Question about bumfee bitcoin core

[cryptoworld99]

Hello,


Just a quick question,

https://bitcoincore.org/en/doc/0.16.0/rpc/wallet/bumpfee/

does bump fee act as a double-spend? since it creates a new transaction ID

Thanks in advance!

[AdolfinWolf]

Hello,


Just a quick question,

https://bitcoincore.org/en/doc/0.16.0/rpc/wallet/bumpfee/

does bump fee act as a double-spend? since it creates a new transaction ID

Thanks in advance!

Yes, it spends the same outputs, but due to the RBF flag most nodes will see this as intended behaviour and thus "allow" it.

RBF also allows you to spend the same outputs to other "addresses" much easier, which is why 0-conf services (casino's) will usually only accept non-RBF transaction to be eligible. (to prevent the "double-spending" of unconfirmed transactions.)

[ranochigo]

Only transaction that has Optin RBF flag can use that feature to increase their fee. The function will create a new transaction which spends the same inputs. In a sense, it is considered double spending.

However, the inputs are realistically never spent twice since only either of the two transactions will make it into a block and thus stored on the blockchain. Thus, by definition, it is not a double spend since the blockchain will only have the inputs being spent once. This is what blockchain is designed to prevent. Unconfirmed transactions with opt-in RBF are never considered secure due to their ease of replacing.

[cryptoworld99]

RBF also allows you to spend the same outputs to other "addresses" much easier, which is why 0-conf services (casino's) will usually only accept non-RBF transaction to be eligible. (to prevent the "double-spending" of unconfirmed transactions.)

Take note that whether you enable RBF/not is only one reason when someone accept transaction with 0-conf. Few services sometimes also have minimum transactoin fee (to ensure the transaction can be confirmed) and upper limit of amount that can be accepted for 0-conf.

Thank you! I understand how this works now