2026-08-14T00:27:37Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:27100 2026-08-12T06:00:27Z ddc:004 open_access

Compressing Correlations via Secret Replication: PCFs from Symmetric Cryptography Ishai, Yuval Krawczyk, Hugo Rabin, Tal Pseudorandom correlation functions correlated randomness secure computation symmetric cryptography We revisit the question of securely compressing multiparty correlations using only symmetric cryptography. A linear correlation C, defined by a linear subspace C ⊆ 𝔽ⁿ, samples a secret random 𝐜 ∈ C and assigns to each party a fixed subset of the entries of 𝐜. Gilboa and Ishai (Crypto 1999) and Cramer, Damgård and Ishai (TCC 2005) provide a general technique for securely compressing many independent samples from C by replicating independent keys of a pseudorandom function (PRF) among the parties. This implies a pseudorandom correlation function (PCF) for C from any PRF, where the PCF key size scales with the number of minimal-support codewords in C. We observe that the above generalizes to other types of useful target correlations C_T by using a secret replication pattern obtained via a random secret assignment of parties in C to parties in C_T. We present several corollaries of this general blueprint. These include a re-derivation of two-party PCF constructions for VOLE and subfield-VOLE over small domains (Roy, Crypto 2022) as well as new multiparty PCFs for small-domain VOLE-style correlations, including scalar-vector multiplication triples and their authenticated variants. Finally, we discuss applications to secure computation. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Yuval Ishai and Hugo Krawczyk and Tal Rabin 2026 Is Part Of LIPIcs, Volume 385, 7th Conference on Information-Theoretic Cryptography (ITC 2026) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ITC.2026.7 urn:nbn:de:0030-drops-271001 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITC.2026.7 eng https://creativecommons.org/licenses/by/4.0/legalcode