Author: Olaoluwa Osuntokun 2020-04-22 04:13:34
Published on: 2020-04-22T04:13:34+00:00
The email exchange discusses the limitations of Bitcoin contracts that rely on nested trees of transactions to confirm, which is at the root of an issue that will affect more complex Bitcoin contracts such as CTV, Duplex, and channel factories. The author argues against the seemingly arbitrary package limits and suggests that computational complexity issues can be ameliorated with a better choice of internal data structures. The simplest heuristic for miners is to accept the higher fee rate package. The email also discusses the possibility of monitoring the global mempool as a prudent mitigation for Lightning implementations to deploy today, but notes that this is complex and requires an active full node with an in-sync mempool. However, this is only a requirement for Lightning nodes that seek to be a part of the public routing network with a desire to forward HTLCs. The email further recommends watching the mempool rather than modifying the state machine to mitigate a class of attack assuming the anchor output format as described in the open lightning-rfc PR. The author suggests that not fixing this issue renders the whole exercise somewhat useless, but adds that a base version of anchors still resolves a number of issues. Finally, the email discusses the idea of making the HTLC output spending more free-form with SIGHASH_ANYONECAN_PAY|SIGHASH_SINGLE, but questions its practicality due to the commit_sig message including HTLC signatures for the remote party's commitment. The author proposes an overhaul in the channel state machine to make presenting a new commitment take at least two phases.
Updated on: 2023-05-20T21:58:52.071381+00:00