I really thought we had seen the bottom in terms of Bitcoiners making irrational and ridiculous arguments against improvements to Bitcoin, to portray themselves as some kind of righteous underdog fighting against corruption and incompetence from within.
Boy, was I wrong.
So first explain some things. With Lightning Channels, you must determine your rate for a one-sided closing transaction in advance. Because the actual UTXO is a multisig, both parties to the channel must sign the transactions that both parties use to unilaterally close the channel in advance. Lightning’s entire security is based on this. If you’ve ever needed one, for example because your counterparty isn’t cooperating, you can’t exactly count on them to cancel one at a higher rate should you need it.
This led to problems during unilateral closure of reimbursements. If the fees were high and have dropped since you opened your channel, you’re paying money you didn’t need. If costs were low and went up, you can’t guarantee your channel will close in time. You can’t use Replace-By-Fee (RBF) because your counterparty has to sign, and you can’t use Child-Pays-For-Parent (CPFP) because all your outputs have a time limit, so nothing you spend on them is valid to after the first transaction actually confirms and several blocks pass.
As a result, anchor exits have been created. They were special outputs that exist without time slots, for the sole purpose of being able to spend on an underlying transaction to increase the Lightning close transaction. However, these created greater capital inefficiencies, requiring a non-negligible amount of satoshis to create this output.
Introduce ephemeral anchors, building on the v3 transaction relay and packet relay (passing transactions in the mempool as groups). The idea is to have an output with a value of 0 that can be issued with OP_TRUE (meaning anyone can issue it). Transactions with a rate of 0 and containing an ephemeral anchor are passed into the mempool as long as there is an underlying transaction where the short-lived anchor output is issued at an appropriate rate.
This allows Lightning channels to sign unilateral closing transactions at no cost, and anyone who needs them can simply use the momentary anchor output to set the rate required at that time. This greatly simplifies Lightning closing transactions and removes the capital inefficiencies of existing anchor outputs. That’s an added bonus everyone can bounce a fee transaction with a short-lived anchor, and not just with the channel owners (or other contract owners).
The ephemeral anchor never even creates the value 0 UTXO in the UTXO set, because it is only passed along with a transaction that immediately issues it in the same block.
So why is this a problem? Or an attack? I have no idea, it’s an amazing simplification that essentially any second-layer protocol, or contract built on Bitcoin in general, that uses pre-signed transactions will benefit immensely. It does not cause bloating of the UTXO set because, as the name says, the outputs used are short-lived. They are not really made permanent.
The only arguments I’ve seen are “spam!” Or “Core developers are scrapping the dust limit!” (A constraint must be passed to the transaction output with a minimum value, and it is not removed for anything other than ephemeral anchors, which must immediately spent by a child being transferred).
I think we are at a point where we need to seriously consider when it is time to dismiss criticism or complaints about technical topics in this area. Or where legitimate criticism ceases to be that, and becomes irrational and illogical crusades against or for personalities instead of reasoned criticism. Because this resistance to short-lived anchors is undeniably the last.
All rational criticism should be welcomed in an open source protocol like Bitcoin, but it’s time to stop humoring irrational tribalism with no logical basis as if it is equivalent to legitimate criticism. It’s not, it’s a pure waste of time and a Denial of Service attack on the process of improving Bitcoin.
This article is a To take. The opinions expressed are solely those of the author and do not necessarily reflect those of BTC Inc or Bitcoin Magazine.