2026-07-22T21:23:55Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:12435 2024-03-06T10:50:08Z ddc:004 open_access

Improved Black-Box Constructions of Composable Secure Computation Chatterjee, Rohit Liang, Xiao Pandey, Omkant Secure Multi-Party Computation Black-Box Composable Non-Malleable We close the gap between black-box and non-black-box constructions of composable secure multiparty computation in the plain model under the minimal assumption of semi-honest oblivious transfer. The notion of protocol composition we target is angel-based security, or more precisely, security with super-polynomial helpers. In this notion, both the simulator and the adversary are given access to an oracle called an angel that can perform some predefined super-polynomial time task. Angel-based security maintains the attractive properties of the universal composition framework while providing meaningful security guarantees in complex environments without having to trust anyone. Angel-based security can be achieved using non-black-box constructions in max(R_OT,Õ(log n)) rounds where R_OT is the round-complexity of semi-honest oblivious transfer. However, current best known black-box constructions under the same assumption require max(R_OT,Õ(log² n)) rounds. If R_OT is a constant, the gap between non-black-box and black-box constructions can be a multiplicative factor log n. We close this gap by presenting a max(R_OT,Õ(log n)) round black-box construction. We achieve this result by constructing constant-round 1-1 CCA-secure commitments assuming only black-box access to one-way functions. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Rohit Chatterjee and Xiao Liang and Omkant Pandey 2020 Is Part Of LIPIcs, Volume 168, 47th International Colloquium on Automata, Languages, and Programming (ICALP 2020) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ICALP.2020.28 urn:nbn:de:0030-drops-124351 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICALP.2020.28 eng https://creativecommons.org/licenses/by/3.0/legalcode