Author: Greg Sanders 2022-10-18 15:51:30
Published on: 2022-10-18T15:51:30+00:00
In a proposal shared by Greg Sanders via bitcoin-dev, he elaborates on potential follow-up work that would make pinning severely constrained in many setups. V3 transactions may solve bip125 rule#3 and rule#5 pinning attacks under some constraints. V3 transactions restrict the package limit of a V3 package to one parent and one child. If the parent transaction includes two outputs which can be immediately spent by separate parties, this allows one party to disallow a spend from the other. In the package RBF proposal, if the parent transaction is identical to an existing transaction in the mempool, the parent will be detected and removed from the package proposal. Sanders proposes Ephemeral Anchors as a policy-only solution to this problem. Ephemeral Anchors means an output is watermarked as an output that MUST be spent in a V3 package. The implications of using Ephemeral Anchors are discussed in detail, including benefits to traditional wallet scenarios, batched payouts, and robust multi-party fee bumping. Open questions are also raised, such as whether allowing non-zero value in ephemeral outputs opens up a MEV and whether SIGHASH_GROUP-like constructs would allow uncommitted ephemeral anchors to be added at spend time, depending on spending requirements.
Updated on: 2023-06-16T02:00:26.308903+00:00