Author: ZmnSCPxj 2018-03-05 13:28:49
Published on: 2018-03-05T13:28:49+00:00
The email discusses the differences between Poon-Dryja (revocation) channels and Decker-Wattenhofer duplex micropayment channels. The maximum lockup period for funds in a channel is proportional to the number of updates the channel can have, with shorter worst-case lockup periods resulting from fewer updates before the channel can only be closed. Poon-Dryja channels have no limit on the number of updates possible and use O(1) lockup time and transactions for an n update limit. In contrast, Decker-Wattenhofer uses O(log n) lockup time and transactions for n update limits. Every payment requires two updates, one to get payer funds to an HTLC and the other to get the HTLC funds to the payee. Although Decker-Wattenhofer has the advantage of being extendable to any number of participants per channel, the construction of Poon-Dryja channels cannot be easily extended beyond two per channel. To address this limitation, Burchert-Decker-Wattenhofer channel factories combine multiple two-participant Poon-Dryja channels that can have any number of updates, with the Decker-Wattenhofer part only updated if all participants agree to redistribute their funds. This results in a potentially infinite number of possible channel updates for individual Poon-Dryja channels while minimizing the O(log n) cost for maximum number of updates for fund redistribution. The email also notes that Rusty Russell’s “shachain” concept reduces storage for a sequence of revocation keys to just 64 bytes.
Updated on: 2023-05-24T21:29:56.130551+00:00