Multi-Party PSM, Revisited: Improved Communication and Unbalanced Communication

Leonard Assouline; Tianren Liu

Paper 2019/657

Multi-Party PSM, Revisited: Improved Communication and Unbalanced Communication

Leonard Assouline and Tianren Liu

Abstract

We improve the communication complexity in the Private Simultaneous Messages (PSM) model, which is a minimal model of non-interactive information-theoretic multi-party computation. The state-of-the-art PSM protocols were recently constructed by Beimel, Kushilevitz and Nissim (EUROCRYPT 2018). We present new constructions of $k$ -party PSM protocols. The new protocols match the previous upper bounds when $k = 2$ or $3$ and improve the upper bounds for larger $k$ . We also construct $2$ -party PSM protocols with unbalanced communication complexity. More concretely, - For infinitely many (including all ), we construct -party PSM protocols for arbitrary functionality , whose communication complexity is . This improves the former best known upper bounds of for , for , and for . - For all rational whose denominator is , we construct 2-party PSM protocols for arbitrary functionality , whose communication complexity is for one party, for the other. Previously the only known unbalanced 2-party PSM has communication complexity .

Note: Revision after TCC acceptance

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: A minor revision of an IACR publication in TCC 2021
Keywords: information-theoretic
Contact author(s): tianrenl @ uw edu
leonard assouline @ ens-lyon fr
History: 2021-10-05: last of 4 revisions; 2019-06-04: received; See all versions
Short URL: https://ia.cr/2019/657
License: CC BY

BibTeX

@misc{cryptoeprint:2019/657,
      author = {Leonard Assouline and Tianren Liu},
      title = {Multi-Party {PSM}, Revisited: Improved Communication and Unbalanced Communication},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/657},
      year = {2019},
      url = {https://eprint.iacr.org/2019/657}
}