Computationally Secure Oblivious Transfer

Donald Beaver

Daniel Mansy, Peter Rindal

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 consider a simulation based security notion that we call endemic security. We show how to construct highly efficient oblivious transfer in the random oracle model that achieves endemic security under a wide range of assumptions, among them DDH, CDH, LWE and coding based assumptions. We construct a secure oblivious transfer based on DDH that takes only a single communication round which allows significant performance gains. 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, we 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.

Christian Tobias

Guoliang Chen

As a basic protocol of Secure Multi-party Computation,Oblivious Transfer(OT) is of significant research and application value.Most of previous oblivious transfer protocols in classical environment rely either on public-key cryptography or on additional computational assumptions which will be very vulnerable under quantum mechanics.Based on the characteristics of Bell States,a new quantum oblivious transfer protocol is proposed in this paper.The correctness and security of the protocol are analyzed and proved.The protocol is secure in the presence of noise on the channel and a potential eavesdropper.Comparing with oblivious transfer protocols in classical computational environment,the protocol in this paper is superior in security,soundness and wire-tapping detecting.

Mehrad Jaberi, Hamid Mala

Manuel B. Santos, Armando N. Pinto, Paulo Mateus

Abstract Secure multiparty computation has the potential to be a disruptive technique in the realm of data analysis and computation. It enables several parties to compute virtually any function while preserving the privacy of their inputs. However, most of its protocols’ security and efficiency relies on the security and efficiency of oblivious transfer (OT). In this work, we make a detailed comparison between the complexity of the hybrid quantum oblivious transfer (HQOT) protocol presented in [11] and the classical OT [12], which to the best of our knowledge, is the fastest OT protocol. We also propose an optimised version of HQOT and discuss several other OT protocols generated from oblivious keys.