Zero-fee commitments for mobile wallets

The proposal in question introduces an innovative approach to handling HTLC transactions within the context of blockchain and digital currency transactions. It suggests that peers should sign two versions of HTLC transactions: one is a default version that does not include any transaction fee and requires additional on-chain inputs, and the other incorporates a high feerate encapsulated within a custom TLV of commitment_signed that aligns with the current observed feerate. This method is presented as a solution to enhance the efficiency and safety of transactions.

A notable aspect of this proposal is the impact it has on the economic dynamics between the mobile wallet users and their peers. Specifically, the high feerate's costs are set to be deducted from the channel opener's balance, which typically would be the mobile wallet in most scenarios. This setup implies that offering a high feerate option to the mobile wallet incurs no expense for the peer. Furthermore, it inherently motivates the mobile wallet to opt for the high-feerate option only when it is absolutely necessary, such as in situations requiring enhanced transaction security or when attempting to reclaim liquidity from channels that have become inactive or obsolete.

This approach underscores a strategic integration of economic incentivization with technical functionality to address transaction efficiency and safety concerns. By leveraging the differential impacts on costs associated with the dual HTLC transaction signing options, it ensures that the system remains adaptable to varying transaction conditions while also promoting judicious use of higher-cost transaction pathways.