## CryptoDB

### Paper: Round-Efficient Black-Box Construction of Composable Multi-Party Computation

Authors: Susumu Kiyoshima DOI: 10.1007/s00145-018-9276-1 Search ePrint Search Google We present a round-efficient black-box construction of a general multi-party computation (MPC) protocol that satisfies composability in the plain model. The security of our protocol is proven in the angel-based UC framework [Prabhakaran and Sahai, STOC’04] under the minimal assumption of the existence of semi-honest oblivious transfer protocols. The round complexity of our protocol is $\max (\widetilde{O}(\log ^2n), O(R_{{{{\mathsf {O}}}{{\mathsf {T}}}}}))$ max ( O ~ ( log 2 n ) , O ( R O T ) ) when the round complexity of the underlying oblivious transfer protocol is $R_{{{{\mathsf {O}}}{{\mathsf {T}}}}}$ R O T . Since constant-round semi-honest oblivious transfer protocols can be constructed under standard assumptions (such as the existence of enhanced trapdoor permutations), our result gives a $\widetilde{O}(\log ^2n)$ O ~ ( log 2 n ) -round protocol under these assumptions. Previously, only an $O(\max (n^{\epsilon }, R_{{{{\mathsf {O}}}{{\mathsf {T}}}}}))$ O ( max ( n ϵ , R O T ) ) -round protocol was shown, where $\epsilon >0$ ϵ > 0 is an arbitrary constant. We obtain our MPC protocol by constructing a $\widetilde{O}(\log ^2n)$ O ~ ( log 2 n ) -round CCA-secure commitment scheme in a black-box way under the assumption of the existence of one-way functions.
##### BibTeX
@article{jofc-2019-30146,
title={Round-Efficient Black-Box Construction of Composable Multi-Party Computation},
journal={Journal of Cryptology},
publisher={Springer},
volume={32},
pages={178-238},
doi={10.1007/s00145-018-9276-1},
author={Susumu Kiyoshima},
year=2019
}