How many confirmations to be sure about a transaction? - page 2.

ranochigo

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Quote from: CasioK on November 01, 2015, 10:11:33 AM

Quote from: pjsonowal on November 01, 2015, 05:27:48 AM

i think 6 confirmations is enough to get sure about transactions that is 1BTC+.
On other hand 3 confirmations is enough for lower amount of BTCs.

Yes these are the best way of getting your bitcoin transaction most securely. But 6confirmation or 3 confirmations are best suited only with latest bitcoin core client only. If you use old bitcoin-qt client then you must wait for some 30 confirmations.

This applies to SPV clients too. They trust the miners without verifying the validity of the blocks.

When pools are SPV mining, they don't check the validity of the block and whether it complies with the network. Those mining pools then generate invalid blocks which get invalidated by Bitcoin core 0.10+ but not anything below or on 0.9.4 or earlier as those Core clients are not aware of the new rules. AFAIK, this isn't a threat right now. Majority of pools are mining on correct rules and creating valid blocks.

CasioK

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Quote from: pjsonowal on November 01, 2015, 05:27:48 AM

i think 6 confirmations is enough to get sure about transactions that is 1BTC+.
On other hand 3 confirmations is enough for lower amount of BTCs.

Yes these are the best way of getting your bitcoin transaction most securely. But 6confirmation or 3 confirmations are best suited only with latest bitcoin core client only. If you use old bitcoin-qt client then you must wait for some 30 confirmations.

pjsonowal

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i think 6 confirmations is enough to get sure about transactions that is 1BTC+.
On other hand 3 confirmations is enough for lower amount of BTCs.

JumperX

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Quote from: winguard on November 01, 2015, 01:15:49 AM

My local exchange coins.ph requires 3 confirmations when cashing out Bitcoin to fiat. So 3 confirmations is sufficient enough.

it really depends on the site if how many confirmation they needed for a transaction to reflect on your balance but atleast 1 confirmation is safe enough and that will not be able to cancel

ranochigo

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Most transactions don't really need confirmations to be in the <50% risk range. It only needs a few seconds for it to proporgate around the network and ensure that there isn't any competing transactions. One confirmation would be secure enough to accept the transaction unless there is a block reorg. It would be back to unconfirmed. Most exchanges requires over 3-6 confirmations as losses are not a choice for them with huge trade volumes.

winguard

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My local exchange coins.ph requires 3 confirmations when cashing out Bitcoin to fiat. So 3 confirmations is sufficient enough.

Mickeyb

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Quote from: idyu on October 31, 2015, 02:36:17 PM

3 should be very safe, i remember before localbitcoins needed 5 confirmations to confirm the deposit and that was really to much and sometimes took long.

This is what I hate about Kraken. They require 6 confirmations. I don't know why they don't lower this a bit. It takes forever to send your coins to the exchange.

Then again they are very security prone. I guess that's why they still keep 6 confirmations.

idyu

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3 should be very safe, i remember before localbitcoins needed 5 confirmations to confirm the deposit and that was really to much and sometimes took long.

StratusOakmont

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i think 3+ confirmations is enough to be sure about a transaction ( higher amount ) otherwise if you are transacting low amount then 1+ should be pretty much to be sure with the transaction.

VirosaGITS

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Quote from: CIYAM on October 31, 2015, 12:25:55 PM

You can't be 100% certain of a Bitcoin tx until a "checkpoint" has been published (which unfortunately is a centralised thing controlled by the devs).

A blockchain "re-org" (where a better chain replaces the current one) can actually go as far back as the last checkpoint (which could be thousands of blocks).

It is extremely unlikely that such a "re-org" could happen (and has never happened so far) but re-orgs of more than 3 blocks have occurred before (the worst such problem was around 6 blocks from memory).

So you basically have to decide upon the risk you want to take in accordance to the amount you are risking.

This is why 6 blocks is rock solid. Even 1 block is relatively secure since the odds of anything being redone is low, and also why 3 blocks is standard. Waiting for 6 block is the sweet spot where it does not take *too* long but it is very safe.

Although at this point i am not sure what kind of event that could invalidate 6 blocks old transaction.

CIYAM

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You can't be 100% certain of a Bitcoin tx until a "checkpoint" has been published (which unfortunately is a centralised thing controlled by the devs).

A blockchain "re-org" (where a better chain replaces the current one) can actually go as far back as the last checkpoint (which could be thousands of blocks).

