Author: Matt Corallo 2020-04-21 02:43:14
Published on: 2020-04-21T02:43:14+00:00
The Lightning Network is a second-layer solution built on top of the Bitcoin blockchain to enable faster and cheaper transactions. However, it has identified a flaw in its update mechanics that allows users to steal in-flight HTLCs enforced on-chain using RBF Pinning. This issue is not new, and there is currently no easy fix.To resolve the issue of maddening prediction games when negotiating future fee rates, the Lightning Network came up with an idea called "anchor outputs," which allows both counterparties to add fees to a transaction being broadcast without getting into the quagmire that is RBF pinning. However, this trick comes with a narrow structure rule.One solution to this problem could be to use some kind of policy rule to allow only the addition of additional confirmed inputs and one (small) output. This would mean that the other party knows that either the transaction has a high fee or their reasonably higher-fee transaction will meet the RBF rules and replace the malicious transaction. Strategies involving full-RBF for transactions not at the top of the mempool and slow-full-mempool-sync would be welcome, but it might not suffice.Another alternative anchor outputs proposal is suggested, where all HTLC output spends need to be pre-signed. Unfortunately, this severely cuts into the lowest-value HTLCs that can be sent "safely" and adds a significant social cost of extra low-value, possibly-uneconomical outputs in the chain.The Lightning Network is soliciting ideas publicly to find a better solution to make lightning's security more practical in a world where Bitcoin miners are paid to operate.
Updated on: 2023-05-23T03:04:45.812626+00:00