Collects questions concerned with the practice of accepting transactions before they reach their first confirmation, i.e. "zero-confirmation".
Questions tagged [zero-confirmation]
48 questions
164
votes
11 answers
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 waiting forever for my transaction to confirm.
Why…
Avram
- 1,929
- 2
- 12
- 10
22
votes
3 answers
How does Satoshi Dice's 'zero confirmations' transaction system work technically?
The popular bitcoin betting game Satoshi Dice sends back payments very fast, they don't wait for confirmations. The user sends money to Satoshi Dice and gets back winnings a couple of seconds later. Here's a quote from their site:
The SatoshiDice…
Max Min
- 561
- 4
- 10
16
votes
4 answers
How secure is zero confirmations?
I sent a small amount of BTC to someone and she was notified within seconds. But the first confirmation did not happen for ten minutes or so.
What is the chance that this transaction could fail between the notification and the first confirmation?…
Alex Millar
- 491
- 3
- 12
13
votes
5 answers
How do I safely accept bitcoins without waiting for confirmations?
Are there any arbitrators that would guarantee the bitcoin transaction such that no one has to wait ten minutes to confirm the transfer of the said bitcoins?
Buckhead_Comp_Ser_Co
- 736
- 5
- 16
11
votes
2 answers
Double spend attack by sending higher fee transaction directly to the pools possible?
The standard client prioritizes TXs by the time of receipt, e.g. a conflicting transaction will not be relayed. This is not enforced by the network, though. Is there anything that would prevent this scenario from happening with…
kermit
- 2,009
- 1
- 17
- 26
10
votes
3 answers
If Bitcoin transactions require ~10 min to clear, how can payments get recognized within seconds?
Bitcoin Monitor offers to issue a notification moments after a payment is sent to a Bitcoin address. Yet if Bitcoin transactions require ~10 min to get written into the blockchain and confirmed as official, how can payments get recognized within…
Crashalot
- 265
- 2
- 7
9
votes
2 answers
Could any standard fee transaction be double spent by using a higher fee?
I realize that if somebody makes a transaction without any fees and there have not yet been any confirmations, then the transaction could be double spent by just spending the same inputs to a different address, but with a standard fee.
My question…
DJG
- 431
- 5
- 11
8
votes
1 answer
What is the Lightning Network proposal? What problem is it trying to solve?
We already have a few questions about technical details of Lightning network, however, …
What is the Lightning network proposal in the first place?
What problem is it aiming to solve?
Murch
- 71,155
- 33
- 180
- 600
7
votes
2 answers
Can I spend a coin sent to myself before it confirms?
If I spend the entire balance in my wallet to another address in my own wallet, do I need to wait until it gets one confirmation in order to spend it, or does the client know it is my own funds and that it can be spent?
This can be done via RPC, but…
Stephen Gornick
- 26,990
- 12
- 67
- 141
7
votes
3 answers
What nodes are best for lessening the risk of loss from a race attack
A successful race attack is one where the payment recipient's node receives a spend transaction yet the next block that is mined has a different transaction that spends the same coin. Thus the payment recipient's transaction will not confirm and…
Stephen Gornick
- 26,990
- 12
- 67
- 141
6
votes
1 answer
Get notified of incoming Bitcoin transaction, as soon as it broadcasted
After a few weeks of searching for an answer, I decided to ask here.
I want to accept a Bitcoin payment, to a specific wallet, and immediately, when the user approved the payment, to receive an indication that the payment was made.
The problem is, I…
Ohad Levi
- 63
- 3
5
votes
2 answers
Double Spending before confirmation
What's to prevent someone from using bitcoin at a store like subway and double spending to buy the sandwich before a confirmation is made? Since subway obviously isn't going to wait for a confirmation, can't a person send bitcoin to subway and at…
John
- 51
- 1
5
votes
2 answers
0/confirmation race attack double spend transactions
I am developing a point of sale bitcoin app, which should accept "fast" transactions (~30 sec for merchant to accept). I researched double spending questions here already, but it is still unclear to me, what happens within the time frame before a…
Stefan
- 405
- 3
- 11
4
votes
2 answers
It's possible to spend a BTC without fee to forge a payment?
I would like to know if it is possible to make a transaction without fee (probably this transaction will never be confirmed) and some time later to take this money back and spend in another transaction?
If yes, can I protect myself against this fake…
Davi cesar
- 51
- 4
4
votes
1 answer
What restrictions are there to the application of opt-in RBF?
It is a common meme in some parts of the Bitcoin sphere that RBF erodes the option of accepting zero confirmation transactions. It would be beneficial if the following questions were answered:
What restrictions are placed on RBF in the deployed…
Murch
- 71,155
- 33
- 180
- 600