International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Statistical Zaps and New Oblivious Transfer Protocols

Vipul Goyal , Carnegie Mellon University
Abhishek Jain , Johns Hopkins University
Zhengzhong Jin , Johns Hopkins University
Giulio Malavolta , UC Berkeley & Carnegie Mellon University
DOI: 10.1007/978-3-030-45727-3_23 (login may be required)
Search ePrint
Search Google
Presentation: Slides
Conference: EUROCRYPT 2020
Abstract: We study the problem of achieving statistical privacy in interactive proof systems and oblivious transfer -- two of the most well studied two-party protocols -- when limited rounds of interaction are available. -- Statistical Zaps: We give the first construction of statistical Zaps, namely, two-round statistical witness-indistinguishable (WI) protocols with a public-coin verifier. Our construction achieves computational soundness based on the quasi-polynomial hardness of learning with errors assumption. -- Three-Round Statistical Receiver-Private Oblivious Transfer: We give the first construction of a three-round oblivious transfer (OT) protocol -- in the plain model -- that achieves statistical privacy for receivers and computational privacy for senders against malicious adversaries, based on polynomial-time assumptions. The round-complexity of our protocol is optimal. We obtain our first result by devising a public-coin approach to compress sigma protocols, without relying on trusted setup. To obtain our second result, we devise a general framework via a new notion of statistical hash commitments that may be of independent interest.
Video from EUROCRYPT 2020
  title={Statistical Zaps and New Oblivious Transfer Protocols},
  booktitle={39th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Zagreb, Croatia, May 10–14, 2020, Proceedings},
  series={Lecture Notes in Computer Science},
  keywords={Zaps;Oblivious Transfer},
  author={Vipul Goyal and Abhishek Jain and Zhengzhong Jin and Giulio Malavolta},