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Questions tagged [transactions]

This tag should be used for questions related to transactions. Transactions are signed messages regarding the transfer or generation of bitcoins. They are broadcast throughout the Bitcoin network and, if accepted, integrated in the blockchain.

129
votes
10answers
293k views

Why is my transaction not getting confirmed and what can I do about it?

I sent a transaction without (or with an exceptionally small) transaction fee using extremely small or unconfirmed inputs while the stars were not standing right. For whatever reason, I have been ...
72
votes
6answers
18k views

How can I accept bitcoins on my website?

I have an online store and would like to begin accepting bitcoins. How can I go about doing this?
66
votes
3answers
23k views

How to redeem a basic Tx?

Given a raw, standard Tx (wiki): 01000000 01 26c07ece0bce7cda0ccd14d99e205f118cde27e83dd75da7b141fe487b5528fb 00000000 8b ...
61
votes
9answers
25k views

How anonymous are Bitcoin transactions?

I read some sources that say Bitcoin transactions are anonymous, some that say they are semi-anonymous, and some that say they are not anonymous at all. In what ways are the transactions anonymous ...
51
votes
6answers
52k views

What is the Merkle root?

The Bitcoin wiki Vocabulary article explains why the Merkle root exists: Every transaction has a hash associated with it. In a block, all of the transaction hashes in the block are themselves ...
48
votes
2answers
36k views

What are bitcoin “confirmations”?

When I receive bitcoins I see a certain number of "confirmations" in the client. What do these mean? Why do most sites make me wait for 6 "confirmations" before a purchase will go through?
47
votes
7answers
10k views

Is there any way to track an individual bitcoin (or satoshi)?

For example, if I wanted to "collect" important bitcoins is there any way to track a coin rather than a series of transactions? If I wanted one of the bitcoins from the infamous "Bitcoin pizza" ...
47
votes
3answers
8k views

How does change work in a bitcoin transaction?

It seems that when you send a bitcoin transaction, all the coins in the sending address are spent in that transaction, divided into the amount that you intended to send, and "change", which goes back ...
47
votes
5answers
15k views

What is relation between scriptSig and scriptPubKey?

Scenario: A is sending 1 BTC to B. scriptSig appears in the Input Script. scriptSig = <sig> <pubKey> Here, public key is the Public Key of the sender, A. (this is the public key ...
44
votes
2answers
21k views

Explanation of what an OP_RETURN transaction looks like

How is OP_RETURN used and why was it introduced in the first place?
44
votes
5answers
25k views

What is meant by Bitcoin dust?

I've seen the term "dust" used to describe small transactions that might be considered as spam by the Bitcoin network. Is there is a generally accepted definition of this term?
43
votes
5answers
8k views

How is Bitcoin supposed to serve as currency when it is all but impossible to spend at the moment (12/2017)? [closed]

It seems Bitcoin is not standing up to the test of use as currency (that is to say heavy use). I tried to pay someone 0.009BTC (about $150) for some goods which I need in a fairly timely manner. As if ...
42
votes
3answers
11k views

Why does Bitcoin send the “change” to a different address?

For example I have an address (A) with 20 BTC and send 9 BTC to address (B). Bitcoin will create a "change" portion of the transaction where the remaining 11 BTC goes to address (C). Why not send ...
42
votes
4answers
35k views

What are multi-signature transactions?

What are multi-signature transactions, and why might they be used? Also see: How does one make multisignature transactions with the bitcoin client? How can I create a multi signature 2-of-3 ...
40
votes
4answers
41k views

How do I see the IP address of a bitcoin transaction?

How do I see the IP address that someone used to send or receive bitcoins with? Is it stored in the blockchain?
39
votes
2answers
5k views

What is the coin selection algorithm?

When creating a transaction in the standard client, what is the algorithm used to determine which unspent outputs will be used as inputs? Has this changed since the first version? What different ...
39
votes
2answers
32k views

Do unconfirmed transactions expire?

