Author: ZmnSCPxj 2021-10-06 00:09:11
Published on: 2021-10-06T00:09:11+00:00
The concept of implementing Fast Forwards using two CSV-variant Spillman unidirectional channels hosted by a Poon-Dryja construction has been proposed by ajtowns. This approach is similar to the Duplex channels proposed by Decker-Wattenhofer. The main idea here is to use two unidirectional channels in a channel-like construction instead of chaining transactions for Fast Forwards. Various Spillman channels and their variants, including `nLockTime`, `CLTV`, `nSequence`, and `CSV` variants, are reviewed in the article. It is highlighted that the `nSequence` variant requires a "kickoff" transaction to start the relative timeout. The article also includes a review of Decker-Wattenhofer Duplex Micropayment Channels which propose a bidirectional channel mechanism with multiple chained stages, including two `nSequence`/`CSV` Spillman variant channels at the end.The article discusses Poon-Dryja and Fast Forwards in the context of Lightning Network and explains how a revocable output owned by the local node in Poon-Dryja can be used to host a CSV Spillman variant. The article suggests using Poon-Dryja commitment transaction as a kickoff transaction for duplex Spillman channels. Additionally, it compares the bidirectional Poon-Dryja with unidirectional Spillman and explores the need for bidirectionality in case of HTLC failure.The article further proposes an alternate idea by aj to have another revocation key for individual HTLCs. Finally, it argues that terminating at Spillman channels reduces the number of transactions hitting on-chain to a constant amount, instead of chaining multiple of them.The proposed new protocol for fast forwards incorporates ideas from various sources including Spillman, Decker-Wattenhofer, Poon-Dryja, and Towns. This mechanism aims to reduce the number of transactions that hit on-chain during unilateral closes while still retaining its usefulness for privkey-offline receivers. This latest development in fast forwarding technology is expected to provide faster transaction processing times and better user experience for cryptocurrency users.
Updated on: 2023-06-01T18:49:53.830627+00:00