Published on: 2015-12-02T09:27:39+00:00
A discussion on the Bitcoin-dev mailing list occurred regarding the use of Sequence for opting in. The CTxOut data structure lacks additional fields for this purpose. One suggestion was to utilize the same scheme as sighash_single, but it raises privacy concerns by exposing change address information. Another proposed option involves pre-committing via a hash and revealing it later, but this approach is complex and not easily feasible with the current transaction data structure.On November 16th, 2015, Peter Todd posted a message on bitcoin-dev discussing the use of Sequence for opting in. He pointed out that it is the only "free-form" field available for this purpose. Luke-Jr proposed opt-in per output, but the CTxOut data structure does not have extra fields for such usage. The message also mentioned questioning the use of the same scheme as sighash_single and suggested considering if input 0 has nSequence... (the rest of the sentence is not provided).Bitcoin Core developers have decided to merge the opt-in Full-RBF pull request. This new feature will enable senders to opt into full-RBF semantics for their transactions, allowing receivers to detect if the sender has done so. Transactions that do not opt-in will still retain the existing "first-seen" mempool semantics. Pending code review, this feature is expected to be included in Bitcoin Core v0.12.0. A transaction is considered to have opted into full-RBF semantics if nSequence < (2^32 - 2), indicating the possibility of the sender reissuing the transaction with a higher fee.The initial version of Replace-by-Fee (RBF) raised controversy due to concerns about double-spending. However, opt-in Full-RBF addresses these concerns by enabling receivers to differentiate between opt-in and non-opt-in transactions. The creation of the opt-in Full-RBF pull request was in response to user feedback, with users desiring more control over the fees paid for transactions. This feature allows users to increase the fee on a transaction that is taking longer than expected to confirm, without worrying about rejection by nodes that do not support RBF.Overall, the opt-in Full-RBF feature offers users greater flexibility and control over their transactions. It also addresses security concerns associated with the original RBF implementation.
Updated on: 2023-08-01T16:53:18.576992+00:00