Homomorphic secret sharing: Optimizations and applications

Elette Boyle, Geoffroy Couteau, Niv Gilboa, Yuval Ishai, Michele Orrù

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

49 Scopus citations


We continue the study of Homomorphic Secret Sharing (HSS), recently introduced by Boyle et al. (Crypto 2016, Eurocrypt 2017). A (2-party) HSS scheme splits an input x into shares (x0, x1) such that (1) each share computationally hides x, and (2) there exists an efficient homomorphic evaluation algorithm Eval such that for any function (or "program") P from a given class it holds that Eval(x0, P)+Eval(x1, P) = P (x). Boyle et al. show how to construct an HSS scheme for branching programs, with an inverse polynomial error, using discrete-log type assumptions such as DDH. We make two types of contributions. Optimizations. We introduce new optimizations that speed up the previous optimized implementation of Boyle et al. by more than a factor of 30, significantly reduce the share size, and reduce the rate of leakage induced by selective failure. Applications. Our optimizations are motivated by the observation that there are natural application scenarios in which HSS is useful even when applied to simple computations on short inputs. We demonstrate the practical feasibility of our HSS implementation in the context of such applications.

Original languageEnglish
Title of host publicationCCS 2017 - Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security
PublisherAssociation for Computing Machinery
Number of pages18
ISBN (Electronic)9781450349468
StatePublished - 30 Oct 2017
Event24th ACM SIGSAC Conference on Computer and Communications Security, CCS 2017 - Dallas, United States
Duration: 30 Oct 20173 Nov 2017

Publication series

NameProceedings of the ACM Conference on Computer and Communications Security
ISSN (Print)1543-7221


Conference24th ACM SIGSAC Conference on Computer and Communications Security, CCS 2017
Country/TerritoryUnited States


  • Homomorphic Encryption
  • Homomorphic Secret Sharing
  • Private Information Retrieval
  • Secure Computation

ASJC Scopus subject areas

  • Software
  • Computer Networks and Communications


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