Non-Interactive Oblivious Transfer and Applications

Maria Dubovitskaya, Alessandra Scafuro, Ivan Visconti

Masahide Kobayashi, Takashi Nishide

Qiong Huang

This paper presents a flavor of OT named Independent Oblivious Transfer in the Public-Key Public-Randomness Model (PKPR IOT, in short), with respect to the open problem given by De Santis. First it gives a non-interactive implementation of IOT, which can independently and obliviously transfer polynomial messages. The implementation is based on Quadratic Residuosity Assumption. Since it is limited to pre-fixed times, then another non-interactive implementation of IOT is presented, which can independently transfer messages for any times. The second implementation requires the sender to be honest and the receiver couldn’t make his choice independently. So, the third interactive implementation is given. It is based on the BBCS oblivious transfer scheme of Rivest, and is rather more efficient than the above two non-interactive counterparts. All the three implementations presented are secure against receivers with unlimited computational power.

Carmit Hazay, Yehuda Lindell

Christian Tobias

Yael Gertner, Tal Malkin

In this paper, we present a new application for , n 1 oblivious transfer, which i s a n i n teractive protocol between two parties Alice and Bob, where Alice has n secrets and Bob has a query i.A t the end of the protocol Bob has the ith secret and no other information about Alice's other secrets, while Alice does not get any information about i.This new application is the Secure Database Access problem.Motivated by this application, we propose an OT scheme which a c hieves low communication complexity and information theoretic security.We use a distributed model for , n 1 oblivious transfer, where Bob interacts with multiple \Alices".In this model, we base our scheme on any PIR scheme, which i s a s c heme where only the privacy of Bob is considered, and use it to construct an OT scheme, private for both parties, without paying too much i n communication complexity.This results in the rst sublinear information theoretic scheme for , n 1 OT.Further motivated by the application of , n 1 OT for polynomial n, w e raise the issue of repetition in , n 1 OT, where both security and eciency are important.We show that previous protocols for , n 1 oblivious transfer fail in this setting.