MultiChannel and MultiPTLC: Towards A Global High-Availability CP Database For Bitcoin Payments

The discussion revolves around the advantages of Multi-Path Time-Locked Contracts (MultiPTLC) over sender-created stuckless payments, emphasizing the efficiency and user-friendliness of the MultiPTLC approach for end-users, particularly those with limited funds and connectivity. The primary benefit highlighted is that MultiPTLC requires the sender to only lock the exact amount they intend to pay plus any routing fees, significantly reducing the risk associated with payment lockup due to failures in the Lightning Network's remote routing nodes. This method aligns more closely with users' expectations, as they do not anticipate multiple units of their payment being locked and potentially inaccessible for extended periods.

In scenarios where payments become stuck due to network issues, traditional stuckless payments could inadvertently lock additional funds, doubling the initial payment amount at stake. This situation poses a challenge in explaining to users why their funds remain unavailable, especially when they wish to deplete their wallet. Unlike the sequential nature of sending and resolving payments one by one, MultiPTLC allows for parallel processing without increasing the financial risk, since only one unit of payment is locked from the sender's perspective. This system mitigates the concerns over funds being tied up due to network failures outside the sender's or the service provider's control.

Furthermore, MultiPTLC offers substantial benefits for mobile users with sporadic internet access. It enables senders to compute necessary transaction details offline and transmit them through a minimal number of IP packets. This contrasts with the need for continuous online presence required by stuckless payments, which burdens users with maintaining stable connectivity to manage payment confirmations. By delegating the responsibility of managing payment reattempts and receiver confirmation to Lightning Service Providers (LSPs), which generally have better connectivity and reliability, the process becomes more efficient and less dependent on the sender's network status.

Lastly, the assumption underlying the preference for MultiPTLC is that most users, reflected by everyday financial transactions, operate well within their liquidity limits, typically utilizing a small fraction of their available funds for payments. This behavior suggests that while stuckless payments might suffice under normal conditions, they fall short during exceptional circumstances or when network reliability issues arise, validating the push towards adopting MultiPTLC to better accommodate user expectations and technical limitations.