2026-08-01T21:23:36Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:20951 2024-09-16T10:19:09Z ddc:004 open_access

Privacy Comparison for Bitcoin Light Client Implementations Kotzer, Arad Rottenstreich, Ori Blockchain Privacy Light Clients Bloom filter Light clients implement a simple solution for Bitcoin’s scalability problem, as they do not store the entire blockchain but only the state of particular addresses of interest. To be able to keep track of the updated state of their addresses, light clients rely on full nodes to provide them with the required information. To do so, they must reveal information about the addresses they are interested in. This paper studies the two most common light client implementations, SPV and Neutrino with regards to their privacy. We define privacy metrics for comparing the privacy of the different implementations. We evaluate and compare the privacy of the implementations over time on real Bitcoin data and discuss the inherent privacy-communication tradeoff. In addition, we propose general techniques to enhance light client privacy in the existing implementations. Finally, we propose a new SPV-based light client model, the aggregation model, evaluate it, and show it can achieve enhanced privacy than in the existing light client implementations. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Arad Kotzer and Ori Rottenstreich 2024 Is Part Of LIPIcs, Volume 316, 6th Conference on Advances in Financial Technologies (AFT 2024) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.AFT.2024.15 urn:nbn:de:0030-drops-209510 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2024.15 eng https://creativecommons.org/licenses/by/4.0/legalcode