claimed not to have received. I was really confused since then, now this morning i ...
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1answer
433 views
Why is there no such thing as a redirected, forged, or fake transaction?
In the past, we had numerous questions about "fake" or "forged" transactions. Such transactions could supposedly be created even without holding any bitcoins, yet would end up in the mempool or even ...
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4answers
157 views
If two parties submit a conflicting transaction between each other, how does the network decide which one is correct?
Let's say parties A and B both submit a transaction to the blockchain with a different version of what happened. Party A submits a transaction saying Party B gave him 3 BTC and Party B submits a ...
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0answers
63 views
How many bitcoin transactions can be verified per second on commodity hardware in 2020?
I am trying to figure out how many Bitcoin transactions could be verified per second.
Am I correct that signature verification is more expansive than computing Merkletrees and hashes and constitutes ...
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1answer
29 views
Is there any open source tool to verify segwit transaction without publishing it?
I have created below transaction:
...
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1answer
31 views
Given a Bitcoin transaction as JSON data, how can I determine the number of confirmations?
According to blockchain.info, 4,198 confirmations have been received on the following Bitcoin transaction at the time of this writing. Give then following Bitcoin transaction as JSON (ref: transaction ...
0
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1answer
47 views
Is it possible to skip verification of blockchain data when using bitcoin core?
Because I need bitcoin core client only for JSON-RPC requests. Will I need pruned initialization or normal initialization of bitcoin core client for successfully running such requests? (I guess client ...
0
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1answer
27 views
How do people using thin clients know the correct merkle path of transactions they've sent without knowing the full block?
User A send a transaction to user B. Those transactions are bundled together into a merkle tree. User A and B can both use the transaction plus the merkle root, plus the merkle path to prove the ...
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0answers
49 views
Transaction validation cost
what relation is between transaction size or a number of input and validation cost? for example, It's o(n) or o(n^2)?
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131 views
Bitcoins stuck in memory pool [duplicate]
I sent my 0.1 bitcoin on the 8th of January from an offline wallet (Bitcoin Core), to an online wallet. Still haven't got the btc in my new wallet. The status on the offline wallet says: "unconfirmed, ...
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2answers
56 views
How do nodes validate that a UTXO in a new transaction is unspent?
Does it check every block in between where the UTXO first appeared and the current time to make sure it didn't get spent then? Or is there some other caching or other method to make the check faster?
0
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1answer
47 views
How can a reciever verify that transaction data was not altered by 3rd party?
My scenario:
My web server:
- Generates private and public, and a wallet address from the public key for a user website account
- Server can not connect to the outside (Can not connect to the Bitcoin ...
4
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1answer
48 views
At what block height may locktimed transactions get included?
Transactions with outputs whose sequence is smaller than UINT_MAX are interpreted as locked until the timestamp or block height specified in nLockTime is reached.
Specifically regarding the block ...
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3answers
188 views
Get transaction data from full node
Background Information
I am building an application that requires the ability to query any bitcoin full node (from a python script using raw tcp sockets) in order to read the OP_Return value listed ...
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1answer
48 views
Can attackers change transactions during a 51% attack?
If in a 51% attack transactions can be reversed, isn't it possible that the chain with more hash rate also changes transactions (for example if x sent 5 btc to y, they would change it to x sent 500 ...
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1answer
45 views
How to verify locking and unlocking scripts?
I've selected an arbitrary transaction id and retrieved its associated transaction details using the blockcypher explorer as follows:
from blockcypher import get_transaction_details
...
0
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2answers
125 views
Verify Bitcoin Transaction
Following the great post [Redeeming a raw transaction step by step example required, I came up with code below but the verification failed.
// pubkeyBytes, len: 65
// ...
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2answers
62 views
Sent BTC from Coinbase, blockchain explorer says Confirmed. Is recipient lying or could something else be the issue?
Sent BTC (approx $500) from Coinbase, Blockchain explorer says Confirmed. Is recipient lying they have not received or could something else be the issue such as his wallet?
Recipient says it could be ...
0
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1answer
38 views
What stopping miner from altering value in transaction to increase transaction fee?
I'm learning bitcoin through this book "Mastering Bitcoin, 2nd Edition by Andreas M. Antonopoulos". I'm at Chapter 6 "Transactions".
Here is my doubt:
Example there is node A, received transaction ...
0
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1answer
70 views
Not able to Spend 2-2 MultiSig UTXO
I created 2-2 Multisig Account 2NECouPA4UVNMzX1K7kekc4W3VudDhMdFkM from msrFNhKwLu9GrT3hFoizz21xEwJ61xMsym and n1NPFEJHBA8j63B5dgJ3aQcufA8VmrN27U, I tried spending UTXO from this account but got an ...
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1answer
75 views
How to tell if a transaction is valid?
So I have been reading up on bitcoin and blockchain for awhile now, but I have yet to fully understand it. I understand that bitcoin leverage on DLT, which uses cryptography to verify transaction. ...
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1answer
106 views
Clarification on the script P2SH, how is executed to Bitcoin core?
This question is a continuation of the my post yesterday.
Today I have a question on P2SH execution so, an example of the script should be this
OP_0 <A Signature> <B Signature> OP_2 <...
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1answer
105 views
Bitcoin check if the transaction is valid
When a node receives a new transaction, that node will check if the one broadcasting the transaction has enough coins to initiate it. Bitcoin follows a UTXO model, therefore the node has to check in ...
0
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1answer
95 views
How does this simple script use the OP_CHECKSIG opcode?
