bitcoin-dev

One-Shot Replace-By-Fee-Rate

One-Shot Replace-By-Fee-Rate

Posted on: January 28, 2024 17:27 UTC

The correspondence between the programmers reveals a discussion on transaction conflicts within a certain system, where they are addressing the intricacies of how specific transactions can conflict and the implications of introducing new elements into this scenario.

The focus lies on the issue that tx_LM and tx_HS initially spend the same input, leading to a direct conflict. However, it is clarified that for the proposed scenario, it is not necessary for these two transactions to be in conflict. Instead, the required conflicts are between tx_LM and tx_LL, as well as tx_LM and tx_RBFr.

An alternative strategy is introduced by suggesting the use of a third confirmed input c3. By having tx_LM spend c3 instead of c2, and tx_RBFr spend both c2 and c3, four distinct conflicts are created:

  1. tx_HS and tx_RBFr would conflict due to both attempting to spend c2.
  2. tx_HS and tx_LS would be in conflict over spending tx_LL:0.
  3. tx_LL and tx_LM would clash because they both aim to spend c1.
  4. tx_LM and tx_RBFr would be conflicting over the spending of c3.

In this revised setup, tx_RBFr would be slightly larger, which implies an increased fee, but the overall numbers are expected to align properly. Although this analysis has yet to be verified with the provided code, there is an opportunity for further review in the following week if it remains unexplored.

The critical point made is that the proposed Replace-by-Fee rules (RBFr) could potentially allow for infinite replacement cycles when combined with the existing RBF rules. This emphasizes the necessity to consider these interactions carefully to prevent such scenarios from occurring within the system.