Cryptology ePrint Archive: Report 2019/706

Endemic Oblivious Transfer

Daniel Masny and Peter Rindal

Abstract: Oblivious Transfer has played a crucial role in the design of secure multi party computation. Nevertheless, there are not many practical solutions that achieve simulation based security and at the same time instantiable based on different assumptions.

In this work, we show how to construct highly efficient oblivious transfer in the random oracle model that achieves simulation based security under a wide range of assumptions, among them DDH, CDH, LWE and coding based assumptions. We revise classical security notions and propose a new security notion that we call endemic security. We construct an endemically secure oblivious transfer based on DDH that takes only a single communication round which allows significant performance gains over previously known solutions. We also instantiate our oblivious transfer with the Crystals.Kyber key agreement. Our implementation shows that both instantiations can be computed in under one millisecond.

Further, our new security notion also allows us to revisit, correct and improve existing oblivious transfer extension techniques. We provide an implementation of an oblivious transfer extension protocol in the ideal cipher model that is actively secure, processing up to 23 million OTs per second and up to 10 times faster than previous secure implementations. We also show that our framework can compute endemically secure OT extension and the base OTs in just two rounds.

Category / Keywords: public-key cryptography / Oblivious Transfer, Oblivious Transfer Extension, OT, Secure Multi Party Computation, Post-Quantum, DDH, CDH, LWE, LPN, Key Agreement, Random Oracle Model, UC

Date: received 14 Jun 2019

Contact author: daniel masny at rub de, rindalp@oregonstate edu

Available format(s): PDF | BibTeX Citation

Version: 20190618:103747 (All versions of this report)

Short URL:

[ Cryptology ePrint archive ]