Nostr Web Client

All anchor/CPFP schemes have this problem. I singled out ephemeral anchors because they haven't been shipped yet; we should be phasing out anchors entirely whenever possible.

It's true that I could have gone even farther and argued that we shouldn't have CPFP or package relay at all. But I think arguing against CPFP is hopeless; arguing against package relay might be worthwhile still.

A problem is lots of more complex L2 protocols that people are excited about seem to need package relay. But maybe that's not true; I haven't thought enough about those details to be sure.

Peter Todd 2y ago

And yes, maybe someone will come up with a way to modify V3 to make it worthwhile. But I agree that without ephemeral anchors the idea doesn't make sense.

Even with ephemeral anchors, for Lightning it's really not _that_ much of an improvement. The second anchors output in anchors channels is redundant. So if we get rid of that, the only savings in ephemeral anchors is the size of the signature/checksig, and that reintroduces tx pinning unless V3 has the tx pinning problem truly fixed.

https://petertodd.org/2023/v3-txs-pinning-vulnerability

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Peter Todd 2y ago

How about I change #2 in the “Recommendations” section from:

“Ephemeral outputs should be strongly discouraged due to the above-mentioned miner decentralization risks; support for them should not be added to Bitcoin Core.”

to:

“Existing usage of anchor outputs should be phased out due to the above-mentioned miner decentralization risks; new anchor output support should not be added to new protocols or Bitcoin Core.”

Sjors Provoost 2y ago

That seems like a more clear articulation of what you're arguing for.