It is extremely unlikely that such a "re-org" could happen (and has never happened so far) but re-orgs of more than 3 blocks have occurred before (the worst such problem was around 6 blocks from memory).

So you basically have to decide upon the risk you want to take in accordance to the amount you are risking.

crairezx20

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I think 4 or 5 confirmation before we know and sure the transaction arrive soon in your wallet address.. before i got only 3 confirmation but i didnt recieve it. and its rejected by a blockchain then the bitcoin 4 day or more before the bitcoin came back to a sender...

quadriple7

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i believe that you might be safe with one confirmation

Amph

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Quote from: coinyoo on October 29, 2015, 03:05:40 PM

When i started to use Bitcoin i had a similar question. Someone told me that 7 confirmation is a must, but better when you wait until it has 20 confirmation as minimum.

above 6, is not needed at all, in most case 3 are sufficient, and in some other case even 1 is okois

usually i do it based on the amount that i'm spending, the more big the more confirmations, up to six

Anmol_Verma

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Bitcoin transactions need atleast 3 confirmations by bitcoin network to be fully trusted and confirmed

98problems

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i believe that you need something like 1 confirmation as people usually cant double spend bitcoins with it

silverleafy

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Quote from: coinyoo on October 29, 2015, 03:05:40 PM

When i started to use Bitcoin i had a similar question. Someone told me that 7 confirmation is a must, but better when you wait until it has 20 confirmation as minimum.

7 is a bit too much. 20 is super overkill. 20 is completely unnecessary in most cases. Of course, there are exceptions like when there was a major fork back in July. But that is easily remedied by keeping your software up to date.

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When i started to use Bitcoin i had a similar question. Someone told me that 7 confirmation is a must, but better when you wait until it has 20 confirmation as minimum.

VirosaGITS

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Quote from: iram66680 on October 28, 2015, 09:55:48 PM

Quote from: VirosaGITS on October 28, 2015, 04:39:31 PM

Quote from: CasioK on October 28, 2015, 02:14:32 PM

Quote from: BTCBinary on October 28, 2015, 12:37:53 PM

Quote from: bitcoinear on October 25, 2015, 03:31:31 PM

Hello,
how many confirmations should a Bitcoin transaction have in order to be sure that the transaction could not be resolved?

Many exchanges use 6 confirmations to be sure that it is not a duplicate transaction. However there are other services that only use 3 and other only use 1 confirmation. But to be sure I guess you'll need 6

Even 1 conformation also accepted in some services. It's solely dependent on how much risk you're ready to take. I believe waiting for 3 confirmation are moderate policy for both the parties.

When i buy games or stuff online, it typically go through instantly, but if you end up scamming them, you're the one in trouble since they have your personal information. I understand for anonymous services, waiting for confirmation is an absolute must, however.

Most don't actually require valid information, you can easily just input a fake information and most would just accept it. It isn't a must for most sites, in physical stores, waiting for confirmations is rarely seen.

In that case, i assume they are dealing with something like Coinbase which i assume cover them in case of a double spending attack?

However the website that i use and give the good immediately, previously obtained my personal information. I guess one way or another they are protected. For instance if its physical product, the transaction will most likely have been confirmed by the time the packaging is ready to be shipped. If its virtual good, like a game on steam, then the code could be perhaps invalidated.

iram66680

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Quote from: VirosaGITS on October 28, 2015, 04:39:31 PM

Quote from: CasioK on October 28, 2015, 02:14:32 PM

Quote from: BTCBinary on October 28, 2015, 12:37:53 PM

Quote from: bitcoinear on October 25, 2015, 03:31:31 PM

Hello,
how many confirmations should a Bitcoin transaction have in order to be sure that the transaction could not be resolved?

Many exchanges use 6 confirmations to be sure that it is not a duplicate transaction. However there are other services that only use 3 and other only use 1 confirmation. But to be sure I guess you'll need 6

Even 1 conformation also accepted in some services. It's solely dependent on how much risk you're ready to take. I believe waiting for 3 confirmation are moderate policy for both the parties.

When i buy games or stuff online, it typically go through instantly, but if you end up scamming them, you're the one in trouble since they have your personal information. I understand for anonymous services, waiting for confirmation is an absolute must, however.

Most don't actually require valid information, you can easily just input a fake information and most would just accept it. It isn't a must for most sites, in physical stores, waiting for confirmations is rarely seen.

Topic: How many confirmations to be sure about a transaction? - page 2. (Read 3620 times)