Channel depletion, LN Topology, Cycles and rational behavior of nodes

The discussion highlights a significant issue in payment systems, particularly focusing on the vulnerability that arises when payments are unresolved for an extended period. This situation becomes problematic as it can lead to a system where new payments are consistently rejected due to the backlog of unresolved transactions. The text points out a potential exploit where a payer could take advantage of this flaw by sequentially releasing payment shards that are each below the maximum milli-satoshi limit (max_msat). By inserting a waiting period between each shard release, the payer could theoretically bypass the system's controls and accumulate a total of 100 HTLCs (Hashed Time-Locked Contracts) within the payment channel.

This method of gaming the system is further exacerbated by two specific factors: a zero fee_base and the practice of rounding down proportional fees. Such conditions make it even more feasible for payers to exploit these vulnerabilities without incurring significant costs. Moreover, the introduction of PTLCs (Point Time-Locked Contracts) adds another layer of complexity to this issue. PTLCs, unlike HTLCs, are not correlatable, meaning they offer an additional challenge in tracking and mitigating such exploitative strategies.

Overall, the text underscores the need for robust mechanisms to prevent the exploitation of payment channels, emphasizing the importance of addressing both the technical and economic loopholes that could lead to systemic vulnerabilities within digital payment infrastructures.