### Secure Multi-party Quantum Computation with a Dishonest Majority

Yfke Dulek, Alex Grilo, Stacey Jeffery, Christian Majenz, and Christian Schaffner

##### Abstract

The cryptographic task of secure multi-party (classical) computation has received a lot of attention in the last decades. Even in the extreme case where a computation is performed between k mutually distrustful players, and security is required even for the single honest player if all other players are colluding adversaries, secure protocols are known. For quantum computation, on the other hand, protocols allowing arbitrary dishonest majority have only been proven for k = 2. In this work, we generalize the approach taken by Dupuis, Nielsen and Salvail (CRYPTO 2012) in the two-party setting to devise a secure, efficient protocol for multi-party quantum computation for any number of players k, and prove security against up to k &#8722; 1 colluding adversaries. The quantum round complexity of the protocol for computing a quantum circuit with g gates acting on w qubits is O((w + g)k). To achieve efficiency, we develop a novel public verification protocol for the Clifford authentication code, and a testing protocol for magic-state inputs, both using classical multi-party computation.

Available format(s)
Category
Cryptographic protocols
Publication info
Preprint. MINOR revision.
Keywords
quantumMPCauthentication
Contact author(s)
christian majenz @ cwi com
yfkedulek @ gmail com
Alex Grilo @ cwi nl
smjeffery @ gmail com
c schaffner @ uva nl
History
Short URL
https://ia.cr/2019/1205

CC BY

BibTeX

@misc{cryptoeprint:2019/1205,
author = {Yfke Dulek and Alex Grilo and Stacey Jeffery and Christian Majenz and Christian Schaffner},
title = {Secure Multi-party Quantum Computation with a Dishonest Majority},
howpublished = {Cryptology ePrint Archive, Paper 2019/1205},
year = {2019},
note = {\url{https://eprint.iacr.org/2019/1205}},
url = {https://eprint.iacr.org/2019/1205}
}

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