Equational Security of a Lattice-based Oblivious Transfer Protocol.

Baiyu Li, Daniele Micciancio

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.

Chunxiao Wang, Wang Ji-zhong

Xiaochao Wei, Han Jiang, Chuan Zhao +2 more

In secure two-party computation protocols based on garbled circuit, oblivious transfer (OT) plays an important role in transferring the garbled keys of the participants. In addition to the traditional OT primitive, many other variants of OT have also been presented, such as outsourced oblivious transfer (OOT), cut-and-choose oblivious transfer (CCOT), cut-and-choose bilateral oblivious transfer (CCBOT), etc. These new primitives significantly improve the efficiency and feasibility of secure two-party computation protocols, mainly in optimising computational complexity and interactive rounds. Among these primitives, CCBOT proposed by Zhao et al. in TrustCom 2015 is a novel one and helps to minimize the round complexity of the outer secure two-party computation protocols. In addition, they constructed a CCBOT protocol based on homomorphic encryption scheme in the malicious model. However, their protocol uses the cut-and-choose technique to guarantee security against malicious adversaries, as a result the protocol has an error probability. The commitment scheme is also inevitably involved in their protocol. In this paper, we present a CCBOT protocol with the security against malicious adversaries based on the Decisional Diffie-Hellman (DDH) assumption. Our proposed protocol avoids using the cut-and-choose technique and commitment scheme. In terms of efficiency, our protocol is much more efficient than the previous protocol.

Eike Kiltz

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.