Interactive tx construction and UTXO privacy, some thoughts



Summary:

The Lightning Network has adopted a modified version of the interactive transaction protocol used by the Discreet Log Contracts (DLC) team, which allows for batching to transmit input/output sets. This modification makes it possible to interleave UTXOs from multiple sources, enabling multiparty coinjoins on lightning, as well as dual-funded opens with many peers contributing UTXOs and outputs for their respective channel opens or UTXO consolidations. The interactive transaction protocol is highly flexible, enabling plausible deniability regarding any UTXOs sent to peers. However, there is a tradeoff between succinctness and adding rounds of communication, which can impact performance/uptime requirements of a node's operations. While UTXO privacy is important, not associating identity with a node in published channels is more critical. Taproot scripts may resolve some issues, but purely on-chain analysis will still be stymied.


Updated on: 2023-06-03T04:26:05.049530+00:00