Published on: 2022-05-27T16:28:40+00:00
In his article titled "Price of Anarchy from selfish routing strategies on the Lightning Network," Lightning Network developer René Pickhardt discusses how selfish behavior of nodes sending Bitcoin over the network can result in higher drain on channels, leading to increased depletion and failure rates for payments. Pickhardt's findings are based on statistical measures and computations using data from the Gossip Protocol and Bitcoin Network that reveal the topology of the Lightning Network. It is important to note that no empirical experiments were conducted to derive these theoretical results. The code for this research can be found in the lnresearch repository.Although these preliminary results focus on some of the strategies currently being deployed by `pay` implementations, Pickhardt has not yet studied the dynamics of the entire game or identified the dominant strategies of routing and sending nodes. While routing nodes appear to have the ability to mitigate some of the effects, they may not be able to engage in selfish behavior or strategies themselves due to limitations imposed by protocol design.Pickhardt hopes that the described effects will not be too severe given the anticipated traffic and usage of the network, ensuring that the technology functions properly at the required scale. He invites thoughts, feedback, comments, and questions from fellow developers regarding his findings. However, he acknowledges that the game theory of the Lightning Network may introduce limitations on the network's capacity to handle traffic in the future.In response to Pickhardt's article, Gregorio references a paper he wrote titled "Modeling a Steady-State Lightning Network Economy." This paper explores an idealized scenario where the Lightning Network has scaled to the size and volume of a self-sustained economy. In this scenario, the number of on-chain transactions becomes negligible compared to off-chain transactions, and payments flow continuously through a network with relatively stable topology. Gregorio notes a link between the concept of "drain" defined by Pickhardt and the idea of "demand imbalance" discussed in his own paper.According to Gregorio, in a network of n connected nodes, there is a tendency towards a state where n-1 channels have perfectly balanced flows in both directions ("self-balancing" channels), while the remaining channels are either unused or experience a permanent tendency towards imbalance. These imbalanced channels, referred to as "stuttering" channels, accumulate balance at one end and are only intermittently available in one direction. Gregorio highlights that the self-balancing channels form a spanning tree of the network graph, which he calls the "core spanning tree" of the payment network.Gregorio attempts to derive practical lessons from this idealized scenario, offering valuable insights to node operators on the current Lightning Network. He questions whether existing rebalancing and fee management tools are sufficient to counteract the tendency towards imbalance. If not, he suggests exploring alternative strategies to "work with the imbalances" rather than directly opposing them. For example, efficient low-latency mechanisms could be implemented to signal when a channel becomes unusable in one direction, reducing the failure rate. Additionally, he emphasizes the importance of a robust network that can handle a high-volume flow of information about channel availability and fee fluctuations.Overall, these discussions shed light on the potential challenges and limitations that may arise from selfish routing strategies and demand imbalances within the Lightning Network. It underscores the need for further research and exploration to ensure the network's scalability and efficiency in handling increasing traffic and usage.
Updated on: 2023-08-01T00:20:38.048848+00:00