Bitcoin Forum

Bitcoin => Bitcoin Technical Support => Topic started by: ethantaylor on May 11, 2017, 02:15:36 PM



Title: What's the effect of "Double Spend" to a transaction?
Post by: ethantaylor on May 11, 2017, 02:15:36 PM
I received a payment about 18 hours ago, and it is still unconfirmed. The transaction log is here: https://blockchain.info/tx/b6deeee2d2bc1b015aa3d73346216cd90dbcd5bda3943771fc5377765ab15e25

I know the low fee might be a factor that causes the delay of the confirmation. But there is another thing that raised my concern: the red label which says "Double Spend!" How can "Double Spend!" affect a transaction? From the info I found on the internet, it is not a good sign.

P.S. I found a transaction acceleration service called ViaBTC and had submitted the unconfirmed transaction to it 15 minutes ago. But I think it is still necessary for me to figure out the effect of "Double Spend!" so I opened this thread.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: ahmedjamal1998 on May 11, 2017, 03:14:03 PM
As far as I know when a transaction is double spent, the first to be included in a block and start receiving confirmations is the going that is going to pass and the other one will be forgotten later on.

Any way, whoever sent you these coins is not trustworthy. He made this double-spent transaction to make you think you received the money. In fact he put lower fees on yours hoping that it won't get confirmed before his.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: newIndia on May 11, 2017, 03:19:00 PM
I received a payment about 18 hours ago, and it is still unconfirmed. The transaction log is here: https://blockchain.info/tx/b6deeee2d2bc1b015aa3d73346216cd90dbcd5bda3943771fc5377765ab15e25

I know the low fee might be a factor that causes the delay of the confirmation. But there is another thing that raised my concern: the red label which says "Double Spend!" How can "Double Spend!" affect a transaction? From the info I found on the internet, it is not a good sign.

P.S. I found a transaction acceleration service called ViaBTC and had submitted the unconfirmed transaction to it 15 minutes ago. But I think it is still necessary for me to figure out the effect of "Double Spend!" so I opened this thread.

Your Tx has got confirmation. So, the "Double Spend!" does not matter to u.

The thing is, the same coin i/p of your Tx was used in some other Tx, which is not yet confirmed.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: ethantaylor on May 11, 2017, 03:29:51 PM
As far as I know when a transaction is double spent, the first to be included in a block and start receiving confirmations is the going that is going to pass and the other one will be forgotten later on.

Any way, whoever sent you these coins is not trustworthy. He made this double-spent transaction to make you think you received the money. In fact he put lower fees on yours hoping that it won't get confirmed before his.
Thank you for explaining the effect. It looks like I need to talk to that person and ask him why he made this double-spent transaction.



Your Tx has got confirmation. So, the "Double Spend!" does not matter to u.

The thing is, the same coin i/p of your Tx was used in some other Tx, which is not yet confirmed.
Yes. Now I'm seeing it has received three confirmations so far. I guess this transaction can now be called a successful transaction. ViaBTC's acceleration really works! I appreciate your explanation.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: RaiCaptchas on May 11, 2017, 04:49:24 PM
As far as I know when a transaction is double spent, the first to be included in a block and start receiving confirmations is the going that is going to pass and the other one will be forgotten later on.

Any way, whoever sent you these coins is not trustworthy. He made this double-spent transaction to make you think you received the money. In fact he put lower fees on yours hoping that it won't get confirmed before his.
Thank you for explaining the effect. It looks like I need to talk to that person and ask him why he made this double-spent transaction.



Your Tx has got confirmation. So, the "Double Spend!" does not matter to u.

The thing is, the same coin i/p of your Tx was used in some other Tx, which is not yet confirmed.
Yes. Now I'm seeing it has received three confirmations so far. I guess this transaction can now be called a successful transaction. ViaBTC's acceleration really works! I appreciate your explanation.

with bitcoin qt its simply possbile to send balance which is not completly confirmed. that means im received ethey BTCcoins from mercatrox which is an Exchange service for XRB/Mrai of the Riablocksproject.
while this transaction is not completly confirmed, im already able to send it and set it up at the blockchain for a futher transaction.
since two hours the first trans was cvonfirmed and the second one two ethey wit 10k sat byte was confirmed then very fast aswell.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: ethantaylor on May 12, 2017, 12:12:50 AM
@ahmedjamal1998 or anyone else,

Could you please help check whether the reply wrote by RaiCaptchas is tenable or not? He is the person who made the double spend transaction. As I understand it, what he means is that the double spend he made is normal and that he had no malicious intention.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: ahmedjamal1998 on May 12, 2017, 12:17:35 PM
As far as I know when a transaction is double spent, the first to be included in a block and start receiving confirmations is the going that is going to pass and the other one will be forgotten later on.

