Paper 2022/887

Round-Optimal Black-Box Protocol Compilers

Yuval Ishai, Technion – Israel Institute of Technology
Dakshita Khurana, University of Illinois Urbana-Champaign
Amit Sahai, University of California, Los Angeles
Akshayaram Srinivasan, Tata Institute of Fundamental Research

We give black-box, round-optimal protocol compilers from semi-honest security to malicious security in the Random Oracle Model (ROM) and in the 1-out-of-2 oblivious transfer (OT) correlations model. We use our compilers to obtain the following black-box constructions of general-purpose protocols for secure computation tolerating static, malicious corruptions of all-but-one participants: \begin{itemize} \item A two-round, two-party protocol in the random oracle model, making black-box use of a two-round semi-honest secure protocol. Prior to our work, such a result was not known even for special functionalities such as OT. As an application, we get efficient constructions of two-round malicious OT/OLE in the random oracle model based on a black-box use of two-round semi-honest OT/OLE. \item A three-round multiparty protocol in the random oracle model, making a black-box use of two-round semi-honest OT. This protocol matches a known round complexity lower bound due to Applebaum et al. (ITCS 2020) and is based on a minimal cryptographic primitive. \item A two-round multiparty protocol in the OT correlations model, making a black-box use of a semi-malicious protocol. This improves over a similar protocol of the authors (Crypto 2021) by eliminating an adaptive security requirement and replacing nonstandard multiparty OT correlations by standard ones. As an application, we get 2-round protocols for arithmetic branching programs that make a black-box use of the underlying field. \end{itemize} As a contribution of independent interest, we provide a new variant of the IPS compiler (Ishai, Prabhakaran and Sahai, Crypto 2008) in the two-round setting, where we relax requirements on the IPS ``inner protocol'' by strengthening the ``outer protocol''.

Note: Full version of the EUROCRYPT 2022 paper.

Available format(s)
Cryptographic protocols
Publication info
A major revision of an IACR publication in EUROCRYPT 2022
Contact author(s)
yuval ishai @ gmail com
dakshita @ illinois edu
amitsahai @ gmail com
akshayaram @ berkeley edu
2022-09-06: revised
2022-07-07: received
See all versions
Short URL
Creative Commons Attribution


      author = {Yuval Ishai and Dakshita Khurana and Amit Sahai and Akshayaram Srinivasan},
      title = {Round-Optimal Black-Box Protocol Compilers},
      howpublished = {Cryptology ePrint Archive, Paper 2022/887},
      year = {2022},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.