Paper 2021/1627

A PKI-based Framework for Establishing Efficient MPC Channels

Daniel Masny and Gaven Watson


The Transport Layer Security (TLS) protocol is a fundamental building block for ensuring security on Internet. It provides an easy to use framework for the purposes of establishing an authenticated and secure channel between two parties that have never physically met. Nevertheless, TLS only provides a simple cryptographic functionality compared to more advanced protocols such as protocols for secure multiparty computation (MPC). In this work, we provide a framework for efficiently establishing channels for MPC over the Internet. We focus on MPC protocols in the oblivious transfer (OT) hybrid model such that it is sufficient to establish OT correlations for such a channel. We revisit and combine different notions of UC security proposed in both the MPC and authenticated key exchange settings. Through this work, we show how an OT protocol can be composed with a secure authenticator to ensure the authenticity of messages sent during the OT. In addition, we adapt and analyse non-interactive OTs based on dense key encapsulation mechanisms (KEMs) in the random oracle model, where the first message, i.e. public key, can be reused. These KEMs can be instantiated based on CDH, RSA and LWE and after a performance and security evaluation, it turns out that the resulting OT protocols are very competitive with the state of the art and are able to leverage existing PKIs.

Available format(s)
Public-key cryptography
Publication info
Published elsewhere. Minor revision. CCS 2021
PKIOTMPCAuthenticationUCReusable MPC
Contact author(s)
daniel masny @ rub de
gavenjwatson @ gmail com
2021-12-17: received
Short URL
Creative Commons Attribution-NonCommercial


      author = {Daniel Masny and Gaven Watson},
      title = {A PKI-based Framework for Establishing Efficient MPC Channels},
      howpublished = {Cryptology ePrint Archive, Paper 2021/1627},
      year = {2021},
      note = {\url{}},
      url = {}
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