Any way, whoever sent you these coins is not trustworthy. He made this double-spent transaction to make you think you received the money. In fact he put lower fees on yours hoping that it won't get confirmed before his.
Thank you for explaining the effect. It looks like I need to talk to that person and ask him why he made this double-spent transaction.



Your Tx has got confirmation. So, the "Double Spend!" does not matter to u.

The thing is, the same coin i/p of your Tx was used in some other Tx, which is not yet confirmed.
Yes. Now I'm seeing it has received three confirmations so far. I guess this transaction can now be called a successful transaction. ViaBTC's acceleration really works! I appreciate your explanation.

with bitcoin qt its simply possbile to send balance which is not completly confirmed. that means im received ethey BTCcoins from mercatrox which is an Exchange service for XRB/Mrai of the Riablocksproject.
while this transaction is not completly confirmed, im already able to send it and set it up at the blockchain for a futher transaction.
since two hours the first trans was cvonfirmed and the second one two ethey wit 10k sat byte was confirmed then very fast aswell.

What does sending unconfirmed balance that you received with double spending !!
Absolutely nothing. If what is true and you received BTC from an exchange and then made the transaction yourself, inputs shouldn't be the same then.

EDIT:
Even if that exchange is managed by you as well, inputs won't be the same for 2 transactions with time interval between them except if inteded.



Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: RaiCaptchas on May 12, 2017, 02:05:50 PM
i already explained this upstairs and newindia aswell :)


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: lizardbtc on May 12, 2017, 04:24:46 PM
As far as I know when a transaction is double spent, the first to be included in a block and start receiving confirmations is the going that is going to pass and the other one will be forgotten later on.

Any way, whoever sent you these coins is not trustworthy. He made this double-spent transaction to make you think you received the money. In fact he put lower fees on yours hoping that it won't get confirmed before his.

It doesn't necessarily mean that person is not trustworthy just because he used double spent - depends if the double spend was to the same address (1st and 2nd time). As in past and now when I send transaction with minimal fee and I wait like 2days or 1 day I usually double spend it with a higher fee to the same address so that I don't want eternity for my transaction to be confirmed.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: ahmedjamal1998 on May 12, 2017, 10:12:57 PM
As far as I know when a transaction is double spent, the first to be included in a block and start receiving confirmations is the going that is going to pass and the other one will be forgotten later on.

Any way, whoever sent you these coins is not trustworthy. He made this double-spent transaction to make you think you received the money. In fact he put lower fees on yours hoping that it won't get confirmed before his.

It doesn't necessarily mean that person is not trustworthy just because he used double spent - depends if the double spend was to the same address (1st and 2nd time). As in past and now when I send transaction with minimal fee and I wait like 2days or 1 day I usually double spend it with a higher fee to the same address so that I don't want eternity for my transaction to be confirmed.

What you're saying is a different case. " I wait like 2days or 1 day I usually double spend it with a higher fee to the same address"

While in the OP's case, it's not the same address to which the coins are sent. The double spending was to two addresses one, of them not controlled by the OP. In the case of low fees it makes sense to double spend.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: pooya87 on May 13, 2017, 04:16:25 AM
@ahmedjamal1998 or anyone else,

Could you please help check whether the reply wrote by RaiCaptchas is tenable or not? He is the person who made the double spend transaction. As I understand it, what he means is that the double spend he made is normal and that he had no malicious intention.

i can tell you one thing.
double spending is not easy and most wallets don't allow the user to do it. the wallets user interface prevents it to prevent newbie accidental double spend and all the problems it can cause.
usually you need to do extra stuff, for example to put simply you would need to go to the console and type in some stuff and manually make the transaction to double spend.


Title: Re: What's the effect of "Double Spend" to a transaction?
Post by: ethantaylor on May 13, 2017, 07:07:27 AM
@ahmedjamal1998 or anyone else,

Could you please help check whether the reply wrote by RaiCaptchas is tenable or not? He is the person who made the double spend transaction. As I understand it, what he means is that the double spend he made is normal and that he had no malicious intention.

i can tell you one thing.
double spending is not easy and most wallets don't allow the user to do it. the wallets user interface prevents it to prevent newbie accidental double spend and all the problems it can cause.
usually you need to do extra stuff, for example to put simply you would need to go to the console and type in some stuff and manually make the transaction to double spend.

Thank you. I'm starting to believe that double spend isn't normal and the source of a double spend is questionable.