2026-07-23T21:48:56Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:25181 2026-03-19T12:59:16Z ddc:004 open_access

Weaker Assumptions for Asymmetric Trust Amores-Sesar, Ignacio Cachin, Christian Kamp, Simon Holmgaard Villacis, Juan Asymmetric Trust Quorum Systems Reliable Broadcast Consensus In distributed systems with asymmetric trust, each participant is free to make its own trust assumptions about others, captured by an asymmetric quorum system. This contrasts with ordinary, symmetric quorum systems and threshold models, where trust assumptions are uniformly shared among participants. Fundamental problems like reliable broadcast and consensus are unsolvable in the asymmetric model if quorum systems satisfy only the classical properties of consistency and availability. Existing approaches overcome this by introducing stronger assumptions. We show that some of these assumptions are overly restrictive, so much so that they effectively eliminate the benefits of asymmetric trust. To address this, we propose a new approach to characterize asymmetric problems and, building upon it, present algorithms for reliable broadcast and consensus that require weaker assumptions than previous solutions. Our methods are general and can be extended to other core problems in systems with asymmetric trust. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Ignacio Amores-Sesar and Christian Cachin and Simon Holmgaard Kamp and Juan Villacis 2026 Is Part Of LIPIcs, Volume 361, 29th International Conference on Principles of Distributed Systems (OPODIS 2025) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.OPODIS.2025.8 urn:nbn:de:0030-drops-251812 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.OPODIS.2025.8 eng https://creativecommons.org/licenses/by/4.0/legalcode