I have this Script P2PKH
<A Signature> <A Public Key>
OP_DUP OP_HASH160 <A Public Key Hash> OP_EQUALVERIFY OP_CHECKSIG
The bitcoin.org documentation say this
The entire ...
0
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1answer
82 views
Bitcoin Signature Verification
I am trying to implement the OP_CHECKSIG opcode of Bitcoin and verify whether a signature is valid or not. I have the signature that I recieve from the transaction data and the public key(the hex ...
2
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1answer
222 views
Verifying a bitcoin Signature and what is the transaction data that is signed?
Given a bitcoin transaction where it is able to redeem it's UTXO's, how can I verify in Java if the signature is actually a valid signature or not. I was trying to use the Bouncy Castle library where ...
2
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1answer
352 views
How does OP_CHECKSIG work
Hi I am learning bitcoin and learning how scripting works and how to use P2PKH. I was wondering how does OP_CHECKSIG work. I want to understand what is the data that the private key signs to create ...
2
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1answer
58 views
How to prevent double spending Bitcoins?
If I create a transaction, my node will check my UTXO's and if i have enough BTC to do this transaction it will be mined.
So let's say I want to spend 12 BTC to Anna.
The System will check if i ...
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3answers
203 views
What happens to transactions included in extinct or invalid blocks?
I have read that a block contains several transactions.
An attacker can forge fake a block.
The blockchain is safe because the system will choose and keep the longest chain.
So the fake block will ...
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2answers
405 views
Is verification of a blockchain computationally cheaper than recreating it?
One of the advantages of cryptocurrencies like Bitcoin that is often repeated is how hard it should be to manipulate past transactions. The reason that is often stated is that you would have to re-...
0
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1answer
44 views
How exactly do transactions work?
When I search for transaction in bitcoin I am able to find explanations which tell me that there are e.g. two persons A and B and A wants to tranfer a number of bitcoin to B. Imagine A wants to pay 2 ...
2
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1answer
33 views
What does “Green address verification” mean in the context of transaction validation?
I am only new to Bitcoin and I would like to know what a "Green address verification" is. I have an Electrum wallet ver 3.3.6 and I think the term is being used in the context of faster transactions ...
0
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2answers
65 views
Bitcoin transactions validation process
I have a general understanding of building blocks. But am hoping someone can fill in the details/gaps. Also, can you correct if something is not right? Thanks.
Scenario:
Bitcoin transactions are ...
0
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1answer
38 views
How can I calculate/estimate how quickly a machine can verify transactions on the blockchain?
If I have some machine with particular specs in mind (processor/memory/bandwidth), how can I estimate how quickly that node can download and verify transactions? In a quick search I wasn't able to ...
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1answer
55 views
Can anyone initiate a Blockchain transaction into the mining pool?
Let's say user A has public key P and corresponding private key P'. Can someone else initiate a transaction for public key P with some wrong private key, let's say P''? Once this goes to the memory ...
4
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1answer
532 views
If I set assumevalid=0 after syncing the blockchain will Bitcoin Core go back and validate historical blocks?
I originally synced my node using the Bitcoin Core default assumevalid value. If I set -assumevalid=0 in bitcoin.conf and restart my node, will my node go back and validate historical blocks?
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1answer
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Following SegWit implementation, is BIP-146 signalling and implementation still on the docket?
Is BIP 146, which defines using the low S value, still on the docket to be signalled and implemented given that SegWit fixed the txid malleability issue by moving the witness outside the transaction? ...
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1answer
104 views
Besides transaction validation, are there any other uses of the Script language in Bitcoin
Script's stack operations are used to validate signatures and scripts of transaction inputs and outputs. Is Script also used to validate block, network, or any other data?
Seem like there are a lot ...
0
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2answers
109 views
Checking if a receiver has enough coins
How do miners verify the blockchain transaction history to check if the sender has enough money if the address can be changed at any time?
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1answer
51 views
How miner makes sure that a transaction he picked up from mempool is actually valid? [duplicate]
I have read and searched enough about the roles and responsibilities of miners here;
For example:
Does the miner first validate transaction before doing POW or he does not validate at all ?
Does a ...
1
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1answer
113 views
Why are only specific transaction types accepted into the mempool?
In the Bitcoin Mainnet, only specific transaction types are accepted:
Bitcoin uses a scripting language to specify (and satisfy) the encumbrances, thereby allowing a whole host of transaction types....
2
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1answer
187 views
Where is sum(vin) > sum(vout) check in Bitcoin Core?
I'm searching the function that validates a transaction according to Protocol rules - "tx" messages especially step 14 sum(vin) > sum(vout).
I found this interesting function CheckTransaction(...
0
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1answer
80 views
Are transactions with the same ScriptSig a security problem?
For instance while looking at the transaction stack of my address, tracing it to exchanges I use, I came across this:
https://www.blockchain.com/btc/tx/...
0
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1answer
423 views
Indexing of transactions in the blockchain
Say we have transaction T(1) from many years ago, at block height 125001; then a new transaction T(2), consuming all the outputs from T(1), comes up around block height 568720 (that's Today). There's ...
0
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2answers
61 views
Bitcoin checks and balances
When a new block is created, does each block need to be validated?
How does it differ from validating transactions?
Why miners would waste time validating transactions and blocks when they could ...
0
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1answer
141 views
How to generate the digest from a raw bitcoin transaction for verifying signature of specific input?
I'm writing a stand alone process that needs to verify that a known UTXO is part of a new transaction with a valid signature.
Inputs [ UTXO, raw transaction, input_number ]
How do to I verify the ...