Do they just sit there unconfirmed (e.g. when you be evil and don't pay a tx fee) forever? Or do they get deleted after a few days?
39
votes
1answer
10k views

How are transaction hashes calculated?

I'm trying to calculate the hash of transactions in bitcoin blocks, but I'm not getting the right answers. For example, the genesis block has a single transaction. Here's how I'm attempting to ...
38
votes
7answers
23k views

What happens if I mistype the address when making a payment?

I sent bitcoins to an address, but I think I made a typo when I copied it. Where did these bitcoins go. Can I get them back?
37
votes
5answers
2k views

How do I accept bitcoin payments at a real world store?

From what I understand, there are some requirements for using bitcoins at a physical store: Both the store owner and the client must have Internet access The client must have a cellphone or a laptop ...
35
votes
9answers
19k views

How is it possible to launder bitcoins?

Some services, such as bitcoinlaundry.com, claim that they can launder your bitcoins. Since all bitcoin transactions are publicly logged, how is this done? Wouldn't it be possible to trace back the ...
34
votes
3answers
28k views

Who gets Bitcoin transaction fees?

Whenever I send bitcoins from one wallet or one exchange to the next there is always a fee. This makes sense with the exchange sites, they are just collecting the fee so they can make a living. What ...
31
votes
2answers
12k views

What is a Finney attack?

What is a Finney attack? Extra points for explaining its purpose, the prerequisites for it to be possible, how the attack can be performed and the origin of the name "Finney attack".
29
votes
2answers
7k views

What is TxIn's sequence?

I'm currently trying to generate the genesis block with my code and I've stumbled upon the TxIn sequence field that is not explained in the Protocol Specification wiki page, nor does it seem to appear ...
28
votes
5answers
9k views

In getrawtransaction, what is the vout integer in the vin list?

I'm working on trawling the bitcoin transactions coming in via getrawtransaction. I haven't been able to find the neccessary documentation to describe the vout integer in the vin array: {"txid"=>"...
28
votes
2answers
20k views

Why are there two transaction outputs when sending to one address?

I did a small transaction some days ago: https://www.blockchain.com/btc/tx/4c07a07dfd9d5b79d168ec6835df876c64e82350a8f9211bf586d858a5aeb9ba Some info: 1JFWE8THcAQQRYx99c43DXSGyoPL9Zs62D is my ...
28
votes
5answers
4k views

Has there ever been a successful double spend attack on the Bitcoin network? If not, is it really necessary to wait for confirmations?

There is a lot of concern about waiting for confirmations to avoid a double spend attack, but has there ever actually been a double spend attack? It seems to be that there are two types of double ...
28
votes
3answers
46k views

What's the minimum transaction with bitcoin?

What's the minimum transaction with bitcoin - local wallet to local wallet. Can I send for example $20 in bitcoins to another person?
28
votes
5answers
2k views

What would happen if a portion of the Bitcoin network was separated from the rest of the network?

Yesterday I asked a question over at SuperUser, so that I could have my facts straight before asking this question. The scenario sets the basis for this question. Regarding bitcoin, what would ...
28
votes
2answers
6k views

Is there some way to merge two wallets or to import/export addresses?

I've got one wallet.dat from my laptop and another on my desktop, each containing various (different) receiving addresses that I use pretty often. I'd like to merge them into a single wallet.dat so I ...
26
votes
2answers
7k views

How many Bitcoin addresses are/have been carrying a balance?

Bitcoin addresses can be generated at will, and the theoretical limit to their number is high. Addresses are constantly being generated to receive funds or balance transactions, but they are also ...
25
votes
2answers
3k views

In order to reduce fees, can I 'consolidate' my wallet by sending the entire balance to a new address in the same wallet?

My balance is currently made up of lots of small amounts I know I'm not going to be using my bitcoin wallet for a while, so I don't care if the consolidation transaction is slow. Would creating this ...
25
votes
3answers
17k views

Is it possible to send bitcoins without paying a fee?

I am using the 0.4.0 release. Is it possible to send bitcoins without paying a fee? Who gets the fee ? Is it only miners discovering new blocks?
25
votes
4answers
7k views

how to monitor +20,000 addresses for new received transactions?

