Published on: 2018-07-14T00:48:15+00:00
In the discussion, the application of sighash_noinput is being explored as a way to reduce the number of stored signatures. This feature allows for spending any unspent transaction output (UXTO) with the respective one-use public key script. However, concerns are raised about privacy when using this method for watchtowers.The use of Eltoo is mentioned in relation to sighash_noinput. Eltoo requires SIGHASH_NOINPUT, which means that only the latest transaction is needed instead of a penalty transaction for every state change. The txid_half + encrypted blob model is proposed as a solution to ensure that no information is learned about each state and how they relate unless a revocation must occur. However, it is noted that this method does not scale well, as it requires one encrypted blob per outsourced state.Another question arises regarding the reuse of signatures for multiple states with sighash_noinput and how to minimize information disclosure to third parties. Although no full design has been established yet, encryption using the txid is suggested as a potential solution.It is also mentioned that the watchtower may need to consider transactions that have already been spent by one or a chain of SIGHASH_NOINPUT transactions, but this is considered to be an easy task.In response to these discussions, Rusty Russell advises against creating a SIGHASH_NOINPUT to spend its own UTXOs in a wallet. He clarifies that this feature is primarily useful for smart contracts with unique conditions, such as lightning.Overall, the discussion revolves around the application of sighash_noinput in reducing stored signatures and the concerns and potential solutions related to privacy and information disclosure in the context of watchtowers.
Updated on: 2023-07-31T20:23:20.161319+00:00