{"paper":{"title":"Competitive Transaction Admission in PCNs: Online Knapsack with Positive and Negative Items","license":"http://creativecommons.org/licenses/by/4.0/","headline":"A deterministic online algorithm achieves O(log B)-competitive transaction admission in payment channels by modeling the problem as an online knapsack variant with positive and negative items.","cross_cats":[],"primary_cat":"cs.DS","authors_text":"Dominik Danelski, Julien Dallot, Maciej Pacut, Marcin Bienkowski, Stefan Schmid","submitted_at":"2026-04-09T13:06:38Z","abstract_excerpt":"Payment channel networks (PCNs) are a promising approach to making cryptocurrency transactions faster and more scalable. At their core, PCNs bypass the blockchain by routing transactions through intermediary channels. However, a channel can forward a transaction only if it has the necessary funds: the problem of keeping the channels balanced is a current bottleneck for the PCN's transaction throughput. This paper considers the problem of maximizing the number of transactions accepted by a channel in a PCN. Previous works either considered the associated optimization problem with all transactio"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"The main contribution of this paper is a deterministic online algorithm that is O(log B)-competitive, where B is the knapsack capacity (initially allocated funds). We complement this result with an asymptotically matching lower bound of Ω(log B) which holds for any randomized algorithm, demonstrating our algorithm's optimality.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the transaction-admission problem in a PCN channel can be exactly captured by the online knapsack model with positive and negative items, without extra constraints from the wider network topology or multi-hop routing.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A deterministic O(log B)-competitive algorithm for the online knapsack problem with positive and negative items, with a matching Ω(log B) lower bound for any algorithm, applied to transaction admission in payment channel networks.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A deterministic online algorithm achieves O(log B)-competitive transaction admission in payment channels by modeling the problem as an online knapsack variant with positive and negative items.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"b2511e6705be14b7e5cfe2f3e1240f99b9ed0a9071b5a11c598f21c1df8525c9"},"source":{"id":"2604.08205","kind":"arxiv","version":2},"verdict":{"id":"5ba67d13-a987-4d79-b948-6aa12b8a8438","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T17:52:37.056262Z","strongest_claim":"The main contribution of this paper is a deterministic online algorithm that is O(log B)-competitive, where B is the knapsack capacity (initially allocated funds). We complement this result with an asymptotically matching lower bound of Ω(log B) which holds for any randomized algorithm, demonstrating our algorithm's optimality.","one_line_summary":"A deterministic O(log B)-competitive algorithm for the online knapsack problem with positive and negative items, with a matching Ω(log B) lower bound for any algorithm, applied to transaction admission in payment channel networks.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the transaction-admission problem in a PCN channel can be exactly captured by the online knapsack model with positive and negative items, without extra constraints from the wider network topology or multi-hop routing.","pith_extraction_headline":"A deterministic online algorithm achieves O(log B)-competitive transaction admission in payment channels by modeling the problem as an online knapsack variant with positive and negative items."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.08205/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}