We present a new multiparty computation protocol secure against a static and malicious dishonest majority. Unlike most previous protocols that were based on working on MAC-ed secret shares, our approach is based on computations on homomorphic commitments to secret shares. Specifically we show how to realize MPC using any additivelyhomomorphic commitment scheme, even if such a scheme is an interactive two-party protocol. Our new approach enables us to do arithmetic computation over arbitrary finite fields. In addition, since our protocol computes over committed values, it can be readily composed within larger protocols, and can also be used for efficiently implementing committing OT or committed OT. This is done in two steps, each of independent interest: 1. Black-box extension of any (possibly interactive) two-party additively homomorphic commitment scheme to an additively homomorphic multiparty commitment scheme, only using coin-tossing and a “weak” equality evaluation functionality. 2. Realizing multiplication of multiparty commitments based on a lightweight preprocessing approach. Finally we show how to use the fully homomorphic commitments to compute any functionality securely in the presence of a malicious adversary corrupting any number of parties.
|Title of host publication
|Public-Key Cryptography - PKC 2018 - 21st IACR International Conference on Practice and Theory of Public-Key Cryptography, Proceedings
|Michel Abdalla, Ricardo Dahab
|Springer Science and Business Media Deutschland GmbH
|Number of pages
|Published - 2018
|21st IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2018 - Rio de Janeiro, Brazil
Duration: 25 Mar 2018 → 29 Mar 2018
|Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
|21st IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2018
|Rio de Janeiro
|25/03/18 → 29/03/18
Bibliographical notePublisher Copyright:
© International Association for Cryptologic Research 2018.