Questions tagged [utxo]

Unspent Transaction Outputs (UTXOs) are created by transactions and allow the owner of an associated address to spend a specific amount.

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1answer
94 views

Do you 'own' Bitcoins purchased via an exchange?

I have been told by some that bitcoin exchanges do NOT record BTC transactions by a buyer/seller on the blockchain, but rather hold them in their own name and ledger - eg, if I buy one BTC via an ...
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1answer
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Double spending UTXOs

I know that the inputs for a transaction(which is not coinbase) are UTXOs. Are UTXOs kept track of by some servers and also the owner's wallet? If there are servers which keep track of UTXOs, is it ...
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what happens to UTXOs when a transaction output script is satisfied?

As per my understanding from the book "Mastering bitcoin", a transaction output contains three things Amount - Bitcoin Value in Satoshis Locking-Script-Size - Locking-Script length in bytes, to ...
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1answer
2k views

How can you consolidate your personal UTXO set? (different wallet answers welcomed)

With network fees so low at the moment, I've seen a lot of recommendations to take the opportunity to move funds to segwit addresses and consolidate your UTXO set. During peak congestion, many smaller ...
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1answer
383 views

How can I get address wise UTXO balance for Zcash t-address

I tried to create user specific account wise zcash t-address, got the following error zcash-cli getnewaddress "testaccount" error code: -11 error message: Accounts are unsupported Is it possible to ...
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1answer
388 views

How to get unspents for inputs using bitcoinjs-lib?

I would like my simple wallet app to automatically select UTXOs for inputs. I realize that I can't accomplish this with just bitcoinjs, but is there something I can add to it to keep track of unspents?...
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1answer
71 views

What are the mechanics of verifying that an output transaction is not spent?

I am trying to understand the mechanics of how a bitcoin transaction works. When the output gets consumed by a later transaction, who and how prevents this output from being consumed a second time? Do ...
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1answer
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BTC not received after sending

I have a transaction sent from Coinbase on 12 Dec 2017. i can see it on the blockchain, fees taken but the rest is unspent. How can I force the transaction to complete. Why didn't it complete ...
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1answer
815 views

Will all UTXOs eventually be worth 1 Satoshi?

If I want to spend 0.4BTC and I only have a UTXO for 1.0BTC, I will send 0.4BTC to the seller's address and 0.6BTC to my address. The seller has one UTXO and I have the other. One UTXO has become two....
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1answer
395 views

What is the Big-O complexity to retrieve the balance for a user?

Here is the Q/A related to: How is a wallet's balance computed?. Based on this: [Q] What is the Big-O complexity to retrieve the balance for a user? Is it O(n), so basically do I have to iterate ...
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get utxo at a certain chain height

I have the reference client running with a complete transaction index. Is it possible to get all UTXO for a certain height of the chain either via bitcoin-cli or some other tool?
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2answers
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what's CCoinsViewDB::GetHeadBlocks for?

I have google a lot, there exists little information, confused with the code comments Retrieve the range of blocks that may have been only partially written. If the database is in a consistent state,...
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212 views

Why do we refer to previous transactions in each transaction?

Isn't it enough to just have the Input Address, Output Address, Amount and Signature for each transaction?
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5answers
196 views

When you receive a BitCoin what do you actually get?

Say someone sends me 0.5 of a BTC to my desktop wallet, is it a digital file or lines of code that they send me which has monetary value? I'm very confused on what you actually RECEIVE with ...
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2answers
106 views

Does using different addresses affect subsequent transaction size, given the same number of inputs?

I'm quite confused about the input count that affect the transaction size, example: x1 = my receive btc address x2 = my another receive btc address x3 = my another receive btc address Scenario A ...
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662 views

Where to find UTXO Metadata API

I'm looking for an API which lets me query for UTXOs on the base of specific meta data, e.g: When was the transaction containing the UTXO issued? From which address? etc. I have found this question: ...
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1answer
105 views

How to distribute UTXOs in hard fork while preserving privacy?

