Author: Johnson Lau 2018-12-21 15:37:05
Published on: 2018-12-21T15:37:05+00:00
The email conversation discusses the proposed idea of tagging an output to make it spendable with NOINPUT. The tagging can be done in two ways, and it is compatible with eltoo. However, it prevents the use of SIGHASH_NOINPUT to support walletless offchain protocols. The idea of "walletless offchain software" is motivated by implementing on-chain wallet features in off-chain systems. Typically, an on-chain wallet has a simple process for making transactions, but it cannot be used to set up a funding transaction for an off-chain system. To take advantage of `SIGHASH_NOINPUT`, they modify the off-chain system setup as per the steps mentioned in the email. With this, an off-chain system need not require its implementing software to implement its wallet. Further, on-chain wallets can directly put their funds into an off-chain system without requiring an on-chain transfer to an off-chain software wallet. This can be helpful when building overall software. However, there are some concerns regarding the proposed idea. Firstly, for Lightning and similar systems, the fact that the Lightning node will give you an address that opens a channel means people will make wrong assumptions. Secondly, dual-funding cannot be done with this anyway. Finally, it may be better to provide some standard way of signing transactions without broadcasting them. In conclusion, output tagging still seems fine even if this particular use cannot be supported.
Updated on: 2023-05-20T18:52:21.589102+00:00