,
Hugo Krawczyk
,
Tal Rabin
Creative Commons Attribution 4.0 International license
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.
@InProceedings{ishai_et_al:LIPIcs.ITC.2026.7,
author = {Ishai, Yuval and Krawczyk, Hugo and Rabin, Tal},
title = {{Compressing Correlations via Secret Replication: PCFs from Symmetric Cryptography}},
booktitle = {7th Conference on Information-Theoretic Cryptography (ITC 2026)},
pages = {7:1--7:22},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-426-0},
ISSN = {1868-8969},
year = {2026},
volume = {385},
editor = {Dodis, Yevgeniy},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITC.2026.7},
URN = {urn:nbn:de:0030-drops-271001},
doi = {10.4230/LIPIcs.ITC.2026.7},
annote = {Keywords: Pseudorandom correlation functions, correlated randomness, secure computation, symmetric cryptography}
}