Let us say I have a UTXO set S = {U1,U2, U3 ..., Uk} on a pre-fork bitcoin blockchain. How do I spend the previous UTXO S so that the new UTXO sets on both the chains are not linkable/tracable? Are ...
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1answer
614 views

How does one reference an unspent transaction output?

In a bitcoin transaction the previous unspent transaction outputs are referenced. How are these referenced? Do outputs have unique reference or maybe as unique transaction reference X output ...
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1answer
3k views

Do all Tx's have UTXO?

I am trying to understand how UTXO works. I came up with these charts https://statoshi.info/dashboard/db/unspent-transaction-output-set I don't understand why the 1st chart (total Tx's with unspent ...
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3answers
1k views

Litecoin litecore-lib receive UTXO and current balance

I have coded NodeJS script for bitcoin for send all balance from by address to some other one. Now I want to do this for the litecoin. For bitcoin I have used bitcore-lib and bitcore-explorers libs to ...
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1answer
378 views

What is crypto-proof UTXO set?

There are many opinions about getting the actual UTXO set of blockchain. Do you think that this important database must be based on data which saved on disk and never modified after, only appended? ...
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1answer
171 views

Why does unspent address index differ between APIs?

I've been using Blocktrail's API: https://www.blocktrail.com/api/docs/lang/nodejs#data_overview to get data for the following unspent address on the testnet: 2N6qMqR9D4BTkD6fS1h6Sq3kRV2FeB1L14j. ...
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1answer
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With 100% segwit transactions, what would be the max number of transaction confirmation possible on a block?

With 100% segwit transactions, what would be the max number of transaction confirmation possible on a block? And, how many utxo can be updated by a block full of segwit transactions?
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How to get unspent bitcoins using bitcoinj

I'm trying to get unspent transaction using bitcoinj like here without using api calls. How can I do this?
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2answers
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Can there be a half segwit, half normal Bitcoin transaction?

I was wondering if it's feasible to compile a bitcoin transaction that is somewhere in between (segwit and non-segwit), maybe one of these scenarios. I'll call the non-segwit inputs, normal inputs ...
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2answers
671 views

Getting a crypto proof UTXO set

How to get a list of unspent transactions outputs (UTXO) from local files? Where is stored this data? In what files this data is fully present? I understand that this list is in "chainstate". But ...
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1answer
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How does Bitcoin protect against doublespends?

I am trying to understand the blockchain and I have read a bunch of these explanations, but they all don't address some of the questions I am still wondering about. So first I'll explain what I know, ...
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1answer
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How to create a tx that cannot be replayed?

I've got a very precise question about (self-)protection vs replay attacks in Bitcoin but to clearly explain myself, I need to explain what I did with Ethereum. When the Ethereum fork happened (ETH /...
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5answers
759 views

Why has UTXO set stopped growing since 2017-06-03?

The bitcoin UTXO set appears to have stopped growing on 2017-06-3 after 5 or more years of nearly constant increase. What are the reasons (or hypotheses) why? Charts below: 2012 to 2017-07-11 https:/...
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4answers
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Why do some transactions have more than one input?

I know a normal transaction has 1 input and 2 outputs (if there is change that is the second output). But what about this scenario? Lets say I'm withdrawing bitcoin from my gemini account and want ...
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3answers
941 views

What is the best way to download a “recent” UTXO set snapshot?

I am using bitcoinj to listen for payments. I need a way to maintain the entire UTXO set in a local database. Can bitcoinj be used to download every block (I think it downloads only recent blocks ...
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878 views

How to directly query leveldb database to get get a record by transaction hash or by sender's address?

I learned that the blocks and transactions are stored locally in .bitcoin/blocks/index and .bitcoin/chainstate databases, respectively. I want to make a direct query to those databases to measure the ...
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1answer
811 views

Parse UTXO of a transaction from chainstate

I'm doing some analysis on the UTXO set by reading from the chainstate database. I was following the documents given by https://github.com/bitcoin/bitcoin/blob/...
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1answer
2k views

How is the UTXO database initialized?

