International Association for Cryptologic Research

International Association
for Cryptologic Research


Communication-Efficient Unconditional MPC with Guaranteed Output Delivery

Vipul Goyal
Yanyi Liu
Yifan Song
DOI: 10.1007/978-3-030-26951-7_4 (login may be required)
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Abstract: We study the communication complexity of unconditionally secure MPC with guaranteed output delivery over point-to-point channels for corruption threshold $$t < n/3$$ . We ask the question: β€œis it possible to construct MPC in this setting s.t. the communication complexity per multiplication gate is linear in the number of parties?” While a number of works have focused on reducing the communication complexity in this setting, the answer to the above question has remained elusive for over a decade.We resolve the above question in the affirmative by providing an MPC with communication complexity $$O(Cn\kappa + n^3\kappa )$$ where $$\kappa $$ is the size of an element in the field, C is the size of the (arithmetic) circuit, and, n is the number of parties. This represents a strict improvement over the previously best known communication complexity of $$O(Cn\kappa +D_Mn^2\kappa +n^3\kappa )$$ where $$D_M$$ is the multiplicative depth of the circuit. To obtain this result, we introduce a novel technique called 4-consistent tuples of sharings which we believe to be of independent interest.
Video from CRYPTO 2019
  title={Communication-Efficient Unconditional MPC with Guaranteed Output Delivery},
  booktitle={Advances in Cryptology – CRYPTO 2019},
  series={Lecture Notes in Computer Science},
  author={Vipul Goyal and Yanyi Liu and Yifan Song},