Generic Fully Simulatable Adaptive Oblivious Transfer

We aim at constructing adaptive oblivious transfer protocols, enjoying fully simulatable security, from various well-known assumptions such as DDH, $d$-Linear, QR, DCR, and LWE. To this end, we present two generic constructions of adaptive OT, one of which utilizes verifiable shuffles together with threshold decryption schemes, while the other uses permutation networks together with what we call {\em loosely-homomorphic} key encapsulation schemes. We then show that specific choices of the building blocks lead to concrete adaptive OT protocols with fully simulatable security in the standard model under the targeted assumptions. Our generic methods can be extended to build universally composable (UC) secure, and leakage-resilient OT protocols

Improvement of One Adaptive Oblivious Transfer Scheme

In 2011, the authors [8] presented an adaptive oblivious transfer (OT) scheme based on Decisional 3-Party Diffie-Hellman (3DDH) assumption. The encryption used in the scheme is a combination of the Boneh-Boyen IBE scheme and a variation of the Hohenberger-Waters signature. The scheme is somewhat inefficient since it combines the two underlying schemes in a simple way. In this paper, we present an improvement of the OT scheme and show its security under 3DDH assumption. The proposed skills are helpful for designing and analyzing other cryptographic schemes

Generic fully simulatable adaptive oblivious transfer

Abstract. We aim at constructing adaptive oblivious transfer protocols, enjoying fully simulatable security, from various well-known assumptions such as DDH, d-Linear, QR, DCR, and LWE. To this end, we present two generic constructions of adaptive OT, one of which utilizes verifiable shuffles together with threshold decryption schemes, while the other uses permutation networks together with what we call loosely-homomorphic key encapsulation schemes. We then show that specific choices of the building blocks lead to concrete adaptive OT protocols with fully simulatable security in the standard model under the targeted assumptions. Our generic methods can be extended to build universally composable (UC) secure, and leakage-resilient OT protocols