The IDs of the unspent transactions are stored in the UTXO database. I assume that it's generated like this by the client: for block in blocks: for transaction in block: utxo.remove(...
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Create an issuance and a send within the same block (XCP)

Using counterparty api I am issuing an asset, signing the raw transaction and sending raw transaction. Api I used is http://counterparty.io/docs/api/#create_issuance As it takes 10 or more minutes to ...
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2answers
3k views

How to Get UTXO using bitcore-lib?

I am using this library to make a wallet service that runs on a web browser. I use the library and browserify it so its compatible with the rest of my jquery. Now this tells me how to make and sign a ...
2
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1answer
616 views

How to work out the balance for an HD Wallet extended private key?

I am working in C# with NBitcoin. I have created an extended master private key, and I can create the hierarchy of derived keys. In TestNet, I have requested some coin from a faucet, and the ...
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2answers
1k views

How can a miner verify that a UTXOs is not spent elsewhere?

How does a miner verify that a UTXO is not spent somewhere else, wouldn't he have to search the entire blockchain from that UTXO and onwards to see if this was the case? Assuming any real scale this ...
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2answers
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Are the outputs of an unconfirmed transaction part of the global UTXO pool?

Well basically that. If a transaction is in the memory pool, that is, it is not yet in a block but nodes and miners know about it and validated it, Can I send another transaction that double-spends ...
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1answer
343 views

How many UTXOs have a marginal fee cost that's higher than its worth?

I define marginal fee cost as the number of bytes required to add that UTXO as an input to a TX multiplied by the satoshi/byte rate of the blocks being found. So for a normal p2pkh UTXO, this would ...
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2answers
456 views

How does a miner know if a transaction has already been included in the block chain? Does he traverse through the complete chain to conclude this?

I am confused on what incentive a miner has on including a transaction apart from the transaction fee. So, if adding a transaction wastes any time, any miner should ideally not add transactions that ...
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2answers
556 views

CVarint serialization format

Recently I started analyzing the UTXO set data that every full node stores in chainstate folder (a LevelDB database). By looking into the code you can learn more or less how the data entries are ...
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1answer
149 views

How can a Bitcoin transaction be used multiple times (If it is so)?

My understanding is that a transaction is a transfer of value between Bitcoin wallets that gets later included in the block chain. So a Bitcoin transaction is used only once in my understanding.
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1answer
385 views

How to get asm and hex from vout

I've got this weird string for a utx message (not my code) CTransaction(nVersion=1 vin=[CTxIn(prevout=COutPoint(hash=41caa5bf2b814135257b26e44b111f55c067f783e3cdf9bdf914e1ef7e403d05 n=0) scriptSig=...
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0answers
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get utx scriptPubKey to become an object

I'm using this python script https://github.com/sebicas/bitcoin-sniffer When I see a utx I look at each output and find the scriptPubKey I expected to see something like "scriptPubKey": { "asm": ...
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1answer
580 views

Why do transactions send coins to the same address as they spent it from?

I often notice transactions such as: 364efe5a906de5971e242f9711008e58a5ab79f136a8044b66615e8662d35f09 Where funds from the address 3PU with 1.38 BTC are split to itself (1.35 BTC) and 37Ek (0....
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1answer
119 views

Do transactions with old UTXOs take longer to confirm?

Suppose I do a transaction with an UXTO created years ago. Would that take longer to confirm because miners would have to look further back in the transaction chain to verify it?
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2answers
4k views

UTXO model vs. account/balance model

I understand that Bitcoin uses unspent tx output and Ethereum account balance based. However, recently there are lots of discussions on that Bitcoin's UTXO database has become too big. Does this mean ...
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1answer
320 views

UTXO all sent to change address?

I have read this question that asks if all UTXOs in an address are sent to a change address or only the UTXO involved in the transaction. As part of a spending transaction, the public address is ...
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2answers
457 views

Is the UTXO set computed from scratch by new full nodes?

When a new full node joins the network, does he, by default, compute the UTXO set from scratch from the blockchain so far; or does he simply trust the UTXO set he received is valid?