I have around 20000 generated addresses which I want to monitor for new transactions. More addresses should probably come. Customers should use every address only once but I would like to monitor ...
24
votes
2answers
4k views

Useful alternative Bitcoin transaction scripts

The Bitcoin wiki describes a transaction's script as something that describes "how the next person wanting to spend the Bitcoins being transferred can gain access to them". The script for "a typical ...
24
votes
3answers
35k views

What is a double spend?

What is a double spend? As someone who uses Bitcoin, what do I need to know about how the Bitcoin system prevents double spends? Are there still circumstances where they can occur?
23
votes
8answers
2k views

Can I send bitcoins with my mobile phone?

Is it possible to send and receive bitcoins with a mobile phone? If so, are there bitcoin clients for Android or iOS?
23
votes
1answer
4k views

What is Transaction Malleability?

The Bitcoin exchange MtGox has stated in this press release that "transaction malleability" caused them to stop sending bitcoins. A recent question asked if it really is an issue. But what is ...
22
votes
7answers
10k views

Why does my wallet need to download the whole transaction history?

I started a wallet, and it is downloading and synchronizing lots of transactions. This takes time and network bandwidth. Why is this necessary? Is this some form of accountability? With Paypal, ...
22
votes
3answers
2k views

What happens when someone sends bitcoin to my wallet?

I didn't get it. Should my wallet be online? What if it becomes corrupted before I make a backup? Can I use my backup wallet that was backed up few days ago?
22
votes
2answers
5k views

What are the pros and cons of Ripple's consensus as compared with Bitcoin's proof-of-work?

One of the major differences between Bitcoin and Ripple is how they process transactions. I can think of three ways in which Ripple's "consensus" scheme is superior to Bitcoin's proof-of-work: Less ...
22
votes
2answers
2k views

What percentage of Bitcoin transactions never complete?

Occasionally transactions will be broadcast to the network that will show in a 0/unconfirmed status in the Bitcoin client. It is also the case that from time to time for various reasons those ...
21
votes
2answers
14k views

Redeeming a raw transaction step by step example required

I am looking, specifically, for a step by step example transaction of sending Bitcoin which uses an actual transaction (How To Redeem A Basic Txn, from a few years back, does a great job of outlining ...
21
votes
2answers
11k views

How to sign a transaction using only an offline computer?

I think it is possible to generate keys on an offline computer and sign. To create a transaction I need to input transactions detail, and somehow I have to transfer signed transaction from offline ...
21
votes
1answer
3k views

What does the Bitcoin client do when it receives conflicting transactions?

I've been assuming that the second transaction will simply be discarded as invalid, while the first waits at 0/unconfirmed until it actually gets into a block (requiring a "-rescan" or similar if the ...
21
votes
1answer
540 views

Have any SPV users lost money because they accepted forged bitcoins?

I'm making a list of real-life examples of occasions where bitcoins were lost to various known attacks. One of these known attacks is that lightweight (SPV) wallets can't verify whether a transaction ...
20
votes
6answers
2k views

How can I send Bitcoins via SMS?

I am considering working on giving Africans access to trade using Bitcoins. In many ways, parts of Africa is more developed when it comes to mobile payments than the west. The success of M-PESA ...
19
votes
2answers
5k views

What happens if my transaction is not accepted because I did not pay fees?

I was reading this thread about a client fork that does not force transaction fees and I noticed the big red warning saying that some coins might get lost if I am not careful. What does this mean? ...
19
votes
1answer
2k views

What protection does Bitcoin have against Denial of Service (DoS) attacks?

What protection does Bitcoin have against DoS attacks? Could you bring down a node by flooding it with data? What happens if someone starts flooding the network with legitimate, yet nonsense, ...
18
votes
3answers
1k views

Can a bitcoin transaction be reversed from the receiving end?

I know this seems like a duplicate of the question 'Can a bitcoin transaction be reversed?' but none of the answers there were explicit enough as they all seemed to assume reversal triggered from the ...