Verifiable Oblivious Transfer Protocol(Application Information Security)

Soongohn Kim, Seoksoo Kim, Geuk Lee

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.

Christian L. F. Corniaux, Hossein Ghodosi

Richard J. Berger, René Peralta, Tom Tedrick

Fenghua Li

Non-committing encryption achieved only semantic security,in contrast,applications often require security against chosen ciphertext attacks.A main ingredient in the previous adaptive universally composable(UC)oblivious transfer protocols are non-committing encryptions.the previous proposals are not UC secure against adaptive adversaries in the so-called non-erase model.A new UC secure oblivious transfer protocols were proposed and schemes utilize two primitives of the verifiably smooth projective hashing and deniable encryption as constructed by.the double trapdoor decryption mechanism based on trapdoor commitment.Our construction is based on the decisional composite residuosity in common reference string (CRS) model.We constructed a two-message(1-round) string oblivious transfer protocol,which improves computational efficient that supports message spaces of size exponential and save O(n)-1 rounds communications efficient than bit-OT protocols.

Lein Harn, Hung‐Yu Lin