Towards more reliable payment path finding via probabilistic modeling the uncertainty of channel balance

Summary:

The Lightning Network developers have made breakthroughs in improving payment path finding and the reliability of the payment process. They suggest using (multi)paths with the highest success probability instead of the shortest or cheapest ones. Probability theory is used to define channel success and failure probabilities, as well as (multi)path success and failure probabilities. By sorting paths by their descending success probability during the trial and error payment process and updating the probabilities from current failures, the number of average attempts decreases, producing a much faster delivery of payments. The uncertainty of channel balances is quantified, and negative Bernoulli trials are used to compute the expected number of attempts necessary to deliver a payment of a particular amount from one node to another participant in the network. The success probability declines exponentially with the number of uncertain channels in a (multi)path. Depending on the payment pair, amount, and splitting strategy, it can be decided into how many parts a payment should be split to achieve the highest success probability. For small amounts, splitting almost never makes sense.Implementations following the recommendation to use a probabilistic approach will tend to route payments along high-capacity channels. While fee-based routing can be easily gamed, providing more liquidity is much harder. Nodes which provide a lot of liquidity and thus utility might be able to charge higher fees, which would probably allow the emergence of a real routing fee market. The research also addresses the question of how to split a payment into k parts and how many funds to allocate to each path to increase the (multi)path success probability. An equal-sized split is not preferable. The paper provides an optimization problem in the general case and how to find a split and paths that maximize the probability of attempts.Rene Pickhardt, a Lightning Network developer and researcher, has expressed confidence in upcoming updates to address security and privacy concerns surrounding Lightning Network payments with uncertain channel balances. The update is in response to a paper by researchers at the Technical University of Munich that identified a vulnerability in the network, which could allow attackers to steal funds from Lightning Network users. Pickhardt also references a discussion on the Lightning-dev mailing list regarding the vulnerability and provides links to the original research paper, a podcast discussing the Lightning Network critique, and a pull request for changes to the Lightning Network protocol. Overall, while there are current concerns around the Lightning Network's security and privacy, developers like Pickhardt are working to address these issues through ongoing updates and discussions.

Updated on: 2023-06-03T03:50:32.523867+00:00