eltoo: A Simplified update Mechanism for Lightning and Off-Chain Contracts



Summary:

ZmnSCPxj has proposed to remove the trigger transaction as `nSequence`-encumbered transactions are only settlement transactions and not any update transactions. ZmnSCPxj suggests that the funding transaction outpoint could have a SCRIPT that allows the funding outpoint to be spent directly by any update transaction, which has `OP_FALSE` at its `witness` script. In creating a mutual close transaction, the update branch of the funding transaction above would be used, again signing with `OP_FALSE`. The drawback is that the mutual close transaction increases by 1 weight unit plus the size of the more complicated funding transaction SCRIPT, which is no longer a regular 2-of-2 P2WSH and indelibly marking it as a Decker-Russell-Osuntokun mutual close. Taproot would help there by implicitly including a plain 2-of-2 fallback.


Updated on: 2023-05-24T23:50:08.777992+00:00