Paper 2013/571

Efficient General-Adversary Multi-Party Computation

Martin Hirt and Daniel Tschudi


Secure multi-party computation (MPC) allows a set P of n players to evaluate a function f in presence of an adversary who corrupts a subset of the players. In this paper we consider active, general adversaries, characterized by a so-called adversary structure Z which enumerates all possible subsets of corrupted players. In particular for small sets of players general adversaries better capture real-world requirements than classical threshold adversaries. Protocols for general adversaries are ``efficient'' in the sense that they require |Z|^O(1) bits of communication. However, as |Z| is usually very large (even exponential in n), the exact exponent is very relevant. In the setting with perfect security, the most efficient protocol known to date communicates |Z|^3 bits; we present a protocol for this setting which communicates |Z|^2 bits. In the setting with statistical security, |Z|^3 bits of communication is needed in general (whereas for a very restricted subclass of adversary structures, a protocol with communication |Z|^2 bits is known); we present a protocol for this setting (without limitations) which communicates |Z|^1 bits.

Available format(s)
Publication info
Published by the IACR in ASIACRYPT 2013
Secure Multiparty ComputationGeneral AdversariesEfficiency
Contact author(s)
tschudid @ inf ethz ch
2013-09-09: received
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Creative Commons Attribution


      author = {Martin Hirt and Daniel Tschudi},
      title = {Efficient General-Adversary Multi-Party Computation},
      howpublished = {Cryptology ePrint Archive, Paper 2013/571},
      year = {2013},
      note = {\url{}},
      url = {}
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