Abstract
We construct the first actively-secure Multi-Party Computation (MPC) protocols with an arbitrary number of parties in the dishonest majority setting, for an arbitrary field F with constant communication overhead over the “passive-GMW” protocol (Goldreich, Micali and Wigderson, STOC ‘87). Our protocols rely on passive implementations of Oblivious Transfer (OT) in the boolean setting and Oblivious Linear function Evaluation (OLE) in the arithmetic setting. Previously, such protocols were only known over sufficiently large fields (Genkin et al. STOC ‘14) or a constant number of parties (Ishai et al. CRYPTO ‘08). Conceptually, our protocols are obtained via a new compiler from a passively-secure protocol for a distributed multiplication functionality FMULT, to an actively-secure protocol for general functionalities. Roughly, FMULT is parameterized by a linear-secret sharing scheme S, where it takes S-shares of two secrets and returns S-shares of their product. We show that our compilation is concretely efficient for sufficiently large fields, resulting in an overhead of 2 when securely computing natural circuits. Our compiler has two additional benefits: (1) it can rely on any passive implementation of FMULT, which, besides the standard implementation based on OT (for boolean) and OLE (for arithmetic) allows us to rely on implementations based on threshold cryptosystems (Cramer et al. Eurocrypt ‘01); and (2) it can rely on weaker-than-passive (i.e., imperfect/leaky) implementations, which in some parameter regimes yield actively-secure protocols with overhead less than 2. Instantiating this compiler with an “honest-majority” implementations of FMULT, we obtain the first honest-majority protocol with optimal corruption threshold for boolean circuits with constant communication overhead over the best passive protocol (Damgård and Nielsen, CRYPTO ‘07).
Original language | English |
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Title of host publication | Advances in Cryptology – EUROCRYPT 2020 - 39th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Proceedings |
Editors | Anne Canteaut, Yuval Ishai |
Publisher | Springer |
Pages | 184-215 |
Number of pages | 32 |
ISBN (Print) | 9783030457235 |
DOIs | |
State | Published - 2020 |
Event | 39th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2020 - Zagreb, Croatia Duration: 10 May 2020 → 14 May 2020 |
Publication series
Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 12106 LNCS |
ISSN (Print) | 0302-9743 |
ISSN (Electronic) | 1611-3349 |
Conference
Conference | 39th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2020 |
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Country/Territory | Croatia |
City | Zagreb |
Period | 10/05/20 → 14/05/20 |
Bibliographical note
Publisher Copyright:© International Association for Cryptologic Research 2020.
Funding
Acknowledgments. The first author is supported by the BIU Center for Research in Applied Cryptography and Cyber Security in conjunction with the Israel National Cyber Bureau in the Prime Minister’s Office, and by ISF grant 1316/18. The second author is supported by Google Faculty Research Grant, NSF Award CNS-1618884 and Intelligence Advanced Research Projects Activity (IARPA) via 2019-19-020700009. The views expressed are those of the author and do not reflect the official policy or position of Google, the Department of Defense, the National Science Foundation, or the U.S. Government. The third author is supported by ISF grants 1861/16 and 1399/17, and AFOSR Award FA9550-17-1-0069. The first author is supported by the BIU Center for Research in Applied Cryptography and Cyber Security in conjunction with the Israel National Cyber Bureau in the Prime Minister’s Office, and by ISF grant 1316/18. The second author is supported by Google Faculty Research Grant, NSF Award CNS-1618884 and Intelligence Advanced Research Projects Activity (IARPA) via 2019-19-020700009. The views expressed are those of the author and do not reflect the official policy or position of Google, the Department of Defense, the National Science Foundation, or the U.S. Government. The third author is supported by ISF grants 1861/16 and 1399/17, and AFOSR Award FA9550-17-1-0069.
Funders | Funder number |
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National Science Foundation | CNS-1618884, 1861/16, 1399/17 |
U.S. Department of Defense | |
Air Force Office of Scientific Research | FA9550-17-1-0069 |
Intelligence Advanced Research Projects Activity | 2019-19-020700009 |
Israel Science Foundation | 1316/18 |